Hello to all, My name is Garry I ran across this forum while searching for ways to make a Polystyrene (Styrofoam) torso. Hope all are having a great fourth of July weekend.
Hi Garry. Thanks for the introduction and holiday greetings. Are you doing a life-sized torso? Realistic or more of an abstraction?
Tops, Thanks for asking, life size or close to it, I currently use Styrofoam heads (from beauty supply stores) and wanted to add a Styrofoam torso as a target for airsoft. Seem like the perfect material light weight, absorbs most BB's and can simulate human form, indoor/outdoor and best of all inexpensive. Or at least so I thought when I first began looking.
If you could locate 'billet' or 'block' EPS and make a set of Masonite templates to hot wire cut a front view 2pcs and a side view 2pcs, you could hot wire bow cut the foam and be rough shaped in minutes. Trouble is storing the block if it is a big one like 2x4x12 feet... Hot wire cutting glued up foam is more challenging and can expose you to more chemical bad ju-ju than just polystyrene. Ventilation is key!
This may be an ignorant question but, is there no way to do a cast or mold to produce the torsos. My ultimate goal is to be able to provide them in high quantities as part of a torso/head kit.
Yes, instead of expanding the pre-expanded EPS beads into billets like in the video, they can be expanded in molds of any shape, the same way molded EPS packaging shapes are made, which is the same way production lost foam casting patterns are made. It's not an easy home/DIY process to manage. The pre-expanded bead stock is hard to obtain in small quantity and has a very short shelf life. Molds and automated molding equipment are prohibitively expensive. If you really had high quantity, I think you'd be better off to hire a business that was already fully capitalized and making molded EPS forms........but the tooling cost would probably still make your eyes water. Best, Kelly
I feel like this is the worst part of it. Otherwise, we would all be casting/machining aluminum dies for semi production runs. Ugh!
Not so sure about that. I have a 260 page AFS book called Lost Foam Casting Made Simple. Whoever titled it hadn't read their own book. Half the book is devoted to manufacturing the foam feed stock and molding patterns. For LF casting to be viable, it needs to allow castings to be combined, separate cores eliminated, and secondary machining and other ops reduced or eliminated. When this is the case, it can be quite beneficial, otherwise, you're better off just make a hard tool and sand or die casting it. Admittedly my problem is I'm not interested in making a lot of anything. If I had a part that had the quantities that justified it, I'd source it from a foundry instead of building a foundry to make it, but I like the development work and at low and prototypic quantities LF is the other way around, especially for the hobbyist/home gamer. Best, Kelly
