Gel Coat Blisters

[talbot]

I know you are just dying to find out how the blister repair is coming along. So is my wife. Here is what the hull looks like after sealing, filling, fairing, sanding, refilling where I screwed up, refairing, resealing, re-re-sanding and re-re-sealing.

Gel coat repair. Patched and faired hull.

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Along the way, I've had to invent several tools. My internal fiberglass patch derrick appeared in an earlier post. It turns out one big challenge is the interior of the centerboard truck, which was blistered just like the hull. Opening the blisters required putting a rasp bit on a drill extension to reach into the narrow space. To fill the divots, I cut the edge from a putty spreader and nailed it to a lathe. Sanding has been the tough one. While you want a barrier, you can't have it too thick or uneven, or the board will stick. Here is my sanding paddle, with sandpaper stapled to the end. It's not very efficient, but I am developing upper body strength.

CB trunk sanding paddle

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And then how do you get all the sanding dust out of the trunk? Fortunately, I had just done a dishwasher install in our kitchen than produced a left over hose with a coupling that just happened to fit on the end of the Shop-Vac. To manipulate it, I taped it to the blade of a keyhole saw:

CB trunk vacuum extension

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Not sure how long the rest will take. Never having done this before, every new container I open is a surprise. Interlux Wash 202 sounds like something you'd buy as a gift at Bed Bath & Beyond in the Soaps & Fragrances section. It turns out to be a chemical weapon that is banned in California. I thought it would be a good idea to try out Interlux Interprotect 2000 (an epoxy sealer, not a condom) on a small scale. One centerboard's worth of Interprotect 2000 is enough to totally dissolve interrelationship 2014. My data suggests that it takes two hours with all windows open and all fans going to reduce vapors to a recohabitation level.

Have you ever seen those film clips from the Shackleton expedition, where the crew are hitched up like dogs, trying to drag the Endurance through the ice to open water? That's what this is like.

[K.C. Walker]

Oh yes, fill/sand, fill/sand, fill/sand… But now it's looking shiny! You've got more small spots than I did. It looks like you didn't have to do that much in the way of fairing which is great. I had some really big areas that I had to fair out, especially near the transom. I ended up doing a lot of longboard sanding and using battens to check progress. Just think though, when it comes time to paint, it's going to take no time at all!

[GreenLake]

I stay away from anything that has MEK in it (if at all possible).

[talbot]

Actually, the fairing has been awful. Following the advice to underfill the depressions, I ended up with something that still looked like craters of the Moon. So then I sanded and filled again, this time going above the surface. I was making no progress with hand or palm sanding. The problem is that my hull wasn't particularly flat to begin with. In the same small area I might be cutting away at the crest of a putty lump on one side of the sander, and grinding into underlying gel coat on the other. In the end, I got out the belt sander and ripped everything down to a least common denominator. I had to then hand-sand all the belt-sander scars, but it was still easier.

The shininess is another (third) coat of sealing epoxy to make sure I'm catching any bare spots opened up by the sanding. I could have done another round of sanding, and maybe I'll get up one morning and rip the epoxy off and cut the hull down to one more level of precision. But I doubt it. I'm burned out. I think I will do a long board sand to check for any outrageous anomalies, and then bury the whole mess deep, deep in barrier coats. Like an old necromancer in a sci fi film, interring some ancient evil. And if any sorry wretches be cursed to uncover this horror, may God have mercy on their souls.

[GreenLake]

There is one trick about fairing that I keep reading about just when I'm done with a project. In that spirit, here it is:

If you find yourself having to build up volume across an large-ish area (where it's not a matter of simply filling things to the rim of the crater), then do this: use a notched trowel to create ridges that extend higher than what you will need. Let them cure. Sand down with long sanding board. On the next pass, fill the grooves.

If I had remembered this trick, I would have had a better success of fairing the "hollow" sections of my hull (somewhere between CB and transom, on either side). Instead, I re-read it just after the paint was dry on the hull. Only to forget it again. Next time, it was the CB, where I needed to add a bit of bulk to get a fairer profile. Struggled mightily, came across the same tip the day after I was done.

