Stern exhaust fitting

[Scott T-Bird]

I'm increasing the diameter of my exhaust from 1-34" to 2" for our re-power. I purchased this Vetus SS fitting to go thru the stern. Our plan is to bore out a larger hole where the exhuast currently exits.

http://shop.sailboatowners.com/prod.php?16075/Stainless Steel Transom Exhaust Connections

That will destroy the glassed flange that was originally built for the exhaust to accept the hose on the inside of the stern.

All of the exhaust fittings that I could find seem to be made for a vertical stern. When we insert this fitting, it will have a downhill slant inside the stern due to the reverse angle of the stern. I'm concerned because I prefer to have a fitting inserted that will have positive drainage.

I'm wondering if I should form a sort of shim for the outer surface and form-fitting backing plate for the inside that will allow the fitting to be inserted to vertical surfaces.

Have others dealt with this issue?

 

[Sailvayu]

When i made some changes to my system last year I just glassed over the hole in the transom and came out the hull in the counter just below the transom. looks like you could do that as well. You could also glass in a new tube on a vertical or even slight down angle. Shimming the fitting is an option as well but you would have to do it inside and out if the fitting uses a inside nut. I would think a shim might add more potential for leaking.

 

[Scott T-Bird]

Thanks for that comment ... I wouldn't insert a new through hull on the counter under the transom because the boat squats when motoring enough that the exhaust would be submerged all the time. I don't like that because I find that when the boat submerges the exhaust, the exhaust tends to ride up the transom into the cockpit, rather than beign blown away from the boat.

... but ... what about the topsides next to the stern? Has that been done? The exhuast could be elevated slightly so it is free from the waterline and still angled down.

 

[Sailvayu]

The only problem with that is that it will still be underwater when heeling if motor sailing. Mine goes under as well but i do not have a problem with the exhaust following the transom back up (station wagon effect) Your transom is a bit larger than mine so that would increase that effect. Seems like glassing in a new tube at a down angle would be your best option in that case.

 

[tommays]

The Cal 29 always had a SS fitting in the hole with the four bolts and it is still in fine shape and caused no problems