I think the fretboard being glued above the scarf joint adds a fair bit of strenght, making the scarf joint the better choice. The fretboard doesnt really give any more strenght with a one piece, because it will break in the grain lines inside the headstock on the other side of where the board is.
Two friends: one with ibanez s (maple scarf joint, rosewood fretboard), one with epiphone les paul (single piece mahogany, rosewood fretboard). The guy with the ibanez was fooling around, balancing it on the butt end strap pin, guitar went straight in the air as he was overcompensating and fell straight down tip of the headstock into concrete. If broke near the joint just like in the video. I took it home, the headstock was still on being held by the now bent truss rod and the fretboard (which didn't bend much and I'm sure it helped). Loosened the truss rod, pulled out the headstock and the rod, hammered the truss rod back straight , assembled it like lego to test fit (it was perfect), applied glue and pressure, left it for two days, tuned it and IT WORKED LIKE NEW. Some sanding and finishing on the back and it's great. 18 years later Ibanez is still great. The guy with the les paul had his in the case and he kinda threw it on the back seat of a car, opened the case and the headstock was off: it broke behind the nut, not like this one in the video, but like countless other les pauls online. It left irregular and much smaller surface for gluing to put it back like I did the Ibanez. He took it to several guitar repair guys, some didn't want to bother, some wanted money nearly as much as a new guitar. He bought new laminated neck Schecter. 10 years later Les paul is still on his wall in two parts. Me, I'm a bass player, mostly owning/owned Fenders with inline headstock (maple with mostly rosewood fretboards). One is still straight, others are bending or are permanently bent towards the fretboard (nothing extreme, but I found it annoying, so I sold them). I have owned scarf jointed basses too and had no problems, only benefits: no bending (at least not perceivable) and equal pressure on the nut from all strings (no string trees or bars needed). From my experience and this video I can tell I prefer scarf joints over single piece.
If anything, the scarf joint underneath the fretboard will make the neck develop deformation in that portion. I had to correct a lot of necks that were like this.
I'd like to see that test as well. I don't build electrics, which is where the straight headstock is often used, so I'm not really setup for that. If you come across someone testing that, please let me know.
Would be very interesting to see the difference between a 17 degree neck and a 10 degree neck, or even a lower angle. I suggest a volute will make very little difference to the test, as both breaks occurred away from the volute area. But, a volute may well make a big difference if you did a test on necks with the trussrod slot cut into them.
I have bounced between 15° and 17° headstocks. I was considering whether that would make a difference, but I went with the more aggressive angle for the test for more of the extreme.
Another great vid. I wonder how much effect a fretboard over the scarf joint would have - I'm guessing it would help absorb quite a lot of the force and maybe stop the break. Whereas the fretboard would have no effect on the one piece ue to where the break occurs.
Thanks for the feedback. Since the impact was coming from the rear, and the fretboard would be on the front, I don’t feel like it would have been a tangible effect. Hard to say though. Several things surprised me in this process.
Tim, I think a 1 piece neck with wings and a backstrap massively improves the weakness of the runout. Also, your first test, with only two pounds, shows us how strong both joints are without any string tension and why loosening your strings during shipment and travel, since the impact of being dropped inside a case case snap headstocks. These are great.
Great feedback! I hadn't considered wings as a means of strengthening the headstock, but that makes a lot of sense. Also a great point about loosening strings during travel. Thanks for the comments.
Yes, someone recently suggested wings as a means of adding strength. I think it’s a good idea. I hadn’t considered wings as an option for added strength, but it seems like a positive reinforcement.
Dude! You did it !!! The result surprised me. Lesson learned though - just don't drop your guitar. Excellent experiment, and a ton of views on this video. See, I told you, you have to break the necks :) But I must say, I cringed a bit to see them snap. Way to go, Bro.
I learned that I should prevent my guitar from falling! All kidding aside this was awesome. I've made my own conclusions from this. Just wanted to thank you for doing this. Great channel.
Interesting series. As previously mentioned: not a large enough sample size to be conclusive. A sample size of 2 provide a clue of what might happen, but you need a much larger sample size to draw any statistically valid conclusions. Would have been interesting to see what affect keeping the simulated string tension would have. You could have suspended 40 lbs of weight from the headstock and then simulated the fall. Another option would have been repeating the drop test, without adding weight, multiple times. Enjoyed watching. These tests did reveal that things aren't as clear cut as we think they are. Thanks for the time invested and sacrificing good material.
I am looking at a Kay neck from 1960s. I see the long grain extends into the head stock with no apparent scarf joint. Is it possible that these necks are steam bent from a simple plank? Imho, the headstock repair would be simpler to repair.
I’ve never considered bending the headstock into place. I suppose it could be possible. I wonder how well it would stay over time under the string tension? Interesting…
@@pilsonguitars I've sanded that neck all the way down now, no evidence of a scarf joint, there are however, readily apparent joints where headstock wings are glued on. I don't think string tension could hurt it, but if it ever encountered steam it would revert to original shape. I have a spare neck, do you want it?
