Painting over old paint... filling, sanding, fairing?

[dccordell]

Hey guys... still working on the old deck boat, slowly but surely. Previously, I hadn't planned to paint the boat, but I got to looking closer and I notice it's been painted already, so I might as well freshen it up with new paint. For now, I just plan to paint the top side which includes the interior portions of the cap. No bottom painting for now. I'm going for a "thousand $ paint job", not the "million $ job" as I think YD puts it? lol

Ok, no problem there... I hope there is enough room on here for one more paint thread! Not the typical "which paint" question though...

The paint that is on it seems to be adhered pretty darn good to the gel coat (or primer). There are some spots that have been scratched and the paint has chipped in those small areas (see pics) but other than that the paint seems to be stuck on good. I try to pry up the paint in these scratched/chipped areas and it doesn't want to pop up, so I'm hoping this means it is OK to paint right over it without stripping it all off. I try to scratch the paint in other areas of the boat and it doesn't seem to want to come off or chip,, or scratch very easily.

My questions....

1. These small spots where the paint has been scratched and chipped... how should I prepare these for paint? Can I just sand them to get it back smooth so that when I paint I won't notice where the scratch/chip was? Or will primer hide this?

2. There are cracks in the paint in some spots(pics), and when I scraped away some of the paint in these areas, it appears the crack goes down into the gel coat (crazing?). Small cracks, they are probably due to stress over the many years of use on this boat and some from when the cap was removed and unsupported sitting on the ground. I have reinforced a lot of these areas inside the hull (around the steps/seats), but some are in spots that don't even seem to flex any, so maybe it's just age? Anyways.. will primer hide these small cracks (maybe even two coats of primer and sanding in between?) or should I try to fill and fair these cracks before painting? If so, what fairing compound should I be able to find locally? Can I use the same stuff to fill tiny holes where something used to be mounted in the console?

3. Should I sand the existing paint prior to painting to help with adhesion? If so, what grit?

I've searched and searched here and the internet in general for paint products. I had decided on the Rusto Pro as many others have, but we only have a few basic colors available here, none of which I really wanted to use, so I searched more and found folks have had good luck from Benjamin Moore M22 paint. My dealer in town has the paint in stock and it can be tinted to just about any color, so it sounds like a good paint to go with.

3. Materials... I'm planning to do the good ol' roll-n-tip method. Small foam rollers, and very soft brushes? I saw one guy on here had better luck using the small foam brushes to tip instead of bristle brushes. Any thoughts?

4. What sort of cleaner should I use after sanding, just before painting? Is anything required? Tack clothes to get the sanding dust off?

Not sure on colors yet, but will likely use a light color so it won't get so darn hot in the sun. And lighter colors will hide small imperfections more than darker colors, right?

So, any advice, input, thoughts, am I crazy/off track?

Sized the pics small so it wouldn't take up the whole screen... hope you can see them!

Pics in order across: Example of the scratched/chipped paint; the crazing; a spot where the paint/gel are totally gone down to the fg underneath; stress crack on the inside near the seat mounts; spot where the paint was cracking and you can see that the gel is cracked too.

 

[ljc1957]

Re: Painting over old paint... filling, sanding, fairing?

Fix the dings/scratches with Marinetex. Just follow the instructions. Prime the boat with marine primer. Wet sand with 600-880 grit paper. Sand between coats untilit's smooth. Clean after sanding with Acetone. I don't know anything about Benjamin Moore paint. Make sure you use an appropriate marine paint. Roll with a foam brush then tip with a good paint brush.

 

[dccordell]

Re: Painting over old paint... filling, sanding, fairing?

So after I get it smooth with primer and sanding, and the final coat of primer, do I need to sand again before paint? Or does the paint need a rough surface on the primer to stick well?

 

[ljc1957]

Re: Painting over old paint... filling, sanding, fairing?

Yes, wetsand it before you paint it. You'll feel it when it's smooth. Also, make sure it's at least 70 degrees, so the paint will set up fast. Oh yeah, I thinned my paint by adding mineral spirits. 30% worked well. This thins the paint, allowing it to lay down smooth. Just watch for runs and fix them with the brush. If you do this right, you'll be amazed at how well it comes out.

