paint questions

[Sutphen115]

two years ago I got my Sutphen froma guy with two huge holes int it. My father and I patched them and he painted the boat. Now I am finding bubbles below the waterline. I was told that it is water underneath the paint. So know I want to repaint it again. What would be the best paint to use. Also how hard would it be to gelcoat the whole boat. Any help would be great.
Thanks Chris

[thovind1]

I'm interested in this as well, because I'm thinking I'm gonna have to paint the cap to my project due to the gelcoat that I'd have to use to patch with, not matching up with the rest of it. Is there a certain way you should paint so as not to get these bubbles?

[Georgia Boy]

I would think that the paint would peel before water got under it. The bubbles are probably spots where the paint has turned loose from the hull "but not Flaked yet" due to some cause. If you are going to paint and it is turning loose I would sand all the old paint off back to the gel, and then clean with a good prep solvent and then prime and paint, and after you have cleaned the hull, try not to touch it with your bare hands because the oil in your hands can cause exactly the kind of spots like you are describing. use a good polyurethane paint and and an epoxy primer if you want the best in strength. As far as Regelcoating you either have to spray it on with a wax in it and as it hardens the wax floats to the top to seal out the oxygen for the curing process. then you have to wet sand the wax off and buff to a shine, the other option you have is to spray the gelcaot using Duratec's additive, I am going to use this on my hull this winter. if you mix it one to one with gel it will spray and air harden just like paint to a high gloss with no wax or buffing. I am not sure on the specifics yet, I am still researching it, but I know it has been used by others on this board, I believe B-mac used it on his boat when he redid his transom on his checkmate. maybe this will give you some help, if not just ask and someone will certainly answer. goodluck. GB

[Sutphen115]

The only question I have is why does it only bubble below the waterline??? The whole boat was sanded and primed before it was painted. Thanks chris

[Reese]

the waterline because that's were the water is...not trying to be a smart ass but blisters generally don't occur above the waterline.

Blisters are caused by water permeating through the outside layer of the paint or gel coat, over time the pressure begins to delaminate this topcoat from the substrate and you get blisters.

My question is how did you fix those two huge holes and what type of materials...bondo, paint, etc., did you use and was it catalyzed.

[Sutphen115]

When we fixed the holes we pulled the deck off and glassed it from the inside with polyurathane and roven woven. Then once we built it up on th inside we fliped the boat over and and smoothed it out with the polyurathane. We filled the little nicks in the front with a marine bondo. I asked my dad if it was catalyzed and he said it was. I am not sure what it is but he said something about it being a hardener. But as far as paint I don't remember.
Thanks chris

[Georgia Boy]

Glassing with Polyurathane before. what brand did he use, I always thought polyurathane was a paint base, not a bonding resin. could you post some pics of what you are dealing with?

[Sutphen115]

Its a polyurathane resin. We got it home depot but its the same stuff body shops sell and what you would get out of defender. I'll try and get pics up of the process.

[Techno]

Most paints aren't made for long time immersion in water. If you've left your boat in the water thats probably what caused the blisters?

I forgot but think Awlgrip and some aircraft paint I can never remember are 2 top contenders for durability.

First you need to find out what the blisters are. Pop one open and see if it is just the paint or if it's going into the lamms. If it's an osmosis blister repainting it isn't going to fix it. After popping it fill it in again with some filled resin or gel so you can use the boat again.
I would think if the paint is bubbled running through the water would peel it right off though.

[Sutphen115]

It's not peeling off though. A couple of them have popped But you just see green under them cause the bot was forest green at one time. The boat is left in the water spring through fall. The boat has so many bubbles in it, it kinda feels like sandpaper.

[Reese]

You must be refering to Polyester resin not Polyurethane.

If you can see the green under the bubbles you did not prep the boat correctly...or you did not use the right kind of paint.

You should have completely sanded the original finish with at least 80-120 grit paper followed by a catalyzed primer or epoxy primer and then a urethane or polyurethane paint.

Even though urethane and polyurethane paints are not supposed to be use below the water line, if properly preped they should hold up pretty well...what type of paint did you use and how did you prep the bottom?

[sho305]

After looking at an old boat I have, I think it is painted with laquer by how it compounds. It was ok(was years ago this happened), then I left it in the water for a couple weeks. It was blue, and popped about 1/4" bubbles of paint off under the waterline every couple inches. Had red primer under the paint and looks terrible. Also, the dock was pretty shallow due to low water at the time, and I could see gas emitting from the mud. I sanded some spots and found the original blue/white gel under it. I know laquer is about the poorest paint there is, but thought it was a strange reaction rather than just peeling. I think pinholes in the paint let water in, as well as the uncatylized primer absorbing water. I am sure laquer is not waterproof too. The rest of the paint is still on there. The bubbles had water inside them.

I still have it and plan on restoring it when I get a large enough place to do it. It is a 'glass '67 Chriscraft.

I also saw a deck boat that spent a lot of time at the dock. It had all bubbles in the factory gel about the size of a quarter. He told me a couple of times he had to get in the bottom when it got slow and get the bilge working. Then pumped out 100 gallons of water he said. I think the water got into the glass and made the bubbles from the inside. I could see no damage/cracks in the gel. This is also MI, and it would have been frozen every winter with the water in the glass fibers that could have made the bubbles. I would guess at that size they originated even below the base of the gelcoat; like in the mat.

[RSM]

Tecno hit the nail on the head and it is caused usually from micro size glass hairs that wick water through the paint or gell. I preped my hull with a product called INERLUX - INTERPROTECT 2000 SYSTEM it seals the hull prior to your finish coat, it is an epoxy with billions of alluminum discs that form a shingle affect. And if your going to leave it in the water all season the only non-biocide paint I have found that will handle this is INTERLUX PERFORMANCE EPOXY it is some durable **** and only comes in white. You will have some money tied up in this system but if your going to leave in the water it's the best way to do it. WEST MARINE sells this stuff but they are higher priced than others if you shop around. Also go to the Interlux web sit it explains the osmosis process and has lots of good info. RANDY

[sho305]

VC Performance Epoxy--is what I used on my bayliner transom, the well, and some of the pad. It was nice stuff, and seems to be just like gel now. It wet sanded and buffed real easy. It was much less cost than car paint. I want to do a whole hull now, but am trying to figure out how to apply color graphics to the stuff. I may have to go with stickers due to the teflon in it. I wanted to use auto colors. It was so nice, I don't want to mess with gel and I'll use this and figure the graphics out another way.

I used some brown gel tint to make it cream to match this bayliner. That worked great. Used a regular auto paint gun and layed it on thick. Very happy with it. Also, I can wipe the lake goo off it easy and the old gel stains at the waterline. That could be from age, but I did buff the old gel back to a nice shine. I sprayed it right over west sys epoxy@80grit on the new transom. I did use some duroglass inside there to fill, but covered it with west's epoxy before I painted.

[Techno]

something to consider. You don't have to paint the bottom with the same stuff you paint the top with---- you don't have to paint the top with the same stuff as the bottom is.

The bottom for the most part is unseen and is primarily a longevity issue. The top is glitzy, so you paint the top glitzy and the bottom with M-1 Abrams armour paint.

[sho305]

I agree, but I really wanted colors on the sides as the belt is pretty high on my hulls. I suppose I could paint up the sides part way to where my graphics would start and still have the epoxy above the waterline. That is about the only way I can figure it. Though I do like the idea of the hull being encased in the epoxy if I did the whole thing with it.