reluctant to silver solder

[va4ngo]

Hello all,
I am progresing well with my "Unusual steam engine" and am getting close to the sta ge where I nee dto silver solder a component.
The Brass valve (5/8" x 1/2") needs to be silver soldered to the vertical body (1/8" sheet brass. I do not intend to ever run this model on steam and would be open to other suggestions for attaching the part (eg. could possibly attach with screws).

My previous attempt (20 years ago) at silver soldering some years ago resulted in putting aside a project due to a disastrous result after silver soldering resulting in destroyed parts for my v4 oscillating engine, hence my reluctance to silver solder previously machined parts.

Different alternatives such as removable strong adhesives would be considered for when I have more confidence in silver soldering.

Cheers
Phil

 

[LADmachining]

Hi Phil,

If the part is not under great stress or high temperatures in use, then low temperature solder as used for electronics will work very well on brass. Just make sure that the parts are spotlessly clean first!

There are solders available in paste form, usually used for building sheet metal model kits amongst other things. Spread a small amount (a little goes a long way) on each surface. Assemble the parts, then heat gently with a small propane torch until the paste melts - you will see it turn bright silver. Allow to cool, clean off any flux residue (which can contain acids which will corrode the metal if not removed) and you are done!

Other options available to you are using an adhesive such as an epoxy resin like araldite or JB Weld, or one of the Loctite engineering adhesive products.

Regards,

Anthony

 

[tel]

Phil mate, get aholt of some scraps of similar sized brass, some 45% silver solder and CIG No 2 flux and 'ave a few practice runs first. Cleanliness is everything, also flame control is everything, don't be a'feared of the process- it's a lot easier than soft soldering once you get the hang of it.

 

[vlmarshall]

Like everyone else has said; Try it again! Cleanliness really is everything.

I made my first attempt at silver soldering a month or so ago, on the boilers for my Cracker locomotives. It went a lot easier than I expected, and they pressure-tested to 150psi, so I must have done something right. ;D

 

[Kermit]

box full of scrap, some steel wool or emery cloth, flux and a torch.

It's like riding a bicycle. Some people find it harder than others but sticking with it always produces a method which works for you.

My experience with soldering goes way back
Rules I've learned
1. Finger oils are very potent anti solder flow compounds.
2. Start heating the area with the flame moving slow.
3. Finish the joint with the flame moving quicker.
4. Don't rush the cleaning steps before applying flux. - Be sure the joint is ready first. (don't use 'used' sandpaper)
5. 'Active' fluxes seldom work as advertised. Manual deoxidation is best.
6. Keep a pencil handy to color places where you don't want solder going.

Good luck, and have fun with it too!
Kermit

 

[tmuir]

If you want to know fear try soldering up an 18K gold bangle that you have just spent $700 on material and unlike copper or brass you have to get gold to an angry bright red colour for the solder to flow. I was sure I was going to reduce my $700 worth of material into $400 worth of scrap but it worked perfectly.

Soft solder this one but as everyone else says gets some scrap and have a go at it.

 

[jthulin]

I agree with what the others have said; and I actually prefer silver to soft solder!

By the way, do you care to share any details of the V-4?

 

[va4ngo]

Hello all and thanks for your words of encouragement, I will give silver soldering another try.

Jeff, the v-4 is being built ffrom plans in live steam in April 1978 designed by Jan Gunnarsson. I started and and abandoned this build around that time. I have actually progressed well in to the build and I will try to post some photos as soon as I have figured out how to. My nephew IT whiz suggests photobucket etc so I will give it a try.

I may now renew my interest in the v-4 after finishing the "Unusual steam engine" also from live steam plans 1978.

Cheers
Phil

 

[jthulin]

I had a feeling that was the engine you were refering to
I have been building one for a while now and posting my progress here:

http://www.homemodelenginemachinist.com/index.php?topic=4864.0

:hDe: does this link work ???

Some of my pictures show my silver soldering results at various stages. Hopefully you still have some parts saved from your earlier attempt and have another go at it!

 

[radfordc]

I built the same engine and soft soldered it. You can see it in the link that Jeff posted.

Charlie

 

[ianjkirby]

Phil,
If you are using the fairly common 1.5mm silver solder sticks, you might find it helpful to beat it down with a hammer on an anvil or similar first, to reduce the thickness of the solder (it will probably split; don't worry about this. You just want to end up with thinner solder). The solder needs too much heat to melt it at the original size, and smaller parts generally melt first. Reducing the thickness of the solder will reduce the amount of heat required to melt it, and your parts will be more likely to survive.
Regards, Ian.