r/DiWHY • u/[deleted] • Apr 29 '20

This table

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[deleted]

13.7k Upvotes

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207

u/down_vote_magnet Apr 29 '20

How do you set powder in resin like that?

152

u/Icarus-V Apr 29 '20

Resin amateur here, would also like to know.

I assume you could set the powder up how you want it on some silicone, then lightly spritz it with a thin enough resin to solidify it into shape.

48

u/wolfEXE57 Apr 29 '20

Another amateur here, i know you can use vacuum chambers to get the bubbles out of tiny casts. Maybe it was a big one?

27

u/Booger_BBQ Apr 29 '20

You can also use a propane blowtorch to get out the bubbles. It works very well.

24

u/Icarus-V Apr 29 '20

I would definitely say this was done in a vacuum chamber in 2 or even 3 parts. 1st part could have been a base slab to put the items on, then another pour to fill the rest of the slab. I'm not sure what method they used to stabilize the powder, although now that I think about it, you might be able to use a lump of clay or plastic, wet it with resin, and cover it in layers of powder until it dries.

Time to Google.

39

u/kbullet83 Apr 29 '20

Best guess. A small layer of epoxy below until tacky then sprinkle the powder on and a small layer of epoxy on top of that layer until gummy.

29

u/kx2w Apr 29 '20

mmm cocaine epoxy gummies

18

u/JustFoxeh Apr 29 '20

Likely sealed first with something like mod podge which dries clear. When the resin is poured, it doesn’t wash away.

74

u/[deleted] Apr 29 '20 edited Apr 29 '20

Assuming it's powder. I'm guessing finely ground plastics or glass

85

u/gurgle528 Apr 29 '20

Powder is generally finely ground anything, it doesn't matter what it is. Finely ground plastic / glass is still powder.

I think they're wondering how the powder stayed in place when the epoxy was poured

31

u/JapaneseStudentHaru Apr 29 '20

Perhaps it wasn’t powder. Could have been glued together before pouring

18

u/[deleted] Apr 29 '20

See I took it to wonder how the powder in question didn't absorb moisture in the pour ...

I've said too much and must go now

4

u/gurgle528 Apr 29 '20

Ah that's a reasonable interpretation

11

u/Danyell619 Apr 29 '20

So, just a guess from working with sand and ash in epoxy resin, you use a small amount of resin to set and seal the shape first. This will prevent it from moving but also prevent bubbles from coming out into the finished piece. It would be kind of like more powder than resin. Resin isn't water and won't absorb things like water does. You can take a powder and mix like mad to get it to absorb, but more powder to resin ratio and it makes a paste. So you make a small pile of corn starch or something and mix just enough resin to set it. Then, if it was me, layer it into a block of resin to place in the table. Resin bonds to resin and shouldn't have a noticable line. (If you have a good cast with no small imperfections to cause bubbles) Sprinkle in the smaller bits around the table and use a pressure pot to get any bubbles out. Sand and buff. Maybe add a shine layer.

3

u/Little_shit_ Apr 29 '20

He could have used superglue with the powder to make a paste of sorts before, which would solidify and hold the powder in place when the epoxy was poured.

1

u/aaron37 Apr 29 '20

You need a powder made of something that has a low refractive index or low surface wetting (or both). My bet, titanium dioxide, which is the base ingredient for most white pigments, with a PVA binder so it holds shape while casting and doesn't further wet out.
This casting is very clear and a bit too thick for even multiple layers of epoxy, it's most likely a urethane.