I have one of these exact foam cutting knives for this exact same foam (2" thick though) and am having a terrible time getting a smooth cut AT ALL. If the blade is too hot or you hesitate a little, as is inevitable on ANY longer or slightly complicated cut (I have a few curves) ... the blade INSTANTLY starts to melt foam and leave those large divots and indentations and, quite often, blackened burn marks and blobs. The blade very, very quickly gets gunked up and the directions with the tool say explicitly DO NOT BURN off the residue (super toxic fumes??). I ignore that prohibition but make sure to have have excellent ventilation and scrape off most of the residue immediately on a piece of wood thus avoiding most of the fumes. Anyway, I am SERIOUSLY disappointed by the often shocking raggedness of the cut and wonder if there is a precise heat setting or precise speed of cut to avoid the sometimes awful result. NOTE: I am making cuts that will be visible ... so the gouges, blackened burns and blobs and such are not acceptable.
As the instructions that came with my hot knife state: do not hold the trigger continuously, especially for long cuts, instead pulse it on and off. The knife remains hot enough to cut for several seconds with the trigger released. Experience doing this will quickly let you learn what works best in your situation. Also, if your knife allows you to adjust the heat settings, try lower settings. Hope this helps.
I have 2 small projects to make out of this exact 4 inch insulation board. Looks like this hot knife works great. Not sure i want to spend $75.00 on a tool for two small projects. Thanks for the video. Never heard of this tool before.
Glad you made this video! I found it while trying to find a video I saw years ago about making your own foam cutter with nichrome wire. I like this much better.
Normal offset teeth sawblades produce clouds of nasty plastic dust. Any blade with a wavy, thin (knife-like) profile will cut clean and dust free. For my project using 120mm sheets, I ground the teeth and side edges off a 9" reciprocating saw blade. Perfect. For thinner sheets, same can apply with jigsaw blades, plus there are proprietary wavy blades for jigsaws. Hand cutting - if thick, use Bahco insulation saw. Thinner boards - probably utility blades and snapping will work best. From UK, you're welcome.
I use a 3" or 4' drywall knife . I sharpened one or both side edges and use that to cut foam board. I suppose I could attach it to an angled board to get an angle on the cut. A file will resharpen the edge.
I found one at menards but the blade is not as thin as yours is. I'd love to find a finer bladed one. I lose probably an 1/4 inch of material when it melts through. I'm only doing 2" though.
I want prefer straighter cuts to go between floor joist, circular saw will make straighter cuts. I probably would've doubled up 2" form board to get a straighter cut...
You probably won't answer this but where do you find 4-in insulation from like that? I just tried Home Depot and they didn't have it. At least not on their website.
I have never cut 4" insulation but on the 2" insulation is insulation I just use a circular kimbersaw.. I think that would probably be faster than a hot knife
Sorry I was doing talk to text and did not prove read my comment comment. Is I use a circular saw is sprinkler saw on 2" pink foam board word and it seems to work great.. Plus it's quicker
@@kjohnsonece1 yeah it didn't work so great it was too hard doesn't really have the power to cut this foam works excellent on softer foams tho but not this insulation type foam I ended up cutting mine with just a thin kitchen fillein knife scored it a few times and worked but a jig saw works too just makes a mess
Pretty much all of these type of Foam cutter are a massive ripoff, they are nothing more than a soldering iron body/heater with a flat tip for which you pay best part of £100!!!
Finally! I've been using a 4" taping knife that I heat-up with a blowtorch.
I have one of these exact foam cutting knives for this exact same foam (2" thick though) and am having a terrible time getting a smooth cut AT ALL. If the blade is too hot or you hesitate a little, as is inevitable on ANY longer or slightly complicated cut (I have a few curves) ... the blade INSTANTLY starts to melt foam and leave those large divots and indentations and, quite often, blackened burn marks and blobs. The blade very, very quickly gets gunked up and the directions with the tool say explicitly DO NOT BURN off the residue (super toxic fumes??). I ignore that prohibition but make sure to have have excellent ventilation and scrape off most of the residue immediately on a piece of wood thus avoiding most of the fumes.
Anyway, I am SERIOUSLY disappointed by the often shocking raggedness of the cut and wonder if there is a precise heat setting or precise speed of cut to avoid the sometimes awful result. NOTE: I am making cuts that will be visible ... so the gouges, blackened burns and blobs and such are not acceptable.
