Refinishing Hardtop

[RedGreen]

I'm trying to refinish my hardtop because the previous owner painted the whole thing spray-can green. I've been working on sanding off the paint but I'm going through a little bit of the glass resin. I have some extra epoxy resin sitting around from another project and want to recover the top with it and new paint. Has anyone else done this? Should the paint go on over the top layer of resin or underneath it?

Thanks for any help.

 

[Sparky_Mark]

I sanded my top and used a urethane coating (PPG Omni, which is a low grade exoxy coating, but way better than anything in a can). I put 3 coats on and have been pleased with the results (no adhesion problems or reduction in gloss). You can have it mixed in any color, but I chose "Appliance White" as it is a common formula. Urethanes will also provide some flex to resist cracking when you remove and handle the assembled top.
The coating cost me around $60 for a quart (included color, activator, and reducer). Higher performance coatings will be more, but I'd suggest that you stick with the professional automotive refinish stuff (PPG, Sherwin Williams, Sikkens, DuPont, etc). You'll get better durability if you use a basecoat + clearcoat.
I did not use a primer in this case (as it is sort of a beater vehicle), but you may consider a primer for optimum adhesion - check data sheets for primers to ensure compatibility with gel coats, then make sure you use a listed topcoat.

 

[albee]

I have not done my top yet, but I have done a few boats. I plan to use my grinder, then patch and fill with resin. Then gel coat and paint.

 

[toddslater]

What grit are you sanding off the rattle can paint ? I wouldn't go any heavier than 80. Are you truly getting into the glass...or are you just into the gel coat...(ie got any glass hairs sticking up ?)? The top side repair of this is the same either way. Mix your epoxy resin & hardener with some West Systems filling and fairing additive (available at your boating supply houses...Eastern Marine etc.) and brush it on the damaged spots...build it up as necessary. If you've gotten into the glass and the spot is weakened...before you attack the top side... flip over the top, run a grinder with some 36 grit in the bad area, get some fiberglass matt, cut it to size, lay it on some saran wrap,mix up the epoxy & harderner, paint it on the repair area, paint it on/infuse it into the matt on the plastic wrap, pick up the plastic wrap/matt and slap it on the repair area. After you get it situated and pressed on and if need be rolled out, just carefully peel of the plastic so as not to lift the matt off and let her set up.

A couple of things, even with the filling and fairing additive, your top side repair will be harder that the surrounding gel goat....sand carefully. Also, there comes a point of diminishing returns, on one of my tops I had @ 25% of it painted with the filling and fairing epoxy....much more than that I may consider an alternative approach. Not that I don't love sanding and sanding and sanding.....
Finally, after you've done your repairs and have the whole thing with scratches no bigger than 80 grit, I'd lay down 3 coats of PPG Omni High Build primer and block the whole thing out by hand with 180 (this will even take care of most of the "factory" pinholes). If after you blocked it all out you have decent primer left (ie you haven't gone through it all in multiple locations), final sand with your DA with 220, or by hand with 400. If you've gone though everywhere, hit it with 2 quick coats of primer and then final sand. Blow it off real good, wash it down with prep solv, tack it and shoot with your PPG. If however, you use someone elses primer (other than PPG/Omni)...use their color. My 02 and what I've done on two of my tops.

 

[RedGreen]

I've been using my random orbit sander with 80 grit sand paper to get the old paint off. I haven't gone through to the glass anywhere, just through some of the gelcoat. The reason I'm asking the question is because it looks like I'm finding some of the original paint under the spray can paint and getting through both layers to the gelcoat. But on surfboards all the painting is done under the final gelcoat to protect it.

I'd love to use the system with the PPG paint included in the epoxy but I've already bought a quart of DuPont paint and have run into a serious budget problem with this project. Looks like I'm going to have to use what I have on hand. I don't know much about paints and haven't had any luck getting any information out of the local shop. I asked for a single stage paint for my first painting project. I looked it up when I got home and he sold me the top of the line DuPont paint. Great. Just what I need for this crappy truck.

Thanks for all the help and I'll try to take some pictures of the progress.

 

[redrustbucket]

I wish my truck was as " crappy " as yours! Sounds like you're making some progress bro, sweet. We're going to try to make a run to Ocala this weekend. Give me a call if you think you can make it.

 

[RedGreen]

Progress is very misleading. Everytime I take a step forward, I find 3 more things that have to be fixed before I can proceed. I've been through this truck enough times to know I want to do this right the first time, unlike every other time I've worked on it. But the budget just isn't there. My wife is about to cut me off, financially and physically.

Case in point: I have the West Marine West Systems epoxy and some DuPont paint mixed to match the original white color of the top. According to the above comments, I've bought the wrong things or I need more paints/primers, which should only run me a couple hundred dollars.

Looks like I'll do it the wrong way and be repainting my truck again in a few years.

As for the front floorboard, from a comment on another thread, I may leave it alone for now and fix it next time I have to pull the transmission out. Then I'll have to cut the tranny hump from the floorboard and replace it all.

Can't make it to Ocala this weekend. I still haven't figured out my overheating problem, so my limits are about 30 minutes on the highway. Besides, the wind is supposed to pick up this weekend. Gotta go kiteboarding!!

 

[toddslater]

Case in point: I have the West Marine West Systems epoxy and some DuPont paint mixed to match the original white color of the top. According to the above comments, I've bought the wrong things or I need more paints/primers, which should only run me a couple hundred dollars.

Looks like I'll do it the wrong way and be repainting my truck again in a few years.

I may have not been all that clear above...it happens sometimes....all I would purchase in addition to what you already have is 1) some filling and fairing additive for the West Marine Epoxy you already have. The epoxy is the expensive part...and 2) since you have Dupont paint....all I would suggest is by some Dupont primer....keep it in the family so to speak.

.....paint under the gelcoat..what the hell is that boaty/surf board stuff ???? you've been hanging out with Lowtide too much

 

[RedGreen]

Sorry. My brother used to own a surfboard company and I hung out in the shaping shop a little too much, and I have a bunch of friends who own boats but are as broke as me. You'll know when I've hung out with Lowtide too long when I take my receeding hairline (my wife would say receedED hairline) and try to grow some dreds.

On to the primer: Do I need etching primer? When do I use etching primer versus "plain old" primer?

This will be the only part on my truck painted with DuPont seeing that the guy sold me the top of the line when I asked for something simple to try out my paint gun.

Thanks for the clarification.

 

[toddslater]

Self etching..."you don't need no stinking self etching". Acid etching primers are more important for squirting on bare metals...especially aluminum...or if your doing some spot work on steel/aluminum and you want to promote chemical adhesion and corrsion protection. Your squirting on fibber glass...and if it's like the two of mine you have factory pinholes looking like little moon craters. Thats why I used a high solids/high build primer on mine to fill those craters in a bit. Here is a link to the dupy auto finishes techie info http://www.performancecoatings.dupont.com/bowstreet5/dpc/en/us/html/prodinfo/oemfleet/oemfleet.html

Depending on what you have in the can for the topcoat (Imron or other) the link above will help guide you to the right family of primers. Glancing at this page the Tufcoat family is high solids type primer. I don't play much with Dupy paints...maybe others on board know which is the best build for the buck out of the dupy stable. I know you have a certain level of distrust with your paint supplier...but he should be able to hook you up with the right high build primer for putting over glass and filling those damn crators. Post his recommendation up here. You'll know he's trying to put you in a ferrari if he starts talking about the new UV cured stuff.....huge $$$$.