My first experience of getting a printed model moulded was a disaster.
It turns out that the stuff used to make the moulds does not play nicely with the printed model and it does not cure properly resulting in a cruddy mould.

I am currently getting my printed models cast into resin, then having the resin models used to make the moulds.
This is a costly step in the process I wish to avoid.

I hear that simply scrubbing and washing the printed model then coating in paint will stop this problem.
I assume this seals the model and keeps the stuff on it away from the mould gloop.

Can anyone with experience shed any light on this for me please?

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http://angelbarracks.co.uk/

It depends what material you used to print the model in. HTM140 is generally good for casting, the printed model could immediately function as a master. RCP30 is also a good material to use.

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Bits Blitz - The place to be for all your bits needs!

http://www.shapeways.com/shops/bitsblitz

Also interested, I tried making some siligum moulds of some 3D printed bits the other day and it just went weird....

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Just some guy

My hobby/painting threads

Army Forge List Co-ordinator

Was that for resin casting kyussinchains ?

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http://angelbarracks.co.uk/

My resin caster asked me to undercoat my FUD Shapeways models before sending the parts to him.

He had some problems in the past with FUD that was porous and behave badly with silicon.

@AB dual purpose, the moulds will work with either resin or metal

I found that the mould halves were distorted and twisted, I'm thinking it's some kind of reaction between the siligum catalyst and the 3D printed material

I may try again, but give the pieces a good scrub in cold soapy water first, and then spray them...

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Just some guy

My hobby/painting threads

Army Forge List Co-ordinator

One problem i've had with stiff RTV was the very rough surface of CAD prints (due to striation) meaning the master had a lot of 'grip' into the mould, led to the master snapping on removal .

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AFK with real life, still checking PMs

I use shapeways and other companies prints for my resin moulds resin and have no issues at all, it is just with the metal that they moulds don't cure..

The issue I understand is that chemicals used to remove the wax works against the curing process of the mould.

Shapeways is a pig for striation so I always sand their stuff down first.

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http://angelbarracks.co.uk/

If you don't want the striations you could always contact this gentleman.

http://blackdragoncastings.co.uk/

He's a regular on the resin addict forums ( http://www.resinaddict.com/forum/index.php), he prints his masters in wax pretty much the same way they do jewelry masters. just a thought.