When you first let go of the board onto the test neck I half expected to hear a "Di-doinggggg" sound. When they broke, they broke similar to how I imagined. I did expect the glue to stand the test as well. It looks as if the scarf joint would be reparable and that the one piece would be better for tackling vampires. Great videos.
No assumptions needed. We wanted to provide data points that we hadn’t seen tested previously. I hope it helps others as they consider their build techniques.
Well, I had to clamp it to place force on the joint. Otherwise, the test would have needed to be done on a fully built guitar. It was heartbreaking enough to bust up perfectly good neck wood. I didn't want to risk a whole guitar.
Hey, did you consider the effect of the pre-tensioned neck with around 220 pounds of force applied by the strings? Pretty sure it will make significant differences.
We did in fact mention that as we got started in this episode. We also tested the effects of string tension, in terms of headstock deflection, in part 2 if you're interested. I'd love to see someone do a break test with a fully tensioned neck and fretboard. We couldn't invest anymore into our testing at this point.
Thanks for sharing this. Great test all round. Perhaps things like V-neck joints are worth it, after all. Interestingly, a volute on a single piece neck is probably not worth it seeing how it broke. It may not actually add much strength if the break angle is not the weakest part.
@@BobStCyr that's really interesting. Thanks for sharing. I assumed the additional long grain surface area of the v would have helped with the glue joint. More areas to go wrong I guess though
I really enjoyed this 3 part series on the pros and cons of 1 piece and Scarfed mahogany necks. I’m not a luthier or physicist. I’m just a 68 yo guitar player that has seen the destruction of some of these highly prized and outrageously priced corporate guitars. If these desirable guitars were cars or had to be certified like electric products the mighty G may have gone bust because they couldn’t pass UL standards, issue recalls, lose revenue because the offerings are all lemon lawed, or would have been forced to stop selling their products. The mighty G products didn’t just break at the headstock. There were some where the mahogany broke at the body/neck joint. Usually in the products w/o a long neck tenon. Wasn’t the design flaw the reason the big G was forced to stop selling their manufacturing and models under the Les Paul umberella? 2. A neck with a volute may have a little more strength, but there were still plenty of those wonders that weren’t just fretless’ but headless. 3. I opened a guitar case one day at a gig and my high priced Custom was now junk. It never fell and no one threw an anvil On the headstock. It just broke in the case overnight With regards to the test while it appears that the first results showed the one piece to perform better could the measurements actually indicate that the scarfed joint was more resilient because it had greater flexibility? 3. In hindsight wouldn’t incremental weight increases be more consistent with how you applied the pressure test? Sorry to be critical but my femur would break if someone dropped twice my weight on top of it. My gut feeling is that one would have would survived longer than the other. It would also be quite telling if data were available for the %age of headstock breaks in 1 piece necks vs scarfed neck joints. That would take the ‘opinion’ variable out of which would be less likely to result in a loss of income from the catastrophic failure the main tool required to perform the occupation of guitarist. The results proved to me that there was a clear winner. That winner was the scarf joint. That repair could be much easier to make due to it not involving massive destruction of the wood in the 1 piece.
Wow, I'm shocked that you had a headstock break without any outside forces! I'm not sure what Gibson had going on there, but that's crazy. I agree on the increase of weight being too much during my testing. I didn't apply enough forethought into my weight increments. The increase was too much, too fast. Your assessment is one that others concluded as well, and one that I didn't consider at the time. A joint that flexes more can be an advantage to durability when experiencing a sudden impact. The downside is, it will likely flex more over time and potentially require more adjustments. Your take on the repairability is also interesting. I'm mainly thinking about new construction and overall maintenance, not necessarily repairability. As a builder, you kinda build with the idea of "surely my guitars won't break." :-) Thanks for the feedback and for watching!
I bought a guitar with a broken neck recently, and had a break right at the scarf, just like this, so I would say to those wondering, No the fretboard probably didn't help. I don't know exactly how the neck broke, but I assumed it was a tip over/drop like this. In my case, I'm planning to repair it simply to see how it goes, but it's not actually necessary since it's a bolt on neck. If it doesn't repair well, I can just replace the neck entirely.
Thank you for doing this experiment! The scarf joint would have a truss rod and fretboard in there providing reinforcement using very dense materials..so in real life, I don't think it would break that easily. The one-piece neck break is a classic Gibson trademark feature and behaved exactly as expected :)
Fretboard, yes. Truss rod, in my case, no. I'm running the truss rod down into the body of the guitar so I'm not getting any help in the headstock area. One thing to consider, if you route your truss rod through the headstock, you are also removing a decent amount of material for that channel, providing less wood in that area for support. Is it compensated by the truss rod itself... not sure.
