Replacing clear coat with gel coat?

[lexkyboater]

A previous owner of my boat used car clear coat instead of gel coat on the upper deck of my boat, and now it's peeling badly. See attached picture. I was thinking about sanding this down and fixing it, but with what? The maroon gel coat isn't great on the top deck, but I was thinking about leaving as is, and just put a clear coat of gel coat over the top. The boat is a 1984 and this would help the looks immensely.

So, can I just use a $5 preval sprayer to apply the clear gel coat, per http://www.prevalspraygun.com/automotive.htm and http://continuouswave.com/whaler/reference/whalerRepair.html? I have a spray gun, but it's not really set up for gel coat, and I've read that airless spray rig is best for gel coats. After that follow up with poly vinyl acetate (PVA) to let the gel coat cure for a few hours? Other articles I referenced that I thought were good were http://aquaskier.com/articles/gel_coat_repair.htm, http://www.mbyc.net/Fleet59/glass_damage.htm, and even http://www.torresen.com/butterfly/butterfly_hullrepair.htm says I could go with an epoxy or urethane marine finish, but it scratches easily. Seems that would be trouble matching the area below the deck. And I'm on a budget. Recommendations? I want cheap, fast, and decent looking. Probably not thinking about reapplying the gel coat color, just the clear, so this shoudn't be a huge and/or expensive job. Local marine shop has the clear gel coat for $40 and the PVA. TIA, Steve

 

[gcboat]

Re: Replacing clear coat with gel coat?

I find this to be a lot better than a Preval system hands down :http://www.leatherworldtech.com/ProductInfo.aspx?productid=C8209

 

[lexkyboater]

Re: Replacing clear coat with gel coat?

Looks good - is it obvious which tip to use with gel coat? Or do they tell you? Does that work like the preval system in that you pressurize the canister with compressed air? Is that an airless spray rig?

I do have a cheapie spray gun, but would it be easier to just get a tip for it that sprays gel coat?

 

[gcboat]

Re: Replacing clear coat with gel coat?

Yea it's pretty much the same as a Preval system but you can spray more and for a longer period of time ( increased capacity ). Plus the tips are a lot nicer. Would be nice to have a 'real' gun, as you mentioned you did. I would consider finding a tip, might be worth it in the long run. My.$02

 

[lexkyboater]

Re: Replacing clear coat with gel coat?

I hear ya, but I've read airless is better. I don't guess the Preval/leather world sprayer is airless is it?

 

[gcboat]

Re: Replacing clear coat with gel coat?

No, compressed air - hence the canister.

 

[ondarvr]

Re: Replacing clear coat with gel coat?

If the clear is peeling, it's because the prep was poor, re-gel coating is much more difficult and not something I would recommend. If you remove the clear and buffing doesn't make the old gel coat look good enough painting is a better option, either with clear or a color. Clear doesn't always make it look great though, just a little better than without it.

You need to use a full sized spray gun and a good compressor to spray the gel coat or you run into problems very fast.

 

[lexkyboater]

Re: Replacing clear coat with gel coat?

That's what I was thinking about originally, but after talking to the boat shop to apply just clear top coat (like DupliColor clear), they said it won't stick to gel coat, because it's plastic. I had originally thought that the reason this is peeling in the first place was because they didn't sand it before applying, but then I got scared about trying this after getting more information. Is there a special type of clear I need to use? I didn't want to repaint because I think matching the bottom paint would be tough. It's an old boat - and I think the clear will be fine.

As far as the buffing, can I take the layers of peeling clear coat off with 400/600 grit sandpaper, then finish up with (Eagle brand?) 1200 grit? I guess this should all be done with wet sanding? Then apply 3M Finesse-It II Finishing Material, and without letting it dry, buff. Can I just use a towel, or do I need to get a buffer attachment for the drill, or get a real buffer? And then finish up with Marine paste wax, let stand 5 minutes and remove with a towel? Any details on this would help since I've only read it about at Aquaskier.com. If I did this, maybe I wouldn't even need to apply clear top coat paint?

Thanks for the reply...

 

[lexkyboater]

Re: Replacing clear coat with gel coat?

This - http://www.boatus.com/boattech/casey/01.htm - also looks good from the making fiberglass shine again post.