 

[Woodonglass]

Re: Painting over old paint... filling, sanding, fairing?

My questions....

1. These small spots where the paint has been scratched and chipped... how should I prepare these for paint? Can I just sand them to get it back smooth so that when I paint I won't notice where the scratch/chip was? Or will primer hide this? Depending on the depth of the scratch you may be able to get buy with a high build primer. A couple of coats of it will fill small spider scratching. All areas should be clean thoroughly with a scrub brush and acetone.

2. There are cracks in the paint in some spots(pics), and when I scraped away some of the paint in these areas, it appears the crack goes down into the gel coat (crazing?). Small cracks, they are probably due to stress over the many years of use on this boat and some from when the cap was removed and unsupported sitting on the ground. I have reinforced a lot of these areas inside the hull (around the steps/seats), but some are in spots that don't even seem to flex any, so maybe it's just age? Anyways.. will primer hide these small cracks (maybe even two coats of primer and sanding in between?) or should I try to fill and fair these cracks before painting? If so, what fairing compound should I be able to find locally? Can I use the same stuff to fill tiny holes where something used to be mounted in the console? 3M Premium filler is what i recommend for filling chips and gouges. It sands and fairs well. Again sand and clean well with acetone.

3. Should I sand the existing paint prior to painting to help with adhesion? If so, what grit? 180 grit

I've searched and searched here and the internet in general for paint products. I had decided on the Rusto Pro as many others have, but we only have a few basic colors available here, You are correct but... You can mix your own custom colors of Rusoleum. It is an oil based Acrylic Latex paint. You can use the White as your base and then mix Artist Arylic Oil Paint from any Artist supply store to get the color you want. I did and got a "Sky Blue". I cul the Artist paint with Acetone first and then mixed it with the Rustoleum until I got the shade I wanted. Worked Great. Valspar also makes a Hardener for the Acrylic Enamel Paint. Works Great as well.


3. Materials... I'm planning to do the good ol' roll-n-tip method. Small foam rollers, and very soft brushes? I saw one guy on here had better luck using the small foam brushes to tip instead of bristle brushes. Any thoughts? I prefer the Roll n' Roll method. Roll it on then wait 5 minutes and then roll it again with a roller that has almost NO paint in it. Works GREAT!!!

4. What sort of cleaner should I use after sanding, just before painting? Is anything required? Tack clothes to get the sanding dust off? I wipe it down with a 50/50 mix of Acetone and Mineral Spirits.

Not sure on colors yet, but will likely use a light color so it won't get so darn hot in the sun. And lighter colors will hide small imperfections more than darker colors, right? Right on both counts!!

So, any advice, input, thoughts, am I crazy/off track?

Sized the pics small so it wouldn't take up the whole screen... hope you can see them!

Pics in order across: Example of the scratched/chipped paint; the crazing; a spot where the paint/gel are totally gone down to the fg underneath; stress crack on the inside near the seat mounts; spot where the paint was cracking and you can see that the gel is cracked too.

My recommendations are in Green Above.

 

[ondarvr]

Re: Painting over old paint... filling, sanding, fairing?

My questions....

1. These small spots where the paint has been scratched and chipped... how should I prepare these for paint? Can I just sand them to get it back smooth so that when I paint I won't notice where the scratch/chip was? Or will primer hide this?

A. If you just sand it smooth will end up with a low spot that may, or may not be noticeable, but is not considered correct. Primer may work for shallow defects, but fillers are needed for deeper ones.

2. There are cracks in the paint in some spots(pics), and when I scraped away some of the paint in these areas, it appears the crack goes down into the gel coat (crazing?). Small cracks, they are probably due to stress over the many years of use on this boat and some from when the cap was removed and unsupported sitting on the ground. I have reinforced a lot of these areas inside the hull (around the steps/seats), but some are in spots that don't even seem to flex any, so maybe it's just age? Anyways.. will primer hide these small cracks (maybe even two coats of primer and sanding in between?) or should I try to fill and fair these cracks before painting? If so, what fairing compound should I be able to find locally? Can I use the same stuff to fill tiny holes where something used to be mounted in the console?

