Bronze brazing is easy - this is what you need to know
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- Опубликовано: 28 авг 2024
- Been doing this for over twenty years with standard LPG (propane). I use this specialized LPG torch: bullfinch-gas....
I use these BOC rods: www.boc.com.au...
Watch my earlier videos for more info on bronze brazing.
Camera: Nikon L820
Note: You can see the bond occur at 12.16. Cheers Rob
Good to hear the surgery is behind you and it's worked out well.
Thanks Rob2. Still the other eye to go, but that's OK at the moment so no rush I expect. Cheers Rob
So good to hear your doing ok Rob ! Great tips here .. ENJOYED
Thanks Shawn. Gotta keep looking forward ;) Cheers Rob
your a catskinner if i ever saw one..your knowledge is so valubal.
Hello Rob,
I am pleased to hear that your eye operation went well... Nice tutorial on the bronze brazing... Another thing I need to learn...
Take care.
Paul,,
Thanks Paul. Yes, definitely worth learning if you intend to repair or do small project work and make lathe tooling etc.
Bullfinch torches are made in the UK - top quality unit and worth every cent of their not inconsiderable price. I have never regretted buying that torch and it gets a LOT of use. The very low running costs are the big payback. Cheers Rob
Goo to see you back so quickly, hope all is well with you Regards Stuart Bell from England👏🏻👍
Many thanks for all your very helpful videos Rob, particularly those relating to brazing. Sorry to hear you have had some eye surgery,
but glad you are now OK.
Apologies for the following tedious long winded effort.
On the strength of watching you in action, I bought a Bullfinch torch here in the UK. Despite my lack of experience, I have found it easy to use and excellent for my modest needs.
I have now reached the stage where I need to do some more brazing, this time on small 0.063" thick 4130N steel fabricated shackles, each made up from about 3" long x 1-1/4" wide rectangular pieces, which have been bent around a form so that each 1/4" mounting bolt passes through the "loop" formed midway along the length of the metal blanks. (using a cunning forming tool described in the drawings) The steel is tougher than it looks and was a b****r to bend, but turned out OK in the end.
The results are quite good, nevertheless, but there is about a 1/16" gap between the resulting resulting two "ears" and the drawings call for these to be brazed around their edges.
A previous batch of these "shackles" were TIG welded very neatly by a local aircraft welder, now retired. He shied away from brazing them but the small gap wasn't a problem then.
Yesterday, I realised that it is difficult to get the flux paste evenly spread inside the small gap. At this stage a small drawing or photo would be helpful, but not sure I can include in the post!
My main problem is that I can't find the excellent "303" flux that you use. Is there likely to be a UK equivalent with similar qualities?
Do you have any ( polite!) suggestions? The flux I have used so far is some horrible pink stuff.
Best wishes from the UK and keep up the good work!
Ian
Hi Ian. It is unlikely that 303 flux is available in the UK, however a suitable alternative will be available. It appears that SIF 101 is very similar : www.weldability-sif.com/products/sif-consumables/fo100050/
Stay away from rods and fluxes classified as "silicon" bronze. These are higher temperature consumables meant for oxy- acet and oxy-LPG.
I hope it works out OK. Cheers Rob
@@Xynudu Thank you again Rob and I will follow up your link and let you know how I get on. I should be able to make some progress now after being stalled for some days.
Kind regards from the UK! Ian
Good to see you back in the saddle!
RUclips was lonely without you.
Great news on the surgery Rob 👍. Great brazing tips .
I love how you describe the process and then show how to do it. Thanks for sharing your knowledge. Greetings from Canada. Thumbs up!
Glad it was helpful! Cheers Rob
Well, you finally convinced me to get a Bullfinch! I have 3 other propane torches as well as a MAPP, which has served me well, but it will be nice not worrying about how much gas I'm using!! Besides, one can never have too many toys. I ended up riding over to Cambridge's today (not far as I'm in the hills). I already have a suitable gauge and hose so just wanted the handpiece and burner, but they only sell the complete kit. I looked at getting just the handpiece and burner from overseas but I wouldn't have saved anything over buying the kit here.