I have never used a scarf joint as it has always seemed suspect to me. I also dont make one piece necks as I have never been able to obtain perfectly quarter sawn stock in that thickness. I prefer to make two and three piece necks. Two piece produced from one piece of straight grained mahagany as near to quartered as possible but cut down the centre and reverse one piece to balance the grain pattern and stresses. My three piece necks are made using a perfectly quartered centre piece with another section cut in half and reversed as in the two piece. This gives me the best possible stability and strength in all directions. I like to use two further sections to make up the headstock width whilst also strengthening the short grain. I sometimes veneer the back as well as the front of the headstock which adds further strength and also incorporate a volute into the design. I have never suffered a headstock break but am confident that my build offers the best protection. I just dont feel the same about a scarf joint. Great video by the way - there will always be people who doubt your testing methods but at the end of the day I believe you have done more than most.
I really enjoyed reading your process. I think you’ve nailed down an extremely solid build method. That’s a lot of work, but I’d bet those look and function impressively well. Appreciate you sharing so that we can all learn from each other. Thanks for watching.
I've only had two necks break on me in my life... both were scarf joints. Ultimately though, nothing is immune from breaking in the right circumstances.
Interesting. Definitely agree, under enough stress, things will end badly. I was mainly interested in the rigidity of the headstock and joint over the break test. I wanted to see which neck provided the least amount of deflection. I was surprised by those results.
I don't like the way one-pieces make use of the wood, but I also don't like the way a visible scarf joint looks. I've also only ever seen a one-piece break closer to the nut, not really ever up into the peghead that far. Can't say I've ever had a broken scarf joint come around, but then again, there are probably fewer examples out there...
I hear you and I agree on both counts. One-piece necks are a terrible waste of good wood, but then that joint isn't awesome looking either. Some do nice work of putting a complimentary piece of an opposing color in the scarf for some decoration. Those look pretty neat.
Reasonable test design, good contribution. But I'd like to see a lot more trials before drawing conclusions. There are so many variables here, you'd need a LOT of trials to draw any conclusions with confidence. Which I know is not practical, so you did all that was reasonable. Different wood species, different glues, different details of the scarf making process, what does a vollute do?, could change the result. If someone wanted to break 100's of necks using that test, I'd be really interested to see the results. I won't hold my breath. Maybe a guitar playing engineering student will do their PhD thesis on it.
Fair points. Having a large sampling of data points certainly provides a better means of coming to a conclusion. My assumption when I started this testing was, most luthiers have probably never gone through any cycle of testing to compare their build methods. My hope was that it provided additional insight into their methods to help all of us become better builders. I'll leave the conclusion to each of you. 🙂 Thanks for the feedback.
I think people who said that the scarf joint should be in the headstock instead of the neck shaft are correct because there would be more glue surface in that case, and the area where the joint is weakest, i.e. along the grain at the glue joint, would be greater, so stronger. If the joint is going to fail it will be in the weakest part of the neck, so we want to make that as strong as possible. We want to avoid having the neck split along the grain.
I could see how that might be a benefit. I'm curious if that method would have resisted the break entirely. If I ever test again, I need a testing weight between the 2 that I used.
That’s true, I did mention that. I would have needed to make a full guitar, all built out, and string it up. A little more than I was willing to go through for the purpose of the test, but I would be interested to see if it would change the results.
The glue was holding onto essentially end grain, which really isn't much. Scarf joints are used to save money, not for their strength. The constant grain pattern, even with some of it being short, still has a good level of cohesion and strength
Scarf joints aren't only used to save money. When I started building with that method, it was to achieve a higher level of resistance to warping/bending of the headstock over time. Yes, it does use less wood, which is a nice advantage as well.
It wasn't clear to me whether the scarf joint broke on the neck or the headstock side of the joint. If it was the headstock side then that would be consistent with a short grain failure, because short grain failures are caused by the wood breaking along the length of the grain, whereas a long grain failure would be caused by the wood breaking ACROSS the length of the grain. Wood is many times stronger (20 times in maple) in the direction of the grain than it is across the grain. This is why my 6 year old grandson can break a board along the grain with a "Karate" chop...
In the scarf, it broke at/near the joint. On the one-piece, it kinda broke in both the joint and the headstock. (a bit of an angled break) Agree with you on the grain strength. That's where part 2 of this series surprised me in the bend/deflection test, because the one-piece offered greater resistance to bending.
Excellent test setup, worthy of Project Farm or Torque Test Channel. However, if the scarf joint was a good joint and the glue line held but the fibers just tore away then why did the break follow outside of the joint? That would effectively not be the joint. It would have broken elsewhere or anywhere. I have to say that I feel the joint wasn't glued well. I have destroyed my own necks in a less scientific manner and the breaks were not following the joints. Matthias Wandel does some excellent joint and glue torture tests on youtube that would give additional insight into what it should look like. I missed in your part 1 the type of glue you were using? The way that you slid the joint together in from the side while using a tight jig likely starved the joint. I am not trying to hate on this because its a great series and I have subscribed in appreciation of it but real world information from repair shops, while not scientific, prove that repairs on scarf joints are rare. I build hippie sandwich Alembic style electrics and so laminated necks along with front and rear veneers over the scarf joint, which I locate in the headstock and not the neck, make an incredibly strong assembly. Please keep pushing conventional wisdom where you see fit!
