Basic Painting Questions

For issues common to different models of DaySailer.
Except Rigging and Sails.

Moderator: GreenLake

Re: Basic Painting Questions

Postby GreenLake » Mon Sep 13, 2021 3:36 pm

For masking the waterline: 3M blue ("edge lock").

You want something that has a very well-defined edge.
~ green ~ lake ~ ~
GreenLake
 
Posts: 7136
Joined: Mon Jun 18, 2007 3:54 am

Re: Basic Painting Questions

Postby marcusg » Tue Sep 21, 2021 12:18 am

So I think I figured out the new name for my boat: F$!k Gelcoat! lol...

After multiple experiments on a variety of surfaces, and never quite figuring out what makes spots not bond, I have 97% of the cockpit floor nicely gelcoated, and then every single place that I've recently repaired with either TotalFair or Silvertip + glass tape went unbonded/cured, even after waiting a week. Put down about two and a half quarts with rollers, which itself was a pain in the ass because it seems gelcoat kind of eats my gloves, but got it down.

Here's what it looks like now after an hour of using up an entire quart of acetone scrubbing away the uncured stuff:

https://drive.google.com/file/d/1S-vqqB ... sp=sharing

(Video link may not be uploaded yet but give her a try)

shizz.jpg
shizz.jpg (78.55 KiB) Viewed 223655 times


shizz2.jpg
shizz2.jpg (78.71 KiB) Viewed 223655 times


My theory is that, even though gelcoat has been proven to bond to epoxy, including the epoxy I used (S3 silvertip) the non-bonding only happened on surfaces that were somehow "corrupt," either by being blushed (which may be the case at the top of the cuddy where there was green Totalfair) or, in the recently fiberglassed fillets, because I didn't wait long enough after the epoxy had cured to apply the gelcoat. I'm not sure. I think it was a good 16 hours between epoxying those fillets and tabbing the transom before I gelcoated, but it had also been somewhat humid weather so maybe there was still moisture in the epoxy unevaporated that messed with the gelcoat.

Or is there some phenomenon where epoxy isn't "really" cured after it's initial curing time? I use S3 Silvertip with the fast hardener which is supposed to be cured in just a few hours.

I definitely wish I'd just bought a bunch of mat and epoxy and re-glassed the whole floor, which would have made for a much stronger and easier surface to paint than the splotchy deal I have going on now. I understood (I think) too late, that Greenlake was recommending to do the gelcoat because it would essentially save me the money + work of painting it (since I could just dye it grey.) But when I made my order I'd planned to paint the floor all along, and even already had the paint when I started this woeful :) gelcoat experiment.

Oh well, at this point I'm sorta commited since I'm not about to sand all the good coat off. My remaining ideas are:

1. (crazily) Try to use my 1/2 quart left to cover up the splotches. This would only be after making sure one of those spots is totally dry and de-blushed and testing it to see if gel holds this time.

2. Do some sort of fairing job with either thickened epoxy, or 3m high strength or QuickFair. Would be tricky because the gelcoat is just a few mils and it would be hard to fair that without wasting a lot of material, plus it's in tricky spots where there are 45 degree angle curves. I'm liable to just make my already amateur fillets look worse.

3. Say screw it and wherever it isn't easy to fair just paint over it and have it look lumpy. (Actually I'm a bit worried about paint adhesion because it was extremely hard to get into the nooks and crannies to remove the uncured gelcoat, and I'm pretty sure I won't have gotten all of it off.)

4. Lay on an extra layer or two of primer in the uncured spots to build them up to sand even with the rest of the gelcoat.

5. Some combination of all of the above.

My main concern is just moving the boat forward, as the cockpit floor is really the last thing holding me from painting and my painting weather is fast disappearing.
marcusg
 
Posts: 133
Joined: Thu Aug 16, 2018 10:39 pm

Re: Basic Painting Questions

Postby GreenLake » Tue Sep 21, 2021 12:53 pm

Bonding to epoxy is possible, but requires care. The mix ratio needs to be exact, so that there's no excess of either component after curing. And you are supposed to wash the surface with water (optionally a bit of soap) to get off any amine blush. You mentioned that you've been reading up on that, so I assumed your sources covered that?

