Fiberglas patch
- Thread starter Westie
- Start date
If it is all beneath the waterline (where the bottom paint is), Take a small grinder and clean up the margins, and bottom of the gouge. (great place for the Dremel Tool). Get some MarineTex epoxy. I keep a small container of the gray and white. Fill in this area slightly proud of the surface. Let it harden, and take a small detail sander, or by hand, and sand it smooth, put some of the bottom paint (may be a good time to do this all around the water line--since that is where it tends to degrade first)
If it is above the water line, then a different repair. You want to fill that area, with mill fibers and polyester resin. Fair it smooth, and then apply gel coat, to match.
I like to have a 20 mil layer of gel coat. Certainly you can build it up with several coats, or apply that much to start with. Choice of application with a Preval sprayer or brush on. For a small amount, I tend to use a brush or plastic spatula. You want the gel coat to be "Fresh". Spectrum color seems to still make a small repair kit for the C Dory. If not, white gel coat, tinted with a very small amount of yellow and brown to match. Again the Dremel tool to clean out the gouge.
For 1/4" deep and wide gouge, no cloth is necessary. If you prefer, and have some cloth, you can lay in some random fibers along the axis of the gouge.
If it is above the water line, then a different repair. You want to fill that area, with mill fibers and polyester resin. Fair it smooth, and then apply gel coat, to match.
I like to have a 20 mil layer of gel coat. Certainly you can build it up with several coats, or apply that much to start with. Choice of application with a Preval sprayer or brush on. For a small amount, I tend to use a brush or plastic spatula. You want the gel coat to be "Fresh". Spectrum color seems to still make a small repair kit for the C Dory. If not, white gel coat, tinted with a very small amount of yellow and brown to match. Again the Dremel tool to clean out the gouge.
For 1/4" deep and wide gouge, no cloth is necessary. If you prefer, and have some cloth, you can lay in some random fibers along the axis of the gouge.
Marco Flamingo
Active member
Polyester fillers like MarineTex and Bondo go through a hardening phase that is called "cheese." For a period of about 5 minutes (depending on temp and amount of hardener) they have a cheddar cheese-like consistency. That's when to use a "cheese grater" type of wood rasp. Easily cleans up an ugly, bumpy mess of filler and with a little finesse you can go directly to hand sanding. Miss that stage and you've made yourself 3 times as much work.
Mark
Mark
Marco Flamingo":2d3emi47 said:
Although I agree that during the "green phase"--many fillers can be pared with a knife, or rasp etc. I do need to point out three things.
Marine Tex, is not polyester, it is epoxy.
Bondo should not be used on a boat. It is a low density filler which will tend to absorb water, and adherence (Secondary bond) is not as good as Marine Tex.)
If you use one of the plastic spreaders, you can get the surface quite smooth, and only a couple of minutes of light sanding will smooth the repair.
I did a similar repair on my cat this weekend, and it took only a minute or two of sanding.
Thanks - since I have a small scrap on the keel, will the Marine Tex Marine Tex Rapid Set by the right product?
http://www.amazon.com/Marine-Tex-Rapid- ... +tex+black
There is a putty but I'm thinking that is for larger structural damage repair.
http://www.amazon.com/Marine-Tex-Rapid- ... +tex+black
There is a putty but I'm thinking that is for larger structural damage repair.
I don't consider Marine Tex for any structural repair. It is a filler. For structural repairs, one needs to use fiberglass materials--usually tape,fibers, or matt. Marine Tex is not often the best item for structural repair.
I have not used the 'rapid set". Reading the reviews, it seems to fine, although there were a couple of people disappointed, where they thought it would be harder like JB weld.
I would give the rapid set a try.
I have not used the 'rapid set". Reading the reviews, it seems to fine, although there were a couple of people disappointed, where they thought it would be harder like JB weld.
I would give the rapid set a try.