On The Bench 215: Eliot Brown’s Nautilus part 3
Finally, in #12, you can see the glassy finish one needs. Note the eye, which I thought I could simply make as one part of the vac-formed body piece. The eye is painstakingly carved Milliput on a very small styrene guide. Yes, in pic #11, you can see a big hole where the eye is and I’d hoped that hole would have sufficient pull to wrap down around the eye. Also in the eye, are two small openings right where I hoped they’d do the most good.
If there’s one thing I can pass along to any of you out there, is the use of a frustum. First, that’s a great word to know, it is a geometric shape that is a pyramid with the top lopped off. I have taken it to mean any shape with a pyramidal base, that is, a forty five degree wall that follows the perimeter of (in this case) whatever it is you’re vacuum forming. I make mine by tracing the perimeter of whatever shape on a piece of plywood. I then use a jig-saw with shoe and blade tilted to 45 degrees. Then, because there’s lots of through-holes to be watched out for, I cut out the interior.
In Pic #13, you can see one Nautilus half resting on its frustum and the other half showing off its frustum above it.
No, you cannot make a straight-walled frustum that you could use for both halves, the udea of the 45 degree wall is to give the plastic “somewhere to go.” when forming around shapes that are close to vertical where they meet the vac-forming table. Otherwise, it seems to bunch up and form big creases.
Picture #14 Mr. Merriman refers to this as a ‘vent verification.’ And it did show me that everything would work out just fine. Except in white styrene, the ‘eye’ was a question. White sty doesn’t behave the same way as acetate. I find that acetate will capture more detail and settle into creases and cracks a little better.
So there was nothing for it but to go straight to acetate. In #15, I took a close up pic of the acetate vac-form shot to try to show how everything was captured. But I didn’t think I could see it well enough. The confusion of seeing through and taking in the other side was bewildering
So, in pic #16, I gave a tentative hit of primer for an over-all lighting test. In reality I just tilted the shape to a nearby light source for a raking angle. For photographic purposes, I have a detachable strobe that allows for all sorts of improved lighting tricks. Thus, I found the eye to be just awful.
So, I pried them off to be cast in resin. And that’s where I halted as other projects called me away. Those other projects I did finish and should post them as I think I learned some valuable lessons doing them. I had to learn casting urethane resins and the mold making. I also realized that I could not cast the “arms” of the Nautilus in resin– too fragile and will have to wait till I learn white metal casting (!).
But the resin casting process, when it works, is as much fun as vacuum forming!