Teardrops n Tiny Travel Trailers

Has anyone used the 130 watt harbor freight Hot Knife , for cutting 2" XPS ? What were your views of the tool ?

I fear it might be way more power than you need. I cut mine with a 15W hot wire, made from a wall wart and a piece of nichrome wire. For doing notches and kerfs, you can use heavier nichrome wire and an old 35W soldering gun.

My $0.02 worth

<Chas>

I have heard they do not last too long, but they may be improved by now. The knife does have a temperature control dial so you can dial it to the temp you want. I have not used one, but have looked at them a few times.

I made a mess with one trying it out....
Wrong technique? I don't know.

It takes some practice. The blade is very thick and the foam seems to melt on the blade. I cut some 2 inch for the floor and put it on the shelf. I would only use it outdoors.

Thank for the information, I just built my own hot wire cutter. It worked better that I expected. About the only problem I had, was the circuit breaker kept cycling. I have a transformer from a HO Trains set from about 20 years ago. Going to try that.

rustytoolss wrote:Thank for the information, I just built my own hot wire cutter. It worked better that I expected. About the only problem I had, was the circuit breaker kept cycling. I have a transformer from a HO Trains set from about 20 years ago. Going to try that.

A model train transformer is about ideal for making hot wire cutters. Variable output, high current capability, and often internal fuses/circuit breakers.

I got real nichrome wire from Amazon. I used AWG16 or 18 for my hot wire "jig saw." For cutting straight pieces out of sheets. And I used 12-14 ga for my "profile cutter" to cut the notches for my angle iron frame and roof spars. I put that in a soldering gun I got at Goodwill for $2.

<Chas>

At this point I'm using 1/16" wire for torch Oxygen/Acc welding. As it was the only wire I had small enough to test with. And I will need to use it with the transformer / for now anyway. Do you have any pictures of you hot wire cutting tools ? they may give me some ideas. Merry Christmas

rustytoolss wrote:At this point I'm using 1/16" wire for torch Oxygen/Acc welding. As it was the only wire I had small enough to test with. And I will need to use it with the transformer / for now anyway. Do you have any pictures of you hot wire cutting tools ? they may give me some ideas. Merry Christmas

They were all one-use tools make just to cut the insulation panels for my trailer. Sorry.

Try the train transformer on low-throttle first, and pay attention if it starts getting warm. It's easy to burn up power supplies when drawing high current such as a hot wire requires. There's a site that provides power and temperature calculators, but if you are using just what you have wire, they'll do you no good.

My first hot-wire cutter ran off a string of 1.5V dry cells. The nichrome wire came from an old (I mean really old) toaster.

<Chas>