That's honest feedback and appreciated. I was also a little curious in how that scarf broke with minimal fiber tear. (by the way, it was Titebond glue) Unfortunately, it's a long road to get back to that point in the build to re-test so I left it as presenting what I found. It would be fun to revisit at some point. Thanks again for watching!
Also, just a side note, but I’ve never actually seen an acoustic headstock break, personally. However, I’ve seen the headstocks of 3 different Les Pauls snap clean off and I’ve always attributed that to the severe angle of the neck, or the tension of the strings at the actual scale length. I know you don’t do electrics, of course, but nothing snaps like an LP under full pressure. So my thought is that string tension and neck angle - which would affect the overall neck tension - would certainly come into play regardless if we’re talking electric or acoustic. While your test methodology is sound, in theory, having a neck attached to a body and under full string tension would give you a much more realistic result. Obviously nobody wants to deliberately break a fully functional guitar, though. Just my $0.02
Yah, spot on. Headstock angle and scale length will play into the tension. Gibson preferred that 17 degree angle (which is what I'm using as well for the test) and it contributed to a lot of those breaks. A full build out and drop test on an assembled guitar is the way to go for that real-world test.
That would be an interesting test. When I first started doing scarf joints, I considered that method but didn't like the overall look. Just personal preference.
I just watched part 2. I commented there and will paste it here. I think my logic still stands. @jonahguitarguy 0 seconds ago I think the test is legit but there are years and years of actual breaks that tell a very real story. Things not accounted for like the fretboard reinforcing the neck right at the nut. The huge truss rod nut access that Gibson and copies use. The fretboard reinforcement at the nut could pinpoint all the stress right at the short grain which would be mad even weaker by removing so much material for the rod nut. Maybe another way to test would be to use two completed necks. Even with truss rods installed. There thing is that until the necks are broken or fail you can't see the whole picture.
nice try, but I think you should have made a neck with fretboard, that Is what make scarfjoint stronger of you have the scarf underneath the fretboard..
As I mentioned, that was a consideration, but we stopped short due to the extra build materials. (time, money, etc.) I’d love to see someone carry on our work and take it to the next level. If you do, please share those results with us!
A volute does jack shyte to strengthen the neck joint. They break just as easy but just have a carbuncle on the break area. Ask Gibson. They tried it in the Norlin era! It justdidn't work!
"I think were gonna get the results were looking for...." You shouldnt be looking to get any results one way or another in a true scientific test..do the test and let the results speak for themselves..i dig the vid though..interesting..i am surprised you doubled the weight at the end. We didn't find out which is stronger hence the importance of going at it slower with that test..see? Just learned something😉
I see your point. My comment around getting the "results we're looking for" is more around finding the best option for building the neck. In the end, we didn't really conclude one way or the other. Each seems to have its own compelling benefit. I didn't think doubling the weight was that significant in terms of how heavy it felt. I was a little disappointed that it broke on that attempt, but the results were educational regardless, and I think it ultimately helped me conclude what I was after. Thanks for the feedback and for watching!
Soo.. build, buy, play what ever makes you happy. Moral of the story don't drop the guitar. Just like a car in an accident, once its been hit its been comprised. People are arguing things that literally don't matter. Just focus on making music.
I think the fretboard being glued above the scarf joint adds a fair bit of strenght, making the scarf joint the better choice. The fretboard doesnt really give any more strenght with a one piece, because it will break in the grain lines inside the headstock on the other side of where the board is.
Could be. I’m hopeful someone will get inspired by the testing and take it to the next level!
Two friends: one with ibanez s (maple scarf joint, rosewood fretboard), one with epiphone les paul (single piece mahogany, rosewood fretboard).
The guy with the ibanez was fooling around, balancing it on the butt end strap pin, guitar went straight in the air as he was overcompensating and fell straight down tip of the headstock into concrete. If broke near the joint just like in the video. I took it home, the headstock was still on being held by the now bent truss rod and the fretboard (which didn't bend much and I'm sure it helped). Loosened the truss rod, pulled out the headstock and the rod, hammered the truss rod back straight , assembled it like lego to test fit (it was perfect), applied glue and pressure, left it for two days, tuned it and IT WORKED LIKE NEW. Some sanding and finishing on the back and it's great.
18 years later Ibanez is still great.
The guy with the les paul had his in the case and he kinda threw it on the back seat of a car, opened the case and the headstock was off: it broke behind the nut, not like this one in the video, but like countless other les pauls online. It left irregular and much smaller surface for gluing to put it back like I did the Ibanez. He took it to several guitar repair guys, some didn't want to bother, some wanted money nearly as much as a new guitar. He bought new laminated neck Schecter.
