9 Attachment(s)
Casting with vacuum and pressure
I often have stuff to be cast, but with a high probability of getting trapped air bubbles that the pressure will not get rid of, but the items being cast do not contain air . In these cases I use Clear Casting Epoxy that gives me a long set-up time and use vacuum initially and then when I think the bubbles are gone transfer to the pressure pot.
Here's a WIP cast I did of resin chips, all sizes from 1-15mm I had in an old chip tube dia 72mm x 240mm long, to be cast in black resin for pepper grinder.
Attachment 372504
I started off attaching some more tube, as the bubbles from the vacuum raise the level of resin considerably, then taped up the joint and lower tube with duct tape in case it leaked (but actually didn't).
Attachment 372505
Then placed in the vacuum chamber whilst in a sink with iced water (hot weather plus extends set-up time) for ~1 minute after full vacuum achieved.
Attachment 372503
Then into the pressure pot overnight to set.
Attachment 372502
Next the chip tube was turned off to show the bubble free blank.
Attachment 372501
Also shown is a 50x50x240mm cast of mini pines I cast in clear that often gets air trapped done a similar way (with a silicon mold).
Attachment 372506
And as usual I mixed up too much black resin. But as usual I have spare molds ready to go for casting. So cast up a 3 pen blank block ~65x25x140 of coloured pencils (cast sideways)
Attachment 372507
Still more left, so cast up some Red Ash I had with a decent hole. As usual though I ran out of black resin, so mixed up another 50mls of flouro green dyed resin to top up the mold. It will end up as pen blanks, knife scales or something else, block is ~65x25x140
Attachment 372508 Attachment 372509
Cheers