I have some brazing rods and flux from many years ago (when I had a PortaColt) so dug them out and promptly brazed a couple of scrap bits of 1" tubing together. Worked well!!! Should also be handy for bending stuff.
Nice!
Good move Richard. Very cheap to run and super handy item. MAPP is out gunned on all fronts by the Bullfinch, especially on running cost.
I first saw it demonstrated years ago at the Kapunda Farm Fair and the Bro In-law bought one on the spot, even though he has oxy/acet. I only bought mine after borrowing his to do some brazing. Went and got one from Cambridge's the next day.
All the Oz distributors only sell the kit. It is well made (industrial quality) and although mine has had a few knocks over the years, it has never had a problem. You should be pleased with it. Cheers Rob
Thanks for sharing! Good to hear that your operation was a success hope you recover soon.
Hi Rob !
Nice to have you back and in good shape !
Nice little demo you made there !
Cheers !
Hi Keld, great to hear from you. Yes, I'm still hanging in there. All the best. Cheers Rob
Hope all's well Rob ,nice to see you again .
Rob, it's good to have you back, glad the op was successful, Anyway, as I've said before I really really like your great
bronzing videos. I have got a gas gun but although not cheap it is still much cheaper than the Bullfinch gun.
Anyway Rob I know you know what you're talking about, so I am saving up to buy one, asap. Thanks, sir, Colin. The UK.
Hi Rob. Glad the eye op was a success and I hope the recovery doesn't take too long. Always a pleasure to watch you brazing, it's good to see what can be done when you have the right tools. I tend to use fire bricks these days as support for whatever I'm working on. They really concentrate the heat and are not too expensive. Cheers, Alan.
Hi Alan, bricks are best if you want to minimize heat loss. For small work like making model engine conrods you need a really flat surface and for that I use a bit of steel square section (as shown) and any heat loss won't matter. Cheers Rob
Excellent video, as always. Congrats on the surgery. I just had both eyes done one three weeks ago and the second a week later. OMG, have not been able to see like this since, well forever. Did a little rest and in the shop! 😊 Life is grand. -Mark
Hi Mark, it makes a big difference. My other eye is ok ATM but I will have it done when the Doc says. It's good to be able to ditch the contact lenses after 50 years (never had an ounce of trouble with them). Glad yours worked out as well. I haven't heard any negatives on the outcome/procedure from people I've communicated with, so the success rate must be pretty high. It was like a production line putting people through the clinic. Cheers Rob
Brazing is under-rated. The wife has a garden hoe that she inherited from her grandmother. It had originally been an iron forging made by her grandfather. At some point the forged head broke and was separated from the handle socket. The two pieces have been secured together for almost a century by a simple bronze brazed joint. While the wife has never tried to break her hoe, it has seen routine service weeding our garden.
Hi Dan, I think a lot of people see it as old technology, and it never gets promoted by tool companies who would rather sell you the latest electronic whiz bang welding machine. Only guys like plumbers and panel beaters understand just how good and even irreplaceable it is. Most people will therefore never try it and have no idea of what it can do. I'm sure that the old rake repair will last another hundred years. Cheers Rob
Hi Rob Glad the op was a success , Can't Keep You down can Ha Ha now just a few weeks away from getting my own Bullfinch torch got LPG and a Pencil Propane they Just Don't get to temp for brazing So Looking forward to getting it got a lot of small jobs Icing to be done Thank You
Hi Martyn, some standard LPG torches can get close, but never good enough for the bronze to flow correctly. That's why a lot of people use high content (45% + ) silver solder as a workaround, but it's not as strong and costs an arm and a leg in comparison (OK for very small/limited use, which doesn't justify buying a BF kit).
The Bullfinch will pay for itself very quickly on running and consumable costs if you use it regularly. I'd be lost without mine (for the type of work I do).
