To Gel or Not to Gel - That Is the Question

[Fishman_Tx]

Ok, blister removal and repair time.
We start this process this weekend of "popping" blisters so that they can drain and dry. We don't have too many but do have a few in a couple of "touchy" places. One of which is on the corner of the upper aft trailing face of the skeg (in the gap twixt the skeg and rudder slab face). See photo.

A lot of the Gel is crazed and the blisters will be ground and filled. Does one NEED to re-gel, if not then what. She'll be getting several layers of paint and bottom coat. Barrier coat? What should one use? It was suggested after the fill and fair to roll a minimum of 3 coats epoxy to seal it.
Your thoughts?


Thx!

[Cheechako]

Genuine epoxy resin coating. (as opposed to "epoxy" primer sold by the bottom paint companies), roll it on and recoat prior to it setting up firm. put the bottom paint on before it completely sets up too.. using primer if you wish. each propgressive coat goes on before complete hardening

[Fishman_Tx]

Ok and as for the 3 coats o' resin, overkill or no? Should I tint the final? What hull paint (not antifoul) works best instead of gel?
Ok I am ducking after THAT question! Here it comes ....let the opinions FLY!

[forsailbyowner]

See yachtsurvey.com for articles on blisters ,blister repairs. Some eye opening information and a great resource for boaters.

[S/V Illusion]

You are allowing the blistered areas to thoroughly dry for a prolonged period, right? If not, it makes little difference what you choose to cover it with as you'll soon be removing it.

[Fishman_Tx]

Originally Posted by S/V Illusion

You are allowing the blistered areas to thoroughly dry for a prolonged period, right? If not, it makes little difference what you choose to cover it with as you'll soon be removing it.

Yup, We got 3 months doing "hard" time (yessir, pun intended) and the bottom is the last to do. I got boocoo deck and engine work still ahead plus the usual bilge work, tankage, etc.. typical refit.

[LtBrett]

I repainted my boat last year, so I've become an involuntary expert on coatings. Bottom paint is thick and hides all but the most obnoxious flaws. Absolutely no need to re-gel coat under bottom paint. Use marine tex or epoxy for your best bond. If the blister is deep, don't be afraid to grind away and re-glass it. Epoxy will bond best, but you can also use a vinylester resin if you are looking to save a little $. You boat was probably laid up with polyester resin, so vinylester will likely be stronger than your original hull. Throw some epoxy barrier coat below your waterline to prevent new blisters, bottom paint, then turn your attention topsides.

For above the water line, the easiest product I've found to work with is called Duraglas. Tiny (and I mean tiny) imperfections can be filled with an uncured green putty whose name escapes me. Uncured putties have very little bond strenght and are only suitable for filling pinholes. I used a high build automotive primer from dupont. Ping me offline if you want to get into those details.

Brett

[Fishman_Tx]

Many thanks El-tee (you military fellers understand that reference). I'll do that for sure. Need all the help I can get. Just like in life, there's the way things oughtta be and the way things are. Books are great but there is no substitute for on-hand knowledge AND practical experience.

[Stevens 47]

Yup, We got 3 months doing "hard" time (yessir, pun intended) and the bottom is the last to do. I got boocoo deck and engine work still ahead plus the usual bilge work, tankage, etc.. typical refit.

3 Months is not long. You should check the moisture content prior applying any epoxy if it is still wet you are going to have problems. Open up repair areas and leave them until the last...do your other stuff first.

[Fishman_Tx]

Exactly what we planned. My Bro and I suspect it'll be longer anyway, probably leave her all winter as yard prices are way cheaper than slip. We're going to pop'n'grind first, then tend to the rest. The bottom is last. We have to look and see how much chop is under the gel. If it's too thick we may be screwed anyway (too porous). If that's the case, we may also try and use a CPES first to seal them before filling and coating.

[Fishman_Tx]

After grinding blisters and sanding all weekend, we succeeded in finding more blisters and also found the Gelcoat is trashed below the waterline. Splits, cracks, pocks, chips, stress cracks, etc...

I've looked at material costs for GelCoat and Awlgrip and found on a per gallon basis, the Gel is cheaper even with the releasing agent. I'm not worried about the labor involved cuz the whole boat will need to be re-done, and this ain't our first rodeo with a sprayer. As it stands, with the repairs needed topside (core replacement and gel repair) I think it just behooves us to re-gel the whole kit and kaboodle. The hard part will be to find the hull planer...

Your thoughts?

[LtBrett]

Fish,

The gel coat is not a necessity below the water line. Grind it off if it bothers you--it's not structural. All you want to do is seal the fiberglass, which is accomplished using an epoxy barrier coat. Gel coat doesn't even seal as well as epoxy. I would recommend grinding back a couple of samples of damaged gel coat to determine if the damage extends into the glass. If it does, you've got a lot more grinding to do. If not (which is more common), sand the gel coat smooth, barrier and bottom coat.

The most frustrating mistake you could make topside is to put a coating over damaged gel coat. The cracks will return. You really need to either grind the gel coat off or route a big enough groove where there are cracks so filler can properly adhere.

After this nightmare of preparation (my boat took over 500 hours of prep work), it would be silly not to go with the best topcoat system.

The alternative, of course, is to recognize that this is an old boat and to tolerate signs of wear. Paint, specifically Imron, is easier to repair than gel coat. Imron the topsides with minimal prep and call it a day. If cracks return that you just can't live with, you can spot repair them. Imron is not to be used below the water line.

Brett

[Fishman_Tx]

The gel coat is not a necessity below the water line. Grind it off if it bothers you--it's not structural. All you want to do is seal the fiberglass, which is accomplished using an epoxy barrier coat.

This is what we were going to do but it's pretty crappy above as well with lots of stress cracks above the waterline. What about planing off all the gel, epoxy coating(min. of 5 coats)tinting the final coat, and then paint the whole hull (and bottom coat below)? If that works, then the same goes for topsides.....

I would recommend grinding back a couple of samples of damaged gel coat to determine if the damage extends into the glass. If it does, you've got a lot more grinding to do. If not (which is more common), sand the gel coat smooth, barrier and bottom coat.

It does and we're finding the blisters are past the first layer of cloth (VERY little mat) and end on top of the roving.

The most frustrating mistake you could make topside is to put a coating over damaged gel coat. The cracks will return. You really need to either grind the gel coat off or route a big enough groove where there are cracks so filler can properly adhere.

It's all gotta go...

After this nightmare of preparation (my boat took over 500 hours of prep work), it would be silly not to go with the best topcoat system.

So then a 2 pack paint system over epoxy would be better than new gelcoat? We have quite a few spots in the deck core to replace incl. the entire bow section port and starboard to the shrouds, a spot aft of the cockpit, a cockpit bench top, and the entire cockpit sole. Leaky-ass hull/deck joint!

The alternative, of course, is to recognize that this is an old boat and to tolerate signs of wear. Paint, specifically Imron, is easier to repair than gel coat. Imron the topsides with minimal prep and call it a day.

I'll check into the Imron system but unfortunately, max prep will be required as tolerance was never one of my virtues. I'm one of those kind who can't seem to stop once I've started. She'll probably be resold before too long anyway to finance the next size up, so want to maximize value...

Thx!

[forsailbyowner]

Gelplane.com Will be buying one in next couple of years when I get enough saved up for project costs.

[tami]

Gelcoat is heavy and hard to shoot. Go back with paint.

AwlGrip (s/as Imron) is good stuff. It's a bit dangerous, have care when applying. AwlGrip is particular about prep.

I have a 10-YO AwlGrip paint job on my trailerable trimaran and it's going strong as ever.