Painting and Gelcoat

[ledzeppelin135]

Ok so I am getting close to painting time on my Harvey. I have most of the cracks and chips repaired and am wondering what to do now. What do I need to do to get the surface smooth and glass like before gelcoating. Also I am looking at doing a two tone type paint. I will be gelcoating the whole hull and sides up to the hull and cap joint. Above that point I will be using some vintage red marine paint to do the top half. I have a HVLP gun from home depot that I believe has a 1.5mm needle. I have sprayed a little bit on cars with descent results so I am wondering how to spray gelcoat out of a gun like that or something similar. I do not want to roll and tip so any help on spraying I would appreciate greatly. Thank you,
Chris

 

[oops!]

Re: Painting and Gelcoat

prep is the key.

sand the glass till its smooth.....(especially the raw glass) just like in auto body....look down the sides....and fill the dimples and pin holes.

remember that gellcoat is very thick.....

when you are ready for the shoot.....clean with acetone and go for it......are you using a pressure pot?....or gravety feed?.... i dont think a gravety feed will work well for you with gellcoat......they work.....but not well. ....you can thin with acetone but only to 10 %....NO MORE.

you are going to get major orange peel......the car guys will laff.,....but that is just the nature of the beast that gellcoat is.

then its sanding time.

go thru some of yd's posts.....he describes the gellcoat shoot setup in a lot of them.

 

[Woodonglass]

Re: Painting and Gelcoat

Yeah, I'm with OOPS, Don't think your HVLP setup will do the Gelcoat. It will be fine for the Top Cap Paint. I'm not a gelcoat guy, but based on what I have read and learned here on iBoats from OOPS and Yacht Doctor, You're gunna need a completely different setup for the Gel. Harbor Freight sells a HVLP POT gun for around $70 bucks. You're gunna need at least a 2.5mm tip to shoot it with. And gotta be pretty quick and have all the cleaning supplies ready to flush the gun. You can ruin the equipment pretty quick if you don't stay on top of it.

OR, You Might be able to use this... $39 bucks off Ebay.

http://www.ebay.com/itm/2-5-Tip-HVL..._Automotive_Tools&vxp=mtr&hash=item35b67d1370

 

[BWT]

Re: Painting and Gelcoat

For smaller stuff I shoot gel all the time with a gravity feed, however I mix my gel 60/40 to 50/50 with Duratec (high gloss additive). It cures with the gel rather than acting like an evaporative thinner. It thins it down to a good shooting consistency and minimizes orange peel. You're still gonna have it, but it does save HUGE on the sanding time, and gives a good hard finish (no need to go back over with a PVA to seal the gel for curing). BUT, like was mentioned above, prep, prep, prep. If the surface you're spraying onto isn't sound, all the work you're doing now will come back to haunt you... If you use this, Duratec needs to be mixed 2% Mek-P

~BWT

 

[ledzeppelin135]

Re: Painting and Gelcoat

Thanks for the tips; it sounds like a pain to spray gel coat so is there something i could spray thru my hvlp with similar durability?

 

[oops!]

Re: Painting and Gelcoat

nothing beats gellcoat nothing.

but there are several epoxy based paints available. however the setup that you were given in the earlier post about a pressure pot is very in expensive.

 

[ledzeppelin135]

Re: Painting and Gelcoat

Ok so I think I have setteled with going with some sort of paint system as I have zero experience with spraying gel coat and have no equipment and do not want to roll it on. I have my HVLP gun that I have sprayed auto paint with before and feel comfortable with that. I am wondering if anyone can reccomend a durable quality and some what affordable paint system for the hull and the topside. The hull will be white and topside red and the boat will only be in the water a max of 8 hours at a time and is on a trailer that has two supports at the back of the boat and the main weight is rested on the keel. If anyone can recommend a primer as well that would be good to put on somewhat crazed gelcoat would be good also. I know I am going to have to sand down much of the gelcoat but am wanting something that would be good to put on top of gelcoat so the crazing doesnt spread to the paint. Thank you!

 

[ledzeppelin135]

Re: Painting and Gelcoat

Anyone?

 

[BWT]

Re: Painting and Gelcoat

I don't know that you necessarily have to give up on the gel approach; if you use the Duratec additive that was mentioned above, you'll be able to spray just fine with your current setup. Gelcoat is much more forgiving than paint. But either way, prep is going to be essential. Crazing or cracks are going to pop through any finish unless they are dealt with prior to spraying. When you can, please post some pics so we can have a better idea of what your working with

~BWT

 

[60Clipper]

Re: Painting and Gelcoat

Just a quick question/observation. What did you fill the cracks and crazes with? If you used vinylester you can gelcoat, if you used epoxy you will have to paint it because if I recall correctly, gelcoat doesn't stick to epoxy, or so I've been told.

Bob

 

[Yacht Dr.]

Re: Painting and Gelcoat

Just a quick question/observation. What did you fill the cracks and crazes with? If you used vinylester you can gelcoat, if you used epoxy you will have to paint it because if I recall correctly, gelcoat doesn't stick to epoxy, or so I've been told.

Bob

Repairs of cracks or small stuff will not really hamper your Gelcoat bond no matter what you use.

What Will hamper your gelcoat is not getting all of the repairs done prior to the application of topcoating ( does not matter if its gel or paint..it will come back ).

If its not a large surface repair..then use whatever suits you.

YD.

 

[60Clipper]

Re: Painting and Gelcoat

yeah, sorry, should have been more specific.

Bob

 

[Yacht Dr.]

Re: Painting and Gelcoat

Its all good .. Gel is a tricky lost poly art that most have shunned ..

YD.

 

[ledzeppelin135]

Re: Painting and Gelcoat

So what exactly should I do about the crazing and what is this duralast stuff that will enable me to spray gelcoat out of my HVLP gun?

 

[BWT]

Re: Painting and Gelcoat

Well, as far as the crazing and how to deal with them, pics are really needed to know the best way to approach this. The Duratec additive that I mentioned is a product made by Hawkeye Ind. http://www.duratec1.com/dp07.html

Here's a link to a thread from this Spring where Duratec was discussed in detail. It should give a pretty good starting point as to what it is and does, as well as some of the advantages and dis-advantages of it's use...
http://forums.iboats.com/showthread.php?t=477071&highlight=duratec

Hope this helps! Let us know if you have any further Q's. Looking forward to some pics

~BWT