10 years later Les paul is still on his wall in two parts.
Me, I'm a bass player, mostly owning/owned Fenders with inline headstock (maple with mostly rosewood fretboards). One is still straight, others are bending or are permanently bent towards the fretboard (nothing extreme, but I found it annoying, so I sold them). I have owned scarf jointed basses too and had no problems, only benefits: no bending (at least not perceivable) and equal pressure on the nut from all strings (no string trees or bars needed).
From my experience and this video I can tell I prefer scarf joints over single piece.
@@pilsonguitarsyou do the test..that's how scientific test works..test change test change......
scarf angle also affect the strength,but that on just my exp
So in this case it would much easier to repair the scarf joint than the one-piece. For me its the scarf joint, used it for all my builds
From a repair perspective, I can certainly see your point. Fixing that headstock would be a challenge.
I suspect if both necks had a fingerboard attached, the scarf jointed neck would have survived. Just a hunch. ☮️
If anything, the scarf joint underneath the fretboard will make the neck develop deformation in that portion. I had to correct a lot of necks that were like this.
Please test the straight headstock vs the angled.
I'd like to see that test as well. I don't build electrics, which is where the straight headstock is often used, so I'm not really setup for that. If you come across someone testing that, please let me know.
Yeah amazing knowledge 👍, next three piece vs 5 piece neck or more.
the more proper glue joints the stronger a laminated neck will be, thats why 13 layer plywood is stronger than 7
Would be very interesting to see the difference between a 17 degree neck and a 10 degree neck, or even a lower angle.
I suggest a volute will make very little difference to the test, as both breaks occurred away from the volute area.
But, a volute may well make a big difference if you did a test on necks with the trussrod slot cut into them.
I have bounced between 15° and 17° headstocks. I was considering whether that would make a difference, but I went with the more aggressive angle for the test for more of the extreme.
Another great vid.
I wonder how much effect a fretboard over the scarf joint would have - I'm guessing it would help absorb quite a lot of the force and maybe stop the break. Whereas the fretboard would have no effect on the one piece ue to where the break occurs.
Thanks for the feedback. Since the impact was coming from the rear, and the fretboard would be on the front, I don’t feel like it would have been a tangible effect. Hard to say though. Several things surprised me in this process.
Tim, I think a 1 piece neck with wings and a backstrap massively improves the weakness of the runout.
Also, your first test, with only two pounds, shows us how strong both joints are without any string tension and why loosening your strings during shipment and travel, since the impact of being dropped inside a case case snap headstocks.
These are great.
Great feedback! I hadn't considered wings as a means of strengthening the headstock, but that makes a lot of sense. Also a great point about loosening strings during travel. Thanks for the comments.
The heavier weight might be more appropriate with a neck on a solid body electric guitar. Great information from this test.
For the one piece, how about widening the headstock with additional strips joined in a long-grained orientation?
Yes, someone recently suggested wings as a means of adding strength. I think it’s a good idea. I hadn’t considered wings as an option for added strength, but it seems like a positive reinforcement.
Dude! You did it !!! The result surprised me. Lesson learned though - just don't drop your guitar. Excellent experiment, and a ton of views on this video. See, I told you, you have to break the necks :) But I must say, I cringed a bit to see them snap. Way to go, Bro.
“Just don’t drop your guitar”. Sheesh, why didn’t you tell me this years ago, dad?! Hehe
Great series! I build exclusively electric guitars, and the main reason I use a scarf joint is to reduce waste.
I learned that I should prevent my guitar from falling! All kidding aside this was awesome. I've made my own conclusions from this. Just wanted to thank you for doing this. Great channel.
Happy to help! Appreciate the feedback.
Interesting series.
As previously mentioned: not a large enough sample size to be conclusive. A sample size of 2 provide a clue of what might happen, but you need a much larger sample size to draw any statistically valid conclusions.
Would have been interesting to see what affect keeping the simulated string tension would have. You could have suspended 40 lbs of weight from the headstock and then simulated the fall.
Another option would have been repeating the drop test, without adding weight, multiple times.
Enjoyed watching. These tests did reveal that things aren't as clear cut as we think they are. Thanks for the time invested and sacrificing good material.
Yes, absolutely. Maybe not conclusive evidence, but at least an insight into the consequences of different methods. Appreciate the feedback.
I am looking at a Kay neck from 1960s. I see the long grain extends into the head stock with no apparent scarf joint. Is it possible that these necks are steam bent from a simple plank?
Imho, the headstock repair would be simpler to repair.
I’ve never considered bending the headstock into place. I suppose it could be possible. I wonder how well it would stay over time under the string tension? Interesting…
@@pilsonguitars I've sanded that neck all the way down now, no evidence of a scarf joint, there are however, readily apparent joints where headstock wings are glued on.
I don't think string tension could hurt it, but if it ever encountered steam it would revert to original shape. I have a spare neck, do you want it?
