The inspiration, the philosophy, and the story behind the Jart can be found on the Jart World Web page. Well worth a visit!

Wednesday, August 24, 2011

a jart is born

After polishing the mould and applying the PVA release agent, I laid up 3 layers of 195gsm glass.
This produces a 225g fuse that is very strong. Here is the first one out, a little porky at 300g, number 2 was the winner at 225g, and they have been consistently this weight since then.

I skipped a bit of picture taking, and ended up here with little to no pictures.

Paint trim and servos to go in and then it's ready to fly.

The moulding process

Here is the moulding process I used.

After cutting out the shape of the plug into some chip board, I waxed the plug and applied PVA again. I then filled in the seam line with an epoxy/cabosil mixture from a plastic bag, kind of like an icing bag arrangement. Once cured the plug was removed and the seam sanded flat. This creates a fantastic seam.

A closeup of the seam, see, no gap :)

First layer of tooling coat on. Each coat is light and must not fillet the corners

1 Layer 160gsm glass, 6 layers 400gsm Biaxial glass and then another layer of 160gsm glass, corners were filleted with carbon tow, should have used glass tow, but it was a pain to get so I just used carbon since I had it already.

Mould just opened after second side was done. Needs a little cleanup(bit of paint came off the plug and stuck to the mould, quick scrape with a plastic scraper got rid of it without damaging the mould surface), but otherwise pretty nice surface

So it starts

After reading much about the Jart, I purchased the plans for Reed and got going.

I decided to use a high density polyester foam for the plug, The shaping was all done with a razor saw and sandpaper. This stuff sands very nicely, but what a mess!
Basic shaping done.

Fin Shaped and epoxied on. Starting to look the part now

First Layer of 160gsm glass on the plug
All sanded down and looking pointy
Canopy mould being laid up. The plug was polished 8 times with Ram wax and them buffed out. Then a layer of PVA release agent was applied with a sponge.