Fiberglass Repair Advice

[trdprotruck]

Hi All,

I have some damage to the stern of my on the port side. Does this look like a repair that can just be done with Marine Tex or is it something I should have a professional fix? Since it will be covered with bottom paint I don't really care about color matching, but do care about the strength of the repair.


https://picasaweb.google.com/lh/photo/c ... directlink



https://picasaweb.google.com/lh/photo/c ... directlink

Thanks,

Randy

[tomchitecture]

It definitely looks like something you can do yourself. I cant tell if you are missing and strand or roving material or just gelcoat and resin. Bondo makes a product that has glass fibers in it called bondoglass. I would sand off an area of paint about 3" around all sides of repair then fill with bondoglass. If you want to be extra sure, I would add a sheet of 2-3oz fiberglass matt while the bondoglass is still curing over the entire sanded area, wet with west system resin and let cure 48 hours. Then I would sand the whole area, feathering out the edges and re-apply bottom paint. Don't use automotive grade matt and resin.

If you don't think you need the matt on top, I have had great results sanding and painting the bondoglass. Looks great and you never knew there was a repair there.

[trdprotruck]

It definitely looks like something you can do yourself. I cant tell if you are missing and strand or roving material or just gelcoat and resin. Bondo makes a product that has glass fibers in it called bondoglass. I would sand off an area of paint about 3" around all sides of repair then fill with bondoglass. If you want to be extra sure, I would add a sheet of 2-3oz fiberglass matt while the bondoglass is still curing over the entire sanded area, wet with west system resin and let cure 48 hours. Then I would sand the whole area, feathering out the edges and re-apply bottom paint. Don't use automotive grade matt and resin.

If you don't think you need the matt on top, I have had great results sanding and painting the bondoglass. Looks great and you never knew there was a repair there.

Thanks for the advice.

Here's a better closeup. I think it's getting into the mat.



-Randy

[Divecoz]

I WOULDN'T......use bondo.. Too many years doing custom cars to take that risk.. Marine Tex is the way to go..
Is that the spelling??? Tex or Tecs????

[kmclemore]

I second that - under NO circumstances should you use Bondo, since Bondo is not watertight and will eventually absorb water and begin get soft to flake away from the substrate.

Use what the factory used - gel coat. Best way it to make a plasticine mold from the nearby or other side's lip, coat it with mold release fluid, and use that to exactly match the existing area. Fill the area, apply the mold and keep in place until completely hard (about 6 hours). If you don't want to go to the trouble of making a mold you could also use Saran wrap. The important part is to not let oxygen get to the surface of the gel while it is hardening, and to maintain the shape you want.

[trdprotruck]

I second that - under NO circumstances should you use Bondo, since Bondo is not watertight and will eventually absorb water and begin get soft to flake away from the substrate.

Use what the factory used - gel coat. Best way it to make a plasticine mold from the nearby or other side's lip, coat it with mold release fluid, and use that to exactly match the existing area. Fill the area, apply the mold and keep in place until completely hard (about 6 hours). If you don't want to go to the trouble of making a mold you could also use Saran wrap. The important part is to not let oxygen get to the surface of the gel while it is hardening, and to maintain the shape you want.

Thanks everyone for the great advice! So does it look like just a gel coat repair (click on pic for close up)? In other words, I don't need to use any fibeglass cloth? Is there a difference in strength between repairing with gel coat vs marine tex?

Thanks again.

[Catigale]

I would just fix with epoxy. Hull is thick down there, and this is mostly just a cosmetic repair in an area that won't b visible.

[Divecoz]

JMHO.. You have some very minor intrusion of the substrate( fiberglass) Actually this will improve your long term adhesion factor ...That is why I suggested, the Marine Tex product.. http://www.marinetex.com
This product is ... structurally supportive. After it cures above water it is drill-able etc etc and is water proof..You can tint it ( to the proper shade of white etc etc.) The grey product is stronger and you can paint it or gel coat it later..
Molds as Kevin suggest..BTDT numerous times J-IMHO.. far more effort and cost involved than the final outcome supports..a Quality Mirror Image Mold Process.... is a PITA.. IMHO for this project..and unless you have done this before it can result in a very disappointing final product for the amount of time labor extended..(if this was the case, you wouldn't be asking..)
If this was a one off..... or a completely unavailable piece, for a Antique / Classic / Rare... high end car etc.. I too would head in that direction.. Its Not, Its Not....By a long shot..
To be honest... Its an easy fix.. You "could " even use 3M 5200 ... some saran wrap and a wall paper seam roller.. and this issue would be done and gone in an hour.. I wouldn't.... because ? ...Marine Tex will be a better solution IMHO and it wont cost a dime more..
Clean the area thoroughly.....sand all rough edges.. clean again.. blablablabla.
On Edit:
I agree with Catigale as well.. Ta Heck with all that aforementioned... Epoxy it and be done..with it.. he's right you'll never see it again..This isn't in the center of the hood on a 2011 Maybach.... Go Sailing!!
Bondo? NO! Kitty Hair? Maybe??
There are as many dirty fixes as there are people doing them.. I helped a buddy repair his girlfriends 69 daily driver Vette with a trashed / shattered rear quarter panel...did it with a dang Chop Gun!! Aligned the parts and "duc-taped the top surface let it cure and filled the crevasses and hit it a few times with the DA.... we had fixed her car a lot... of times ( not good at parking ) and we even had paint in the pot to match...
As Per Your Question:: Is there a difference in strength between repairing with gel coat vs marine tex?
Yes Marine Tex is no less than 10 times more resilient as Gelcoat.. Gelcoat has Zero Strength..

