Anyone try this? (reverse vacuform)

MillenniumFalsehood · Post by **MillenniumFalsehood** » Sat Dec 17, 2005 2:50 pm

I was wondering if it would be possible to do a reverse vacuum-form to make large detailed parts. Like taking a female mold, not too deep, and laying a piece of heated styrene on top of it. Then attach a vacuum to the bottom of the mold, and pull the styrene down, using a heat gun to warm over the styrene and force it to conform to the mold. Then of course, pull it out. Would this work?

modelnutz · Post by **modelnutz** » Sat Dec 17, 2005 3:50 pm

Yup....it's just another form of vacume forming.
Big problem is in getting enough pin holes in all inside corners of your mold to draw the air out from all the details.

What type of mold material were you going to go with ?

Modelnutz 8)
"the name sez it all"

DX-SFX · Post by **DX-SFX** » Sat Dec 17, 2005 6:10 pm

A lot of the military aircraft garage kit makers already do just that. It means you can reproduce engraved panel lines and other details (subject to the usual vac form limitations). The best material for making vacform moulds like this is metal filled epoxy resin. The other advantage is that because the plastic sheet tends to shrink very slightly as it cools, you can generally release the forming much easier than from a male mould. Some low volume manufacturers have gone a stage further and make injection moulded kits from epoxy moulds.

I made up a mould to reproduce B58 Hustler engines complete with moulded in panel lines and one for the body of Thunderbird 1.

MillenniumFalsehood · Post by **MillenniumFalsehood** » Wed Dec 21, 2005 4:47 pm

I was going to make a copy of the primary hull of the large cutaway kit. I wanted to get the 90 degree angles without a noticeable curve in them, like on the bridge and on the planetary sensor. I was going to use sheet styrene from Evergreen.