@@pilsonguitars
More info, I am not seeing a heel joint on this neck. It must be carved from a block.
When you first let go of the board onto the test neck I half expected to hear a "Di-doinggggg" sound.
When they broke, they broke similar to how I imagined. I did expect the glue to stand the test as well.
It looks as if the scarf joint would be reparable and that the one piece would be better for tackling vampires.
Great videos.
Thanks for watching and for the feedback. Now I can’t unhear the “didoinggg”. 😁
At least it is easier to repair,thank you for your help. Regards Richard Weir from down under
Could not assume anything without the fingerboard in place for the scarf joint.
No assumptions needed. We wanted to provide data points that we hadn’t seen tested previously. I hope it helps others as they consider their build techniques.
if it was falling off a stand, it wouldn't be clamped??
Well, I had to clamp it to place force on the joint. Otherwise, the test would have needed to be done on a fully built guitar. It was heartbreaking enough to bust up perfectly good neck wood. I didn't want to risk a whole guitar.
Hey, did you consider the effect of the pre-tensioned neck with around 220 pounds of force applied by the strings?
Pretty sure it will make significant differences.
We did in fact mention that as we got started in this episode. We also tested the effects of string tension, in terms of headstock deflection, in part 2 if you're interested. I'd love to see someone do a break test with a fully tensioned neck and fretboard. We couldn't invest anymore into our testing at this point.
I've had 2 headstock breaks in the last 30 years, both looked exactly like your one piece break.
Thanks for sharing this. Great test all round. Perhaps things like V-neck joints are worth it, after all.
Interestingly, a volute on a single piece neck is probably not worth it seeing how it broke. It may not actually add much strength if the break angle is not the weakest part.
I've tested the V joint - it's weaker than either the scarf or the solid neck. The only necks I've ever had break were v jointed.
@@BobStCyr that's really interesting. Thanks for sharing. I assumed the additional long grain surface area of the v would have helped with the glue joint. More areas to go wrong I guess though
I really enjoyed this 3 part series on the pros and cons of 1 piece and Scarfed mahogany necks. I’m not a luthier or physicist. I’m just a 68 yo guitar player that has seen the destruction of some of these highly prized and outrageously priced corporate guitars. If these desirable guitars were cars or had to be certified like electric products the mighty G may have gone bust because they couldn’t pass UL standards, issue recalls, lose revenue because the offerings are all lemon lawed, or would have been forced to stop selling their products. The mighty G products didn’t just break at the headstock. There were some where the mahogany broke at the body/neck joint. Usually in the products w/o a long neck tenon. Wasn’t the design flaw the reason the big G was forced to stop selling their manufacturing and models under the Les Paul umberella? 2. A neck with a volute may have a little more strength, but there were still plenty of those wonders that weren’t just fretless’ but headless. 3. I opened a guitar case one day at a gig and my high priced Custom was now junk. It never fell and no one threw an anvil
On the headstock. It just broke in the case overnight
With regards to the test while it appears that the first results showed the one piece to perform better could the measurements actually indicate that the scarfed joint was more resilient because it had greater flexibility? 3. In hindsight wouldn’t incremental weight increases be more consistent with how you applied the pressure test? Sorry to be critical but my femur would break if someone dropped twice my weight on top of it. My gut feeling is that one would have would survived longer than the other. It would also be quite telling if data were available for the %age of headstock breaks in 1 piece necks vs scarfed neck joints. That would take the ‘opinion’ variable out of which would be less likely to result in a loss of income from the catastrophic failure the main tool required to perform the occupation of guitarist.
The results proved to me that there was a clear winner. That winner was the scarf joint. That repair could be much easier to make due to it not involving massive destruction of the wood in the 1 piece.
Wow, I'm shocked that you had a headstock break without any outside forces! I'm not sure what Gibson had going on there, but that's crazy.
I agree on the increase of weight being too much during my testing. I didn't apply enough forethought into my weight increments. The increase was too much, too fast. Your assessment is one that others concluded as well, and one that I didn't consider at the time. A joint that flexes more can be an advantage to durability when experiencing a sudden impact. The downside is, it will likely flex more over time and potentially require more adjustments. Your take on the repairability is also interesting. I'm mainly thinking about new construction and overall maintenance, not necessarily repairability. As a builder, you kinda build with the idea of "surely my guitars won't break." :-)
Thanks for the feedback and for watching!
I place my scarf in the headstock that is then covered by a veneer. Gives you the best of both worlds and it's pretty well hidden
same here
I bought a guitar with a broken neck recently, and had a break right at the scarf, just like this, so I would say to those wondering, No the fretboard probably didn't help. I don't know exactly how the neck broke, but I assumed it was a tip over/drop like this. In my case, I'm planning to repair it simply to see how it goes, but it's not actually necessary since it's a bolt on neck. If it doesn't repair well, I can just replace the neck entirely.