[K.C. Walker]

We should all go out right now, I mean right now, and buy that notched trowel! This will remind us next time. Maybe we should even tape it to the side of the Microlight container. Oh right, we swore there wouldn't be a next time.… And then we forget that part.

With hindsight, I wish I had bought premixed fairing compound instead of mixing up the microlight and epoxy. It would've saved a fair amount of time. I didn't realize how much of it I would use. I found using a 4 foot batten really helped. I could easily tell where the low spots were, using a marker to outline the area/areas that needed filler. As soon as the filler set up I'd go back with the batten and mark all the high spots so I knew where to concentrate my efforts. I used a micro-plane, which is sort of part file, part hand plane, and part super sharp cheese grater. If I would get to the filler before it hardened completely it made sculpting quick. On the longboard I stuck with 36 grit and wished I'd had 10 grit. I definitely worked up a sweat and definitely slept well from the effort. It's extremely difficult to fair a surface with small sanding tools such as disk sanders and belt sanders.

[talbot]

Whoa. JC, you're telling me you actually straightened out the concave areas aft of the CB? I have treated those as the natural (if crappy) contours of the original hull maintained by a combination of original sin during manufacture and 40 years of sitting on trailer bunks. Who am I to tamper with what gravity and Bangor Punta hath wrought?

I've been keeping things level about 12" at a time. I just went down and put a bar on the hull. Depending on how far forward you want to have a straight line from the transom, I get two areas up to 1/4" deep, each about 12"x48". In other words, it would take a cubic foot of putty to fill up to the tangent line. Did you just lather the filler on top of the sanded gel coat? Did you use any additional glass for structure?

My first thought is that, had I stripped the hull down to the fiberglass and recoated the whole thing with Kevlar (a brief fantasy), this is the kind of thing I would have done because I would be in a position to work with the structure of the hull. But all I set out to do was seal the original material.

My second thought is that I'm going to run this by my long-suffering technical advisor at Interlux to see if he has a maximum recommended thickness for this king of application.

Finally, I'm impressed and somewhat intimidated. If you ever sail on my boat, I will make sure to have it in the water before you arrive, so my hull work will be hidden.

[GreenLake]

I've used SystemThree's QuickFair. It has the consistency (and look) of soft-ice, including a chocolaty color. (Safety reminder, lock the kids out of the garage while mixing). I never found a good way to measure it, but so far every batch I've done has set, either eyeballing was good enough, or the stuff's forgiving. It sands really well, no need to go for extreme grits.

I give it a coat of neat epoxy before painting. For that, the best approach I've found is to squeege it on. The few ridges left from the squeegee are more easily sanded than any brush marks or stipples.

I used a 2' sanding block made from a length of 2x1 with a drawer handle in the middle. I bought the sticky sandpaper that's sold in 2" strips on a roll, followed by sanding with a half sheet pad. I used an orbital sander to get the old paint off and to sand flush some of the spot repairs, but not for fairing.

I attempted to get the hollow spots out, but ended up only reducing them. Part of the issue was that I ran into a statue of limitation wrt to use of my friend's garage.

[K.C. Walker]

Talbot,

My technical advisors at MAS epoxy definitely thought I was nuts. And, I will admit to it. I did eliminate those trailer bunk divots. I already had put so much time into the boat, I wanted it to be fair. I started out sanding (grinding) as much of the gelcoat down as I could, to get closer to fair. At the transom I even went into the glass mat a little bit. The mat isn't that structural, it's mostly there to keep the cloth from printing through the gelcoat. Also, when I did the core on the inside of the boat I ground the stringers out and that helped eliminate some of the divots depth. The core was all the structure I needed and then some. So, though I may have started out with divots a quarter inch at the deepest spots I didn't have to fill that depth. Also, that's just the deepest spot and most of it tapers out so that it's much less. Though, it feels like filling a half inch!

It's a good thing I like this boat and continue to think it's the perfect little boat for me.

