Soldering a mainspring barrel to the wheel.

[Dick HParticipant @dickh]

Hi, I´m slowly getting back to a clock loosely based on John Parslow´s Skeleton Clock. The barrel is soldered into a recess in the main wheel. Both parts are brass.

The original article suggests either soft soldering or silver soldering. I´m not sure  I have the kit (ie. enough heat) to silver sold the parts together and would prefer to soft solder them. Has anybody got any tips as to how to make a tidy job of it without getting solder everywhere?

Dick

[Bill PhinnParticipant @billphinn90025]

Solder will flow towards the hottest part of the job and potentially solidify on to any part in the heating zone that has flux on it.

In jewellery fabrication, it’s particularly important to control solder flow. This is done in three ways: the judicious and sparing application of flux, using pallions of solder or balled-up solder placed on the work before the job is up to flow temperature, and the painting on of solder flow inhibitors such as liquid paper.

I’m unclear how big the job is so can’t really advise on the size of torch/burner you’d need.

[SillyOldDufferModerator @sillyoldduffer]

I’ve successfully protected the area around a similar soft soldered joint, not a clock, with a generous coating of Tippex Correcing fluid.  Kept off solder and flux spatter.  I removed it with Nail Polish remover (Acetone).

Wait for a clockmaker to reply though – my application didn’t have to be perfect.

Dave

[Dick HParticipant @dickh]

Thanks for the replies. I´ll go looking for some Tippex but I haven´t seen the stuff for years.

As to the size of the bits, Wheel is about 6.35 mm thick and 63mm is diameter with a 2mm  recess to accept the barrel which is about a 1 ” piece of 2″  dia  1/8″ brass tubing. (Sorry to mix units but I work in mm but the original article is imperial but some of the dimensions were apparently converted from metric).

Dick.

[Michael GilliganParticipant @michaelgilligan61133]

 

If, as stated, there is a recess provided for location, then a soft-soldering job should be very simple.

Get both parts thoroughly clean, then drop a ring of ordinary multicore [wire] solder into the recess [wheel lying horizontal] .. add the barrel and heat until the solder ’flashes’ around the joint. Gravity and capillary action are your friends.

Let it cool before moving the assembly.

You need to get the heating arrangements, and the volume of solder, ‘just right’ … but some pre-planning should get you in that Goldilocks Zone.

MichaelG.

 

 

[BazyleParticipant @bazyle]

Place the wheel flat on a piece of vermiculite board. Place barrel in place and apply minimal amounts of solder wire pieces on the inside up against the joint. When heated the solder will wick into the joint by capillary action but not go outside the joint as there is no driving force for it to do so, unless you have put silly amounts on to provide a pressure head. Any mess will be on the inside out of sight.
You could also use a flat piece of steel to put it on and heat from underneath but it is harder to get the tube as hot as the wheel at the same time.
If the inside is to be visible because it is crossed out the solder can be prevented from flowing along the arms using a barrier paint (tippex) but test first that it holds up under heat.

[David SeniorParticipant @davidsenior29320]

Tippex is still available – I bought a bottle just last week as I have some soldering to do and had heard of the concept of using it to limit the solder flow.

Dave

[John HaineParticipant @johnhaine32865]

Modern Tippex not so good.

[bernard towersParticipant @bernardtowers37738]

you need the one with the red writing on the bottle not the green one!!!!!

[cedric 1Participant @cedric]

Before there was Tippex, ancient fossils used Milk of Magnesia to mask soldering jobs. No idea if that is still available? Probably rebranded as some expensive acid reflux cure.

[Dick HParticipant @dickh]

Thanks folks, I´ll go shopping.

I haven´t done much in the workshop for well over a year. This is part of the restart. 90% of the bits of a clock have been sitting in abox since covid.

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