Thank you for doing this experiment! The scarf joint would have a truss rod and fretboard in there providing reinforcement using very dense materials..so in real life, I don't think it would break that easily. The one-piece neck break is a classic Gibson trademark feature and behaved exactly as expected :)
Fretboard, yes. Truss rod, in my case, no. I'm running the truss rod down into the body of the guitar so I'm not getting any help in the headstock area. One thing to consider, if you route your truss rod through the headstock, you are also removing a decent amount of material for that channel, providing less wood in that area for support. Is it compensated by the truss rod itself... not sure.
I have never used a scarf joint as it has always seemed suspect to me. I also dont make one piece necks as I have never been able to obtain perfectly quarter sawn stock in that thickness.
I prefer to make two and three piece necks. Two piece produced from one piece of straight grained mahagany as near to quartered as possible but cut down the centre and reverse one piece to balance the grain pattern and stresses. My three piece necks are made using a perfectly quartered centre piece with another section cut in half and reversed as in the two piece. This gives me the best possible stability and strength in all directions. I like to use two further sections to make up the headstock width whilst also strengthening the short grain. I sometimes veneer the back as well as the front of the headstock which adds further strength and also incorporate a volute into the design. I have never suffered a headstock break but am confident that my build offers the best protection. I just dont feel the same about a scarf joint. Great video by the way - there will always be people who doubt your testing methods but at the end of the day I believe you have done more than most.
I really enjoyed reading your process. I think you’ve nailed down an extremely solid build method. That’s a lot of work, but I’d bet those look and function impressively well. Appreciate you sharing so that we can all learn from each other. Thanks for watching.
Dude-- your apron's crooked. 😉 Very informative video. Keep up the teaching.
I've only had two necks break on me in my life... both were scarf joints. Ultimately though, nothing is immune from breaking in the right circumstances.
Interesting. Definitely agree, under enough stress, things will end badly. I was mainly interested in the rigidity of the headstock and joint over the break test. I wanted to see which neck provided the least amount of deflection. I was surprised by those results.
I don't like the way one-pieces make use of the wood, but I also don't like the way a visible scarf joint looks. I've also only ever seen a one-piece break closer to the nut, not really ever up into the peghead that far. Can't say I've ever had a broken scarf joint come around, but then again, there are probably fewer examples out there...
I hear you and I agree on both counts. One-piece necks are a terrible waste of good wood, but then that joint isn't awesome looking either. Some do nice work of putting a complimentary piece of an opposing color in the scarf for some decoration. Those look pretty neat.
Reasonable test design, good contribution. But I'd like to see a lot more trials before drawing conclusions. There are so many variables here, you'd need a LOT of trials to draw any conclusions with confidence. Which I know is not practical, so you did all that was reasonable. Different wood species, different glues, different details of the scarf making process, what does a vollute do?, could change the result. If someone wanted to break 100's of necks using that test, I'd be really interested to see the results. I won't hold my breath. Maybe a guitar playing engineering student will do their PhD thesis on it.
Fair points. Having a large sampling of data points certainly provides a better means of coming to a conclusion. My assumption when I started this testing was, most luthiers have probably never gone through any cycle of testing to compare their build methods. My hope was that it provided additional insight into their methods to help all of us become better builders. I'll leave the conclusion to each of you. 🙂 Thanks for the feedback.
I think people who said that the scarf joint should be in the headstock instead of the neck shaft are correct because there would be more glue surface in that case, and the area where the joint is weakest, i.e. along the grain at the glue joint, would be greater, so stronger. If the joint is going to fail it will be in the weakest part of the neck, so we want to make that as strong as possible. We want to avoid having the neck split along the grain.
I could see how that might be a benefit. I'm curious if that method would have resisted the break entirely. If I ever test again, I need a testing weight between the 2 that I used.
One thing this doesn't account for is the 160lbs of string pull to assist the impact.
That’s true, I did mention that. I would have needed to make a full guitar, all built out, and string it up. A little more than I was willing to go through for the purpose of the test, but I would be interested to see if it would change the results.
The glue was holding onto essentially end grain, which really isn't much. Scarf joints are used to save money, not for their strength. The constant grain pattern, even with some of it being short, still has a good level of cohesion and strength
Scarf joints aren't only used to save money. When I started building with that method, it was to achieve a higher level of resistance to warping/bending of the headstock over time. Yes, it does use less wood, which is a nice advantage as well.
It wasn't clear to me whether the scarf joint broke on the neck or the headstock side of the joint. If it was the headstock side then that would be consistent with a short grain failure, because short grain failures are caused by the wood breaking along the length of the grain, whereas a long grain failure would be caused by the wood breaking ACROSS the length of the grain. Wood is many times stronger (20 times in maple) in the direction of the grain than it is across the grain. This is why my 6 year old grandson can break a board along the grain with a "Karate" chop...