 

[ondarvr]

Re: Replacing clear coat with gel coat?

Paints stick very well to a well preped gel coat surface, even clear, but you need to use a good automitve clear, a rattle can won't cut it. Sanding with 600 grit to remove the old stuff will work and then buff it to see if it looks right. You need a real buffer to do a good job, it can be very difficult to do it by hand or with a drill motor.

 

[thinksun]

Re: Replacing clear coat with gel coat?

ondarvr is right. Prep is everything and clear coat can work awsome which usually gets applied at and above hull joint. Sand down using 300 grit into top of old gel to make sure oxidation is removed. The finish can look flat and dull but will look like new with the clear. If you have colored metalflake that has gone silver adding a little powdered pearl tint to 1st coat of clear really brings the accent color out. Gel application is difficult, costly and if your a do-it-yourselfer could take till next year- hrs of labour to finish-IMO.

Here is pic of a boat I am spraying soon. The boat is a green gelcoat with blue metalflake. On the topside the metalflake has mostly turned silver so I will add powdered blue pearl to clear so the reflecting flakes are blue. The picture shows 200 grit sanded gelcoat (white and chalky) with a spot of clear that makes it look new.

I use Dupont Nason Clear - automotive not gelcoat.

http://www.filehive.com/files/0629/sidewinder-rehab-005.jpg

 

[lexkyboater]

Re: Replacing clear coat with gel coat?

Local boat shop said the best recommendation he had was to use a Nylene that you just brush on. He said that it's been used for years on yachts to go over fiberglass, and it has good uv protection, but you'd want to keep your boat covered when not in use. He said you don't have to buff it after you're done, and it's self-leveling, and will bring back shine. I called them to check on the type of marine compounds, wax, etc. and we got off on what I've got to start with. When I spilled the beans and told him some advice I'd got online about not using clear gel coat over the top of gel coat, this is what he recommended. It would be nice if I could just sand, buff, then wax to get it to look good.

The local shop also told me that the gelcoat is usally very thin and sanding is not usally recommended unless you want to reapply the color. I have painted tractors of all things with that good Dupont paint in a spraygun before. It's high quality stuff and just looks great, but I've never cleared anything.

How much powdered pearl do I use and where to get it? At the Dupont paint shop?

 

[ondarvr]

Re: Replacing clear coat with gel coat?

Gel coat is applied much thicker than paint, so sanding and buffing works well to restore the color and shine. It would be nice to just sand and buff what you have, just be careful not to sand into the flake, if you do it can be difficult to make that area look good again. Try a small area to see if it works. I don't know what Nylene is.

 

[thinksun]

Re: Replacing clear coat with gel coat?

I have painted tractors of all things with that good Dupont paint in a spraygun before. It's high quality stuff and just looks great, but I've never cleared anything.

How much powdered pearl do I use and where to get it? At the Dupont paint shop?

If the Nylene is self leveling I would think it is difficult to use on other than flat surfaces and would be a slow cure and subject to dust contamination.
I am pretty good at buffing and polishing but nothing is easier, faster and longer lasting than a properly applied clear. Clear is very easy to apply. For the 1971 16' Sidewinder Low-Pro project I purchased two quarts of Nason Clear with activator (no reducer required) which should give me nearly 4 coats. The powdered pearl is sold in bulk at a Dupont store which cost me $10.00 for a small bottle that will do 1 Gallon. A $100 Devilbiis gun and a rental compressor would be all you need if you don't already have.

A lot of auto paint stores sell pearl in liquid used generally in base color coats. Liquid pearl can mottel (blotchy) as I have found Dupont powdered pearl very uniform. The first coat of pearl clear can be an ugly application- hold the gun back (18") and spray multiple directions in order to avoid streaking. Any coat of clear should not be heavy as it looks better with multiple coats. Next two coats of clear go on using regular spraying technique.

I have added another picture of Nason SelectClear 496-00, small bottle of pearl powder and a typical HVLP gun with a $5 water filter.

 

[lexkyboater]

Re: Replacing clear coat with gel coat?