For larger brazing jobs Hampdons sell an oxy/LPG kit for half the price of the Bullfinch kit and it would beat it hands down, but it costs 10 times more to run (primarily oxygen cost at 4:1) and you have to wear UV eye protection when using it, which is a bugbear, particularly for small work. Obviously you can now buy the oxy bottles which makes this type of kit a lot more attractive cost wise than during the bad old BOC rental rip off days ;')
Once again it all comes down to how often you would use it and at that price it's very tempting to have for the occasional big job. I'm tempted.
Have fun.
Cheers Rob
One thing that I notice Rob is that when you are brazing with the Bullfinch that you run it so much longer than I would using oxy acetylene. I would think that oxy propane would be the same. I have a smaller torch with different tips and have the opportunity to use the cutting torch as well. It is great for bending metal as well. It is very versatile and find with the smaller tips on light jobs it does not use a lot. I can use propane as well so have the best of both worlds. It will braze or heat so much faster that I think it goes a long ways in lowering that 4 to 1 cost ratio of using oxygen. I also find it so much easier to use as well and I never have to move the brass with something. That's just my 2 cents worth anyway.
I do own my own tanks as well so after many years it has really paid off.
Dale in Canada
Hi Dale, all good points. They both have their uses and are worth having. Cheers Rob
Fantastic to see you are doing well after the first eye op Rob ! Funny thing is i see so much tig brazing on youtube it isn't funny and with the slow death of metalwork in high schools i'm sure some younger people won't know about oxy welding , brazing , silver soldering or even soft soldering.
I can only agree with you Ian regarding gas welding. Everyone is TIG and MIG happy these days. Even stick welders are seen as low tech. The eye is going good so far. Thanks for the positives. Cheers Rob
G'day Rob. Great tutorial thanks for the video.
I love oxy / propane. Cuts beautifully too.
I'm very tempted to get an oxy/LPG brazing set now that you can buy the oxy bottles rather than rent. This kit looks good value: www.hampdon.com.au/oxygen-and-LPG-brazing-kit
Cheers Rob
@@Xynudu Bought oxy bottle from Bunnings, small but doesn't get much use (have plasma too). I am so glad to be out of BOCs grasp.
On my 2nd set of hoses from Ebay , I don't understand how that if they have the appropriate Aust. certification numbers on them
they can split so fast even though they have never been in the sun or wound tight.
That mixer in the add will take a standard cutting head that takes LPG tips.
Pre heat takes a little longer, but it cuts through rust without blowback, and the cut quality is fantastic with the right settings etc.
I just bought some LPG cutting tips (the heating tips are the same for LPG and acetylene) and an LPG reg for the old oxy set
years ago and it has paid for itself many times over.
Great to hear your op went well. Tom
Interesting to know about the heating tips Tom. LPG and Acetylene use different grade hoses and it's recommended not to use LPG with Acetylene rubber hose. Apparently the LPG degrades them. That might be the problem. Cheers Rob
@@Xynudu Thanks for that Rob, I didn't know.
I have an old repurposed oxygen concentrator. Produces up to 20 PSI some 80% O2. Using propane it works remarkably well with a small Purox torch. Brazing is sweet. Will melt steel although I did not try to weld yet. Only drawback - it takes close to a minute from startup to get up to proper O2 concentration.
Hi Rob, nicely done, as you say, just like the soldering process. I need to look out for one of the bullfinch torches, they look really capable. Glad the eye op is out the way. Cheers, Jon
Hi Jon, make sure to get the burner/torch components as listed in the link: bullfinch-gas.co.uk/blowtorches/autotorch-brazing-sys/autotorch-brazing-kit-detail
Bullfinch make a range of torches/burners and they are NOT all component interchangeable and brazing capable, so make sure to get the right one.
The eye op turned out to be no worse than going to the dentist. 6 week recovery/healing time. Interesting experience.
Cheers Rob
Thanks Rob for the tips on this video,going to make a boiler after the engine so will be very helpful.
