Water Pump

I am not happy with the casting I have for the water pump on my 4" traction engine and I am thinking about fabricating it from stock material using silver soldering. Is this practical and if so what material should I use? The drawing says cast iron but I am not sure that I have the skill to silver solder CI. Can brass be used or is this a no no?

Any guidance in this matter would be much appreciated.

As it does not see heated water then brass and/or bronze should be fine and a lot easier to solder. I made my 2" Fowler one as a brass fabrication.

Whats the engine?

I fabricate small brass components (by silver soldering) and the only problem I really have is where some parts are much larger than others. It is very easy (I've found) to melt the smaller parts if you don't take care. I imagine your pump will be quite large - so will need a fair bit of heat.

These days I try build up the heat around the components a bit more gradually, allowing everything as far as possible to warm up evenly and I often use a specially designed brazing hearth to help with this. This magnificent sounding bit of kit is actually a large coffee tin with a hole in the side which is lined with Kaolin Wool! You sound like you might need something a bit larger but the idea will be the same. I purchased the Kaolin blanket here (see link) and it works very well and has lasted a surprisingly long time.

**LINK**

I also try to make my smaller component parts so they either slot together and/or are pinned/screwed where possible. I know many modellers use iron wire to bind things together but I find it easier to make the components hold themselves in place and where necessary machine away any tabs/pinning afterwards. It is obviously easier to plan this before you make the parts than when you come to braze them (again I learned this the hard way). Your larger pieces may not be such a problem.

My apologies if there is any element of 'egg sucking' & 'teaching Grandmothers' for you here George.

IanT

JasonB, the engine is a Garrett. That's good news as I am reasonably happy to work with brass.

IanT, no sucking of eggs here I assure you. Your comments are taken on board and much appreciated.

Many thanks to you both.

George S

Not having see a drawing of the pump but assuming most of the attached bits are going to be tubes into holes could you not use soft solder. After all that's how copper radiators were made.?

regards Martin

Unlikely just to be tubes in holes, this is teh pump valve on my Fowler, don't think I would want to risk softsolder.

And complete with body from a 3" as I don't have a pic of mine