Does brass distort when heated up to silver solder?

You can't do this with a blind bore, but with a through bore you can regain some hardness in the brass by forcing a hardened steel ball through the bore, it also makes the bore round and parallel.

Ian S C

When brass is at high (silver-soldering) temperatures, it is very soft indeed. If you pick up your nice hot fabrication to dunk it in the pickle, then the pliers you use to hold it with will very easily distort the brass.

Don't ask me how I know this...

And you can also get a knurled effect where the jaws of the pliers gripped the job too.

Don't ask me how I know this...

Repeatedly plunging a red hot cube of steel into water will over time change it's shape to spherical by differential contraction and stress relief. Similar things will occur with brass so maybe hot plunges into the pickle are not such a good idea after all.

regards Martin

I've decided to have another go along the lines of how 'Fizzy' has suggested.

I've made a new gun metal cylinder. I have drilled the centre out some of the way to reduce the mass a bit to help with silver soldering. I'll solder the top and bottom plates on. Then put it in the lathe and drill and ream the cylinder to size, then solder to the valve body. I wouldn't think the final solder would distort the cylinder because the end away from the valve body will be a lot cooler and so hopefully keep it all round. As it was also up to temp for the initial soldering if it was going to distort then I'd like to think it would have happened then.

So that's my game plan.

Edited By Greg H on 12/12/2016 11:55:14

I suppose once you've sunken the plier knurl straight into the job it could be significantly deep impressions. However, superficial surface blemishes can be taken out with an orbital/spherical sanding disk, the purpose of them isn't to so much cut material but to coarsely buff and agitate the surface faces of material. It's very useful for finishing bits of plate metal when held firmly against the sanding table. This may be old hat but I mean well to distribute some hints.

Michael W

I would still leave a few thou to ream out with a D-bit after the final soldering. A D-bit is easy and cheap to make and will cut to the end of the bore.

Russell.