QUOTE (ddyke @ 6 Nov 2010, 03:58) <{POST_SNAPBACK}>What do you use to backfill a vac body so you can repop it?

I use plasticine. I knead it until it is really soft and fill only small amounts into the shell at a time. Since the plasticine stays "warm" and soft for quite a time you may remove excess material easily, and if the outline has changed a bit during pressing the plastcine in you are still able to correct it. Works well even with thin bodyshells.
When the plasticine has the room temperature again it is stiff enough to repop the body.

- Ah yes, meanwhile I use single color (brown) Plasticine, this makes the process more controllable.

Roland

 

Thank you Roland

 

I use plaster to fill the original and then remove the plaster and you have a mould (once it is dry) that is ready to vac form over and is suitable for 10 to 20 bodies IF you are careful. I use tape and air pressure to get the originals off the plaster if they are hard to remove.

 

Here's a link to a good thread from member howmet tx that runs through 2 part mold process for vac forming undercut stuff:

http://www.slotforum.com/forums/index.php?showtopic=46672

Thanks for the tip on the plasticine though - that's pretty sweet !

 

QUOTE (gluebomber @ 14 Nov 2010, 01:31) <{POST_SNAPBACK}>.......Thanks for the tip on the plasticine though - that's pretty sweet !

Well, I do it this way because sometimes one wants to copy a real rare shell and if this one has distinctive undercuts it might be diffcult or dangerous to release the plaster from the shell. It´s not alway possible or wanted to destroy the shell to get the plaster mould out of it.
No problem with plasticine. Takes some time to peel it all out but the shell remains by all means as new.

Ah yes, of course my intention is to copy the shell in silicone. Whereas - you might use it filled with plasticine for vacuforming as well. Leads to shells a few hundredths bigger...

Roland