So I was making plans to build horn speakers and I was going to make them out of wood, and for whatever reason, I've decided to 3d print a mould and cast some mono body epoxy-resin horns with pretty rose petals . . .. but how would I get something like that 4'x4'x5' de-gassed? I can't find anything commercial or industrial and I suspect that options would be exorbitant. The only thing I can think of is welding up some sheet steel myself. Is anyone aware of any tutorials on building a vessel? Am I taking the wrong route? Are there epoxy resins that tend to dry clear?
thx
thx
Epoxy resins for making counter tops are very clear, the big box home improvement stores have them.
People degas casting materials with something like this- 5 Gallon Vacuum Chamber Product Information | Smooth-On, Inc. and then pour it carefully so as not to trap air. Very low viscosity materials sometimes don't need degassing. We degas clear epoxies at work in a centrifuge, but that's not suitable for large quantities or for anything with a filler as it settles to the bottom!
The 5-Gallon pre-degassing sounds like a great idea. The wall thickness of the horn will be under 12mm, should be much less than 5-Gallons. Use resin casting.
thanks
thanks
Sounds like a very interesting project and I would love to see the end results. To minimize bubbles there are a few things you can do (like Conrad Hoffman also said):
- Use very low viscosity casting resin with a long pot life.
- Degas the mixed resin using vacuum before casting.
- Try not to introduce bubbles when mixing and pouring. Will require a bit of practice.
- Vibrating the mould helps the bubbles to surface.
- Surface bubbles can be removed with a small burner or blow torch, if this will not melt your mould.
Keep us posted.
- Use very low viscosity casting resin with a long pot life.
- Degas the mixed resin using vacuum before casting.
- Try not to introduce bubbles when mixing and pouring. Will require a bit of practice.
- Vibrating the mould helps the bubbles to surface.
- Surface bubbles can be removed with a small burner or blow torch, if this will not melt your mould.
Keep us posted.
Join the Vancouver Hack Space: Vancouver Hack Space - 1601 Venables St, Vancouver, BC, V5L 2H1. They have de-gassing equipment. E
Hydrocal 21 is great for making molds/plugs from also, can likely find info on the web, is pretty low cost.
You can't put 5 gallons into a 5 gallon chamber. Until the liquid has almost fully de-gassed under vacuum, it will continue expanding as the dissolved / bubbled gases inflate and cause the liquid to decrease in density. Watch a degassing video to see this in action.
Right. And I'll have to do some calculus to get the volume of resin needed for the job. I might need a larger sized degasser.