Gelcoat Damage

[Jabberwock]

While sailing back from the Scillies yesterday in quite large seas we picked
up a pot buoy off Lands End. The larger buoy cleared itself and we were left
with a small buoy banging itself against the rudder and skeg which could not
be removed safely in the prevailing conditions. Luckily the propellor still
functional so we had no proplem making it home.

On looking at the boat today I could see a small area on the rudder (2x3 in
?) and a smaller area on the skeg where the gelcoat seems to have been
removed by the repeated impacts. Is this serious and does it require
immediate rectification? If so, given that I can easily beach the boat for a
few hours between tides, is an interim repair possible for the rest of the
season to avoid the expense of having the boat craned out for pucker repair
to the gelcoat.

Any advice much appreciated

John Noble


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[BrendanS]

In the absence of anyone more expert.

If you're down to fibreglass in that area, given that it's under the water line, a quick repair would be better than leaving it until end of season. The longer you leave it, the more chance of the water wicking into the fibreglass that's been damaged.Get a tin of white gelcoat off the shelf (or a matching colour if the chandlers stocks a range) clean with styrene, let dry then coat with gel coat. Will last the season, then you can grind out and do the job properly later if you want a good cosmetic job. If you can dry it out thoroughly first, it would be preferable

If you want a quick bodge job, just fill with two part epoxy. It'll do the job, and stop water getting into the grp strands. More difficult to grind out later than a layer of gelcoat.

Is the gelcoat completely gone, or is a layer still there. What condition is the grp in the area of damage?

<hr width=100% size=1>Err, let me know if Depsol enters the forum, I'll go and hide

 

[Jabberwock]

Thanks for the reply. The gel coat seems to have been completely rmoved at least from the 2in by 3 in area on the rudder to expose what looks like fibrelass matting to my inexperienced eye. At least the area is out of the water for a couple of hours each side of low water as the boat is on a mud berth. Obviously though to dry the affected area out the boat would need to be craned out which I am hoping to avoid.

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[oldsaltoz]

G'day Jabberwock,

I very much doubt epoxy resin will harden in less than 2 hrs, and it will not stick to a wet/damp surface.

You need to dry it, or find a product that will stick to a less than dry surface, and keep further moisture out; sorry to say I don't know of one that will work for sure.

It is however important that you prevent water getting in, the longer you leave it the further it will penetrate, if the end of any strands are visible, or there are broken strands, water will travel up them (They are hollow) via capillary action and dissolve resin at the exit point.

Hope this helps. . . ..



<hr width=100% size=1> Old Salt Oz /forums/images/icons/cool.gif Growing old is unavoidable. However, growing up is still optional.

 

[chriscallender]

I'm no expert but know that Plastic Padding make a 2 part gelcoat repair kit available in most chandlers that dries quickly (can be sanded in about 15 - 20 minutes if I remember the instructions correctly) and I think would keep the moisture out for the rest of the season. It would be easy to do it within a tide, even allowing for spending a while sanding the repair smoothish after it dries.

One down side I can think of is that you will also be sealing in any moisture that has already got in, so when you do the final fix, you will want to make sure you remove all the Plastic Padding stuff and then try to get it all as dry as poss - easier said than done in British winter. Also, if there's power on the scrubbing grid, a good dry off with a hairdryer or similar followed by a clean up with sandpaper would do no harm before you do the temporary repair.

Good luck

Chris


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[gjgm]

just to add that while gelcoat colour matching is hard,( and the new area wont fade as the old area anyway) theres nothing mystical about gelcoat, so dont be nervous. Follow the advice already given,slap it on, cover it to keep the air of the surface (or it wont harden) and sand down with various wet and dry. Plastic Padding make a marine filler than sets in 10 mins I think, but not sure up to what size area it can be used. It greeny colour though, but they also make a gelcoat filler that takes slightly longer I think. Maybe what you need to get you through the season. Just note gelcoat needs at least 15degrees to set -so you cant do it outside in winter, if you decide to wait for proper repair.

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[wiggy]

You could try Dr Ding or similar repair putty. It comes as a putty like jam rolly polly! mix it up slap it on, even under water, and it set very hard. can be bought from most chanldlers

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[mtb]

Why not use a hot air gun as long as you dont get it to close it should help the drying out process.
You will also need to give the gel coat a good surface to grip and of course a degrease.

Cheers
Mick

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[MLBURGE]

It would be better to do some sort of repair until the boat is lifted out for a 'proper job'
If you've got say 2 hours of work time then when the areas are accessable wipe them off dry and if possibe apply a gentle heat with a heat gun or i suppose you could use a hot hairdryer if using a heat gun dont let it get to hot as this can bubble the surrounding gelcoat, do this for at least 20 - 30 mins get it as dry as poss.
Then sand the area to be filled with a course grade of glasspaper.
Then degrease the area using acetone or cellulose thinners would be ok.
Then fill the area with a fast drying epoxy resin you can add one of the filler
powders to thicken if the repair is deep, if its just a thin surface repair then you could just use a couple of tubes of 'araldite' or similar mix the tubes and this should be thick enough to fill straight on and will dry 10-15 mins if not quicker. Once hard you could sand the areas a bit if you want to.
whole job shouldn't take more than 1.5 hours.

Do do the job properly when lifted out and make sure its well dry.

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