looking for a better way to fix a leak in a board well

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MN3

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Posted: Jul 16, 2019 - 09:10 AM

I have a small leak in my centerboard well (usual spot for leaks)

it is in a spot that is gonna be really hard to access - requiring sanding via a 4' extension and even then, it is on a curved surface that i am not sure how i can actually scuff up well

i can just about reach the hole from under that boat but it's tough - and i don't really want to sand above my head for extended periods of time

the biggest issue is post cure - the epoxy is gonna be reallllll tough to smooth and it's in a tight fitting spot on the board well= any edge is gonna skuff up and possibly damage the board when it's moved into spot

any product like a 2 part pool epoxy i can reliable stuff in there that will last for years?
samc99us

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Posted: Jul 16, 2019 - 11:07 AM

These are tough problems, tight spots in the back of a board well..

The best approach I've found is to mix some G/Flex 655, and place in the known leaking area with a bent acid brush attached to a dowel rod. Apply vacuum to the hull if you are really concerned, it should suck the epoxy into the area.

The other option if its a really thin hole is the same approach but with raw West Systems or other epoxy. I find the G/flex a good option in board trunks though because its a tiny bit flexible and normally the trunks themselves are super thin glass that tends to flex a bit under load.
samc99us

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Posted: Jul 16, 2019 - 11:13 AM

Standard (unfilled) G/Flex 650 might be perfect...the thing with the 655 is it is filled just enough to prevent runs and sags which is why its pretty perfect for a repair on a vertical surface where a run results in nicked boards...
MN3

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Posted: Jul 16, 2019 - 11:25 AM

Good info Sam thanks

any suggestions for a cheap vacuum unit?
pknapp66

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Posted: Jul 16, 2019 - 11:45 AM

Do you have drain plugs in your hulls? I used a small shop vac on one of my H18's that had a leak in a seam
in the dagger well. Worked good to draw in the epoxy. Just had someone stick the vacuum hose over the drain
hole while I applied epoxy. Went quick and we did not maintain any vacuum after the epoxy was drawn in.

Thinking out loud you could install a vacuum gauge in a spare hatch cover to monitor how much you have in the hull.

Edited by pknapp66 on Jul 16, 2019 - 11:47 AM.

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Pete Knapp
Schodack landing,NY
Goodall Viper,AHPC Viper,Nacra I20
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MN3

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Posted: Jul 16, 2019 - 11:56 AM

i have drain plugs - used them to fill the hull w 15psi this weekend to find the holes (with soapy water)

i have a small shop vac - was worried it might suck "too much" (haha)
Dogboy

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Posted: Jul 16, 2019 - 12:36 PM

No way to internally access the hull? Getting a glass patch on the inside is going to be a much more reliable and permanent solution than using straight epoxy on the outside.

How bad is the leak? If you’re only talking a small amount, might be better off just leaving it alone and living with it (sponge out through an access port periodically if it really bothers you).

And on another note, wholy crap, 15PSI? I’ve detected leaks in boats by just blowing into the drain plug with my mouth. Surprized you did not damage the boat with that much pressure.

sm
pknapp66

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Posted: Jul 16, 2019 - 01:10 PM

I used the shop vac in reverse to find the leak with soapy water. You can remove the vac and kinda gauge
how much you are pressurizing the hull by the air coming back out of the drain plug.

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Pete Knapp
Schodack landing,NY
Goodall Viper,AHPC Viper,Nacra I20
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MN3

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Posted: Jul 16, 2019 - 01:24 PM

QuoteNo way to internally access the hull?

not without cutting an access hole on the bottom of my inner hull - that is not a good solution to me

QuoteHow bad is the leak?

couple gallons after 7 hours of sailing = too much for my happiness + if it gets worse ...

QuoteI’ve detected leaks in boats by just blowing into the drain plug with my mouth.

it wasn't 15psi of pressure in the hull - that was the setting on the compressor
i used a wet cloth around the nozzle and it certainly was not a tight fit
also 4 small holes in my deck prevent any real pressure (turning blocks for the centerboard bungee that were removed) - but noted: it doesn't take a ton of pressure to blow bubbles in soapy water
klozhald

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Posted: Jul 16, 2019 - 01:42 PM

There was a three way puncture in my Prindle centerboard well from a rock that got wedged inside. It was past my fingers up from the bottom. I laid the cat on its side, tied to the fence, so that the injury was facing up. I used paint stir sticks with sandpaper glued to them to rough up the area. Using Marine Tex, which is thick to go on and dries very hard, I applied it with another paint stir stick. A strong flashlight helped me make sure I got it as smooth as possible, then more sanding to keep it from scratching the centerboard.
My $0.02...
YMMV
Good luck!

