Primer

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The surgical gloves are a great thing to use. I however have had a hard time adapting to them because I prefer to do my prep and painting by "FEEL" so I don't wear gloves. I do however, clean and then clean again. With the naked eye you rarely see your own fingerprints but leave it to the clear coat to bring them right out to front and center for everyone to see! And no waxing is gonna remove them.

As for chemical reaction if you've ever worked on a boat that's had a ton of different colors there's a great chance you'll have problems if you don't remove it all with sand paper or cover it with a damn good quality primer. I tried using cheap primer one time and when I laid masking tape to mask areas of flames or checkers it would pull everything right up ruining my paint job. Nothing sucks more than sanding freshly sprayed paint!

 

[Preston_Hall]

I thought that's the reason for using primer? Other than for a smooth fill, the only reason to prime is to prevent separation, no?

I wasn't really refering to the primer separating from the surface or the paint. I have seen primers themselves separate. When the paint peels off there is primer on the paint and on the original surface. Just for giggles let's say there is .002" layer of primer. When it separates there is .001" on the boat and .001" on the paint chip that came off.

 

[dannyual767]

Hey guys, great topic. Are you guys talking about priming fiberglass or wood hulls? I like to build so the wooden hulls are what I usually work with. (I do have an Aeromarine Avenger as well.) I've made a lot of mistakes building and trying to paint these wooden Dumas hulls through the years.

My real question concerns sealing the wood. I've ordered and just started using a thin, sealing epoxy (Low V epoxy from Progressive Epoxy Polymers, Inc) for my wood hulls. It gets down into the wood grain and waterproofs the wood. It's sandable as well. I was planning on priming after the initial coat (or two) of sealing epoxy. Does this sound right or can I use one of these high tech, automotive primers right over the wood without the epoxy sealer. I tried asking this to the PPG paint house guy a while back and he had that "deer caught in a headlight" look!

BTW, this auto paint stuff is real expensive! The PPG paint store also carried Valspar auto paints that were much more reasonably priced. What do you think? It should be plenty good enough for rc boats, right?

 

[GTR]

Hi Guys

The key with wood boats is that it must be fully sealed with epoxy before attempting any paint. A lot of people don't actually fully seal the wood trying to keep the weight down. Although I know a lot of people don't bother but to paint f/glass you should really chemically etch it with metal etch first before spraying. I didn't talk about washing the boat down with a preparation cleaner because I took it for granted that everybody would do that. :blink: It takes a bit of practice to be able to prep wash a boat hull and not touch the painted surface with your hands at all. The surgical gloves trick can work if you wash the gloves after putting them on - otherwise you touch the outside of the gloves with your hands when putting them on, something most people overlook. <_<

 

[Mike Hughes]

You want to seal the wood first. You don't need to seal the fiberglass as it is already sealed with the epoxy that it is laid up with. The big question about the paint, is it going to stand up to the nitro that we use in our boats? I am not sure about Valspar. I shoot PPG Concept. Yeah it is expensive, but not that more than the K&B epoxy paint. They jsut don't sell it in the half pint sizes. I resisted for a long time until my K&B paint finally ran out. Then I bite the bullet and got the good stuff. More color selection and better quaility.

Mike

 

[dannyual767]

Okay, so it sounds like I'm going in the right direction to seal my wood hulls with this thin (Low V) epoxy sealer. I'm trying to keep weight down to a minimum but I want the hull to last. I've built wood boats when I was a teenager and didn't seal them. The wood didn't like the water . I'll take just a little extra weight!

I just pulled out my Valspar brochure. It is automotive paint and I'm sure that it's pretty tough stuff. Maybe not Ferrari or Porsche quality, but hopefully more than adequate for my boats. I moved last winter so I hope that I can find it here in Ft Walton Beach, FL. It sure will save me some coin that's in short supply these days.

 

[Don Ferrette]

"I just pulled out my Valspar brochure. It is automotive paint and I'm sure that it's pretty tough stuff. "

Just because it's automotive paint does not mean it will handle exposure to nitro. If it is typical basecoat/clearcoat enamel it won't. You want to use an acrylic urethane single stage paint like the PPG Concept (DCC) that we keep talking about. :huh:

 

[Mike Hughes]

When sealing the boat, brush on the epoxy and then scrap it back off with a puddy knife. Wipe the knife back in the mixing bowl. Wipe it down with paper towel. You can do this in small sections on the boat and then repeat it on the other sections. Works well. Also cuts down on the epoxy waste and the weight added. I usually do two coats with a light sanding in between.

Mike

PS Make sure you use the paint that will hold up because, how much is your time worth when you have to tear it all done and do it again.

 

[dannyual767]

Don, thanks for the headsup on urethane vs enamel. I did assume that since it was auto paint that it would stand up to nitro fuels. I took another look at the notes I wrote at the paint shop and I was looking at Valspar AC-200MS acrylic polyurethane clear. It has to be mixed with an activator so hopefully it will stand up to nitro. They've got a nice selection of single stage urethane colors as well. Heck, I don't even know if I'll be able to find that stuff here in Ft Walton Beach. It's quite a bit smaller than Ft Lauderdale, where I used to live! I may have to spring for PPG which I know I'll be able to find.

Mike, I'm going to try that method when I seal the outside of my hull. Do you wipe the hull with the paper towel to remove the excess epoxy after you've scraped it.? If so, does lint tend to be left behind from the papertowel?

 

[GTR]

If you can't find (afford) PPG try finding a DuPont agency as they also make good quality automotive 2 pak paints (Branded as Imron usually). There is also Spies Hecker, Glasurit, House of Kolor and a couple of others that make good quality paints. There is no quick or cheap way to get a good fuelproof finish without laying out the $$$$.

You can always befriend a smash repair shop locally and see if they mind doing the odd job for booze or a few $$$$ using their leftover paints.

 

[dannyual767]

GTR, I've thought about doing that, too. Here in Ft Walton Beach, there seems to be plenty of paint and body shops everywhere :unsure: . I'm not sure what that means :unsure: . Maybe they'd sell me a small amount of leftover paint. I'll check out the local paint supply houses first, then move to the paint and body shops if the supply house prices are too high.

 

[Mike Hughes]

Yes. There is not much left after you scrap it down. Scrapping it just save epoxy waste. The paper towel will get the stuff you miss with the scrapper. It can leave lint if you use the cheap white paper towels. I use the blue ones. It does not really matter anyway because you going to sand it down anyhow.

Mike

 

[dannyual767]

Mike, that papertowel thing is a great tip. It could've saved me 3 or 4 oz of weight from sealing the inside of my SK hull under the deck. I got way too much Low V thin epoxy sealer in there :angry: . I won't make the same mistake in the aft end (radio compartment) nor with my Dumas Miller American that I'll start building later this summer or in the fall.