Gelcoating DS1 bilge

[GreenLake]

As a pandemic project, with nowhere to go, I started to refinish the bilge in my DS 1. I had taken out the floor boards. That left the bilge exposed, which had an ugly mix of raw laminate (where the floor boards had rubbed through, failed paint, stubborn paint and some patches repaired with gelcoat. I chose gelcoat for that project, partially as an experiment, but also because I wanted something that would go on in one coat, cure quickly and not force me to wait for a week or longer before i could use the boat again.

I mentioned some of the details of that in another thread, which I will quote below for context.

Enough time has elapsed for the results to be evaluated for durability, so I will add some evaluation in the next post.

I've been experimenting with large-scale application of gelcoat. (Evercoat hi-bond, white, with wax).

... Gelcoat is applied in a much thicker layer than paint, and is also more durable. It can be tinted, there are special tints that are sold, but as far as I can tell, a few drops of universal tinting agent (the one compatible with oil paints) seem to work just as well. It takes very little to get a nice gray color for a floor.

The thing about gelcoat is that by nature, it does not cure in the presence of oxygen. So you can get it with wax mixed in which will create a thin layer allowing the gelcoat to cure. That's not always perfect, so you get something called PVA, a liquid that you can spray (you may need to get one of the paint sprayers with a gas cartridge) on top of the gelcoat to improve curing. ...

You can apply the gelcoat by brush, roller or just squeegee it on. For the floor, especially if your laminate is rough, you may not care about achieving a perfectly smooth surface, just a durable one. I only had a pint, which was enough to do the area from cuddy to aft of CB on both sides, and it's nicely uniform now and sealed many places where laminate had been exposed by something scraping on the floor.

I would recommend to fill any deeper gouges first - to remain chemically compatible, something like 3M high strength marine filler which is polyester based. (If you are careful to wash off any amine blush with soapy water and then scuff sand, gelcoat should bond to a bit of epoxy repair as well).

I know of professionals who will re-gelcoat a deck, so that can be done, but I might hesitate doing that only because of the higher quality of the job expected for a deck: it has to just look good and I'm not as sure my technique is up to that. But for the floor, I wouldn't hesitate.

Update on the gelcoat experiment.

I've now done the rear third of the cockpit (between the seats). It had everything from exposed laminate to several layers of failed paint (plus drips from decades ago when the seats were painted). I mixed 10oz of white gelcoat (with wax!) with a few dollops of black tinting agent to get a basic medium gray. After adding 12 drops of catalyst / oz, and mixing well, I dumped all of it into the cockpit and used a spreader to distribute.

As an extra precaution, I sprayed a thin film of mold release using one of those paint sprayers with disposable cartridges.

Result is a bit rough in places but if I want "really nice" I have a set of floorboards to cover it up. As it appears at quick check, no problem with curing and it looks so much better than before. I'd have to work on my technique a bit before trying a deck or surface like that, but because the underlying surface was never totally smooth to begin with, "perfection" wasn't an option but "durability" is a goal. Gelcoat, because it cures by catalyst, can be applied in thicker layers than paint and I'm pretty confident that I'm not going to wear through this new coating.

The question remains what I'm going to do with CB trunk and the less critical areas of the cockpit (such as upper ends of cuddy walls and some of the transom areas). I'll probably extend the gelcoat in all places that can end up with standing water anytime a tarp fails and use paint for the remainder. The CB trunk has failing/flaking paint on it today, in the cuddy, protected from UV, the old paint is in very good shape, except that it's now a slightly different color. My conclusion is that with some practice and good gelcoat (like Evercoat premium one step which I used today) gelcoat can be an alternative to painting the cockpit floor.

I ended up doing the CB trunk, and a bit of the cuddy walls above the level of the floor boards, but stopped there.

[GreenLake]

Several seasons have elapsed, I've used the boat perhaps a hundred times, so now is a good moment to take stock.

I did the gelcoating in three batches and not all at the same time, but it appears I did not have any problem with matching colors.

The first photo shows how I deliberately left brush marks when applying the gelcoat. My main reason was that I didn't want to sand and fair the bilge to perfection, so this helps blend with existing imperfections. I also had not given up on the idea of perhaps restoring the floor boards, in which case the part I did in the first two batches of the repair would have been hidden again. In the end, I liked it enough to also do the CB trunk and left everything exposed.

Aft third of cockpit with gray gelcoat

cockpit-floor-1.jpg (155.64 KiB) Viewed 100 times

The second photo shows the CB trunk, with a visible repair from the PO at the bottom edge. Probably a bit of laminate to hide a crack where it meets the hull. It's still visible, but much less than before. I should have probably sanded off and redone the repair, but impatient. In front of the repair are a few spots where the gelcoat failed in small patches. That was one the areas I worked on first, and likely made the mistake of spreading the gelcoat too thin (and not spraying it with PVA). Small areas seem to not have cured, but merely "dried", and subsequently scuffed off. The damage is largely on one side only.

To fix it would require color matching a batch, grinding off the affected area, and then re-gelcoating it. It still looks so much better than the "raw" bilge did before that I'm not super motivated to do anything about it.

Middle section of bilge and CB trunk

cockpit-floor-2.jpg (203.79 KiB) Viewed 100 times

Overall, this looks better, especially the parts I stand and walk on when raising the mast, than I would expect from any of the paints I've used. I was definitely a bit too cavalier on the prep and should have practiced my technique in a hidden spot first. The gray color worked as intended, nothing shows on it. If you look very closely at the first picture, you'll see that the bilge hasn't been cleaned for a while, but whatever smudges there are are not "in your face".