Why are you silver soldering clock parts? (Non adjustable assemblies are
drive fitted or riveted; even soft solder is only used on cheaper French
clocks. I have never seen silver soldered parts unless used to repair a
broken original part.). Silver solder heat (1100 degrees min) takes the
hardness out of the brass and steel which cannot be then be rehardened
without the solder joint moving. And since brass must be work hardened, you
cannot reharden it without changing the shape/dimensions anyway. Over time
soft brass gets charged with abrasives and acts as a lap, the soft steel
wears and will not yield a high polish.

As for the soldering, you may be using too much heat, your soldering block
may be contaminated, or you may not have adequately cleaned your parts. If
you have everything cleaned, you should need very little flux at the joint
and even less solder. There should be no need for thermal paste or
antiflux.

When I silver solder I use a very small flame from a jeweler's torch and
"sneak up" on heating up the parts. The instant the solder flows I back
off. I use propane/oxygen which I believe produces a cooler flame then
Mapp. I have used this torch to fuse brass to steel in making a balance
wheel so I know it is more than adequate heat for any job in clockmaking. I
wonder if the Mapp torch is simply too much?

--
Regards,
Dewey Clark
http://www.historictimekeepers.com
Restorations, Parts for Hamilton M21s, Products for Craftsmen
Makers of Historic Timekeepers Ultrasonic Clock Cleaning Solution

"Roger Jensen" wrote in message
news
I am silver soldering brass and carbon steel in making clock parts using a
high temp solder and a MAPP gas torch. What might you recommend to
minimize
the amount of cleanup needed, thermal paste? Is so what's good etc, or are
there other means. My end results are polished parts and what ever can be
done to make it easier is what I am after.

Thanks,

Rog