Hi Dave, I'd suggest you use silver solder making the boiler rather than solder. I think you will find it a lot easier to use and also much stronger/extremely heat resistant. I've never had much success using hard solder on boilers (maybe it's just me) but Alan from RetroSteamTech does all his that way OK. Glad you found the video useful. Cheers Rob
Wonderful as always Rob, thanks for sharing
You're welcome. Cheers Rob
Clean job, looks great.
Love your‘don’t use this it’s crap’ style of presentation.
Have you done any big stuff?
I’m probably going to have to put two studs in a 2” scale traction engine boiler.
The size is only limited by the mass (heat sink effect) involved. I have done 4" diameter cylinder work without issue by working my way around it. What you are planning will be no problem for this torch. Cheers Rob
Thanks! Looks amazing, does this also work to repair pits and holes in bronze sculptures?
I can't reliably comment on that as I've not tried it. In theory it should work OK as manganese (and other) bronze brazing rods are an amalgam of metals which lowers the melting point of the bronze main component. So you should be able to work the rod without melting the job. How the colour will match is another issue. Cheers Rob
G'day Rob. I've watched many of your brazing videos, and I always learn a bit more. This time I focused in on your non-heat-dissipating supports, the thin-walled steel or the brick. I noticed your brick was just that, a proper brick, and not a "fire brick," which are pricey little things. Any difference, in your opinion, between a garden-variety brick and a "fire brick?"
Hi Rick, no real difference for heat application like this. Firebricks are made for prolonged high heat application, but basic red home bricks will work fine and have been used for fireplaces for centuries. Just make sure to keep them dry or steam could explode surface fragments at you. Cheers Rob
Quick question Rob the torch I'm planning on comes from Hampton Welding supplies in W.A. seems to be a fairly complete kit for $400 AU , on e-bay seems about the best value ??
Hi Martyn, yes Hampdons appear to be the best place to buy the kit from my observations (all their pricing is very competitive and fast/free delivery) . I know several viewers in the USA who also bought from them as it's not available in the USA or Canada (strange) and only the Australian POL connector is compatible with the female USA gas connector (the UK one is not).
POL thread pitches vary a bit by country and even though the USA POL connector thread profile (depth and shape) is not an exact match, the Oz male connector will screw on and do the job quite nicely. Cheers Rob
Only use a brick if you are SURE it's dry!!!
Ask me how I know😮
About time I got a first comment in on one of your videos Rob! Thanks for the tips, did I hear you correctly that borax can be used as flux? I have used borax before as flux, it seems to work OK. I noticed at work it looks like they have some pre flux coated braising rods, I will have to have a closer look, I have never used them before, have you? Came across your Ducati video the other day, very nice. I have a 1980 Darmah SD900. It has been parked up for about 3 years, hope to have it running again soon, it is in fairly good nick so looking forward to riding the old girl again.
A lot of brazing fluxes are Borax based. You could probably use Borax for GP steel work. I've heard it works OK. Bronze and brass are a bit more particular and unless it's the right formulation the filler won't stick.
I have tried no name brand fluxed rods and don't like them. A good brand like BOC may be better, but you are still not able to control the amount of flux you add and it really only needs to be added first, so it has time to work before the bronze filler rod goes on. Plain rods are way better IMHO.
My poor old 860 GT bevel has a gearbox problem ATM, probably from standing and I can't get it into any gear. Had the clutch apart, but I think the GB is gummed up on the splines. I need to investigate, do an oil change and see what's up. The 750 F1 is good to go, but I've had no opportunity to ride it recently. Such is life.
Cheers Rob
@@Xynudu I hope the 860 is not too much of a drama Rob, I am sure you'll get it sorted.
All the old Taglioni era Ducks are going up in price these days. The bevel engines cost a packet to rebuild or buy. I worked with a guy that had a Darmah SD900. It used to vibrate a lot (which shouldn't happen if it's built/tuned right) and I had a suspicion the crank wasn't set up right, but that was his problem, not mine. My 860 needs a makeover as all the chrome bits are pretty tatty/rust pitted condition now - it's showing it's age. Cheers Rob
@@Xynudu Yeah for sure, I did a search on 1970'sand early 80's Ducatis for sale in Australia and was surprised at prices, same with my 1976 KZ900 Kawasaki and 1980 GS1000S Suzuki these have gone up a bit now too. Wish I had kept every bike I've owned over the years, would have a great collection if I had.