[talbot]

It's the perfect little boat for a lot of people. Most of them just don't know it.

Anyway, my crew is home sick today, so I am giving the grinding and chemical warfare a rest. I'm recently unemployed, so I'm supposed to be out looking for work anyway. It would be a shame to put another grand into the boat and then have to sell it for $850.

--T.

[K.C. Walker]

Of course, that's the problem with our boats. The good thing is you can buy them for less than $1000, a lot of times and if you're careful. The downside is, no matter how much work you put into them, you're not going to get much more than $1000. It's the old hole in the water surrounded by (X), in our case fiberglass, into which you pour money and time.

As long as we get our sailing time out of the boats, it's probably not much worse a deal than most boats. My dentist, a friend, just retired and in the last year spent an incredible amount of time at the boat shop where another friend of mine built him a Herrischoff 12 ½. This is a nice wooden day sailor a little smaller than ours. It's a gorgeous boat. With all the time he put in and also about $50,000, I think it's likely he will never get his money back for it and that doesn't count the time he put in sanding and varnishing. Cape Cod Shipbuilding makes a fiberglass version of this boat for $44,000! We have the advantage of low cost of entry.

[GreenLake]

For a number of years I kept careful track of money spent on my DS. It came to less than 1K / yr, including the price of boat and trailer. I think total costs of sailing as a hobby are perhaps 2-2.5 times that, because I then would need to include clothing, sailing related reading, expenses for towing vehicle attributable to boat, beer after the beercan races, even some travel (not to forget boats acquired since).

Still not anywhere near those figures you quoted.

[talbot]

I guess we are in the bargain basement. I added up the cost of a new Cape Cod Day Sailer, equipped and prepped as mine is, and I came up with $17,495. That's not including any of the customizations we've discussed on this forum.

So, let's see. If I've spent about $6,500 so far, I'm about $11,000 ahead. What will I do with all the money? Oh, right. Pay $1,000 a year for the next 11 years, then donate the boat as a planter to my retirement home.

[GreenLake]

Those boats have a lot more life in them than 11 additional years.

I think you should modify your plan to sell on retirement (from sailing) and not a day sooner.

But seriously, since these boats easily last several decades, they are best compared to houses. When we buy a house, we know that in the most likely case, all we'll be is a temporary steward of it. (Exceptions prove the rule). Likewise, we are only stewards of our DSs...

In your calculation, I don't think that actual, minimal costs will be 1K. If I exclude major refurbishing projects, sail purchases, trailer rebuilds, etc, and only look at the "quiescent" years, the minimal maintenance figure is much less than that (and even in those years I managed to take the boat out a few times).

[seandwyer]

I agree about the total costs being less than a thousand. I think the initial couple of years ownership account for most of the dough shelled out--but there is an eventual leveling off.

Last year was one of my most expensive years, as I refinished all my woodwork, modified my thwarts, and replaced the transom wood. This year I will replace my blocks and invest in some legitimate barber haulers. But the thing is, I don't have to. I could go on using the same hardware that's been there for 45 years. Nothing wrong with it.

But once I get those blocks, and a new jib next year, possible rig for and purchase a spinnaker the next, I will be good to go for a while. Oh, I guess that's when I will decide the centerboard and rudder need to be reshaped or replaced. OK, never mind. But I think you see what I mean--a guy that can be content with things can get to that leveling off phase and feel like he's sailing for free.

One question I have about this fairing project: if you fill in those divots from the trailer bunks (mine are quite noticeable to me) how much weight are you adding to the boat? Also, is it possible to alter the boat's balance, suddenly being heavier in one part of the hull than in others? Has anyone done this and noticed a change?

In a couple of months my boat will be coming off its trailer and will either be in water or on a nice form fitting lift until November. I'm hoping to get some of that distortion out of the boat, just by having it off the bunks for an extended period of time for the first time in it's life. I'm also planning to rebuild the bunks and turn them into something far more forgiving that the 2x4s and rollers it sits on now. As for the boat going back to its original shape--I'm probably dreaming.