Cleaning up Bronze Castings

[Susie]

I am SURE this has been featured many times on this forum, but with over 300 results from my search, I'm at a loss.
Apologies.

I'm new to casting and have been experimenting with casting hand carved wax in bronze and silver.
I love it.

However, is it normal for the pieces to come back with such a rough surface?
If so, what's the quickest method in bringing it back to a smooth surface? I made sure the wax was beautifully smooth and have to spend ages filing, sanding and using rubber eveflex wheels to get the piece back to smooth again.
Does a tumbler do this?

(If this has already been discussed, i'd be grateful for a link).

Sue

[Dennis]

Hi Susie,
Your casting should come back with as good a finish as your wax. If not , confront your caster or go elsewhere.

If it is rough, then tumbling with steel shot will leave it rough but shiny. However you can use abrasive media and might get suitable advice on this by phoning Betts metals.
http://www.bettsmetalsales.com/c-Jewellery-Tools/

Dennis.

[Susie]

Thanks Dennis. I think I'll speak to the casting company.


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[josef1]

Not to step on Dennis's toes but I think casting will give a rougher surface than the wax. Its the investment powder that does it,if you can imagine the investment is similar to very small grains of sand and thats what gives the bad surface finish. You can use a tumbler magnetic pin polisher to remove this but old fashioned sanding and polishing gives the best results. Can you post a picture ? I may be able to tell you if its normal or if its a bad casting

[Dennis]

No problem with toes: that's what forums are for, but a high spec investment such as Kerrs Satin Cast Xtreme Investment Powder should give superior results.
I dont do them myself now, but have had castings back from West One Castings, which for my purposes only needed the sprue insertion points cleaning up and then a soapy brass brush. Dennis.