ORIGINAL: bentwings
I've just been lurking lately but following your progress with great interest.
I'm guessing you are going to make a female mold from your foam plug. In that case I'd lay a .5 or .75 oz layer down first over the foam. Lightly sand this and add progressively heavier cloth to make a strong layup. Then I'd finish sand and follow up with a .5 layer and finish the skin as you want it. I would guess that you will need 3-4 sections in the mold to get a good release. Plan where these parting lines are going to be and how you will operate them.
From here it will be a matter of making sure you get a good release from the to be built in place mold. Essentially you will build the mold right on the plug. You probably will need some mat and heavy cloth for strength. You probably will want a gell coat first to gather the detail and finish. You will need some kind of frame work to ridgedly hold the mold together with some built in alignment holes and pins.
I'd leave off the exhaust detail and let your customer do this with your carefully detailed instructions. You would only need one mold this way.
Since you will be making 4 cowls per plane this mold will get a lot of use so build it strong. I don't think you could over kill it.
Hey Greg,
Good to see your are still around and following on my progress.
Yes you are right, i will be making female molds of this plug, it will either be 3 sections or maybe 4, i will decide that after i do initial glassing. I of thinking on the same lines as you mentioned. As i have been seeing couple of good threads of guys making molds out of plugs they also are building there molds with multiple layers of cloth, this is to make the mold strong and last for long time. I plan to do the same here also.
As for details of the exhaust, i will leave it now as it's not a big deal to figure out, i will provide detailed instruction for them and leave it up to individual builders to takecare of that themselves.
As for adding details like rivets and panel lines, i will do those once i have glassed it and primed it with Duratec EZ primer, this will do two things, one as primer and other as capturing all the details and being good mold release at the same time.
Gelcoat ,yeah maybe.