Bronze casting

[chriscallender]

Hi

Wondered if anyone has any practical experience of sand casting of bronze parts. I need a new rudder shoe made up and after doing a bit of research on the internet, I'm toying with the idea of making it myself... being able to make parts from bronze would be a pretty neat thing to be able to do, and I don't mind spending some time (but not an indefinite amount) making a furnace etc. Would be a useful skill for fixing things in the future.

Some questions

- How hard is it to learn by trial and error? How realistic is it that I would be able to get a decent result (ie a usable part)? I have done basic fabrication in steel and stainless steel before so I can weld etc but casting metal would be completely new to me. This rudder shoe doesn't need to be a precision part (will be bedded down on goop) but needs to be big, solid, strong and well made.

- What is the best bronze alloy to use underwater. Silicon bronze?

- Alternatively, any recommendations for a company that could do this work for me? The idea would be to use the old cracked rudder shoe as a pattern (I'm going to thicken up the walls and I suspect the old one failed due to chemicals in the antifouling, anyway it lasted about 25 years and I'll be very happy if the replacement lasts another 25... DId a few searches on google but its not clear whether the companies I found are really doing one off castings.

- Any other hints or tips welcome...

Chris

 

[steve28]

I saw some parts being made up a few years ago, they used old propellers cut into small bits for the material, heat source was gas (alot) melted in a crucible then poured into the sand cast mould.

Steve

 

[earlybird]

I think that you will find the effort of DIY bronze foundrywork rather much for a one-off, but if you're determined, there are one or two books worth reading. "Foundrywork for the amateur" by Terry Aspin is one. there is another by Ivan Law, can't remember the title. Both are aimed at model engineering.
I think my approach would be to contact a supplier of ME castings, eg A J Reeves is but one. They will know foundries that deal in small quantities of gunmetal castings, Good luck, but I think that you will find the price fairly high.

 

[Leighb]

I don't know where you are based, but Classic Marine in Woodbridge, Suffolk are very good at making bronze castings from patterns. They would replicate your old unit easily.

They made some lovely bronze cleats for me several years ago to replace the original 1930s ones that had fractured.

They were not expensive either for a one off.

 

[TheoSr]

Look here:

http://www.backyardmetalcasting.com/index.html

Have fun,
Theo

 

[wotayottie]

as an alternative, take advantage of modern technology and make one out of epoxy and carbon fibre. lighter so you'll go a bit faster.

 

[DownWest]

No personal experience of Classic Marine, but friends and press speak very highly of the outfit.
I bought a CD from www.myhomefoundry.com for when I have time to tackle DIY casting. Full instructions for furnace and moulds with all the techniques needed. $20 usd. if I remember.
But you would be nuts to do it for just a couple of fittings. Make the patterns (the time consuming bit) and get a casting firm to do the rest.
A

 

[TQA]

If you do have a go at the DIY backyard bit remember the safety gear. Making a mould and getting the metal hot enough is not difficult but getting the pour done without any incidents is another matter.

Ask me how I know!