GELCOAT PINHOLES

[MIKE_MCKIE]

At the risk of being told its on a previous thread (I have done a search of the last year) my 1970 Bowman 26 was somewhat neglected (before I bought it!) so I am in the process of T cutting and polishing the deck and coachroof moulding. I have noticed a few clusters of small pin holes in the gelcoat & would prefer to eradicate the holes properly, not just fill them with polish. They are only a mm deep (or less)and do not appear to have had any adverse effect on the rest of the moulding.
Any ideas peeps?
Ta v m
Mike

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[AndrewB]

As you say ...

... no need to go back a year.

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[Hardley]

If no polish has been put in the holes, wipe surrounding area with acatone, prepare a small amount of gelcoat and work it into the holes with your finger (gloves are recommended, but I can't work with them on) clean fingers and excess gelcoat off with acatone.
If polish has got into the holes, it will have to be cleaned out first, which means making the hole larger of course. use Stanley knife for this.
When gelcoat has hardened off, rub down with wet & dry Paper ending up with 1200 grade or finer, then rubbing compound and wax polish.
Hope this helps.
Hardley

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[AOWYN]

We had this problem after one season with a brand new boat back in 1972/3. The cause was air bubbles in the gelcoat, probably caused by the operative not leaving the gelcoat to settle after stirring it with an electric stirer. The pin-holes became apparent after the boat was polished and the skin of the tiny airpockets was broken by the abrasive cleaner. Rather like shaving the outer skin of a block of Aero chocolate.

The builder, denied that there were pinholes even when he stood by the boat next to a collection of pins which were protruding from the holes after the surveyor stuck them in to prove that the holes were there. (C J Roy, Macwester if you want to know).

The recommended solution then was to abrade the surface, fill the holes and then paint with several coats of two-pot polyurethane.

Based on our experience this would still be my advice as well, (but try to use a paint from a manufacturer who is not testing his product on the consumer rather than in his own laboratory (International if you want to know, but that was 30 years ago and for the benefit of the lawyers I am sure that they finally developed a fine product and are wonderful people who love their mothers etc)

The final outcome, after three repaint jobs and many months of boat out of commission was a very good finish that lasted a lot longer than a dark blue gel-coat would have done and still looked great many years later.

If your boats pinholes are only just showing, consider yourself lucky and thankful that the gel-coat was thick enough to contain air-bubbles in the first place.

Good Luck



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[oldsaltoz]

G'day Mike,

Try this in a small area, it might save you a lot of work; apply a coat of acetone and pressure clean and area to remove polish from pin holes.

Fill the pin holes with gelcoat using credit card size plastic spreaders, leaving little or no gelcoat on the original surface, cover this with cling wrap and tape the edges down after squeezing all the air out.

Give it a couple of days to cure, remove the clink wrap and polish.

Hope this helps. . . . . .



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[MIKE_MCKIE]

G'day all,
Many thanks for all the advice, much appreciated. Looks like acetone, gelcoat and elbow grease should do the trick. I shall have to ask my friendly local GRP expert to make up some gelcoat same colour as existing tho, as I'm sure that if I try, the boat will look like I've taken a shotgun to it!
Brgds
Mike

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