I Need Some Deck Painting Advice.

sail sfbay · Oct 19, 2021

Before you consider paint you might want to see this video on repairing spider and hairline gelcoat cracks: How To Fix Spider Cracks, Hairline Cracks, and Crazing in Boat Gelcoat [MATERIALS LIST] | BoatUS - YouTube. Grind out the crack with a dremel tool, fill with color-matched gelcoat (with colloidal silica to thicken the gelcoat and mekp catalyst), wet and dry sand, apply rubbing compound, glaze, wax and buff.......and when you are done your marina neighbors and sailing friends will think you are pro!

You can do a search on this forum "repairing gelcoat spider cracks" and you will find many threads on this subject.

Siamese · Oct 19, 2021

You could, but it's going to look AWFULL. That is, until it peels off. Which probably won't take very long.

If it was a wood boat, and the wood was thoroughly sanded and primed, house paint could be a a good choice up on deck.

Fiberglass is going to do a lot better with paints and primers that are engineered for it. Unless you're willing to do the recommended procedures with the right materials, you'd be better off not painting. Which would be a reasonable choice.

Also, I wouldn't expect boat paint to hide cracks. Grind 'em out, fill with the appropriate epoxy products.

dlochner · Oct 19, 2021

House paint will chalk and peel off. You will rue the day you applied it.

In general the more effort you put into prepping the boat for paint and the more expensive paint you use, the better the results, the happier you'll be, and the resell value of your boat will increase.

Alexseal paint is getting very good reviews for ease of application, final appearance and longevity. If I was going to paint my boat, this is the paint I'd use.

PaulK · Oct 19, 2021

Siamese said:
Also, I wouldn't expect boat paint to hide cracks. Grind 'em out, fill with the appropriate epoxy products.

The primer for 2-part polyurethanes does fill cracks quite nicely... for a while. Our cracks stayed hidden about 6 years, though the paint itself (2-part polyurethane)held up for about twelve before getting chafed off in spots. If you do fill with an epoxy product, make sure to use something that is UV stabilized. Standard epoxygoop stuff succumbs to UV degradation and turns an opaque brown. This is why cedar-strip kayaks and canoes are all varnished. It protects their epoxy from the UV rays so you can see the wood grain. We made the mistake you may be about to make, and filled cracks on our J/36's deck with an epoxy microballoon mix. A few weeks later we had brown stains everywhere we had applied the epoxy, looking MUCH worse than the cracks. We ended up having to paint the entire deck and cabin trunk. We gave the "easy-to-use" one-part polyurethane Brightsides a try, and found that it held up on the deck for about a week. Though it might be OK on topsides, it was not tough enough for foredeck duty. Interlux seems to have realized this, and now has a product called Interdeck. We tried that too, when our first 2-part poly wore off after about 12 years. It looked good for about a season, then started to look shabbier and shabbier. So it got sanded off, and we repainted the whole deck again with 2-part poly, which we think the new owner will enjoy for at least another decade. Properly preparing the surface for painting is an incredible amount of work, and is essentially the same for any paint one would want to use. If that is the case, does it make sense to have to do the preparation once every season, once every two or three seasons, or once every twelve years?
It makes the most sense to avoid painting if at all possible. Gelcoat is much thicker and tougher than any paint. If you do have to paint, as we did, 2-part polyurethane is the way to go, even if it is more expensive and trickier to apply.

ShawnL · Oct 20, 2021

My hull above the water line was painted (poorly) by a previous owner. I lived with it for this season, but the paint is coming off in large flakes in places and just looks bad, so something needs to be done. I'm pretty sure I already know the answer to this, but once it's painted, do you have to stick with paint? I'm thinking it's theoretically possible to get back to gel coat and maybe make it look ok, but it would be way too large of a project to even consider.

dlochner · Oct 20, 2021

ShawnL said:
My hull above the water line was painted (poorly) by a previous owner. I lived with it for this season, but the paint is coming off in large flakes in places and just looks bad, so something needs to be done. I'm pretty sure I already know the answer to this, but once it's painted, do you have to stick with paint? I'm thinking it's theoretically possible to get back to gel coat and maybe make it look ok, but it would be way too large of a project to even consider.