My own tentative conclusion is that polyester filler seems less sensitive than gelcoat. If you are painting the surface anyway, then I would try that (or more QuickFair) to cover any gaps in the gelcoat for a level surface. Gelcoat is thick enough that you can sand it to even it out.

I don't think I quite realized that your plan was to put down gelcoat then paint. I did my cockpit with gelcoat because I feel that the surface is tougher than paint especially for the parts you walk on. Painting over gelcoat would be the same as painting over filler, fairing compound etc. as the paint's characteristics would define the durability of the surface. The gelcoat in the cockpit worked out well for me; a certain roughness in the application is a "feature" in my view, so I haven't bothered to try to sand it.
~ green ~ lake ~ ~
GreenLake
 
Posts: 7136
Joined: Mon Jun 18, 2007 3:54 am

Re: Basic Painting Questions

Postby marcusg » Tue Sep 21, 2021 1:17 pm

I’m definitely guilty, I realize, a falling for the allure of new projects and new products that I can try on my project. I think that it’s a bit of an explanation why I took on this way to big project to begin with, when I could’ve made it much easier than trying to learn almost everything about overhauling the boat at once. And my new addiction also explains Why I got sucked into a rabbit hole like Joe coding my floor without having perspective on why I was actually doing it. It’s gelcoat it’s new it must be fun right?
marcusg
 
Posts: 133
Joined: Thu Aug 16, 2018 10:39 pm

Re: Basic Painting Questions

Postby marcusg » Tue Sep 21, 2021 1:18 pm

We’ll that’s not entirely fair to myself I suppose because it’s not just that stuff is new but also the excitement at learning something new…
marcusg
 
Posts: 133
Joined: Thu Aug 16, 2018 10:39 pm

Re: Basic Painting Questions

Postby GreenLake » Tue Sep 21, 2021 1:29 pm

Marcus,

only you know why you are doing things. And, from a distance, spread out in time as well, it's hard to have and maintain a good understanding of someone else's project, or I might have been able to head you off.

Moving forward, if you will paint anyway, then do a skim coat of some filler that is good for skim coats (check instructions). QuickFair should be fine, if you've used that. Then sand everything (filler and gelcoat) to get a nice smooth surface, and follow instructions of paint manufacturer. (Don't use too high a grit so your paint has something to hang onto).

You may be advised to coat with epoxy and/or use a primer. All depends on what's in the description for filler and paint. (Even when QuickFair cures to be sandable, I'm not 100% on whether that always means it's actually mixed in the proper proportion, i.e. w/o excess hardener. The latter may screw with layers above).

Few here have had the luxury of having fixed multiple boats. We all tend to be "new" or "recently new" and can only report what worked.
~ green ~ lake ~ ~
GreenLake
 
Posts: 7136
Joined: Mon Jun 18, 2007 3:54 am

Re: Basic Painting Questions

Postby marcusg » Fri Oct 01, 2021 11:45 pm

Painting going mostly well so far. Put on one or two coats of EZ-prime over the whole inside and outside of boat over two days. Washed first with their Bio Blue, as that made the most sense for me living on a farm with animals and so on. Sanded prime with 150 by hand just to frost it. Then mineral spirits.

Primer went on pretty well and filled, or at least somewhat hid, the many, many gelcoat cracks. They're still there, but now it's just "character" instead of crappy looking.

Surprisingly, unlike the matte finish green EZpoxy I just did my canoe with for practice, the semi gloss white on my boat has a ton of orange peel, and just general weirdness. Like some sags even which I didn't get at all with canoe. Not sure if I put the white on too thick or what...All I can think is that maybe it's also just the glossiness shows it all off more? But I was using the performance enhancer like before, it wasn't thinned or seeming to need it, and my roll and tip technique is halfway decent so I don't think it was that.

Although one difference was I used my screwdriver paddle to stir todays white Ezpoxy and it was suuuuper bubbly for the first half hour really of rolling it on. Dunno if that was all from me or what, but I was knocking down probably 1000 bubbles every 18-24" of tipping...

