Repairing 1/2" hole on bottom of fiberglass hull

hempfarmer

Petty Officer 3rd Class
Joined
Oct 13, 2009
Messages
80
Hi everyone,

My CVX-16 started leaking a few weeks back. I have drained it out (the best I can) and put a fan on the hole for the last 7 days to ensure the area is dry.

The hole is about 1/2' wide and right down to the foam. Since the hole is not visible I am not worried about how the patchwork will look, mainly concerned that it will stay in place for the next 5 years.

Is the next step just to purchase a fiberglass repair kit and follow the instructions? Is there anything I should be filling the hole with before trying to repair the fiberglass?

Any advice is greatly appreciated.

Thanks,
Russ
 

Woodonglass

Supreme Mariner
Joined
Dec 29, 2009
Messages
25,924
Re: Repairing 1/2" hole on bottom of fiberglass hull

Pics always help us to help you so we can see what you see. If it's only a 1/2 inch hole and not a 1/2 foot hole ("1/2' wide and right down to the foam") then you should be able to do an outside only repair with no issues. Yes the standard FG repair kit should have all you need. Basic technique will be to use a dremel tool or detail sander and sand the area about 2" in diameter and dish it out a bit. Then clean the area well with Acetone. Cut the Glass Mat and Cloth into progressively larger patches starting with a 1/2" piece progressing to a 2" piece alternating between mat and cloth. Apply the smallest one first. Wet all of them with resin and smooth out as best you can. Resin should cure in about an hour or less. Sand and feather then either cover with gelcoat or paint and you're good to go.
 

hempfarmer

Petty Officer 3rd Class
Joined
Oct 13, 2009
Messages
80
Re: Repairing 1/2" hole on bottom of fiberglass hull

Thanks for the response.

My main goal is to ensure this thing stays water tight. I have been reading that epoxy resin is better for below water applications. It seems like the standard repair kits are poly.

As a person repairing fiberglass for the first time might it be better to use epoxy resin? I don't have to apply a clearcoat after.
 

hempfarmer

Petty Officer 3rd Class
Joined
Oct 13, 2009
Messages
80
Re: Repairing 1/2" hole on bottom of fiberglass hull

This is the original problem hole:
IMG_0916[1].jpg

Here is the hole I drilled to see if there was any water in the boat. (was dry foam)
IMG_0919[1].jpg
 

Woodonglass

Supreme Mariner
Joined
Dec 29, 2009
Messages
25,924
Re: Repairing 1/2" hole on bottom of fiberglass hull

You can use epoxy but really not needed. Now that I see the hole I would amend my repair explanation and add that you should use some thickened resin to fill the hole first and then apply the patch. Or as you say you might get by with just mixing some strands of glass, cabosil, and epoxy to the consistency of peanut butter and patch the hole with it. Problem with that is you have no backer to keep the patch from just pushing on into the boat. I'd still go with what I described before. But, it's your boat and you can do as you see fit.
 

hempfarmer

Petty Officer 3rd Class
Joined
Oct 13, 2009
Messages
80
Re: Repairing 1/2" hole on bottom of fiberglass hull

Great advice, thank you. I'll now have to go see what my local retailers have available.
 
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