Transom replacement on I/O

[abl1111]

When I did my transom - I made a clear cut across each hawsalls, port and starboard, unscrewed the cap from the hull - and removed the back piece of cap to access the transom. I removed the transom with a circular saw, flatbar, grinder, chisels etc. I ground it so there was no wood remnant left. One days b*tchy work.

I used (2) 4x8' pcs of 3/4" ply wood. I glassed them together with several layers of mat and held them together with 10 or so cinder blocks, tool boxes - anything heavy I could find - on a flat floor. You want 'ooze out all sides.

Then (2) of us held the plywood against the back of the transom and a third guy used a pencil and outlined the transom's shape - chines and all (w/ that back cap off, it makes everything easier ). With a circular saw and jig saw, cut the outline of the new transom out.

Then, we did a lot of dry fitting to tweak the new transom to fit.

When ready, we glassed it in - I don't remember the exact layup. I did have a guy make for me the equivalent of (2) HUGE "C" clamps out of 3"x3" box tube. They were 3 - 3 1/2' long and about 10" wide - 4-5, Large 'thumb screws', which were tightened with a wrench, were added to each side of the long sides of the C clamp to tighten down and squeeze the newly glassed in transom to the hull. I've seen guys screw the new transom and hull together at this point - which is easier than making the clamps I had made... However, the clamps worked great. After, the clamps were a gift to the fiberglass guy who mentored and helped me.

We filled in any voids with epoxy or Duraglass - then, smoothed all out and covered with mat and roving, being sure to overlap enough over the sides of the hull to provide good structural integrity.

It was a solid, professional job and I learned a great deal. 90% of my transom damage was from the transom cap fish box drains. They use a garboard tube and that area flexes A LOT. The garboard tube either rots or moves from its bed allowing drain water to flow into the transom - over several years - the transom is cooked ! The other was from the through bolts of the inner and outer transom plate.

My project was a conversion from a twin i/o to a single so it was more involved, but this is the transom portion.

Hope this helps you with your project.