In the scarf, it broke at/near the joint. On the one-piece, it kinda broke in both the joint and the headstock. (a bit of an angled break) Agree with you on the grain strength. That's where part 2 of this series surprised me in the bend/deflection test, because the one-piece offered greater resistance to bending.
Excellent test setup, worthy of Project Farm or Torque Test Channel. However, if the scarf joint was a good joint and the glue line held but the fibers just tore away then why did the break follow outside of the joint? That would effectively not be the joint. It would have broken elsewhere or anywhere. I have to say that I feel the joint wasn't glued well. I have destroyed my own necks in a less scientific manner and the breaks were not following the joints. Matthias Wandel does some excellent joint and glue torture tests on youtube that would give additional insight into what it should look like. I missed in your part 1 the type of glue you were using? The way that you slid the joint together in from the side while using a tight jig likely starved the joint. I am not trying to hate on this because its a great series and I have subscribed in appreciation of it but real world information from repair shops, while not scientific, prove that repairs on scarf joints are rare. I build hippie sandwich Alembic style electrics and so laminated necks along with front and rear veneers over the scarf joint, which I locate in the headstock and not the neck, make an incredibly strong assembly. Please keep pushing conventional wisdom where you see fit!
That's honest feedback and appreciated. I was also a little curious in how that scarf broke with minimal fiber tear. (by the way, it was Titebond glue) Unfortunately, it's a long road to get back to that point in the build to re-test so I left it as presenting what I found. It would be fun to revisit at some point. Thanks again for watching!
Also, just a side note, but I’ve never actually seen an acoustic headstock break, personally. However, I’ve seen the headstocks of 3 different Les Pauls snap clean off and I’ve always attributed that to the severe angle of the neck, or the tension of the strings at the actual scale length. I know you don’t do electrics, of course, but nothing snaps like an LP under full pressure. So my thought is that string tension and neck angle - which would affect the overall neck tension - would certainly come into play regardless if we’re talking electric or acoustic. While your test methodology is sound, in theory, having a neck attached to a body and under full string tension would give you a much more realistic result. Obviously nobody wants to deliberately break a fully functional guitar, though. Just my $0.02
Yah, spot on. Headstock angle and scale length will play into the tension. Gibson preferred that 17 degree angle (which is what I'm using as well for the test) and it contributed to a lot of those breaks. A full build out and drop test on an assembled guitar is the way to go for that real-world test.
Try a scarf joint running through the headstock rather than the Asian splice.
That would be an interesting test. When I first started doing scarf joints, I considered that method but didn't like the overall look. Just personal preference.
I just watched part 2. I commented there and will paste it here. I think my logic still stands.
@jonahguitarguy
0 seconds ago
I think the test is legit but there are years and years of actual breaks that tell a very real story. Things not accounted for like the fretboard reinforcing the neck right at the nut. The huge truss rod nut access that Gibson and copies use. The fretboard reinforcement at the nut could pinpoint all the stress right at the short grain which would be mad even weaker by removing so much material for the rod nut. Maybe another way to test would be to use two completed necks. Even with truss rods installed. There thing is that until the necks are broken or fail you can't see the whole picture.
Yes, I like that idea and would love to see the results of a test like that. Great thoughts!
nice try, but I think you should have made a neck with fretboard, that Is what make scarfjoint stronger of you have the scarf underneath the fretboard..
As I mentioned, that was a consideration, but we stopped short due to the extra build materials. (time, money, etc.) I’d love to see someone carry on our work and take it to the next level. If you do, please share those results with us!
@@pilsonguitars I agree with you, It would be a waste of money and materials doing such a realistic test
A volute does jack shyte to strengthen the neck joint. They break just as easy but just have a carbuncle on the break area. Ask Gibson. They tried it in the Norlin era! It justdidn't work!
yeayyy Scarfed Joint with volute is the way..
I would say they both broke due to short grain. Grafting the headstock by that method just relocates the short grain.
in a scarf join the neck grain is long in both directions, that is the idea behind using ot at all
What destruction hath my father wrought?
"I think were gonna get the results were looking for...." You shouldnt be looking to get any results one way or another in a true scientific test..do the test and let the results speak for themselves..i dig the vid though..interesting..i am surprised you doubled the weight at the end. We didn't find out which is stronger hence the importance of going at it slower with that test..see? Just learned something😉
I see your point. My comment around getting the "results we're looking for" is more around finding the best option for building the neck. In the end, we didn't really conclude one way or the other. Each seems to have its own compelling benefit.
I didn't think doubling the weight was that significant in terms of how heavy it felt. I was a little disappointed that it broke on that attempt, but the results were educational regardless, and I think it ultimately helped me conclude what I was after.
Thanks for the feedback and for watching!
Soo.. build, buy, play what ever makes you happy. Moral of the story don't drop the guitar. Just like a car in an accident, once its been hit its been comprised. People are arguing things that literally don't matter. Just focus on making music.
Hey, at the end of the day, it's all about making some music. Play on!
Strap failure!
Ah, good call. That is definitely one of the more common drops.