The sanding is taking an extremely long time. I spent about 20 minutes with 400 and 320 grit and sanding wet, and it's just not taking it off. Should I go to 200 grit or try a random orbit sander? Not sure if the peeling clear is actually car clear coat or not, but it's some tough stuff. Even when I get past the clear to the maroon gel coat, I only see just a few silver metal flakes, so I'm not sanding too deep.

I did buy some of that Nylene from the local boat shop for $30 for a quart can. They said it dries in 2 hours and you just have to brush on. It has UV inhibitors and lasts for 7 years the can says, so it must be tough. I figured I'd try it, since they've been using it on yachts for years, so it must look good if someone would dare put it on something as nice as a yacht. And it's designed to go over fiberglass gel coat. I also figured this sounded easier than masking and spraying. If it doesn't work, I can always sand and spray clear. They say you put it on with a nice urethane brush, and they recommended that you wet the brush with warm water first and shake it and squeeze it out, then trim any loose bristles for a better finish. And they said you should only paint it on in one direction, not back and forth. Just drag the brush one way each time. They said you'll be able to see your reflection in it. If I can eventually get the boat sanded down, I'll report back with pictures on how it turned out.

 

[thinksun]

Re: Replacing clear coat with gel coat?

Clear coat is very hard. If you use power tools stay away from inside corners or round outside ones. 180 works well dry before using 320, sanding the clear is not the same as sanding gelcoat. A buddy used 100 grit and finished with 200 dry before clear, a little coarse for me but turned out great. If your applying a finish whether Nylene or clear it must stick, and in my opinion finishing with 400 is too smooth for good adhesion. The test pic I posted earlier was using 80 grit on gelcoat then a single blast of clear which was smooth and looked good for color.

I just did a gelcoat repair on a boat bottom and man that stuff is hard to sand.

 

[lexkyboater]

Re: Replacing clear coat with gel coat?

Thanks for the feedback. Picked up a cheap $13.88 1/4 sheet sander at Wal-Mart yesterday as I thought that would work better than a round, random orbit. Ended up buying 220 and 320, and will probably pick up some 180 to dry sand per your recommendation. That should take it off quick, but will be real careful. Sounds like finishing off with 320 wet sanded before the Nylene should do the trick? It sounds like you're saying the gel coat is harder than clear coat since you're using 80 grit on yours? If that's the case, sanding the clear off should give me some wiggle room so I don't take the gel coat down too quick when the the clear coat is gone. The boat shop said that any sanding contours would be covered up with the Nylene coating, so it sounds like you basically sand like you would getting ready to clear it.

 

[lexkyboater]

Re: Replacing clear coat with gel coat?

I ended up going with 60 grit and it takes the clear off at a decent rate. Anything less is a LOT of work to get it to bite with the 1/4 sheet sander. After a full day's work, it still has a lot of clear left over. Can I use acetone or mek to take it off? After removing the clear, it's more obvious that a lot of silver flake is showing, especially on the right side. I think it needs paint or gel coat, and seems like you guys are saying that either epoxy or urethane paint is better than trying to gel coat over the top of existing gel. My only concern is how far to take it down before painting? How do I get a consistent maroon flake if the right side especially is showing silver flake now? Will maroon paint make both the gelled flake and the silver-color flake look maroon in color like the bottom of the boat? Or do I get the paint shop to mix metal flake in the paint to match?

I'm concerned about the color and gloss matching the bottom of the boat. Should I clear coat it or use the nylene I recently bought? When you paint, do you need to let it dry, scratch it with a scratch pad, then clear it? I've painted with my spray gun, but have never cleared anything.

Also, I've got a white design in the top deck on the left and right sides only. Should I just paint all that maroon, or mask and spray the white first, then the maroon?

Thanks for all the help, Steve

 

[lexkyboater]

Re: Replacing clear coat with gel coat?

Here's the white design in the top deck.

 

[byrdman64]

Re: Replacing clear coat with gel coat?

I have a 89 nitro that sat under a oak tree for 2 1/2 years clear coat is gone but for a few places and a few repair spots are dull yellow and the silver metal flake is dull and red metal flake pin strips are as well.
I was wanting to refinish my boat as well
the nylene sounds like the way I want to go but where can you find it?
and also with the metal flake being faded I was under the impression that you dont want to sand it?