Once painted, it will always be painted unless all the paint is removed. Paint type matters. 1 part polyurethane can go over anything, gelcoat, 1part poly, or 2 part poly. 2 part polyurethane can go over the primer and 2 part poly, but it can't go over 1 part poly because the solvents in the paint will soften the 1 part poly.

Preparation and religiously following the paint manufacturer's directions is the only way to get a good paint job. Also, stick with one brand. If there is an application issue or longevity issue and there are different brands of paint, the companies won't support you.

Joe · Oct 20, 2021

I used Kiwi grip on non skid deck areas. It's water based and will definitely solve your spider crack problem. Not that expensive I used about 1 1/2 gal. for all of my 27 footer's non skid. Looks good, comes in different colors.

Charlie Jones s/v Tehani · Oct 20, 2021

On my decks I've (on both boats) had great luck with Interlux Interdeck. Non skid mixed in already and has held up for years

sail sfbay · Oct 20, 2021

AlastairLC..........never have tied Hairline Fix - MagicEzy but its worth a try for a cheap fix.........you can always grind it out and re-gelcoat.

jssailem · Oct 22, 2021

Do you have something more than gelcoat flexing going on in that area of the deck?

You have 4 potential thru deck fittings that could be letting water in beneath the top deck into the core. Creating a "spongy" feeling deck. I would first try to affirm that the core in that area is not compromised.

dmax · Oct 22, 2021

jssailem said:
Do you have something more than gelcoat flexing going on in that area of the deck?

You have 4 potential thru deck fittings that could be letting water in beneath the top deck into the core. Creating a "spongy" feeling deck. I would first try to affirm that the core in that area is not compromised.

Yes, those cracks could be caused by water in the core freezing and expanding. Get/borrow a moisture meter to see of the core has high moisture content.

jssailem · Oct 22, 2021

AlastairLC said:
It looks more like general wear and tear.

You may have to sand the deck flat, Fairing compound to smooth, and then paint with a "non" skid paint or a paint and additive product.

I found the BoatWorksToday - Youtube site to be helpful in showing solutions for fiberglass repairs.

Boatworks Today | Boating Help For The DIY

Boating Help For The DIY on Boatworks Today…

www.boatworkstoday.com

TomY · Oct 22, 2021

AlastairLC said:
Mirage's decks, smooth and nonskid, are is very good shape, just some hairline cracks showing.
I’d like to touch them up, mostly to cover and seal the cracks.
What I read in books, and online, talks about cleaning, sanding, priming, and painting with specialized (read more expensive) marine paint.
Do I really need to do all that? Can’t I just wash the decks and slap on some good quality acrylic exterior house paint?
Thanks for any advice you can give me.

Yes, you can.

No 'slapping' though. Roll and tip.

TomY · Oct 22, 2021

AlastairLC said:
Thanks Tom.
What paint do you use? (Looks the right color too.)
Is she for hire?

That was Valspar Acrylic enamel (floor and deck I think). I've used Rustoleum acrylic enamel also and was pleased. That's a base and can be used for several shades of 'buff' or whatever.

Acrylic holds up better than oil for me, anywhere it gets a lot of abrasion like on the deck or the dinghy interior, house top.

Plus it doesn't flake like oil, I think, because it is tougher and goes on thinner.

That is also the reason it doesn't cover as well as oil and may need another coat over oil, if you have a lot of contrast to hide. Figure 2 at least. AND, it takes longer to cure than oil so allow a couple days of drying and at least that long before using.

It's one part but I think I got about 5 seasons out of the last coating of acrylic. I'm happy with that. It's far from perfect but I'm happy to be using the same nonskid pattern that was cast in the decks 60 years ago. If you want 'yacht quality', you should remove everything, sand it down, fill, spray two part, inside a building.

My daughter and I can paint these decks in a few hours. We should have done another coat this last time as it's a little thin. Taping is as big a job as painting. But it'll serve for a few years at least.

I Need Some Deck Painting Advice.

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