[Shop-talk] High-temp electrical insulation needed

[Wayne]

john niolon wrote:
> the fiberglass tubing will work fine... any electrical supply house 
> should have it in rolls... don't know where you are but 

Thanks for all the tips on the insulation.  A friend also suggested the 
car parts place, which I hadn't considered.

I got the oven going with a temporary fix.  I used teflon pipe tape on 
the wire;  figured this would handle the voltage and heat.  Then put 
some rubber fuel hose over that as a standoff from any hot parts.  It's 
good for under-hood temps, and I expected it would smoke a bunch before 
igniting.

With the oven working, I did some semi-destructive testing that may be 
of interest.  I had four materials:  teflon pipe tape, heat shrink 
tubing, vinyl electrical tape, and rubber fuel hose.  I put then in the 
oven on aluminum foil and cranked it to 250dF.

250dF:  heat shrink tube shrunk, all materials intact
350dF:  electrical tape melted, fuel hose smoking lightly (removed them 
from test)
400dF:  heat shrink "sticky" and starting to melt, but no worse than 
when normally heating to shrink (removed from test).  Teflon intact.
450dF:  Teflon intact.
500dF:  Teflon intact.

So I think I'm gonna leave the teflon on there, and just find some 
fiberglass sleeve to go over it for mechanical strength.

After the testing, I remembered I have that clear green masking tape for 
powder coating.  It's good at 400 - 450 in the PC oven.

   -Wayne