1973 22-2 Transom modification

[c master]

I have 4"long crack in the corner of the transom opening.  I am repowering from twins to a single 150 4-stroke, and it's been strongly recommended that I rebuild the transom, filling in the low "notch" in the center, filling in all holes, and taking the transom to 25" all the way across.  I have a highly regarded fiberglas shop that can do the work.

Filling in the 20" notch means that a 25" shaft will work, and the additional 5" should keep the aft floor drier, minimize splashes, etc., especially losing around 200 lbs (net).

Question:  Can the wood in the transom be dug out without removing the inner or outer layer of glass?  Or is it better / cheaper to just cut off the outer skin, remove the wood and add Coosa or equivalent, then replace the original glass?

The thru-hull transom drains are an issue, right?

[RickK]

One way to do it is to use a chain saw with a 20" bar. It is the easiest way to dig out the old coring.
Where exactly is the crack? Inside or outside?

[c master]

The crack is outside, on the starboard side of the transom cutout, originating from the upper edge of the "cutout", going to starboard about 4"   It is only on the out 'face' of the transom...not across the top edge.  I wish I had a photo but I'm nowhere near the boat right now.

I know the wood is damp toward the bottom, so eventually it will need to be replaced entirely.  Adding a $16000 motor is do-able, but also spending $10000 to build the full height transom is a little beyond my budget...although I'd probably add a lot of value to the boat.

[RickK]

Is the crack about an inch down from the top and follows the top? If so, that crack is usual.  The liner inside the boat comes up the front of the transom and comes over the top of the transom.  Over the years the crack appears - I would say most of the Ospreys had this problem.

This is what the crack on mine looked like.  It really isn't structural, it's just covering the top of the transom core.  Most people just seal it with caulk.

 
When I rebuilt my 170 I cut into the top of the transom - the crack is usually seen just at the top of the wood core.