Gelcoat repairs

[pappaecho]

My new secondhand boat is in generally very good order for a 22 year old boat. However, round the bow area there are a number of dinks caused by the anchor, which have been badly repaired.
I need to grind out the badly repaired areas and re gelcoat but... how do you apply a gelcoat on a vertical surface without it running? Might it be better to use a colour matched filled epoxy resin system which does not "sag".
Ideas please as we need to find SWMBO something to do after she has cremated the turkey.
On a second subject, the boat has been epoxy tarred, and the moisture levels recorded by the surveyor are some of the best he has seen... the bad news is that on 24 points on the hull he has ground away the epoxy tar to get at the gelcoat.
How do I repair those areas?

 

[alan]

You could try a gelcoat filler and wait for it to go a bit "green" before using it.
Or else a gelcoat putty is probably the best and correct thing to use. You can make your own putty by thickening gelcoat with talc (also called talcum or soapstone); talc is sold in bags specially for thickening paints and gelcoats. If you have to match the colour of the gelcoat then mix in some colour to the gelcoat, then add talc until you get the consistency that you require, then add the catalyst.
Remember to open ou the dings a bit in order to give the new gelcoat an area to "bind" on. Also dont forget to opverfill as polyester gelcoats shrink on curing; any excess can be rubbed down smooth after cure.
You can use epoxy putties on polyester resins/gelcoats but they are more expensive.

There is a good book on the subject:

The Fibreglass Boat Repair Manual by Allan H. Vaitses (Published by McGraw Hill group).

If it not too late then it would make a good Chrissie Pressie.

Alan.
Nettuno, Italy.

 

[geoffatstanpit]

If the forecast for tomorrow is right I don't think it'll sag very fast! But if it does, stretch some wide sellotape over the repair to hold it in place. You'll still have to cut it back to fair and polish but it will stop it drooping.

Geoff

 

[aitchw]

If using gel coat for the repair you need to tape it anyway for it to cure. It won't cure if exposed to the air.

 

[ickyman]

O'yes it will - if you add wax to the gel - ask your supplier for wax to add if you already have the gel or ask for gel-coat with wax already added if you have not purchased it yet.

 

[davidwf]

I use Plastic Padding Gellcoat repair to great effect. Much eaiser to use than Gell Coat that requires sticky tape over it to cure. Blended in well on my Dufour no probs at all.

 

[robind]

Remember to feather out the potential repair or a "map of australia" will be evident if a light colour. A good tip for over filled repairs, is to (using a sharp chistle or old style razor blade) pare off the excess carefully (when dry but not hard) to reduce the need for too much sanding.
best of luck.
Rob

 

[gjgm]

it would be better to do the repair at 15 degrees and above, which isnt winter time! Depending on the size of the chips and the exactness of the colour match will decide the route to go. For small chips, and accepting a pure white finish, a tube of gelcoat repair paste for about £7 is the easiest. In fact its very easy. If you want a good colour match, you ll need various pigments and some talc or colloidal silica. CFS do all you ll need, but you need to buy trade quantities ! (mind you, thats cheaper than buying some tiny quantity anyway).Id estimate £50-75. Id guess some near matched topcoat (thats gelcoat with wax), and maybe two to three pigments For off white/cream try red, black and white, maybe some yellow. And a couple of hours practising. And these pigments seem to to get everywhere, so some surgical gloves and some mixing sticks is a must, or you ll contaminate your carefully mixed paste! Bear in mind it changes colour a tad when hardened. Just depends how close you want to get. Even Professionals can take a few hours to get a perfect match, so dont expect too much! Mix up, and then take a spoonful and add hardener to that bit.Good thing is, once you ve got it right, you ve got half a litre of good match left for any other dings. (and enough materials for half a boat!)