Hi Rob. I'm really enjoying your channel, thanks for your knowledge. I'm wondering if I can use this method of bronze brazing (or other filler) to attach 1/4" round stock to thinner expanded/mesh metal. I assume you'd focus heat on the larger piece and move over to the thin metal 75% of the way through to get a nice bond. Is that a good application of this method?
That would easily be done with this brazing torch. The flame temperature from LPG will not melt ferrous metal (similar to MAPP gas) so you don't risk burning up the job. You could do it the way you describe or heat and apply bronze to the round stock and then move to the mesh and re-heat. This would keep over run to a minimum. You may have to key the mesh as well. The one issue you may have is removing any flux residue without damaging the mesh. Cheers Rob
Thanks, Rob. I gather the aesthetic I’m trying to accomplish is something that is done with expensive equipment. But I’m going to try it nonetheless.
It should work fine. I always apply the flux first (just a minimum amount) and then wipe the rod on the job when fully up to temperature. Unlike solder, you can't overheat/oxidise manganese bronze or silver solder. Use the smallest diameter rods available for best control and to reduce over spill. You could probably do that sized job with a small HHO generator/torch. Good luck. Cheers Rob
@@Xynudu Thanks as usual. I have one other question, which is that Bullfinch torches are getting harder and more expensive to source in the U.S. I wonder if there are any others that can be modified to use propane tanks for brazing purposes as your model does.
As far as I am aware the Bullfinch torch is not sold in the USA or Canada. USA viewers have sourced theirs from Australia as the POL gas connectors are compatible. The UK and European ones are NOT, as the thread profile is different. The Bullfinch uses a cavitation swirl effect to achieve high temperature and I am unaware of any other brand torch as high temp or that can be modified. I have tried boosting a standard propane torch with compressed air, but the flame is too large and wooly to be of any use. Cheers Rob
Hi Rob,
As a young bloke I was introduced to brazing in the 1960s.. We used Tobin Bronze, as in racehorse, for everything, and it worked.
It doesn't seem to be available anymore. Do you know what the modern substitute is?? Now we have silicon bronze, manganese bronze, aluminium bronze and god knows what else. I can't afford to hold such an inventory for the occasional brazing job. I've got about 500 grams of the old stuff left, do you think it will see me out???
Cheers
Stavros
Hi Stavros, good news. BOC Gas still sell Tobin Bronze : www.boc.com.au/shop/en/au/brazing-alloys-flux-/boc-profill-tobin-bronze-gas-welding-rod
I noticed this last time I was in there buying manganese bronze. They do smaller packets, but the red plastic tubes are better value. I expect panel repair shops still use Tobin a lot.
Cheers Rob
Rob what’s the difference between the manganese/bronze rod you’re using and say Harris brand safety Silv-45( made of silver, copper, zinc) or other silver containing rod when brazing?
Silver content rods like Silv-45 are able to be used at a much lower temperature than any form of primarily bronze brazing rod. This makes them suitable for joining copper and brass components, which would otherwise melt. Basic low silver content rods are what plumbers use for copper plumbing. In Australia it is called "Yellowtip" because that is the colour code.
However, to be able to bond to ferrous metals (steel, cast iron etc) the low temperature rods must have a very high silver content (50 +%) . This makes them very expensive in comparison to bronze rods. The silver join is also not as strong.
People that do very little ferrous metal brazing sometimes use high silver content rods for small jobs like adding carbide tips to tooling etc. This is more cost effective than buying an expensive high temperature torch/equipment. The one exception is to buy MAPP gas gear for bronze brazing, but the consumables are expensive for extended use.
Cheers Rob
@@Xynudu thanks for the detailed reply rob. I already have a oxy/acetylene set up for HVAC brazing but have never brazed anything but copper lines and would like to try other materials. You were a big help thanks again.
