Pinholes in gelcoat after spray

[craig mclean]

In my exp. I found thinning w/ acetone destroys the pigment, thus causing your patch to look chaulky, more noticable with time. Even using wax can often cause your patch to sometimes yellow. If using wax carefully examine it prior to use. If you see a film on top its to cold and definitly will cause problems. If you can't control temp use PVA its almost fail save. When using PVA don't spray to soon the water based material will shoot into the gel causing very rough orange peel. don't wait to long or it won't do the job and the gel will still be tacky.
Some of the best looking repairs i've done (many thousands of sprays) I didn't put anything in. Note only when the gel coat has a high viscosity and was thinned w/ styrene by manufacturer. the only thing to remember is that when not using addatives your patch will be tacky. So make sure to apply at leased 25-30 mils so you can wash it with acetone then sand.
this method is great if your having problems, it will tell you if your addatives are screwed up or if your spraying meathod is. out of all the thousands of repairs i've done. I have never had perosity in my patch caused from to thick to quick. Because even though the gases may get trapped they are very close to the surface and are sanded out. you see it alot more in gel sprayed in the mold, because the deeper you sand the closer you get to any gases going away from the mold surface.

[fiberglass jack]

your right ive sprayed some repaires with out any wax and turned out good instead of washing down with acetone i used airdry with styrine with washed away the tack and also left a film of wax whiched helped to fully cure the gel i like to post cure it with a heat light for a couple of hours or let it sit in the sun lets the gel get really hard . have you ever vaccum bagged a gel repair ive played around with it and it works just spray the repair area with gel and then place apeice of sheet wax over and then bag it the repair is flat and smooth the sheet wax will conform to most shapes it gives a good result but as i said iam still playing with it, Iam lucky that the place i work we are allowed to play mad scienetist most of the time

[craig mclean]

Thats very interesting, i was wondering what on earth you were talking about w/ wax paper.Doesn't the paper press to deep in places showing through? or does it stay level in vaccum? If you perfect it i would love to know. How big of an area did you try this?
I know on small nicks and gouges i like to prep the surface, mix a small amount of gel coat, dab it on then cover with scotch tape. it seals the spot and the glue does not affect the gel coat. plus it makes the repair pretty flat.

[fiberglass jack]

not wax paper sheet wax say 1/8 thick you have to make sure the repair area is deeper then the rest of the surface so when when you sand the repair will be flush to the rest of the gel this way you can get lots of gel into the repair its the same idea as scotch tape but only larger how i came up with this is that i often resin infuse my fiberglass repairs and thought why not do the same with gel

[craig mclean]

I've got to play with that, great idea. Where can you get sheet wax? Unfortunatly I don't have materials for bagging. I know about the concept but have never worked with it.

[fiberglass jack]

you should be able to get sheet wax from a mould making sulplier and for the vaccum gear buy yourself a west vaccum generator that you can use with a airline costs about 100 bucks and if i ever read about the mclean system for vaccum gelrepairs i want half

[buckknekkid]

jack, races are coming up. if you want to get involved call me.

[fiberglass jack]

sounds good will give you a call over the weekend hope your talking powerboat and not snailboats.