[trdprotruck]

Thanks everyone! You guys really make this website awesome. I was a little hesitant at first, but now I think I am just going to clean up / bevel the damaged area and then fill it with Marine-Tex.

Thanks again,

Randy

[Divecoz]

Truck::: Just use the grey product.. its, as I said, stronger..and with saran wrap and a piece of thin cardboard( note pad backing) using a seam roller for contour..and she'll look purrrrrrrfect..

Thanks everyone! You guys really make this website awesome. I was a little hesitant at first, but now I think I am just going to clean up / bevel the damaged area and then fill it with Marine-Tex.

Thanks again,

Randy

[Catigale]

Dont use blue - it will slow your boat (had to get that in, sorry)

[DaveB]

You probably have water penitration thru the laminites and requires drying out that could take a few weeks. You can use a heat lamp on the area once you rounded the area to natural form.
Adding anything on a water staurated fiberglass layup will not hold.
Dry it out with a heat lamp or heat gun at times and be sure it is total dry.
Looks to me you need 3 layers of mat or 7.5 oz cloth (Mat is much stronger than cloth tape)
Marine Tex is only a fill for voids in non strutual repairs and yours is a structual repair since it involves exposed fiberglass laminites at the transem.
Marine Tex is also a epoxie and not recommended for gelcoating over.
I work at a Major Water Park and do all the maintance on the fiberglass slides and many of my boats I owned.
I would recommend a Professional as they have mosture sensensors and can solve you problems.
You cover it up with epoxie or Polyester resin it will pop out very quickly.
Just my 2cts.
Dave

It definitely looks like something you can do yourself. I cant tell if you are missing and strand or roving material or just gelcoat and resin. Bondo makes a product that has glass fibers in it called bondoglass. I would sand off an area of paint about 3" around all sides of repair then fill with bondoglass. If you want to be extra sure, I would add a sheet of 2-3oz fiberglass matt while the bondoglass is still curing over the entire sanded area, wet with west system resin and let cure 48 hours. Then I would sand the whole area, feathering out the edges and re-apply bottom paint. Don't use automotive grade matt and resin.

If you don't think you need the matt on top, I have had great results sanding and painting the bondoglass. Looks great and you never knew there was a repair there.

Thanks for the advice.

Here's a better closeup. I think it's getting into the mat.



-Randy

[Divecoz]

DaveB Help me out here?
What causes you to believe there has been deep penetration of the laminates? ( I have worked on and drill through and repaired numerous places on my boat )
This fracture looks(?) rather fresh (?) No aquatic growth to be seen ..no discoloration.. no depth of destruction..
What is your basis for discouraging the use of Marine Tex for anything but filling holes?
I have used this product numerous times.. I have had No Negative issues with it ..This is no new comer to the boating world this product has been around for close to 40 years..... From their site..
Can I drill and tap Marine-Tex Epoxy Putty?
Yes, after it has fully cured Marine-Tex is drillable and tapable
Can Marine-Tex be used to repair gelcoat?
Yes, please see "how to..." section for details.
How high of a temperature can Marine-Tex withstand?
Depends on pressure and conditions. Up to 250°F constant temperature in a dry environment, with spikes up to 300-325°F.

What does Marine-Tex adhere to?
Metal, fiberglass, glass, masonry, ceramic, wood, most plastics.

What does Marine-Tex NOT adhere to?
Plastics like polyethylene and polypropylene, and also any unclean, oily, greasy, or otherwise contaminated surface.

Can I apply Marine-Tex under the water?
Yes, but the Marine-Tex is likely to wash away in moving water while it is trying to cure. The FlexSet is better for underwater applications because it is of a denser consistency.

Can I apply Marine-Tex in dry conditions on a below-the-water-line application?
Yes, the Marine-Tex is an excellent choice for repairing gouges or holes that are located below the water-line. Once cured, Marine-Tex is impervious to water and many chemicals. Since putties will go only where they are placed, be sure that the Marine Tex has completely encapsulated the problem area. It is a good idea to sand the perimeter of the repair so that the Marine-Tex achieves a grip on the solid surface around the repair.

[Scott]

since Bondo is not watertight and will eventually absorb water

Pssst, Bondo is a trade name, not a product. There is Marine bondo of course. This filler looks promising.



http://www.jamestowndistributors.com/us ... o?pid=6146

[Divecoz]

That's true Scott.... Lie Klein's and Channel-locks , Kleenex and a Zillion other things

since Bondo is not watertight and will eventually absorb water

Pssst, Bondo is a trade name, not a product. There is Marine bondo of course. This filler looks promising.



http://www.jamestowndistributors.com/us ... o?pid=6146