Anyways...gonna sand that soon with 120-220 for second coat. Not sure how much I want to take off to get it smooth again, or if I should just sand it lightly and trust that I can always wet sand/polish the orange peel and unevenness off later.

I'm also just glad we're getting this heatwave in Wisconsin so I have perfect painting weather.

IMG-8863 (Small).jpg
IMG-8863 (Small).jpg (52.81 KiB) Viewed 223514 times

Have benches and centerboard walls painted, everything else just primed.

IMG-8864 (Small).jpg
IMG-8864 (Small).jpg (67.96 KiB) Viewed 223514 times

Will do anti-skid pads with EZdecks. As well as the floor.
marcusg
 
Posts: 133
Joined: Thu Aug 16, 2018 10:39 pm

Re: Basic Painting Questions

Postby marcusg » Tue Oct 19, 2021 4:08 pm

Got a warm day and put the second coat of Ezpoxy white for topcoat...but this time I sanded with 120 grit beforehand and after coat I can see sanding scratches all over on boat. I'm now assuming when they said sand with 120-200 grit between coats, they didn't mean 120 OR 200, lol...

What would be my easiest option, considering painting days are getting hard to come by, and I still need to do the non-skid? Should I just suck it up and 200 grit sand and do a third coat, or can I get those scratches out when (and if) I wet sand the whole boat to polish it up? Thanks.
marcusg
 
Posts: 133
Joined: Thu Aug 16, 2018 10:39 pm

Re: Basic Painting Questions

Postby GreenLake » Tue Oct 19, 2021 4:32 pm

120 sounds like a bit coarse for sanding before coating, but you shouldn't go higher than 200. Although, I happen to have lots of 220 lying around and I'd wonder whether that 10% makes enough of a difference. I wouldn't go 320, for example.

However you write that you sanded "after coat"? You mean, after each intermediate coat? If that's required, you'd want to be in the upper range.

I had a quick look at their online application guide, and they mention sanding only for the substrate (before the primer).

Image

However, in their PDF they suggest sanding the first coat with 200 grit. Definitely not with 120. And not for subsequent coats.

https://www.pettitpaint.com/media/4776/pettit-paint_topside-finishes-process_technical-bulletin.pdf

If you have some paint left over, do a small sample to verify that the scratch marks you see are from your sanding between coats, and not, for example, from earlier rough sanding of the gelcoat. While you are at it, do half the sample with the suggested grits from the guide. That should allow you to verify that their instructions work. If you want, do a third part of your sample in a way that lets you experiment with how you can improve your results with an additional coating.

I know this stuff can be frustrating, and I've had some stuff not come out the way I planned.
~ green ~ lake ~ ~
GreenLake
 
Posts: 7136
Joined: Mon Jun 18, 2007 3:54 am

Re: Basic Painting Questions

Postby marcusg » Sun Jun 05, 2022 12:01 am

So, after all the repairing of the past two years, the paintjob is pretty much done except for a few last coats on the furniture and rudder. Starting to put things back in place and remember what went where and get new bolts and nuts for the corroded ones.

IMG-0230 (Small).jpg
IMG-0230 (Small).jpg (80.74 KiB) Viewed 222260 times


One question, though, is about the coamings. As you see in the pic, mine are a special custom set that came with the boat (that I painfully refurbed.) And there's a 2" or so "ledge" that overhands on the outside of the deck, between the seatback and the guides/clamps. When I took the coamings off, they each had a long flat strip of silicone between this ledge and the deck. If there's nothing there, water will be able to get under there and drip right onto the seating surface. I don't have a ton of experience with using silicone, other than to seal woodstove pipes going through the roof, but I imagine I'd buy some kind of silicone caulk, and then sandwhich that between the coaming ledge and the deck (of course, only once I'm ready to screw the coaming on and have everything set to attach it.) Any thoughts or any specific type of silicone?

IMG-0302 (Small).jpg
IMG-0302 (Small).jpg (57.13 KiB) Viewed 222260 times
marcusg
 
Posts: 133
Joined: Thu Aug 16, 2018 10:39 pm

Re: Basic Painting Questions

Postby marcusg » Sun Jun 05, 2022 12:08 am

Another picture of the same coaming as in the last pic, but this time laying where it will be attached. In case there's any confusion.

