Failure of an Idea

[Mojo]

I bought an 8 ft piece of aluminum stock today to use as a cutting surface for my hot knife. I screwed it onto my cutting table so I could use clamps and a top piece of aluminum as a guide.

FAILURE............ The knife cut for crap. I believe after thinking this over that the problem is I used aluminum stock and it acted as a heat sink, sucking the heat from the knife blade.

I went back to using a steel straight edge to cut on and it worked fine.

What do you think ? Is my theory correct or am I out in left field on this ? Why would the heat knife cut perfectly on metal but not aluminum ?

Chris

[MinUph]

I have some clip on heat sinks for soldering wire and the are aluminum. So you theory might well be valid.

[Mike]

Aluminum is very. Inductive of heat so I'm sure your right. M

[JuneC]

Not that I've ever tried it, but it appears the only thing worse than aluminum is copper or gold  ???

    http://www.engineeringtoolbox.com/thermal-conductivity-d_429.html

June

[Bob T]

I've had the very same thing happen using an 8' long aluminum straight edge. I've learned to not press the hot knife so hard against the straight edge. With some practice, you can get it to work fine.

[SHHR]

Chris, when I weld a long stretch of sheetmetal, I always back it up with a peice of aluminum or brass to quench the heat and prevent distortion on the metal.  if you look, most heat sinks on electronics are aluminum. that material will quickly wick any heat away. stay with your steel plate or if you want a good durable peice, shell out a few more bucks for a peice of stainless.
Kyle

[joebolton]

I think aluminum is ok, cause it is inductive of heat. I have tried the similar experiment and it worked!

[Qwerty27807]

Big 18x18 floor tile works well.

About $1.69 at Home Depot.

Line up several if needed.

[Darren Henry]

Personally; I still prefer to use the foot and cut wherever I want. That said; before  we got the foot when I first encountered these knives, we just put a used piece of Barker board down to cut on.Where your cuts are usually straight lines I can see using the straight edge, try the Barker board or similar think.

[Mojo]

I went back and started cutting the fabric according to Bob T's suggestion. I didn't put any pressure on the knife and just allowed the weight of it to cut the fabric. it worked great so I am using the aluminum strip again. :)

Thanks Bob T for the suggestion.

Chris