You're welcome. If you try brazing steel/ferrous I totally recommend you buy some manganese bronze rods. Much cheaper and stronger. Once again not all rods are the same quality. The amount of manganese varies and this has a major effect on melt temperature, adhesion and flow. I only use BOC rods, as most others I've tried are pretty much rubbish in comparison. I only use uncoated as that allows you to control flux rate.
www.boc.com.au/shop/en/au/boc-profill-mang-bronze-gas-welding-rod
www.boc.com.au/shop/en/au/boc-profill-mang-bronze-gas-welding-rod-grmb-112
Buy the bulk red plastic box/pack and it works out a lot cheaper. Also make sure to use 303 flux.
Most issues people refer to me are wrong type or poor quality rods and the wrong flux type. You would be surprised how often people buy TIG rods and wonder why they don't work with LPG and MAPP. Unfortunately this is often the result of misleading advertising and poor customer advice.
Cheers Rob
Do you know of a fitting that will convert from BPS to NPT for these torches?
Try an industrial gas outlet like BOC or anyone that sells gas welding equipment.
Have you tried using silicon bronze Rob? I've heard it's for TIG only and it's for hard facing (hard in relation to the other bronze rods). Any chance of giving it a go?
Yes, I have tried it - no go. You need TIG or oxy boosted gas for that. LPG isn't hot enough even with the Bullfinch. OXY/LPG would handle it easily. Cheers Rob
The brick material isn't ideal as it may split and bits fly off when heat is applied
Not if it's dry. I've never had an issue.
Hi Rob, no doubt you have posted the brand name of the 303 flux and where to buy it here in Adelaide. I have searched on the BOC website and they have the Tenacity 20 Flux Powder, this seems to fit the bill but it is not the Eze 303. What do you recommend ? Glen. ( Down South)
Hi Glen, the Eziweld 303 was made in Sydney but the guy recently retired and stopped production.
The best alternative now is to buy from Hampdons in WA who are cheaper than BOC Gas and have free delivery : www.hampdon.com.au/CA-Flux-Copper-Brass-Flux-250g-303-OXY-LPG-Brazing
That's what I bought, but haven't tried it yet. It's a 303 flux so it should be good. A container of flux, like a packet of rods, lasts a long time ;) Hampdons actually have some good deals on a lot of their stuff - I really like their oxy/LPG brazing kit : www.hampdon.com.au/oxygen-and-LPG-brazing-kit
I would seriously consider buying this in preference to a Bullfinch now you can buy oxy bottles, but running costs are a lot higher - 10 times more (due to the 4:1 oxygen cylinder use cost). For bigger jobs (which I rarely do) it would be more capable.
Cheers Rob
@@Xynudu Thank you Rob i will go onto the Hampdon site and have a look, i have all the oxy gear, Ex plumber :-) and yes....it is a bit expensive to have hanging around but very handy still. Really enjoy your videos too. Glen.
Hi Glen, definitely give them a go. They had the item to me in just a couple of days. The videos are a bit of fun, glad you get something out of them. Cheers Rob
@@Xynudu Thanks Rob, i ordered the flux, CA 303 Flux Copper & Brass Flux 250g - OXY LPG Brazing . I will just pick up a pack of 5 Mang/Bronze rods from Bunnings. Just need to have a few sticks for a couple of small jobs. Cheers Glen.
Hi Glen, I've never used the Bunnings rods. BOC are definitely the only rod I would recommend. Be interesting to hear how the Bunnies go. Cheers Rob
does anyone know of a torch like the bullfinch here thats available in America?
I doubt there's anything available Josh. I know of two USA viewers who bought Bullfinch kits from Hampdons in Western Australia (listed on Ebay). Only the Australian POL connector will fit the USA propane cylinders - the UK thread is not compatible/different pitch profile. Cheers Rob
@@Xynudu Also you have to be careful of the model of Bullfinch. A close friend (:^)) bought a Bullfinch off Ebay that turned out to be incapable of producing brazing temps. Poor chap.