how to patch a 2-3mm hole below water line?

[Ken13559]

Some months back while helping a friend mount his batteries I drilled a 2-3mm hole through the hull, below waterline. Needless to say, a fountain of youth sprung up. As temporary measure, I slot a drill bit through the hole and fountain stopped.
Now I've a chance to repair the hole as he'll be beaching the boat to change prop and do some antifouling paint. Question is how do I repair the hole? Drill it bigger then stuff with epoxy? Drill bigger and driver a wedge through the hole?
Please advise.

 

[Bill Roosa]

I'd just fill it with epoxy and be done with it. there is the matter of wet core material which I can't answer as that would be location dependent.

 

[DougM]

How much time have you got after the boat is beached? That could be an issue.
One way is to clean out the hole and fill with a thickened epoxy. For insurance you could feather out the area around the hole on the inside and add a few layers of progressively larger fiberglas cloth patches, which could be done when the boat is back afloat. fortunately, it's not a very big hole.
I don't even want to ask how or why you managed to put the hole in the hull in the first place.

 

[Ken13559]

The hole is only 2-3mm diameter so it's kinda seems difficult to put any epoxy into it. I think we'll have say 3-4hours of useful time on beach. Suppose I could put some epoxy in a syringe and pump it in the hole from outside? Then put a sticker tape to the hole to prevent the epoxy from dripping out?

 

[31seahorse]

Did you consider using epoxy on the inside of the hull? Cut a piece of wood of reasonable size (2" X 2" perhaps) and epoxy that over the small hole area. That would approximate a backer plate in appearance from the inside.

Questions: (1) Are you two still friends following the "drill" incident? (2) Will he/she allow you to touch the boat?

 

[Rick Webb]

Syringe

Mix it on the hot side so it does not all drip back out. Epoxy has enough surface tension that it would probably not be an issue seems to me.

Or a stainless steel screw on the inside ground off on the outside and covered with epoxy on the inside if you can get to it sounds like that however is not an option.

 

[Ted]

How to patch hole below waterline

If you're not sure how much time you have before the patched gets wet, use G-Flex epoxy to make the repair. G-Flex will totally cure under water even if it is applied to the boat while it is still submerged. I would make the hole slightly larger to assure that the epoxy will completely fill the hole without any voids. Use a countersink bit to flare the hole on the inside and outside which will increase the bonding surface and create a "rivet" type of mechanical attachment too. G-Flex is perfectly fine to be used in an application where it remains submerged. It's an easy fix. Just follow the directions on the product literature.

 

[duality]

moe, larry, or curley?

 

[kloudie1]

No reinforcement necessary on something this small..I think Ted is right on ; flare/countersink the outside of the hole about 1/8" deep.. mix some G-Flex with a filler to thicken it a little then butter it into the hole and cover with a piece of duct tape to keep it from any possibility of dripping.. It can be fared and cleaned up at next bottom job.. I wouldn't make it much bigger! only enough to get to dry hull material.

 

[Steve Dion]

I would put some duct tape on the outside and spread the filler from the inside. Leave the tape in place and be done with it. The tape will fall off in due time.

Your local marine supply should have what you need.

Of course we do not know what materials are available in Singapore so good luck.

 

[finding41]

Here is a link to all you will ever need for fibreglass repair.
http://www.youtube.com/user/boatworkstoday?feature=watch
His videos allowed me to fix this small hole in the bottom of my boat. It started as a 5" crack.... Then was a 7x11" hole. Now you can't find it from underneath.

 

[Ken13559]

Did ...
Questions: (1) Are you two still friends following the "drill" incident? (2) Will he/she allow you to touch the boat?

Glad to say we're still friends. I did most of the maintenance repair and installations work for him ...free. So I guess I can still make one more hole before he cross me off his friends list.

 

[Ken13559]

If you're not sure how much time you have before the patched gets wet, use G-Flex epoxy to make the repair. G-Flex will totally cure under water even if it is applied to the boat while it is still submerged. I would make the hole slightly larger to assure that the epoxy will completely fill the hole without any voids. Use a countersink bit to flare the hole on the inside and outside which will increase the bonding surface and create a "rivet" type of mechanical attachment too. G-Flex is perfectly fine to be used in an application where it remains submerged. It's an easy fix. Just follow the directions on the product literature.

Ok, just my thought on the repair. see attached.

 

[Ken13559]

Here is a link to all you will ever need for fibreglass repair.
http://www.youtube.com/user/boatworkstoday?feature=watch
His videos allowed me to fix this small hole in the bottom of my boat. It started as a 5" crack.... Then was a 7x11" hole. Now you can't find it from underneath.

Thanks for the youtube link. Useful.

 

[petersea]

If there is core damage that will become a timely delay to repair correctly you can always install a thru hull assuming small area and space permits then cap it off. This will at least buy you time and stop any further damage to the core until you can haul boat for a more extended time.

 

[kloudie1]

Your repair looks perfect, Ken. I didn't know that you had useful top side access.. all the better! Something like this: http://www.westsystem.com/ss/six10-thickened-epoxy-adhesive/ would make mixing and filling easy..

 

[Ken13559]

Petersea, good idea to put a thru-hull, unfortunately its right at where the batteries sits.
Kloudie1, thanks for link.

 

[woodster]

Your repair looks perfect, Ken. I didn't know that you had useful top side access.. all the better! Something like this: http://www.westsystem.com/ss/six10-thickened-epoxy-adhesive/ would make mixing and filling easy..

man that is some good stuff ...just make sure when you order it you get some extra mixing tips for future use as it can be stored if you keep the little cap that comes with it ....

regards

woody

 

[Tree]

Here's what I'd do: Find a glass or tile drill bit 3/8 or 1/2 and lightly drill on both sides to turn the hole into an hour glass shape. Mix up some west epoxy and paint both sides lightly. Then add thickener to the rest of your batch till it's peanut butter thick. Take a little piece of wax paper and cut a circle slightly larger than the new external size of the hole and put that on the sticky side in the center of a two inch piece of duct tape. Then put a dab of the thickened epoxy on the outside part of the hole and then do your best to center the wax paper over the hole. Feather the epoxy out gently with your fingers and finish up with a single edge razor blade to fair it to the shape of the boat. Then do the same on the inside. After it sets up pull the tape off and the wax paper should come off the epoxy easily. On the outside, touch it up with a palm sander and dab on a little gel coat (you should be able to find a very small bottle of touch up gel coat of the correct color) You're done! Unless you want to then touch up with bottom paint to match the rest of the boat.

 

[Ross]

There is a very good epoxy putty that is sold in stick form and you just cut off a piece and mix the core with the outside and stick it into the hole like chewing gum and it will be thumbnail hard in ten minutes. Trim it with a sharp chisel and sand it smooth.