# foam/hot knife??



## debbie5 (Mar 2, 2007)

All righty then- I'm looking to get a hot knife or wire-foam-cutter-thingie...I have cut enough foam that I'm sick of the lil balls and shavings that cling to everything. I have no clue even what they LOOK like. So, I'm coming here for suggestions: 

will I still have lil static-y balls & shaving if I use a hot knife? (NO dirty jokes!) 
are you able to get a nice rounded cut?
does it leave a texture behind?
do they come in diff sizes or outputs?? 
if so, which do you prefer?
are there types of foam that you cannot use it with? 
anything I should or should not look for in one? 

Thanks in advance. :jol:


----------



## Allen H (Feb 13, 2010)

will I still have lil static-y balls & shaving if I use a hot knife? (NO dirty jokes!) 
N0
are you able to get a nice rounded cut?
YES
does it leave a texture behind?
Very slightly dimpled, as if you passed briefly over the foam with a heat gun
do they come in diff sizes or outputs?? 
Yes
if so, which do you prefer?
Harbor freights model is the right price
are there types of foam that you cannot use it with? 
NO
anything I should or should not look for in one? 
The blade shouldnt touch any thing when you set it down
http://www.harborfreight.com/130-watt-heavy-duty-hot-knife-66182.html

I have that one and love it, but If you want to spend more-
http://www.demandproducts.com/Hotwire-items/search.php?l1=8,15


----------



## wdGoof (Jun 7, 2011)

I bought this kit at the MidWest Hauters Convention this year, and have been very happy with it. http://hotwirefoamfactory.com/home.php?cat=

Specifically I bought the 4-in-1 kit and found it very versitile. Very clean cuts, with no clingy balls. The cut can be as rough or smooth as you want depending on how steady your hand is. Works on almost everything. My kit came with a variable power supply for all tools. It is really safe, the wires heat up and cool down very quickly, with everything else remaining cool to the touch. I added a sled guide to mine as well for engraving. The one caution is make sure you have ventilation or a fan. You dont want to breath the fumes.


----------



## debbie5 (Mar 2, 2007)

whats a sled guide? like a template for making straight cuts??


----------



## wdGoof (Jun 7, 2011)

The sled guide holds the tool at a specific depth so you get uniform consistency when ungraving. It can also be set at an angle for molded edges, or run along a straight edge for exact cuts.


----------



## debbie5 (Mar 2, 2007)

Cool! Thanks for the feedback! VERY helpful info.

Allen- the page you linked to shows several knives..which one did you get? The Craftsman one warns about overheating & limits time of usage..not good.
can you sculpt with a hot wire? Or is a knife better for that??


----------



## jaege (Aug 23, 2009)

I use the _Hot Wire Foam Factory _knife too. It works really well.


----------



## flesh1031 (Jun 28, 2011)

I have the harbor freight one and it works perfectly. Its like 20$ so if you happen toburn it out or swipe the power cord with the knife (speaking from experiance there) you can cheaply relpace it.


----------



## Spooky1 (Aug 25, 2008)

I have both the Hot wire sculpting tool (http://hotwirefoamfactory.com/-K02-Sculpting-Tool-Kit.html) and the Hot wire knife (http://hotwirefoamfactory.com/-K11-Crafters-Hot-Knife-Kit.html). I use the sculpting tool more when making tombstones. Then I use a wood burner engraver I got from Michael's (love those 40% off coupons) to do the lettering.


----------



## RoxyBlue (Oct 6, 2008)

Added note about the knife - if you're making something like a celtic cross, the knife is the way to go because it lets you make a starter hole and then slice out those inside openings typical of a cross tombstone. The sculpting tool is perfect for outside curves and edges.


----------



## DireDebb (May 14, 2011)

I also have the Hot Wire Foam Factory tool kit, sled, and hot knife. And although they don't smell nice, styrofoam fumes aren't toxic (the dust, however, is dangerous to your lungs).


----------



## Allen H (Feb 13, 2010)

I have this one-
http://www.demandproducts.com/Hotwire-items/item.php?l1=8,15&sku=GROUPHKT

and several of the Harborfreight models. Im 90% certain that the Harbor freight model and the Hot wire model are the same tool If thats true then the Harbor freight model is less expensive.


----------



## RoxyBlue (Oct 6, 2008)

DireDebb said:


> I also have the Hot Wire Foam Factory tool kit, sled, and hot knife. And although they don't smell nice, styrofoam fumes aren't toxic (the dust, however, is dangerous to your lungs).


Carbon monoxide is one of the combustion products when burning styrofoam, so you still should only use foam cutters in well-ventilated areas (preferably outside).


----------



## fritz42_male (May 5, 2009)

wdGoof said:


> The sled guide holds the tool at a specific depth so you get uniform consistency when ungraving.


So is this ungraving another term for exhumation?


----------



## Bascombe (May 18, 2010)

RoxyBlue said:


> Carbon monoxide is one of the combustion products when burning styrofoam, so you still should only use foam cutters in well-ventilated areas (preferably outside).


Carbon monoxide is the least of the problems with polystyrene foam.

When you cut it with a hot knife it releases hydrogen cyanide which incidentally is the same gas that the Nazis used in the death camps in WWII.

To overcome this, you should either:
A. Cut the foam in a fume hood that evacuates the fumes from you and scrubs the gasses from the air
B. Wear a respirator (not the silly white particle mask that doesn't help) with cartridge filters
C. Cut outside on a breezy day with the wind at your back to evacuate the fumes from you.

