Hull Scratches-MarineTex

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Dec 20, 2009
54
MacGregor 26D Fort Worth
West Marine recommended that I use Marine-Tex Epoxy Putty to fill scratches in the hull. After reading the instructions, it says that gel-coat will not adhere to epoxy putty.
Should I be using gel-coat to fill these scratches and nicks?

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Are boat hulls painted with gel-coat, or is it just the finishing layer on fiberglass and it is painted over it?
 

caguy

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Sep 22, 2006
4,004
Catalina, Luger C-27, Adventure 30 Marina del Rey
The gelcoat is the first layer and is sprayed into the mold before the fiberglass and resin is applied. They sell this stuff. It is pretty easy to use. and appears almost seamless.
 

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Jun 5, 2004
997
Macgregor 26D Boise
Marine Tex is great stuff- but over the long run, it will turn chalky when exposed to UV. Gelcoat will not do that. I expect to get into gelcoat repairs this year. The PO repaired a lot of gelcoat damage along the rub rails with Marine Tex about 5-6 years ago- it now looks like doggy-doo. YMMV
 
May 4, 2005
4,062
Macgregor 26d Ft Lauderdale, Fl
fwiw,
I've had these guys computer color match some gelkote for me... its almost perfect, and they added wax so I don't need to seal it, for it to kick. (its slightly too white, probably cause it was matched from an interior panel.)

http://www.fgci.com/

it was about $50 for a qt.

if anyone really wants to do this, I'd could take a interior panel down from my 88 26d for them to match.
(its only 15 min from work)

but you might find someone locally that can do this.

cheap sprayer:
http://www.amazon.com/Preval-Sprayer-PVE267-Spray-Gun/dp/B000TRL9PY
 
Last edited:
Dec 20, 2009
54
MacGregor 26D Fort Worth
Marine Tex is great stuff- but over the long run, it will turn chalky when exposed to UV. Gelcoat will not do that. I expect to get into gelcoat repairs this year. The PO repaired a lot of gelcoat damage along the rub rails with Marine Tex about 5-6 years ago- it now looks like doggy-doo. YMMV
Thanks, I will take the Marine-Tex back
 
Dec 20, 2009
54
MacGregor 26D Fort Worth
The gelcoat is the first layer and is sprayed into the mold before the fiberglass and resin is applied. They sell this stuff. It is pretty easy to use. and appears almost seamless.
I'll give this a try, thanks
 

Doug J

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May 2, 2005
1,192
Hunter 26 Oceanside, CA
Gel Coat

I wouldn't use Marinetex.

I used the same stuff caguy suggested, Finish Gel Coat - Waxed, no need to cover. Matched almost perfect right out of the can. I think the factory used the default color, no tinting, so thats good for us, we can get the stuff right off the shelf and it will likely match pretty good.

You can use a dremel tool to clean up the damaged area, flaring the edges a little. I use acetone to clean it off before applying the gel coat. I know some say not to use acetone, but that's what I've used for years, never had any trouble.

Once the gel coat has hardened I use a small block of wood, wrap some wet/dry sandpaper around it, 600 grit. You can use a more coarse paper to bring down high spots quicker, but be careful, finish with 600. Using a spray bottle with water, slowly sand keeping it very wet. Be careful not to go through the gel coat around the edges.

Patience will pay off here, it's better to go at this slow. You might have to re-apply two, three times or more to get it just right. Rub it out with fiberglass rubbing compound, then finish it with a coat of wax.

Here's before and after pic's of my boat. When I first got it ther were some big gouges on the bow area where the PO hit the trailer. There was also some real long deep scratches along the sides.
 

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Dec 20, 2009
54
MacGregor 26D Fort Worth
Doug,
The bow on my boat almost looks as bad. Your finished repair looks great.

I have heard people say to smooth the gelcoat with some water on your finger when it starts setting up?
Is there any point in doing this or will I most likely have to sand it anyway?
 

Nik

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Mar 15, 2008
247
MacGregor 26D Valparaiso, Indiana
One thing that folks have failed to comment on is to "CLEAN, CLEAN, CLEAN" The area before, during and after the prep work. Waxes and especially ones that have silicone in them can stay for a very long time. As you start working the edges you will drag these remnants into your repair area. This can lead to potential bond failure. Another trick to use, is to also (kinda) reactivate the fiberglass underlayer by brushing a bit of styrene in the repair a little bit before doing the fill. This helps to make a more chemical bond rather than just a mechanical one. Just remember to CLEAN CLEAN CLEAN. You can use Acetone, Naptha, Xylene, Tolulene, MEK (will soften the gel and fiberglass with prolonged exposure). All very active solvents. Remember to wear Nitrile gloves (Walgreens), Latex will be eaten by most of these, or your hands will have all the oils sucked out of them and plenty of ventilation.
 
Dec 20, 2009
54
MacGregor 26D Fort Worth
One thing that folks have failed to comment on is to "CLEAN, CLEAN, CLEAN" The area before, during and after the prep work. Waxes and especially ones that have silicone in them can stay for a very long time. As you start working the edges you will drag these remnants into your repair area. This can lead to potential bond failure. Another trick to use, is to also (kinda) reactivate the fiberglass underlayer by brushing a bit of styrene in the repair a little bit before doing the fill. This helps to make a more chemical bond rather than just a mechanical one. Just remember to CLEAN CLEAN CLEAN. You can use Acetone, Naptha, Xylene, Tolulene, MEK (will soften the gel and fiberglass with prolonged exposure). All very active solvents. Remember to wear Nitrile gloves (Walgreens), Latex will be eaten by most of these, or your hands will have all the oils sucked out of them and plenty of ventilation.
I'll do that, thanks...
 

