Some success (finally) with lost resin investment casting

[Mcgyver]

Hi Dick,

Thanks for the encouragement.  Been sick for a few days and was travelling before hand so slow getting back to you.

I really really want to make Siraya Cast work but just have had endless problems.  You really caught my attention claiming it was you best for consistency.  Mine all centre around surface finish issues (using new Plasticast, R&R's supposedly tougher material for resin, but also had the same issue with ultravest) which I believe is damaged caused during burnout (expansion of the material?).  Burnout is a long slow PID controlled cycle R&R recommends.  Siraya the most reasonably priced; but I can't get it to work!

I've kept very detailed notes and will post them here in the next day or so.  Would be great if you could look them over and give any pointers.

I also found their curing instruction frustrating.  Initially VOG gave hot acold water process he says Siraya told him to use, but that was NOT what their web site.  Several fails with both approaches (all done under glycerine).   

The last time I tried I used VOG's new advice on Siraya, it to was a fail.  I also tried various curing times, from an hour to seven.  Still get fails.    Prints were always good, just fails on the casting surface finish.

cheers
Mike

[Dick Morris]

Just to clarify, a couple of other resins I have used worked as well as Siraya, but cost significantly more or became unavailable when the supplier stopped shipping to Alaska. Neither worked any better and one required a higher burn out temperature. Siraya is not only cheaper, but with Amazon shipping is free. In fact, when I bought a couple of bottles in September I caught a sale at $67.50 for a 1 KG bottle. (I try and have enough on hand to get me through the winter before it gets cold. I don't imagine leaving it to freeze in the mailbox would do it any good.)

I'd like to do a side by side comparison between curing in glycerin and in the air. I've had a couple of pieces that I had to cure in air because they were to big for the amount of glycerin I had and I'm not sure I could see a difference, but it wasn't an apples to apples comparison. Also, I'm not making jewelry, I'm making locomotive parts. Surface finish is still important, but probably not as important as for jewelry.

Attached are photos of some of the best results I've had that I know were with Siraya Tech, so I know what is possible. Now the challenge is to consistently get this quality.