If you can smell it, you are being poisoned.


----------



## drzeus (Jun 25, 2011)

I've been looking at this model. Pretty cheap and looks just like the others. Anyone tried this?


----------



## debbie5 (Mar 2, 2007)

Hmmm..bad fumes. Maybe I could use the knife to cut dried hemp plants??


----------



## debbie5 (Mar 2, 2007)

Oh- and thanks everyone for the helpful suggestions!


----------



## ouizul1 (May 22, 2010)

You might want to use your hot knife outside, or in a well-ventilated environment, when cutting/carving foam. Styrofoam, and the pink or blue foam boards, are usually made from expandeded polystyrene or isocyanurates/polyisocyanurates. Both of these materials off-gas toxic fumes when melted or burned. Some of the expanding spray foams are also contain isocyanurates.

Not saying don't do it...just be aware...and have plenty of fresh air. If you start getting a headache, it's time to take a break and get some fresh air.

A quick internet search on both materials, or a search for their Material Safety Data Sheets (MSDS) should turn up a list of the toxins produced.


----------



## ScreamReaper (Feb 21, 2010)

*Harbor Freight*



Allen H said:


> will I still have lil static-y balls & shaving if I use a hot knife? (NO dirty jokes!)
> N0
> are you able to get a nice rounded cut?
> YES
> ...


Hey Allen,

Do you know if Harbor Freight also has a hot wire sculpting tool and an engraving tool as well, to go along with the hot knife?


----------



## BioHazardCustoms (Aug 5, 2009)

ScreamReaper said:


> Hey Allen,
> 
> Do you know if Harbor Freight also has a hot wire sculpting tool and an engraving tool as well, to go along with the hot knife?


Unless they have added it in the last few weeks, Harbor freight does not carry a hot wire tool. As far as an engraving tool, I use a cheap wood burner from Wal-Mart (It's in the craft section, costs about $10) This tool comes with numerous sculpting tips, has an on-off switch, and is very versatile. Hope this helps!


----------



## GhoulishCop (Sep 25, 2009)

Debbie,

I've used the HFT knife, a hot wire cutting table, and a homemade hot wire tool, and of all of them I prefer...a regular *jigsaw*!

There are definitely benefits to each of the tools, but for simplicity and ease of use -- and no worries about fumes, burns, or anything else -- a basic jigsaw can't be beat. It gives you virtually smooth cuts too and allows you to make intricate cuts that might not be possible with a hot knife (it's a pretty big, thick blade). It also gives you more control then the hot wire tools too.

FWIW, my celtic cross was cut completely with a jigsaw, including the interior holes: you just push the blade in and start cutting.










So if you've got a jigsaw already, I wouldn't waste any money buying a new tool that has limited applications other than for cutting foam.

Rich


----------



## BioHazardCustoms (Aug 5, 2009)

Good point Rich. I've also used a reciprocating saw as well ( I use a lot of 3 inch foam) and it works well. I built a hot wire foam cutter just in an effort to get more intricate designs. I'm still working on learning to use it, but it does have applications that I can see being a benefit in the future.


----------



## Pumpkin5 (Aug 8, 2010)

:jol:I LOVE THIS THREAD! I am learning so much...thanks for posting it Debbie, and thanks forum members for all the wonderful replies! You guys are a plethora of knowledge....and then some....


----------



## GhoulishCop (Sep 25, 2009)

Bio,

You're right about the details with the foam cutter. I've been working with the white foam so much recently that I forgot about the benefits of using a table with blue or pink insulation. You can definitely make intricate cuts with it.

Unfortunately, I haven't had need to make real detailed cuts like that though. Perhaps this year I'll do so and then have to get my table back from the friend I gave it to.

Rich


----------



## susan from creepy hollow (Jun 17, 2007)

Now i want a hot knife! I was asked to loan a few tombstones to our town's theater for their production of A Christmas Carol, which I did quite willingly. Then they called back and wondered if I could make one specifically for Scrooge with his name and all carved into it. I agreed (of course!) but had to do the carving indoors due to in-climate weather. beads and scraps everywhere! What a mess. But the stone turned out decent, they were very happy with it. They gave me a mention in the program, 4 tickets and a kickin' new tombstone for Creepy Hollow's cemetery next year! wanna see?
Here it is at the house when i finished it (messed up the spacing a lil, but it was ok i guess) I scratched the skull into it upside down with my thumbnail, then x-acto'd it and went from there. 1st one i'd ever done!









and onstage. bad pic, but look closely, and you can see the TALL ghost of Xmas future


----------



## EverydayisHalloween311 (Oct 14, 2011)

That's a cool scrooge tombstone. I really want this to be the year I get into making things out of foam. Definitely buying a hot foam knife


----------



## EverydayisHalloween311 (Oct 14, 2011)

Wow ghoulish cop great job on Celtic cross. A jigsaw? Heck yea


----------



## Pumpkin5 (Aug 8, 2010)

EverydayisHalloween311 said:


> That's a cool scrooge tombstone. I really want this to be the year I get into making things out of foam. Definitely buying a hot foam knife


:jol:Maybe if you are really, really good, Santa will bring you a Hotwire knife in your stocking........

P.S. Susan that is a very cool tombstone, nice work!


----------



## susan from creepy hollow (Jun 17, 2007)

thanks y'all


----------



## stick (Jan 21, 2009)

I agree with the jigsaw in cutting a lot foam it is a lot faster and having better control


----------