As the instructions that came with my hot knife state: do not hold the trigger continuously, especially for long cuts, instead pulse it on and off. The knife remains hot enough to cut for several seconds with the trigger released. Experience doing this will quickly let you learn what works best in your situation. Also, if your knife allows you to adjust the heat settings, try lower settings. Hope this helps.
This circular saw blade looks like a better option.
Bullet Tools 7.25 in. CenterFire Dust Free Foam Blade for cutting EPS, XPS & Poly-ISO insulation
I just finished cutting some foam board this evening, I used a putty knife, worked like a charm.
I have 2 small projects to make out of this exact 4 inch insulation board. Looks like this hot knife works great. Not sure i want to spend $75.00 on a tool for two small projects. Thanks for the video. Never heard of this tool before.
Glad you made this video! I found it while trying to find a video I saw years ago about making your own foam cutter with nichrome wire. I like this much better.
Normal offset teeth sawblades produce clouds of nasty plastic dust.
Any blade with a wavy, thin (knife-like) profile will cut clean and dust free. For my project using 120mm sheets, I ground the teeth and side edges off a 9" reciprocating saw blade. Perfect. For thinner sheets, same can apply with jigsaw blades, plus there are proprietary wavy blades for jigsaws. Hand cutting - if thick, use Bahco insulation saw. Thinner boards - probably utility blades and snapping will work best. From UK, you're welcome.
I use a 3" or 4' drywall knife . I sharpened one or both side edges and use that to cut foam board. I suppose I could attach it to an angled board to get an angle on the cut. A file will resharpen the edge.
They use to sell them with a slee with a bendable knife to cut nice thick molding for ceilings and more 20 yrs ago in socal
My question would be how it would work with board that has foil-backed card on the flat surfaces? I could see that burning rather than 'melting.'
Have you checked with Owens-Corning about toxic chemicals released and suggested protective gear?
Cool I just wish I would have come across this before i started my project rather than when I was about done cutting the foam. .
Thanks, exactly what I was looking for!
I found one at menards but the blade is not as thin as yours is. I'd love to find a finer bladed one. I lose probably an 1/4 inch of material when it melts through. I'm only doing 2" though.
Needs plenty of ventilation. Toxic fumes but works well.
Lots of black left over on the board
Can you post the resistance of the blade itself? how many ohms it has?
Do you have a link for purchasing this?
Electric wire works pretty good also.
I want prefer straighter cuts to go between floor joist, circular saw will make straighter cuts. I probably would've doubled up 2" form board to get a straighter cut...
THANKS A LOT, WHERE CAN I PURCHASE IT
Will it work ok to cut a wedge?
Cordless version?
Is there a battery operated unit?
Hi -- we are thinking about doing the same sort of project in our attic. How did your project turn out?
Looks like it works well, wonder if there is anything cordless for on the jobsite, thanks.
Cordless would be cool. I didn't see any cordless models but did not look extensively.
You probably won't answer this but where do you find 4-in insulation from like that? I just tried Home Depot and they didn't have it. At least not on their website.
You have to order from a construction building supplier. Not a home supply store.
great, thanks for sharing 👍
where did you get it?
A mask of some sort is definitely what you need against those fumes
Do you ever name the tool?
4:35
I have never cut 4" insulation but on the 2" insulation is insulation I just use a circular kimbersaw.. I think that would probably be faster than a hot knife
Sorry I was doing talk to text and did not prove read my comment comment. Is I use a circular saw is sprinkler saw on 2" pink foam board word and it seems to work great.. Plus it's quicker
What's the link??
It’s impossible to do perpendicular cuts through 2 inch foam board with this knife
@@edwardpeders9582 that's exactly what I ended up using - returned the hot knife back to Amazon
💪💪💪
Put an aluminum or wood straight edge down and get better cuts also
KickAss!
use a fan to blow the smoke away from you..
video starts at 2:27
Razor knife score and snap!
for $90 bucks, Ill make my own with a $1.69 PMW regulator and a tossed out power cord.
You could of used a $12-15 bread electric knife it would of cut it fine also
Did you try it as I was thinking the same thing.
@@kjohnsonece1 yeah it didn't work so great it was too hard doesn't really have the power to cut this foam works excellent on softer foams tho but not this insulation type foam I ended up cutting mine with just a thin kitchen fillein knife scored it a few times and worked but a jig saw works too just makes a mess
Pretty much all of these type of Foam cutter are a massive ripoff, they are nothing more than a soldering iron body/heater with a flat tip for which you pay best part of £100!!!
perhaps don't keep the brand name a secret?