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Scale 25% Krier Kraft build, a tribute to grampa.

BalsaDust

Moderator
Looking good. Another thing to try when trying to seperate the parts. I have heard it works well once you have one side opened a little bit to use some compressed air between the mold and the part.
 

Snoopy1

640cc Uber Pimp
Don't know we're you get the patience to do all this work for a cowl. But I do appreciate it nice to see how it is done and the work that goes into making a cowl. Looking good. But now I know why if I need a cowl I always end up making it out of balsa wood.
 

Bipeguy03

150cc
Looking good. Another thing to try when trying to seperate the parts. I have heard it works well once you have one side opened a little bit to use some compressed air between the mold and the part.

I have an air wedge, which freed up most of it but it was just stuck to hard at that one spot. I'm suspecting that there was a pin hole there that I didn't see and the resin got down to the cloth on the plug and grabbed it.

I was wondering if you might need to stiffen the mold some as it's fairly large.
Doc

If I wasn't as cheap and got some 9oz Rutan Cloth and put 6 or 7 layers on it I could have got away without the wood brace. But I have a bunch of 3 to 8oz E-Glass so it gets a wood brace lol

Don't know we're you get the patience to do all this work for a cowl. But I do appreciate it nice to see how it is done and the work that goes into making a cowl. Looking good. But now I know why if I need a cowl I always end up making it out of balsa wood.

I did this for a living for a few years, and once you get the hang of it composite work is pretty fun. Just have to be ready to fail, because no matter how much practice you get, you'll eventually get a plug that won't let go, or a mold that bubbles, a part that cracks pulling it from the mold ect. ect. ect.

Actually wish I could find another composites job, :)
 

Doc

50cc
Yeah it takes a lot of glass sometimes to make a large mold really stiff and like you said the ply works and saves some materials(money). Sometimes that aerocell stuff can help but I'm no expert.
Doc
 

Bipeguy03

150cc
Huston we have a cowling!

After some headaches with the mold and the resin I used to lay up the part I finally have a cowl. So the resin issue was I used non waxed polyester resin and couldn't get it to fully surface cure. after a couple of hours reading on some Corvette forums I learned that if you cover the sticky resin with some saran wrap it to seal it off from the air it will surface cure. I thought that just heat would cause a cascade effect to cure the surface. Guess you learn something new everyday, like I'm going back to using vinyl ester resins lol.

Then I mocked the cowl up on the fuse and about had a heat attack as it looked like crap to me, just seemed like it didn't fit correctly in any direction, and looked like a tin pot slapped on the nose. I was starting to think I was going to have to start over from square one. Then I got the ruler out.

I realized that the cowl was sitting almost a full inch to far forward, I pushed it back to where it was supposed to be and wahlah!

332.jpg


Getting ready to lay up the second half of the mold. After the release problems I had with the first side, I broke out the PVA, even though I hate the stuff! lol

333.jpg


Second half of the mold laid up and curing, I laid up the second half right on top of the first half.

334.jpg


Second half pulled off the plug, still had a little stick but nothing a credit card blank wouldn't scrape off. After this It was just trimming, wet sanding and waxing.

335.jpg


The cowl halves are laid up and curing, I fist brushed some resin and thixo into the mold to make a gel coat and then used 2 layers of unidirectional cloth on 30 degrees followed by 2 layers of bidirectional.

336.jpg


337.jpg


Cowl out of the mold and joined. These 2 pictures are before I found that it was sitting forward almost and inch to far. At least to me the cowl doesn't look like it fits the rest of the airplane, looks way to big until I pushed it back were it belongs.

338.jpg


339.jpg


340.jpg


With the cowl pushed back where it belongs, now it looks right! And now I'm quite happy :D

341.jpg


Ready to put a little putty on it and slap on a coat of primer. Then clean the shop and take a break from the Krier for a couple weeks. I have the Mike Hurley Extra you see in the back ground that I am building for a friend ready to throw some Monokote on it. I have to have a clean shop for that so the Krier has to get pushed aside for a few days. :(
 

stangflyer

I like 'em "BIG"!
Hey that cowl looks very nice. Just the right fit. Just don't take too long getting back to this build. Course, if you wanna....ya could always add to this thread with the work you're going to do on the Extra. (Just sayin'!)
 

Doc

50cc
Just curious, why didn't you lay up the cowl as one piece with the mold halves clamped together. I understand doing fuse halves separately cause you cant get into them but this baby was wide open at the back and should have been EZPZ. It would have eliminated the step of joining the cowl halves.
Doc
 
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