Transom rebuild in a '73 cruisers with seacast

larboc

Seaman
Joined
Jul 26, 2001
Messages
61
The bottom of my transom is shot in this boat, way too hard to split the deck to get access from the top and full inside access so I'm filling it up with seacast. I already went in through the I/O hole and used an auger bit to remove the wood in the center section of the transom, but the outer sections are angled enough that I can't get a bit in there. I used a pressure washer to blast out the trim tab holes and they are all connected (entire bottom of all transom panels are rotted out and gone). Original plywood was 3/4". The crack at to bottom of the I/O hole is of moderate concern, however I think once there is something solid behind it, it should be okay after getting vee'd out and filled with epoxy/csm.
PSA, a 15hp pressure washer with the single stream tip can delaminate fiberglass if you hit an existing hole.
kzGBTME.jpg


tNG8bq8.jpg

UEsUjRG.jpg

Zxp6Ybq.jpg

wFbUSEu.jpg

WXkA1wL.jpg




I was using this boat last year with no signs of issues, but when I was getting ready to float it this spring I noticed the crack at the bottom of the I/O.

The center section around the IO was 3/4" plywood, everything outward of that was 1/2" wood (balsa?) endgrain, as is the bottom of the hull. Looked like they took a 2x4 of balsa and cut it into 1/2" slices and stacked it in, then fiberglassed over. I guess it's a common wan to do it and the theory is that the resin seals the end grain so it won't rot if exposed to water. Turns out that's total B.S.

Bhh8ZXC.jpg

zFgBlzH.jpg

QkBaKTm.jpg


The transom inner skin is turning out to be a major PITA to get out where the core is still good. I'm having to cut it into a lot more sections than I wanted so it may end up getting a completely new inner skin rather than patching together 10 pieces.
A 12" long sawzall blade is so far working, then the pressure washer blasts the wood off the fiberglass. I tried cutting the wood with the pressure washer but it isn't really any faster than the sawzall nor does it allow for larger sections to be removed.

My plan now to get to the hard to get to areas of the upper outer transom is to drill a 1/2" hole through the corner off the hull from the outside with a long ship auger bit and start grinding away. Any suggestions appreciated.

Already ordered $1200 worth of seacast, fiberglass, spacer blocks, and biaxial.

I'll get the transom done and then I'll need to figure out how to fix the bottom of the hull where the balsa core rotted away, they make a self leveling product that I think would work for that.

Somehow the stringers are in really good shape except for some cracking at the back of the port stringer where it was probably fatigued from the loose transom. No rot some how.
 
Top