Codetector (Small).jpg
Codetector (Small).jpg (67.73 KiB) Viewed 222260 times
marcusg
 
Posts: 133
Joined: Thu Aug 16, 2018 10:39 pm

Re: Basic Painting Questions

Postby GreenLake » Sun Jun 05, 2022 3:54 am

From a marine supply store you should be able to get a special closed-cell foam weatherstripping tape that you can tape between the deck and the coaming. You would place it as far to the water side of things as possible, where possible is defined by whether there's a consistent gap narrower than the tape, so it stays compressed a bit for a good seal. That should keep the water out. I'm using that for my regular coamings, which are just straight boards, so there I placed the tape at the top edge of the gap.

You can get various types of foam tape, so check around. It shouldn't need to be wider than 1/2", but it needs to be thick enough for your gap. Some run up to 250 mil, that would work for rather substantial gaps, even accounting for some compression. The shop I used to get mine from, now advertises only something that's more than double the length you'd need for DS coamings and more than double the width, so you may be better off looking at the 3M site and see whether you can order there directly or get a dealer or online source for the correct product number.
~ green ~ lake ~ ~
GreenLake
 
Posts: 7136
Joined: Mon Jun 18, 2007 3:54 am

Re: Basic Painting Questions

Postby marcusg » Sun Jun 05, 2022 7:55 am

That sounds much easier to deal with than goop, but I’d be concerned that it would offset my coamings st an angle on the deck/or take away the support of the deck, since the coamings are half supported on the inside (perpendicular to the deck) and half by the deck itself. Maybe just a wider piece of that tape?
marcusg
 
Posts: 133
Joined: Thu Aug 16, 2018 10:39 pm

Re: Basic Painting Questions

Postby GreenLake » Sun Jun 05, 2022 11:30 am

You can get that tape in 1" x 1/4". 3M 4504. It's not cheap. I think you might be overthinking this. But I don't know how your coamings are attached. If they are screwed in as opposed to simply resting on the deck, I think you should be fine. The tape compresses. Even if you only have screws from the cockpit side every few feet, that should support these in in the vertical dimension well enough so you can sit on them, even if they don't also rest on the deck. Remember, pressing down on a horizontal screw loads it in shear, it's strongest.

You can also get some other kinds of tape (look for "conformable") that is double sided and much thinner and can be used like a gap-filling adhesive. Not sure you need that.
~ green ~ lake ~ ~
GreenLake
 
Posts: 7136
Joined: Mon Jun 18, 2007 3:54 am

Re: Basic Painting Questions

Postby marcusg » Sun Jun 26, 2022 2:18 pm

Boat is just about put together, and have been in contact with my local sailing club which has a lot of DS boats. They have a very reasonable yearly fee, and the option right now between keeping my boat there on my trailer or on a DS-size lift. I'm a bit fearful of putting my freshly rehauled (albeit amateurly so) boat outside for storage, but at the same time the ease of launching (keeping my mast in one piece and installed, no need to be hard on boat + our second vehicle constantly towing back and forth) plus the social aspect of meeting other sailors at the club is definitely alluring. One of them mentioned to me it would be a good idea to get a boat cover if storing outside, and recommended this distributor: https://www.sailorstailor.com/products. ... UHorekkACU

What is people's experience with storing outside (and on lift) versus trailering and the wear on the boat? And on covers? I was looking at something like this one (a cockpit cover) because it's both the cheapest one they have, and seemingly doubles as a tent to camp in the boat.

cockpit cover.jpg
cockpit cover.jpg (162.37 KiB) Viewed 222074 times


It's funny...in these last days of putting all the furniture and cleats back on, I keep finding huge things that I must've either overlooked in the past two years, or just said "fuck it, I need to sail sooner than later." Like, basically every one of the structural members fiberglassed under the deck are rotten. Someday will need to either cut them off and reinstall, or ream them out and fill(?) them with something? Oh well. Another reason I'm worried to keep the boat outside.
marcusg
 
Posts: 133
Joined: Thu Aug 16, 2018 10:39 pm

PreviousNext

Return to Repair and Improvement

Who is online

Users browsing this forum: No registered users and 13 guests

cron