Acrylic Mold Box

Looks great, even in pieces! :smile:


OK OK OK, gosh you guys are such high pressure. I just poured another one and dug up a junky brush I dont mind thrashing with acetone, and brushed resin into the fine details… And now, we wait… again… maybe a little longer than last time… :smiley:


Bwahahaahha… hey man, no pressure! I’d be fine just seeing the final result. Quality takes time. :slight_smile:


Hahaha I’m just playing around, the pressure is my own antsy-ness. LOL. It’s STILL too hot here to be working in the garage and I’m going a little car-crazy. :slight_smile:

The more I think about it, the more I can justify being lazy in casting techniques and just play up the weathered, beat-up aspect, and increase their marketability with every one of them being slightly different. :rofl:


No it’s not. Down another latte, we all wanna see how this thing turns out and we don’t have all night!:roll_eyes:

(in case it’s not obvious, I am totally kidding)


Do it, do it, do it…lol Totally not putting pressure on you…but now I can’t sleep until I see it done!! :stuck_out_tongue_winking_eye::joy:


You have totally got me stoked about trying something like this! I’m pretty sure I have all the stuff to do it.



The mold and newer casting are sitting out in the garage to take advantage of the heat helping to speed the cure, but won’t be good til morning at least :slight_smile:


This seems a little better and yet a little worse at the same time :smiley:

Guess I need to break down and order the intended resin because it has much lower viscosity than what I’m currently using, and adding the metal powder is compounding the air bubble issue.


Are you doing any tamping down or pressure vacuuming of the part before it hardens? I’ve never done it, but everything I’ve read seems to indicate it really alleviates bubbles in the final product.


This particular resin is better suited for curing under pressure, because it is a water clear resin marketed for making perfectly clear castings, lenses, optics, etc. I did tamp the mold after brushing the resin. It’s also just not the best resin for this application, with a viscosity of 675cps versus 100cps of the other resin I use that’s actually formulated for this purpose. As an example I cast about 300 parts to build the battery pack in the electric car using the 100cps resin and not a single air bubble at the mold face.


Wow this is amazing, love that detail. Do you just use a standard epoxy resin and mix it with metal powder?
So using pressure…would that be like placing the mold in a pressure cooker vessel and pumping in compressed air as opposed to doing the same thing but pulling a vacuum? Does pressure push the particles together? Can you determine the density based on resistance? Oh I can’t wait to play with this when the forge arrives.


You can mix the metal powder into just about any resin, but the resin itself may or may not be suited to casting, like a laminating resin for composite parts or similar.

Urethane resins from Smooth On are a bit more tailored to applications like this.

Yep pressure casting uses a pressure pot. You put the whole mold into it and connect the compressed air. The pressure only squeezes out any remaining tiny air bubbles.


This seems counterintuitive to me. I know a vaccum will draw out air bubbles, never would have thought pressure would “push out” bubbles?


The air bubbles get compressed 'til they’re microscopic. Still there, you’d just never see them in an optically clear part and any bubbles on the mold face will not be noticeable on the finished part.


I get the concept once you mentioned it but just wouldn’t have occurred to me previously.


Similar to CO2 in beer😆


I’m glad to see this work flow (engraved-casting) comes out pretty decent.

I do a lot of casting (car reproduction badges and stuff) and was wondering how well casting engraved stuff would work. Good to see that it comes out pretty decent with respect to surface finish, especially with how well silicone picks up every line. So many ideas here.

I’ve also had a lot of success with embedding fiberglass cloth or very thin metal wire in the resin to improve bulk object strength (e.g., the crack in the earlier casting), also cuts down on resin usage.

Have you thought to try any of the low-melt metals yet?


Can you share how to make the box?

It looks like that box is probably a square and four rectangles of acrylic, welded/glued together with acrylic cement/solvent (I.e., “weld-on” or “sci-grip”).

I am not sure what details you are asking for here. There is a lot about working with acrylic and making boxes in the forums. You should be able to find a lot of that using the forum search (magnifying glass in the upper right).

If you have specific questions, you could also start a new thread in Community Support. This is several years old and, fewer people are going to notice your post here.