A. Primer will hide the cracks right up until you use the boat for the first time, maybe less time if it?s a rough ride to the boat launch. They need to be ground out completely and filled, possibly with glass to prevent them from returning.

3. Should I sand the existing paint prior to painting to help with adhesion? If so, what grit?
Sanding is required, the grit is determined by the primer and/or paint you are using.

A. If using primer 180 to 320 will work. Before painting with a low cost paint use 320 or 220 and there is no need to wet sand, just use a DA (correctly). I use as coarse of a grit as possible for good adhesion.

I've searched and searched here and the internet in general for paint products. I had decided on the Rusto Pro as many others have, but we only have a few basic colors available here, none of which I really wanted to use, so I searched more and found folks have had good luck from paint. My dealer in town has the paint in stock and it can be tinted to just about any color, so it sounds like a good paint to go with.

A. I know some people like the Rusto stuff, never heard of how the stuff you listed works, but I don?t use either one. You can always blend two different colors together to get the color you want.

3. Materials... I'm planning to do the good ol' roll-n-tip method. Small foam rollers, and very soft brushes? I saw one guy on here had better luck using the small foam brushes to tip instead of bristle brushes. Any thoughts?

A. No opinion.

4. What sort of cleaner should I use after sanding, just before painting? Is anything required? Tack clothes to get the sanding dust off?

A. Use what the paint manufacture recommends, or get a product designed for that purpose, Napa has them.

Not sure on colors yet, but will likely use a light color so it won't get so darn hot in the sun. And lighter colors will hide small imperfections more than darker colors, right?

A. Correct

So, any advice, input, thoughts, am I crazy/off track?

A. For thinning use only the products recommended by the manufacturer. They may recommend a sandpaper grit also. Make sure the paint on the boat right now is compatible with the new paint you plan to use. It takes about 50% of the work to get to good paint job as it does to get a great paint job, that last 10% in the finish quality is 50% more labor.

By the way, these are the normal ?painting a boat? questions.

 

[ondarvr]

Re: Painting over old paint... filling, sanding, fairing?

We were typing at the same time, I had to answer some calls and you got in before me, pretty much the

same answers.

 

[dccordell]

Re: Painting over old paint... filling, sanding, fairing?

Yep, thanks a lot to all of you guys.. that clears things up and helps a lot. I hadn't even thought about mixing my own color in the Rustoleum... that's a great idea! Now I know what I need and how to get started.. will return if any more questions come up!

 

[Woodonglass]

Re: Painting over old paint... filling, sanding, fairing?

Ondarvr is correct about big cracks, you should take a dremel tool to ream them out and the clean, fill and fair.

 

[Yacht Dr.]

Re: Painting over old paint... filling, sanding, fairing?

I'm going for a "thousand $ paint job", not the "million $ job" as I think YD puts it? lol

So, any advice, input, thoughts,

Nope..you have it covered it seems .. Good luck ..

YD.

 

[dccordell]

Re: Painting over old paint... filling, sanding, fairing?

Quick question on the roll and roll method... how many times do you normally use the "tipping" roller before chunking it? Can you wash it after tipping and reuse it a couple times, or is it best to just chunk it and use a new one for every section? Trying to figure out how many to buy...

Edit: Another question... After calling all of the boat shops in town and then the auto body shops that they recommended to find the 3M Marine Filler, it seems that nobody has it in town!! And they can't even order it for me... so is there a similar product I could try, or should I just go ahead and order the filler online and wait? The guy at one boat shop suggested that I use a product by Evercoat called Fiber Tech. It looks like it is for fiberglass repair jobs, but I get the impression from the website that it isn't so much for fairing out small cracks, because it says to use lightweight filler or poly glazing putty for finish layer. But he said it sands real easy, so.. What do you guys think?? I only considered it because it is in stock in one of the stores in town, not the store that recommended it though.