Can you solder a thrmal fuse in place?

Mar 02, 2011 13 Replies

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?



All the thermal fuses I've seen were crimped on.

TDD

You COULD, but why would you want to? Why don't you just put a 6ga. wire shunt in there, and that should work .......................

I have successfully soldered quite a few. Don't try it with a small or low wattage iron though. I use a 250 watt weller gun - barely need to touch it to get the solder melted - use aligator clips to hold it in place and act as a heat sink.

The ones with the pigtails can be soldered in just fine. Leave the pigtails full length and hold the pigtail next to the body oy the fuse with needle nose pliers to act as a heatsink.

Jimmie

Yep more stuff has been burned up by using too small an iron that too big .

Jimmie

LSMFT wrote in news:R4Abp.67432$ snipped-for-privacy@newsfe10.iad:

different TEMPERATURES,I hope.

the old thermal fuse should have the temp marked on it. Probably in Centigrade.

Crimp is best.

I like hemostats.(surgical clamps) keep the fuse wires long.

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

I use needle nose pliers as a heat absorber. Hold the pliers shut with a rubber band on the handles/'''WW

With a 250 watt Weller no heat sink you could attach to the thermal fuse is going to increase the time required to melt the solder on the joint by a measurable amount, but a good heat sink will definitely keep excessive heat from reaching the fuse.

I know the 250 watt iron is overkill, but nothing beats it for FAST.

You've all given me something to think about. Thanks.

I think I'll solder, with a heat sink far from the end of the wire to be soldered and nearer the fuse.

One thing I was taught LONG ago with "heat sensitive" components was to use ALL of the lead length AND put some kind of "heat sink" between the solder joint and the component. A "hemostat" type clamp works just fine, thank you.

Do that and your thermal fuse will not even get "warm to the touch" when you install it.

I tried that years ago. I don't think it worked well for me. The crimpable part was small enough to go into the fireproof woven white tube, but not big enough to crimp well, at least not with the tools I had.

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