Morning all,
Apologies now, I like to be descriptive...
I was out sailing solo last week and happened to step on the wooden cover for the OB well. (I'm making an uneducated but logical guess here that it IS the outboard well) CRUNCH as I fell sideways. All was good with me however my foot had broken the cover completely in two. I was glad it wasn't my son or wife spraining an ankle or worse No surprise, it was a rotten mushy mess on the bottom side, poorly prepped for a life of being wet! Currently making a new one (penetrating epoxy + suitable paint).
I noticed the well was half full of water (rain water?maybe)
Bailing the water out & I suddenly see bubbling water filling the well (she's SINKING! my first thoughts ). Jamming my finger in the hole on the floor of the well stopped it . Once the well was half full, it stopped coming in.
QUESTION: I'm guessing this is not normal and that ' hole ' is a through hull fitting that should only be one-way from the OB well to the sea, is this correct?
Many thanks in advance..

An outboard well is just that- a sealed hole through the boat that the outboard is fitted into. It is normally full up to the waterline level. Sounds like you have a different engine type or mount, and the well was partially covered over to reduce the drag. A hole in the bottom of a blanked-off well is often necessary, because on many designs, the well is also the cockpit drain.

I made my own OB well in a yacht that had a diesel engine previously. Like any well, if the surrounding parts are sound, strong and the epoxy joins everything and excludes water, then you're fine. I haven't sunk yet in the past 6 years and it lives on a swing mooring. The bottom of my well is above the waterline by about 5cm.

It seems with your OBW that the waterline of the yacht is above the lower level of the well. As you accelerate the front of the yacht will rise up and the stern of the yacht will squat a little, and this depth will increase by a few centimetres. Also, it seems that the cover was made of timber and rotting. So, you need to make a new one. If the level of the OBW is below the waterline this cover's job is to smooth out the surface of the hole and prevent turbulence. As regards bailing out the water and bubbles appearing: maybe a small hole is there to allow the OBW to drain, and the bubbles are from turbulence. And putting your finger there stopped the level rising above the half-way mark which must have been the waterline. As to normality, as the boat travels over waves, the water will surge into the well, and then drain back out of the well. Just relax.
Given that the cover plate is underwater most of the time, it needs to be soaked in penetrating epoxy and it needs to be heavier than water, or is pushed downwards somehow, so it doesn't float upwards.
Some photos can help explain what is happening, and we can tailor our answers better next time.

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Yara said..
An outboard well is just that- a sealed hole through the boat that the outboard is fitted into. It is normally full up to the waterline level. Sounds like you have a different engine type or mount, and the well was partially covered over to reduce the drag. A hole in the bottom of a blanked-off well is often necessary, because on many designs, the well is also the cockpit drain.

I see now, many thanks Yara. I was a bit worried for a while there. Yes it's the cockpit drain AND the outlet for the manual bilge pump.
Cheers,
Mark.

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FabulousPhill said..
I made my own OB well in a yacht that had a diesel engine previously. Like any well, if the surrounding parts are sound, strong and the epoxy joins everything and excludes water, then you're fine. I haven't sunk yet in the past 6 years and it lives on a swing mooring. The bottom of my well is above the waterline by about 5cm.

It seems with your OBW that the waterline of the yacht is above the lower level of the well. As you accelerate the front of the yacht will rise up and the stern of the yacht will squat a little, and this depth will increase by a few centimetres. Also, it seems that the cover was made of timber and rotting. So, you need to make a new one. If the level of the OBW is below the waterline this cover's job is to smooth out the surface of the hole and prevent turbulence. As regards bailing out the water and bubbles appearing: maybe a small hole is there to allow the OBW to drain, and the bubbles are from turbulence. And putting your finger there stopped the level rising above the half-way mark which must have been the waterline. As to normality, as the boat travels over waves, the water will surge into the well, and then drain back out of the well. Just relax.
Given that the cover plate is underwater most of the time, it needs to be soaked in penetrating epoxy and it needs to be heavier than water, or is pushed downwards somehow, so it doesn't float upwards.
Some photos can help explain what is happening, and we can tailor our answers better next time.

Thankyou Phil really appreciate the extended reply to my question, it's helped alot and you're quite right: photos will help! I didn't even think about that. Next time I'm out on the boat will take some pics of it.
The OBW on my Thunderbird was different, it was in the lazarette and had nothing draining into it. There was only a small amount of water in there despite it being just under water level, and access to the water was gained by lifting up a small ' door '. You learn something new everyday
On the next haul out, I'll be investigating the door/flap on the bottom of the well, fingers crossed its not like the OBW cover on the cockpit floor I broke! I've just made up a template for that, back out on the boat Tuesday to make sure it fits then 1 or 2 coats of penetrating epoxy, 1x standard epoxy then a few good coats of white external paint+ anti slip coating. It should outlast me
Thanks again for your answer, much appreciated

I don't really do penetrating epoxy - it is just epoxy with extra thinners and not required. I glass all external plywood to stop checking. If you want a piece of ply to last well then sheath it in 6oz cloth. To do the edges cut little strips of cloth 50mm wide at 45 degrees to the strands. It will accordion a lot if you pull it, but will wrap around the edges of the ply too. Rout the edges to get the glass to wrap around.

I love ply but never leave it bare externally (internally is fine with 3 coats of full (not thinned) epoxy), epoxy without glass is not enough (and I use a lot of epoxy). Don't buy epoxy from Whitworths and don't use everdure (expensive) I use these guys.

trojanfibreglass.com.au/product/500-series-epoxy-laminating-resin-51-2/

cheers

Phil

I agree with Phil. That trojan epoxy is good stuff too.

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Kankama said..
Don't buy epoxy from Whitworths and don't use everdure (expensive) I use these guys.

trojanfibreglass.com.au/product/500-series-epoxy-laminating-resin-51-2/

cheers

Phil

+1 for Trojan

Trojan, haven't heard of that brand but I will give it a go thanks heaps!
Personally I've used Bote Cote in the past with good results, can't fault it yet.
I try to stay clear of Whitworths unless it's an urgent buy as the Drummoyne shop is located on the way home from my mooring. It's rather convenient some days, but I mostly let my fingers do the walking (I'm sure we remember that jingle )

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Kankama said..
I don't really do penetrating epoxy - it is just epoxy with extra thinners and not required. I glass all external plywood to stop checking. If you want a piece of ply to last well then sheath it in 6oz cloth. To do the edges cut little strips of cloth 50mm wide at 45 degrees to the strands. It will accordion a lot if you pull it, but will wrap around the edges of the ply too. Rout the edges to get the glass to wrap around.

I love ply but never leave it bare externally (internally is fine with 3 coats of full (not thinned) epoxy), epoxy without glass is not enough (and I use a lot of epoxy). Don't buy epoxy from Whitworths and don't use everdure (expensive) I use these guys.

trojanfibreglass.com.au/product/500-series-epoxy-laminating-resin-51-2/

cheers

Phil

Thankyou Phil, much appreciated like you I also make sure all wood in an external location is properly sealed. And interior wood for that matter. ' piece of mind ' rather than piece of rotting wood
Cutting the shape out today & hopefully will have it finished in time to get the family on the boat to watch the Sydney to Hobart race

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Lazzz said..

Kankama said..
Don't buy epoxy from Whitworths and don't use everdure (expensive) I use these guys.

trojanfibreglass.com.au/product/500-series-epoxy-laminating-resin-51-2/

cheers

Phil

+1 for Trojan

Just checked them out, I'm impressed (and they're Australian too which is even better). Definitely going with Trojan from now on, looks to be a top notch product and it's actually not super expensive