Casting defects - what is tolerable?

[roz]

Hi,

I recently had some silicone moulds made from some masters, and just got my first lot of castings back from them. I'm not really sure what to expect. Are defects expected? Some have some strange curves on them and other marks. I can repair them but just wondering if this is normal or if I should be hoping for a better quality?

Thanks in advance

Roz

[Luci]

There is always a certain amount of cleaning up on castings but if there are big pits ect I send them back. Can you send pictures?


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[Dennis]

A silicone impression should be a faithful reproduction of the original. If not, the same defect will occur on successive castings.

You might need to see the silicone mould to be sure, but if you are not firm, you wlll have the wool pulled over your eyes. Dennis.

[roz]

Hi both, thanks so much for getting back to me. I don't think most of the defects are in the moulds as there's differences between castings. Some have defects some don't. I've taken some pictures to show what I'm talking about where some have a problem and some don't! I've circled the affected areas.

Thanks for your advice!

[josef1]

The line your seeing is from the mould half's its can be caused because the wax injector pressure is to high but you will always get some evidence of a seam in reality the hole in the model is from the casting process maybe dirt or the investment not been correctly vacuumed difficult to say from the pictures

[Luci]

I'd say that was a normal clean up but maybe I'm to forgiving.


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