VAC BAGGING LEADING EDGES ??
 

Howdy Gang.....

I've got a balsa sheeted wing for a speedplane that I will be covering with FG cloth. I plan on doing both sides at once with a couple partial underlayers of 2 oz and 3/4 oz overall.

I'll be vacuum bagging it.

What I don't know is how the leading edge overlap / wrap is accomplished? I can foresee this area being disturbed as the bag gets sucked down. Same goes for the rounded wingtips.

Do you expect to get a perfect, finished product around the LE and tips, or do you figure on wrapping them after the vac bag session?

RE: VAC BAGGING LEADING EDGES ??
 

Not sure if you are wanting a glossy surface or not. I can tell you what I have done for a surface intended to be primed and painted.



Put your cloth down on the surface and wet out with resin, add a layer of peel ply and breather cloth. Flip and do the same on the other side. Bag the part, I have been wrapping parts with an electric blanket to speed cure to 12 hrs.


After pulling out of the bag and peeling off the peel ply you will be able to sand off the flash with 220 and then smooth out the surface with 220 and it is prime ready. The glass will wrap around the edges nicely. If you want a glossy surface and plan to use mylar as a surface form, you will need to work the leading edge and tip.

RE: VAC BAGGING LEADING EDGES ??
 

Thanks for the reply.
I'm mainly interested in no air bubbles, incomplete lamination, wrinkled cloth, etc. The surface finish isn't as important. My past experience with trying to get overlapping 3/4 oz cloth layers to stay put without accidentally getting air pockets and other nasty outcomes.....hasn't been 100% good.

RE: VAC BAGGING LEADING EDGES ??
 

http://www.geniebuild.com/harleys_genie.html
That will tell you everything you ever want to know about bagging.

RE: VAC BAGGING LEADING EDGES ??
 

Thanks for showing me that Rich. It looks like a good idea to do the LE and wing tips beforehand, then do the bagging afterward, not doing any kind of LE wrap in the final layup.

RE: VAC BAGGING LEADING EDGES ??
 

I have done this with Carbon, cut a strip about 1 inch (depending on LE) and then run this down the leading edge and around the tip.

With the carbon, i wanted a gloss finish; so was pretty generous with the epoxy !

Then placed the wing on the bottom Mylar (which also has a lay up on it) and then added the top mylar (another lay up) and dropped it into the vac bag.

With the LE (under suction) the mylar's rap around and nearly touch each other, but not quite.

Cheers
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RE: VAC BAGGING LEADING EDGES ??
 

The CF on the LE sounds good. This plane will be hand launched out of a rough hay field.