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I have been putting some miles in on the HMD19 and with the weather getting better i am looking toward repainting the hull. The boat was originally painted 13 ~ 15 (?) years ago. As far as i can tell, the hull is built per the plans with 1708 cloth on the bottom side only. The sides are just epoxy coated. There is some checking starting to happen on the sides where there is no cloth. I am curious what the general consensus is for the best way to prep/repaint in this situation.

My plan was to sand the entire hull with 80 grit to smooth out the checking. Then skim coat over the affected areas with some quikfair, then cover it all with the 2 part system 3 yacht primer. Still undecided on what the final paint will be.

I have the quick fair and the primer already. Note that the boat will not live in the water, it will be covered, outside in my side yard.

I am worried that the checking is something that once started is only going to get worse. Am i going to be repainting in a year if i don't strip all the existing paint/primer off and recoat with neat epoxy?

I don't have any close up pictures of the checking, but this shot gives you a pretty good idea of what I'm working with.

What was the hull sides made from - what type of plywood? If it is fir it will continue to check I think.

Personally, I'd take the topcoat off with 40 grit and mask off the bottom and put 4-6 oz glass on the sides. A couple of neat coats, fair, prime. The checking will never come back. You get a light abrasion resistant layer.

Lots of work, but my recommendation against checking.

There is lighter cloth, but I have no experience working with it.

It is something of a two person job to lay that glass. One person usually holds the glass while the other rolls precut off a tube. It likes to move so easily and you will have to lay it on a prewetted hull since it is vertical. I doubt you could tape it up and the tape is a nightmare to pull anyhow.

You can prefair a bit this way as well as I expect during the sanding; you may see some things you don't want to glass over.

Is it the ply wood or the paint that is checking?

Evan_Gatehouse wrote: ↑Mon Feb 22, 2021 2:58 am What was the hull sides made from - what type of plywood? If it is fir it will continue to check I think.

Evan, I am 99% sure it is Okoume. I haven't found any fir plywood in the boat yet and old pics from Yoda confirm that.

fallguy1000 wrote: ↑Mon Feb 22, 2021 8:34 am Personally, I'd take the topcoat off with 40 grit and mask off the bottom and put 4-6 oz glass on the sides. A couple of neat coats, fair, prime. The checking will never come back. You get a light abrasion resistant layer.

Lots of work, but my recommendation against checking.

There is lighter cloth, but I have no experience working with it.

It is something of a two person job to lay that glass. One person usually holds the glass while the other rolls precut off a tube. It likes to move so easily and you will have to lay it on a prewetted hull since it is vertical. I doubt you could tape it up and the tape is a nightmare to pull anyhow.

You can prefair a bit this way as well as I expect during the sanding; you may see some things you don't want to glass over.

Dan, That is exactly what I am hoping to avoid. Hanging glass by myself on the side of the boat would be a mess at this point. I know that certain/most of the boat designs here don't require glass all the way to the gunnels for strength, but it would certainly be a good idea to do it for longevity.

I am leaning toward just a sand/repaint. If the problem returns then i'll sand it all off and glass it, but at least this will buy me a season or two.

cape man wrote: ↑Mon Feb 22, 2021 9:41 am Is it the ply wood or the paint that is checking?

That is an interesting question that i hadn't considered. I'll do some more investigative sanding and see what I can dig up. The more I think about it, the more i think that there was really no wood peeling off at the checks.

Thanks all!

If it is just the paint, take it down to the primer (assuming it was primed before paint), add a new coat of primer and a quality two part top coat. If indeed it is all Okume you shouldn't see the plywood checking, especially on a displacement hull. Is the checking above the waterline? That hull did spend a long time out in the elements before you took it on, but I can't imagine the Okume would be "checking". If the ply is checking, you need to think about seriously sealing it in epoxy and perhaps adding some glass.

Cowbro/Cape Man, Although I never say never, we have not experienced Okoume checking. I know this boat was in the weather for some time but still we don't believe the Okoume will check!!! Jeff

I have a bird feeder with a 30"X30" piece of 1/2" BS 1088 Okume as the platform for the seeds. It has a tin roof, but is open on all sides and sits in the full sun. Besides the weather, it gets regular portions of bird, squirrel, racoon, opossum, and other critter fluids and other secretions. 11 years later there is no checking or even warping and it is just neat wood - no epoxy or varnish. Bet I could sand it and it would look like new. I bet it is just the paint.

Jeff wrote: ↑Mon Feb 22, 2021 11:18 am Cowbro/Cape Man, Although I never say never, we have not experienced Okoume checking. I know this boat was in the weather for some time but still we don't believe the Okoume will check!!! Jeff

I will snap some good pics at lunch. This makes sense and makes me feel a lot better.

