"Spot" fiberglass repairs (ie. around exhaust), is it possible?

[Stee6043]

Is there any product out there that can be used to DIY repair small cracks in fiberglass that won't look silly? I have some hairline cracks around each of my exhaust ports. I'm not worried about it structurally but I am wondering if I can do something to prevent further deterioration?

Thanks in advance for any suggestions!

 

[The Bill Collector]

I had few chips here and there when I bought the boat and had a highly recommended gelcoat/fiberglass guy repair them for me. Under $300 @ the time.

 

[Lazy Daze]

Are the cracks radiating out from the exhaust port, or are they more like circumventing around the hole? If you knock on the cracked area, does it feel/sound solid?

 

[Stee6043]

Are the cracks radiating out from the exhaust port, or are they more like circumventing around the hole? If you knock on the cracked area, does it feel/sound solid?

They are radiating out, not circumventing. They are still solid as I just polished over them. I do have one "chip" in the area on my strbrd side but I'm not entirely sure it was due to the cracking or something else hitting (chip came with the boat).

What does that make you think??

 

[Lazy Daze]

It could be from an impact, but radiating cracks lead me more towards thinking they are coming from a chip or a hard, inside corner or even a screw hole. Often times, you can trace the cracks back to a common starting point. 99% of the time these are just cosmetic and since you said the area feels solid, that lends more credence to that.

The only way to stop these from continuing is to drill a small hole at the end of the crack - just deep enough to get to the underlying glass. To fix the cracks, you need to widen each crack to a V-shape and then you can fill with gelcoat (Spectrum Color can sell you the right stuff) and sand/buff. The new gel may not match 100% due to the age of the original gel, but it will awful close.

 

[Stee6043]

It could be from an impact, but radiating cracks lead me more towards thinking they are coming from a chip or a hard, inside corner or even a screw hole. Often times, you can trace the cracks back to a common starting point. 99% of the time these are just cosmetic and since you said the area feels solid, that lends more credence to that.

The only way to stop these from continuing is to drill a small hole at the end of the crack - just deep enough to get to the underlying glass. To fix the cracks, you need to widen each crack to a V-shape and then you can fill with gelcoat (Spectrum Color can sell you the right stuff) and sand/buff. The new gel may not match 100% due to the age of the original gel, but it will awful close.

Very helpful. Thank you, sir.

 

[fwebster]

Dennis, please excuse me for sort of correcting your post above..........But, this is a common problem for inboard Sea Rays. The construction is the problem. Sea Ray marks the exhaust posts in the mold, then when the hull is popped out, the exhaust ports are sawed into the hull sides for the engines and generator exhaust outlets. Next, the assembly method is to shove a precast fiberglass tube into the exhaust holes that were sawn in to the hull and glassing them into the inside with resin and mat. The last step is to fill the outside of the outlet with gelcoat thickened with cabosil then sand the area to fair it with the surrounding hull and finally buff the outlets so they match the sheen of the rest of the hull.

Cabosil is just a ground up powder and as such has very little tensile strength. Over time and with some engine vibration, the area where the cabosil is faired to the hull will get some cracks, usually radiating away from the exhaust outlet. The cracks are more prevalent where the filler is thickest near the outlet. Any repair to the cracks, short of grinding away the cabosil and repairing the area with with resin and mat or fiberglass cloth will be temporary and will come back fairly soon.

You can do a gelcoat repair as Dennis described, and it will last a while but you will eventually revisit this job. It is really not a hard or time consuming repair....it just requires the correct tools and materials and if you are out of th e water for the winter, it would be a good time to schedule it with your favorite glass guy.

 

[Marc Rainaldo]

On our previous boat we had some cracks too around exhaust. I repaired it with talamex gelcoat. I added some glass stuff to make the gelcoat thicker else it wouldn’t stick.(there are also other gelcoat fillers that I could have used better especially on vertical areas).

Very important that you remove the gelcoat around the crack as deep and far until you don’t see the crack anymore

It was my first gelcoat repair so I am not an expert at all with gelcoat.

How it holds I don’t know, 2 months after the repair we sold the ship....

On our new boat we have a lot of spider cracks and I gonna try to fix that this spring. Then I gonna try it with a gelcoat filler.

 

[Lazy Daze]

No worries, Frank. Thanks for chiming in with better detail. I had been thinking of the SS exhaust trim rings that some of the boats use.

We used to run into thick gelcoat in various parts of the little sport boats on a regular basis, too. Often times these were on the deck where the gelcoat was allowed to "pool" since the decks are built upside down. Things have gotten better, though, in that respect. But, yeah, thick gelcoat stinks. It's relatively flexible when it's thin, but it's just too brittle when it gets thicker.

 

[sbw1]

Is there any product out there that can be used to DIY repair small cracks in fiberglass that won't look silly?
Thanks in advance for any suggestions!

If you want a permanent, professional fix, North Shore Marina repaired my last two SRS with this exact problem. Repair was invisible and lasted for the ten years or so I owned each boat. Jack is the glass guy and really knows how to fix fiberglass problems. The repair was not terribly expensive. Right in your neck of the woods.

 

[Stee6043]

Very helpful info! Thanks everybody.

I wouldn't mind using a pro for a few hundred dollars. Sadly, I'd likely pay just as much for the haulout. I store at a marina with no services.

Thanks again, everybody. This definitely gives me a great idea of what I'm up against.

 

[fwebster]

The cracks around the exhaust ports are cosmetic. I haul out for a few days every February to check the bottom and hardware, the condition of the bottom paint and to detail the hull. I save non-critical repairs to avoid just the situation you are describing.