On Thu, 03 Mar 2011 04:07:13 +0100, Sjouke Burry
wrote:

mm wrote:
Can you solder a thrmal fuse in place?

Someone gave me a disassembled sandwhich maker (heater). The
plastic/Bakelite? is broken where one of the four screws goes, but can
probably be fixed fine with PC-70.

The thermal fuse is burned out.

I have about 6 new thermal fuses of different sizes.

Can I solder the fuse in or must I crimp it?

In the past I've figured soldering would melt the fuse, but I haven't
had such good luck with crimping, probably because I don't have the
right sleeve or maybe not the right tool. With wire cutters, there's
a tendency to cut right through the whole thing, and with anything
duller, it's hard to squeeze hard enough.

Also, in the past the temp has burned off the melted fuse. What temp
would use for this small device, which I think just warms two slices
of bread. Would the amperage be a clue at all? The melting temp
of bread?

If I wanted to solder it, I would cool the fuse with a wet cloth, while
soldering.
However, the fuse is to protect against over heating, and a solder
contact failing before the fuse acted, could make a nice, fatal short
somewhere.
So you better crimp it. A sloppy crimp is better than a solder joint.

60/40 melts at 370F.
PB94B melts at 295C, or 563F.

Most thermal fuses are significantly less than 200C - the most common
is 167C - so you are NOT going to melt the solder - and I've seen a
lot of "crimped" connections done without the right tool that would
heat up under load enough to blow a thermal cutoff fuse if the
connection was on a thermal fuse. Particularly in solid wire, where
these units are very often installed.
Best DIY? Crimp and solder