Cowbro wrote: ↑Mon Feb 22, 2021 1:11 pm

Jeff wrote: ↑Mon Feb 22, 2021 11:18 am Cowbro/Cape Man, Although I never say never, we have not experienced Okoume checking. I know this boat was in the weather for some time but still we don't believe the Okoume will check!!! Jeff

I will snap some good pics at lunch. This makes sense and makes me feel a lot better.

Here's a question that may/may not help solve the riddle: Which direction are the checks running and which direction is the grain of the outer layer of ply, and do they match?

Pictures:




In the second image i scrapped away the paint with a pocket knife. I can stick the blade in about 1mm into the wood. This is about as bad as it gets. I am pretty sure these cracks/checks are in the same direction as the plywood face grain.

I'd do what you did after sanding it all down to primer.

I'd use some plain epoxy on that and follow it immediately or wait an hour and apply fairing. I don't like really super dry lumber for holding compounds and I precoat it. Now and then I take a risk, but that looks really dried out.

Glass each side and fair and be done messing with it.

Sorry. But I'm honest.

fallguy1000 wrote: ↑Mon Feb 22, 2021 4:47 pm I'd do what you did after sanding it all down to primer.

I'd use some plain epoxy on that and follow it immediately or wait an hour and apply fairing. I don't like really super dry lumber for holding compounds and I precoat it. Now and then I take a risk, but that looks really dried out.

Glass each side and fair and be done messing with it.

Sorry. But I'm honest.

I think you are right. I was really hoping I would scrape off the paint and the wood would look solid. That crack has me concerned. I'll sand it all down and reassess. I am picturing some neat epoxy squeegeed into each crack.

Cowbro wrote: ↑Mon Feb 22, 2021 6:42 pm

fallguy1000 wrote: ↑Mon Feb 22, 2021 4:47 pm I'd do what you did after sanding it all down to primer.

I'd use some plain epoxy on that and follow it immediately or wait an hour and apply fairing. I don't like really super dry lumber for holding compounds and I precoat it. Now and then I take a risk, but that looks really dried out.

Glass each side and fair and be done messing with it.

Sorry. But I'm honest.

I think you are right. I was really hoping I would scrape off the paint and the wood would look solid. That crack has me concerned. I'll sand it all down and reassess. I am picturing some neat epoxy squeegeed into each crack.

Neat brush painted into each crack hard, and then you can wait say 30 minutes for it to run out or force fairing into it right away. But you can also use peelply to catch the excess before you set fairing compound into it.

I just hate when that stuff gets super dry cuz it drinks resin and I am always nervous you won't bond to it. Making a too thin fairing mix that won't drysuck and it will sag out of there on the horizontal.

I think the best way is to expose them all. Put a piece of tape and peelply just under them all as a drip catcher, paintbrush them with neat, after they all have time to drip out and kick a bit; say like an hour; take a metal scraper and clean off any excess runs and remove the peelply and tape drip catchers, then insert fairing compound. Come back and sand them all with 60 grit. Fair them all a 2nd time. Glass it all. Final fairing and paint. You can do much of that work with a beer in hand. Some of it with a beer after the work.

The glasswork will cover some of them, but I'd grind some of them out. I'd probably go 6 oz glass to avoid any of the lighter checking printing out...hopefully.

That'd be my likely approach.

You should never need to mess with it.

Make sure to neat coat the woven 2-3 coats because it will like to print through under dark paint if you don't post cure it some. Otherwise you can also put it out facing hot sun each side for a day before you final sand it for paint and that may do the trick. But some of the old checkng or weave can print through rather easily. Then you'll be looking at a future paint job addressing that issue. Dig?

If it's just a few spots I'd patch with epoxy and paint. If it's a whole repaint I'd be mighty tempted to use some cloth over all of it. Done once and never worry about it again.

Ouch. That is the ply cracking. I see some sanding in your future. Only change in my recommendation is to use epoxy mixed with wood flour to fill the cracks after soaking them in neat epoxy. Stronger than fairing compounds. It's a bitch to sand when fully cured, but it will only be the small areas where you find similar issues as that last pic.

Unfortunately you will need to get all the paint and primer off before applying epoxy and glass.

second capeman

I would use only fumed silica in the mix, but wood flour and silica are both harder than fairing compounds for seam repair.

I mostly coined in here to add that a lighter paint color may reduce the tendency for printing through and for that checking to occur.

Dark colors get really hot in the sun when ambient temps are already 100F. I'd say that boat has a bit of sunburn.