Blue Stuff and acrylic resin casting

[Henry Lauder]

Finally getting my hands on some Blue Stuff (what too me so long!), I’ve been experimenting with casting some bits and pieces for diorama building and sing Green Stuff and Milliput.

https://flic.kr/p/2nZHMEN

The results were good but something like 1 in 3 came out with imperfections from either not packing the putty sufficiently firmly (leaving folds and join marks between successive pieces added to the mould. Or, with failure to adequately pack the mould to the outer edges, losing detail.

https://flic.kr/p/2nZFikr

I have recently discovered Green Stuff World Acrylic Resin, and being a pourable consistency when mixed is a big step forward from using putty.

https://flic.kr/p/2nZLCt7

Ensuring adequate drying time (at least an hour) seems to overcome the fragility I experienced on finer castings. I did have some bobbles but they are easily repaired. Well worth a try and very convenient with the resin powder only mixed with water.

https://flic.kr/p/2nZLCsW

A few more thoughts on my blog post:
https://senlachill.blogspot.com/2022/11/green-blue-and-white-stuff-adventures.html?m=1

Eergh - apologies, the images didnt embed! 🤣

[Pattus Magnus]

It looks to me like your casts are turning out okay overall, just a matter of refining how to work with the casting materials. I played around with resin casting for a few years and found that getting good results was mainly a matter of becoming experienced.

That said, my castings are still more variable than commercial work- the next step up would be to make a vacuum chamber, but that’s a gadget too far. I have found that a lot of imperfect castings can still be used, either as is (ex flawed window frames going into ruined buildings, or can be touched up with a little green stuff filler. Once they’re painted small flaws are often not so noticeable anyway.

Keep us updated on your experiments, I am interested to see how they develop!

[MaleGriffin]

Thank you for sharing. I'm planning to do some of my own casting and this helps.

[Henry Lauder]

Thanks and overall, I think you’ve hit the nail on the head! Very few are complete fails and more experience with the materials should bring a greater degree of consistency. And true enough, without proper silicone moulds and a vacuum chamber,I’ve got to moderate my expectations. I am working up to building masters for and casting a range of windows and doors for a scratch built Old West town I built. Will update for sure!

It looks to me like your casts are turning out okay overall, just a matter of refining how to work with the casting materials. I played around with resin casting for a few years and found that getting good results was mainly a matter of becoming experienced.

That said, my castings are still more variable than commercial work- the next step up would be to make a vacuum chamber, but that’s a gadget too far. I have found that a lot of imperfect castings can still be used, either as is (ex flawed window frames going into ruined buildings, or can be touched up with a little green stuff filler. Once they’re painted small flaws are often not so noticeable anyway.

Keep us updated on your experiments, I am interested to see how they develop!

[Henry Lauder]

Thank you for sharing. I'm planning to do some of my own casting and this helps.

Glad to hear it - will keep sharing the journey for sure. What are you looking at casting?

[snitcythedog]

Very nice write up. 

The green stuff acrylic resin appears to be a repackaging of Pebeo plaster.  It is nice stuff but comes off with a bit too smooth a finish for my tastes with larger pieces.  If you can find a dental or casting plaster (not Plaster or Paris) you should get more bang for your buck and the surface will take paint better.  If you are looking for more blue stuff at a better price check out evilbay or amazon for oyumaru.  It is the same stuff and a bit cheaper if you are looking for a lot of it. 

If you are thinking about casting in plaster, resin or want to work up to silicone mold making there are some real good tutorials on the Hirst Arts tips and tricks page.  https://hirstarts.com/

[Pattus Magnus]

The tutorials Snitchy points out on the Hirst Arts website are well worth checking out- I found them very useful. The suggestion of using dental plaster or the hobby equivalents (Merlin’s Magic is one brand) is also a good idea. It requires a bit more careful measurement than conventional plaster but the final castings are much more durable.

[Captain Harlock]

It is possible to get good castings with blue stuff /oyumaru, even fully detailed minis. If you have a solid frame (Lego work great) its much better. In my experience the key is in the way you fill the mold with epoxy putty. You need a tool to help you pack the material in and you have work in small little chunks. A silicone brush works the best. For very difficult spots you might need to wet them with a tiny bit of isopropanol. If you use big chunks and just hope that they will catch all the small details by pressing hard, it wont work. You will end up with tiny pockets of air. The good thing with epoxy is that the castings will be very hard. The bad is that it takes about 12 hours to cure.

The ''acrylic resin'' Greenstuffworld sells can be found in bigger quantities and better price. I have seen it been marketed as Jesmonite and White Stone. But as it was mentioned Im sure that Pebeo makes some too. I think its some kind of refined plaster/porcelain not an actual resin.

The best route is the one that goes through polyurethane resin and silicone molds. The problem is that many pros act like medieval blacksmiths and are too precious with their knowledge. A vacuum chamber can be easily made at home, you dont need all that super expensive acrylic sheet and pots. I managed to make one out of a big thick wide glass jar used for pickling vegetables. A vacuum pump would be ideal but even an old refrigerator motor will do the trick. My first attempt was with a hand pump . It worked actually but... yeah... 

I tried to cast resin with oyumaru (better and cheaper that Blued Stuff) but the exothermic reaction results to soft detail because the mold is softening up. There is a way to have cheap silicone molds by using a mix of construction silicone + starch. You can make a putty that will work for things like buildings and terrain. But its kinda messy.