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Sheet In!
Bob
_/)_____/)_/)____/)____/)_____/)/)__________/)__
Prindle 18-2 #244 "Wakizashi"
Prindle 16 #3690 "Pegasus" Sold (sigh)
AZ Multihull Fleet 42 member
(Way) Past Commodore of Prindle Fleet 14
Arizona, USA
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MN3

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Posted: Jul 16, 2019 - 02:05 PM

thanks for all the input

I have used wax paper on repairs before . - just as the epoxy or gel-coat kicks off i add the wax paper and smooth it out with my hand (or tool) - just not sure i can access this spot like this

QuoteI laid the cat on its side, tied to the fence

Bob, why did you tie your cat to the fence? afraid it might get loose? :)
klozhald

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Posted: Jul 16, 2019 - 02:31 PM

MN3Bob, why did you tie your cat to the fence? afraid it might get loose? :)

Truth be told, it has gotten away from me many times, but not so much in the back yard. I was taking no chances though!

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Sheet In!
Bob
_/)_____/)_/)____/)____/)_____/)/)__________/)__
Prindle 18-2 #244 "Wakizashi"
Prindle 16 #3690 "Pegasus" Sold (sigh)
AZ Multihull Fleet 42 member
(Way) Past Commodore of Prindle Fleet 14
Arizona, USA
--
nohuhu

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Posted: Jul 16, 2019 - 03:06 PM

QuoteQuote
I’ve detected leaks in boats by just blowing into the drain plug with my mouth.

it wasn't 15psi of pressure in the hull - that was the setting on the compressor
i used a wet cloth around the nozzle and it certainly was not a tight fit
also 4 small holes in my deck prevent any real pressure (turning blocks for the centerboard bungee that were removed) - but noted: it doesn't take a ton of pressure to blow bubbles in soapy water

Roger, Roger!

Any possibility that wax paper or sandpaper sheets could be taped to the centerboard (or a spare), to correctly shape and smooth this area?

It might help create the right clearance, Clarence...

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Prindle 18
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MN3

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Posted: Jul 16, 2019 - 03:34 PM

nohuhu
Any possibility that wax paper or sandpaper sheets could be taped to the centerboard (or a spare), to correctly shape and smooth this area?

It might help create the right clearance, Clarence...

Surely you can't be serious

PS superb idea! -
traphappy

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Posted: Jul 16, 2019 - 03:40 PM

I will offer two ideas that are probably both bad... But hey, who knows. First bad idea: Stand boat with bows up (yeah, easy to do, lol), dry thoroughly, sand, clean, and allow West System 105 to flow into gap. Second bad idea: dry thoroughly, sand, clean, smear West System 610 into the back of board well, build up the back edge of the daggerboard with tape, lube the hell out of it, then slide into the well. Hope you can get the board out. If you can get it out easily, then you'll be in the clear. Very important to evenly apply the tape so it slides out later.

Edited by traphappy on Jul 16, 2019 - 04:41 PM.
MN3

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Posted: Jul 16, 2019 - 03:53 PM

it's not in the "back" of the well
it is on the side (towards the inside of the boat)

looking down the well it is about 4" above the bottom lip (which has a gasket on it)
it is in a curved area of the well (i assume these curves are there for added strenght - the well walls are crazy thin like Sam mentioned above)

the curve area has a "bowl" shape to it (think of a 1/2 baseball) and it is inside the curve - that is where the real challenge is to sanding it is out of reach and in a spot that a flat item wont be able to get to

This image is looking down - the yellow strip in the middle is the gasket with a bunch of soap suds on it (this is from a phone video i shot while checking for leaks)
nohuhu

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Posted: Jul 16, 2019 - 04:38 PM

Will the area accomodate a small repair patch?

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Prindle 18
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MN3

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Posted: Jul 16, 2019 - 04:57 PM

i doubt it - if i can put that patch there i could put glass

the issue is really sanding it down afterwords
traphappy

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Posted: Jul 16, 2019 - 05:34 PM

Why not just do the repair, lube up the board, and put it in place? If lubed it should come out without issue.
samc99us

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Posted: Jul 17, 2019 - 08:47 AM

Ah yes. I've done this repair on the beach, but on an Infusion Mk. 2 which has more room to work I think than what you have there. Tip boat on its side and work from the bottom with the same technique I mentioned. I would try and get glass in there if possible, and traphappy's suggestion of a waxed up board is a good one.