Vacume Bagging Question

[Toast]

I've stuck this thread in this area cause there seem to be alot of clued up guys here.
I am doing a fair bit of bagging lately and have everything working well. My wings are mainly carbon over blue foam thought I have had success with glass over white foam.
The main problem I have is colouring the skins. I am waxing the mylars and then spraying them with laquer, but whenever I use a clear coat the wing comes out cloudy. It only clouds up a couple of minutes after it comes out of the bags and takes about 5 mins to do so. Why?
Should the paint be left to dry completely or still be tacky? Would enamel or polyeurothane paints be any better?
Its happened 3 times now and its starting to annoy me (Edited for inappropriate language).
Would be great to hear what method the likes of Craig and co use.
Cheers
:confused:

[Craig Toutolmin]

I too use lacquer. Usually plain old Rustoleum white. I have used Painter's Choice (non-lacquer) for other colors. My use of paint on the mylars is more for function than esthetics. It seals of the top skin so when I sink in the spar the epoxy does not weep through. As for your problem with clouding clear coat, I could only guess that it needs to dry for a couple days.

I'd recommend spraying the clear coat after the wing is finished and the LE paint and paint repairs have been completed.

[Toast]

Ooops, sorry about the strong language guys.
Craig, I have another question for you. I notice in one of the articles I have seen on the net about how you bag up wings, you run a layer of S'Glass cloth over high load areas like joiner tubes and spars. Do you find this leaves a noticable lump on the surface of the skin after bagging, due to the increased thickness of the skin at these points? Do you sand these areas down or do you find they are acceptable?
Thanks for answering my last post so fast. Have been in the shed all day trying different paints.
Cheers
Brett

[Craig Toutolmin]

I don't do that any more. I put the focus on stronger joiner box/spar junctions.

[Steve C]

Brett,

I agree with Craig. Use the right stuff in your spar and joiner system and you don't need any extra glass making lumps in your skin.
My thermal sailplane has only 2 x 1.4oz skin and the joiner boxes are still in the wing with years of strong launches :D

Steve C

[Tony D.]

Yo Toast,

I recommend Krylon, spray a light mist coat and let it dry for an hour or so then a slighly heavier coat, let dry then another coat and let all dry for a few hours.

If you have enough patience to leave the wing in the bag for 48 hours and then pull the wings out and leave the mylars on for another 24 hours you will get a shiny, smooth mirror like finish.

Oh, and you don't need heavy coats of wax, 2 light coats well buffed will get you where you want to be.



Tony Dempsey

[hkrussell]

>Thanks for answering my last post so fast.<

It's not like the guy has a job or something. All he does is bill MediCal and fly fast toys!!

Ken
SRSB!!!

[Craig Toutolmin]

Hey, I resemble that remark! Except non of my dentists are medical.:)

[Toast]

Well guys, the wings are in the bags, so it's wait untill tomorrow night to see how they come out.
Does anyone have any good tips on getting your leading edges perfect out of the bags? I have thought about running a strip of carbon or kevlar along the L.E. of the core before putting it in the mylars, but I recon that would leave a lump just behind the edge where the cloth ends.
So far I have found the best way (especially if you sand through the L.E by mistake)is to lay wetted out tows along the edge then put the wing back in the bag. Very messy system tho.