Attached is a picture of a chip in the gelcoat on the lip of my starboard hull. My question is how to best deal with it. Can gelcoat alone bridge this gap, or should I use Marine-Tex? Any other product to recommend? There are several other chips like this, and I'd like to have the lips be smooth.

Thanks!

And here is one more pic...

clean out any dirt / sand
Clean out with thinners (can never remember the right one)
rough up the surface (where the gel is missing) so the gel will have something to key into
Apply gelcoat / gelcoat filler and then cover with baking paper (grease prof paper) and then allow to cure.

File / sand and polish and job done.

Something like that is a small looking chip - should only take a few minutes to fix (depending on ambient temp).

Clean with acetone.

You might want to add some fumed silica to the gelcoat to thicken it a bit so it doesn't just flow out of the gap.

gel coat alone is fine. You can buy a small can that will cure without sealing for little cash.
I would not introduce any other materials as the colour difference will almost always show through on fairing.
Wash with warm water and a brush.
You will need to mix about four times and apply to get depth.
This will give you a chance to match colour.
White gel coat with tiny amounts of yellow introduced will do it.
Yellow can be normal boat paint or house paint as amount is very minimal.
So, you have to mix at least once to understand how much catalyst to mix.
Should end up invisable to naked eye.

NEVER underestimate the power of west system epoxy and 98cent can of white spray paint. Easy to blend! Let the purists whimper!

Depends on the level of repair you're after. If a 5' repair is acceptable (you won't notice it from 5 feet or further away), I would probably use Marine Tex on a spot like that. Clean it with acetone, wear gloves (so you don't make the Marine Tex any darker with dirt/smut while kneading it), and apply it leaving it a little above the final surface. As it hardens, you can shape it a little with a razor blade. Once it's fully hardened give it a final sanding and you'll have a good 5 to 8' finish.

If you want a 2' finish, you should probably fill and smooth with bondo, then spray or brush gelcoat on top of that and seal with plastic or PVA. Then wetsand, wetsand a little more...realize you sanded away all the gelcoat and have to spray again...then wetsand a little more, and buff for a great shine and perfect repair. It will be difficult to build up gelcoat alone on that area that thick so you'll probably need to first fill it with bondo (as built, it was originally sprayed that thick in a female mold before the fiberglass and resin were added).

However, I seem to recall that one of those generic gelcoat repair kits had the gelcoat in a really thick form...that might just do (but you have to add the tint to the gelcoat to get the color right).

1. Clean area with acetone. Sand with 40 grit, feathering out the edges.

2. Hand sand with 80 grit.

3. Wipe with acetone, and then with Styrene, this will create a chemical reaction to the old gelcoat and allow for the old and the new gelcoat to become one instead of only stick.

4. Mix gelcoat putty and apply.

5. The putty should be higher than the surrounding area to allow for sanding.
Let dry for approximately 1 hour.

6. Sand with 80 grit on a sanding block.

7. Spray with gelcoat. Let dry.
Wet sand using 400 grit, 600 grit, then 1000 grit.

Gelcoat putty :
Gelcoat + Pigment + 5% paraffin wax + Filler (Thixotropic Silica, Talc, Glass Microspheres.....)

Gelcoat to spray:
Gelcoat + Pigment + 5% paraffin wax + 10%-15% Styrene Thinner

you can use preval spray gun

http://www.prevalspraygun.com/

before you start It is recomended to test this not on the boat

Woah, excellent!

Wow, thanks to everyone for the input! I'll hopefully get to tackle these chips within the next few days, so we'll see how it goes.

1. Remove any loose material with a Dremel type tool.

2. Fill the gap with Evercoat Forumla 27 (polyester resin paste) and let harden. This stuff goes off pretty fast. Your working time is about 5-7 minutes depending on the amount of catalyst, temperature and humidity. It's hard and ready to sand after about 15 minutes.

3. Sand to the desired contour.

4. Get a Preval disposable aerosol paint applicator, fill with thinned gelcoat/catalyst and spray over the repaired area. You can add wax to the gelcoat mix but I use mold release (PVA) sprayed over the still wet gelcoat. You need to seal the gelcoated surface from air. You need to do this in order for it to cure. Otherwise the surface will not cure and be tacky.

5. Let the whole thing cure until hard (overnight to be safe).

6. Flare the repaired area to match the exisiting material using various grits of wet/dry sandpaper. Repeat steps 4, 5 and 6 if necessary to get the desired thickness/coverage.

7. Rub out with rubbing compound and buff to desired gloss level.

NOTE: Do not use an epoxy based product (i.e. Marine Tex) to fill-in the damaged area. Polyester based gelcoat will not cure if sprayed over epoxy.

This process works very well for polyester resin repairs. Repairing damaged carbon (rudders/daggerboards) is another process (epoxy) and another thread. Good luck.

Any idea of where to pick up Styrene locally?

Home Depot, Lowe's, Ace Hardware and my local West Marine do not carry it.

Is there a suitable alternative product?

I'm sure it's available locally, but I've not been able to find it. You can typically get it at any place that deals in gelcoat. Try US Composites http://www.shopmaninc.com/index.html They're at least in the right state.

Where can I find the thread on gelcoat over epoxy repairs?

Not much to it really, I've good results gelcoat over West System Epoxy. Just make sure the epoxy is absolutely cured (like a week), cleaned thoroughly (water/soap to remove amine blush), and sanded with nothing higher than 220 grit to give a decent mechanical bond. Our N20 boards and rudders were repaired with epoxy (the rudders quite extensively) and when I ran out of time, I gave to a local boat guy to finish up. I expected him to use Imron (since I know he prefers it), but he knew I preferred gel coat and finished them in gel coat. They've got approximately 700 miles on them and they still look great - even in the areas where the rudders rub the castings going up and down.

That's what I thought, as I haven't had too much difficulty with gelcoat over epoxy on some small repairs.

I hadn't thought about softening the old gelcoat with styrene before shooting the new gelcoat... That would have helped a bit when feathering the finish....

Thanks Jake....I located some at a local Auto/Marine Paint Supply store.