Doug J

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May 2, 2005
1,192
Hunter 26 Oceanside, CA
No Water

I have never used water on my finger to smooth the gel coat, and wouldn't consider it. I use small tools, such as palette knives, which can be found at art supply stores.

I learned to do this many years ago as a teenageer, working in Michigan at a Sea Ray Boat dealer, which at the time was the largest in the world. I visited the factory many times, and learned from what I saw the pros do. I ended up doing a lot of minor gel coat repair, in all different colors. If you have an older Mac as I do, you're in luck, because the gel coat is plain white.

Realize the method I describe is for minor scratch repair. More serious damage will require other techniques.

1) Remove loose or jagged edges. Sometimes you can simply/carefully use a knife to do this. You want to flare the edges a little, slope them. A dremel works great for this. Go slow, be careful, you don't want to make the repair area bigger.

2) Clean the area, light sanding wouldn't hurt, to get wax etc., off the surrounding area as Nik said. I use acetone to get all the dust and everything else off, just prior to apply my first application of gel coat. Use an appropriate size pallette knife for the job. Try to keep the layer you apply as low as possible. It will shrink when it cures. Don't assume you're gonna have it fixed in one application. Don't smear the gel coat all over the place. Keep it on the repair area, overlapping the surrounding original gel coat minimally. The flaring you did previously will be important to allow feathering.

3) Once it's hardened, use a small wood block, 1x1x3 or thereabout, wrapped with wet dry sandpaper. You can start with 400, but finish with at least 600. Use a spray bottle of water, keeping the area dripping wet. I'll have the sanding block in one hand, sanding mostly in a circular motion, though it does depend on the contours of the area you're repairing, using light pressure. Spray bottle in the other hand, spraying right over my sanding hand almost constantly. As the sandpaper wears fold over, wrap around the block again to get a good surface and continue. Get comfortable, take your time, slowly keep working at it. Soon you'll see the edges are exactly the same level as the surounding area, but likely a low spot in the middle. (Note: As you go along, dry the area with a towel for examination. If it's really wet you won't be able to tell when it's perfect).

Dry everything, clean with acetone, apply another layer of gel coat, let cure and sand some more. Repeat as many times as necessary to fill the void. Be very careful not to sand so much on the edges, so as to go competely through the original gel coat to the matte below. Also, apply fairly thin layers. In other words, if the gouge is real deep, don't try to fill the void in the first application, it'll take a lot longer to cure.

3) Once it's perfect, rub it out with fiberglass rubbing compound to remove the fine scratches. The finer the sandpaper you used to finish, the better finish you'll get.

4) Apply a coat of wax -- DONE!

Here's a couple more pic's. The second shot is after I finished the repair, and I just waxed the entire hull. Down low there was a lot more damage you couldn't see in my previous post. There were some long scratches along the sides, and some other misc gouges. That's why I like gel coat, it's easy to fix, no need to paint!

I did the repair in June 2005. The other pic is the way it looks today, there's no sign of the repair coming loose. It's still very hard to tell where the repair is. In fact I might be the only one who can tell, most people would never know it was repaired.

Right now I'm working on some mods to the interior. There's some unsused screw holes put there by the PO in the liner. I'll fix those the same way. Screw holes are very easy to fix.
 

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Sep 20, 2006
2,948
Hunter 33 Georgian Bay, Ontario, Canada
This is a great discussion guys. I hope you don't mind but I moved it to Ask All Sailors. I think just about everyone gets a knick, scratch or two on their boats.
 
Dec 2, 1999
15,184
Hunter Vision-36 Rio Vista, CA.
It depends on your ability to match the color or not. Sometimes you may be better off polishing out the scratches and living with them. Mismatched color look terrible in my opinion.
 

zeehag

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Mar 26, 2009
3,198
1976 formosa 41 yankee clipper santa barbara. ca.(not there)
have you ever tried smoothing gelcoat repairs with wax paper?? the shipwright who built a boat for me recommended that but i havent had to try it yet----he said it makes it perfect without any hassle----and he smoothed over the wax paper with a block-type tool---left wax paper on it--looked like it worked well....was just household wax paper.......
 
May 20, 2004
151
C&C 26 Ghost Lake, Alberta
Mr Bill,
I work part time for a Macgregor dealer.
Macgregor sells tinted gel coat for their boats - we keep tins of white, beige, blue for touch ups - matches perfectly.
Not sure if they still sell gel coat for your 26D though!
However, your new gel coat will fade over time, so if it's dead on now it won't be in a few years. Perhaps yours will fad right in to the old colour.
sam :)
 
Oct 22, 2008
3,502
- Telstar 28 Buzzards Bay
Sam—

I'd point out that on any older boat, even if you can get the factory colored gelcoat, it won't match due to oxidation and UV exposure.
 
May 20, 2004
151
C&C 26 Ghost Lake, Alberta
Yeh, that's what I'm getting at.
But with the factory stuff, if it starts off the right colour, it's got a better chance of fading after a few years to match the original (faded) boat colour. After all, the boat was that colour once!
Tinting gel coat so it fades to the right colour is impossible for a male! Only women understand what tone and warmth are in colours. I'm still working with the standard Microsoft 16 colours!
sam :)
 
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