I am planning on spraying a clear gel into a mold for the first time and wondered
How you can tell if its covered the mold all over?
How much do I have to thin the gel with acetone?
How many coats and time between coats?
thanks.
my .2$s, i dont thin it. use a 2.0 tip or 2.2 tip (if your using HVLP) NO FILTER! and also make sure its SUPER CLEAN!
i do 1 layer, not to thick that it runs, and spray it in the area i only need. i take off the rest. make sure to take off the tape when your done spraying so if it hardens, when u take it off the chips dont fall into the mold.
the mekp usually thins it out
1 where you spray it, it should be or by looking and checking with a thickness gauge 
for clear coats I use about 15-20 mil thick for molds I go with 25-30 mil
2 donāt use acetone, use styrene at about 5% but only if you need to so the gel coat will sray properly for you
3 only 1 coat should be done/needed, if you need to apply more you need to do it before the first layer starts to gel. if you wait too long and the first coat starts to gel you will run into alligatoring problems
RE: #3 above, I canāt get complete coverage on the first coat. Unless I move at a snailās pace with the gunā¦even then I still get some transparency. Itās like a splatter fest ending in a lot of orange peel:mad:
This is using an HVLP drilled to 2.0 and spraying tooling gelcoat. Iām guessing regular gelcoat will go on nicer?
Is it ok to thin with MEK?
Dont worry about doing the multiple coverage passes. So long as you let it tack for a minute you should be fine. It lets the gel sag out where it wants and you can add more.
I dont thin out anything with styrene or mek or acetone. It makes for inconsistant cures.
If you thin with anything, use the styreneā¦its part of the base anyways.
I was just telling JM that my tooling gel woas where from being sold a āsprayableā tooling gel. I dont like that kind of tooling gel and Ill be trying to mix in some cabasil to thicken up the tooling gel for brushable mixtures.
I hope it works.
Yeah I remember your problem with that gelcoat. Let us know how it goes.
Sorry if this is a thread hijack, somewhat related.
This is a pic of duratec surfacing primer sprayed with above mentioned gun. I sprayed per duratecās instructions and thinned with about 8% MEK. Can I get a smoother surface than this?
Iād like to see pix of gelcoat you guys have sprayed.
looks like overspray.
Looks like either 2 low line pressure, or maybe you are using a spray gun with drilled out nozzle, and the air passages in the gun simply arent big enough to allow proper atomisation?
Yes on the nozzle. Iām using duratecās line pressure, maybe I need to up it.
It looks to be spraying dryā¦
like its coming out with a super rough texture.
Personaly I dont mind it. It gives me an idea of how thick Ive shot it so I dont blow thru wet sanding it.
I start at 220 immediately jump to 400 then 1000 and finaly 2000 and buff accordingly.
A class āAā plug produces a class āAā mold.
Doesnāt look too bad. That is the nature of polyester surfacing primers. They are essentially sprayable body filler. Because of the larger fluid tip required to spray these coatings, the gun has less ability to atomize the coating which equates to more orange peel. Luckily, Duratec cuts extremely easy if you sand it before it cures rock solid.
I shouldāve mentioned, the dry-er area at the bottom IS overspray. I sprayed two of these side by side.
I agree with perfeng702, Iāve sprayed high solids poly-primer on cars etc and it basically looks like this. And I wasnāt too concerned as I knew Iād be sanding it anyway. Also, duratec and tooling gelcoat are thicker than normal gelcoat.
What I would like to know is how my regular gelcoat spraying will come out. Letās see some pix guys!
Hereās some Valspar tooling gel thinned with high gloss additive.
Not so great lighting:
~25 mils using an HVLP with 2.2mm tip.
Cool, that amount of texture, I can get consistently. I was just wondering if I could do any better and get it to really lay down and blend in.