Transom Repair

jorgeinmiami · #1 08-01-2014, 05:24 PM

I am going to do my transom and at the same time raise it from 20" to 25"

I will be going from the outside and not use ply wood and use coosa or something similar.

My questions

What would be the best material to use?

How much of a lip do I leave around the area cut out to work with in replacing the skin of the transom back?

To get to the 25" transom what is the centerline measurement up from the bottom up to where the engine mounts?

Any of course any and all advise welcomed!!!

Thanks

jorgeinmiami · #2 08-04-2014, 07:33 PM

In between getting a house I bought to flip ready for sale I have not had much time to work on the boat.

Today I left early due to being rained out I had some time to cut into the transom.

It's not the worst I've seen here but it was bad, one side was just completely gone and fell to the floor and the rest was wet and rotten.

When I have some additional time it's grinder time and then order me a sheet of coosa board to replace the rotten wood.

I've seen were some have used a electric chainsaw to get out the part under the edges.

But how do you get the whole new piece into place or does it go in 2 pieces?

Anyone have a source here in South Florida?

DonV · #3 08-04-2014, 08:40 PM

Man I've seen that "rotten wood" visual on mine and it's not pretty. I poured my transom so I did not have to deal with the wood. If I did I would use two layers of 3/4' marine plywood or composite. I would then make a cardboard template(s) to fit in as tight as possible, so cover all the corners.This may not be the best way to do it, however I would place each sheet, front and back sheet, in the cavity in two pieces. Confusing I know. I would cut the sheets vertical at 80/20 right for one and 80/20 left for the other. You can then trim them to fit much tighter and fill all the gaps. Doing it in two pieces would enable you to wiggle the wood all the way to the sides and top....trial and error well before glassing. The middle of the transom would be solid 1 1/2" with the seams on opposite ends, one seam on the inside piece and the opposite seam on the outside piece. Lots of 1708 and epoxy resin and there will be no flex. As it is now you could never get a real tight end to end...top to bottom coverage with a single solid sheet of plywood. Confused?

jorgeinmiami · #4 08-04-2014, 08:45 PM

I think i got it thanks so then next is to take out the old wood then grinder which i love so much and then install new transom shkuld be done by tomorrow afternoon LOL
More like 2 weeks

Normagain · #5 08-04-2014, 09:15 PM

When I did mine I went 25 1/2" at the center line. I ended up on the third bolt hole which put the anti cavitation plate about 3/4" above the bottom of the boat. I am planning on trying one more bolt hole (only one left) because the plate is still a bit buried when running. If I were to do it again, would probably build to 27" at center line which would put the bracket almost directly on the transom top surface at the lowest possible mounting position, plate close to 3/4" above the boat bottom. I have a 1974 20' SF with the typical small flat surface rather than straight to v bottom. I knew from past outboard experience that the real measurement for a 25" shaft is closer to maybe 26 1/2" mounted but was warned not to do what I knew I should. Lesson learned. If your going to add any metal trim, adjust accordingly, would be nice if someone were to actually measure a 25 transom. Mine is ok as I do have probably enough wiggle room but I have a friend who has a bad habit of backing into the swell, lol.

jorgeinmiami · #6 08-04-2014, 10:09 PM

Thanks for the input I think 26 1/2 it is
I like the metal on top the transom but screwing it in just leads to water intrusion down the road so I probably will go without. I do plan to either re-install the factory splash well or a starboard flat splash well ....I do not back into swells

CHANCE1234 · #7 08-05-2014, 05:30 AM

Quote:

Originally Posted by Normagain

When I did mine I went 25 1/2" at the center line. I ended up on the third bolt hole which put the anti cavitation plate about 3/4" above the bottom of the boat. I am planning on trying one more bolt hole (only one left) because the plate is still a bit buried when running. If I were to do it again, would probably build to 27" at center line which would put the bracket almost directly on the transom top surface at the lowest possible mounting position, plate close to 3/4" above the boat bottom. I have a 1974 20' SF with the typical small flat surface rather than straight to v bottom. I knew from past outboard experience that the real measurement for a 25" shaft is closer to maybe 26 1/2" mounted but was warned not to do what I knew I should. Lesson learned. If your going to add any metal trim, adjust accordingly, would be nice if someone were to actually measure a 25 transom. Mine is ok as I do have probably enough wiggle room but I have a friend who has a bad habit of backing into the swell, lol.

I absolutely agree with this. I built mine to 25 as well and I need to raise one more hole too which is the last hole for me too.

rockdoc · #8 08-07-2014, 02:45 PM

DonV that is a great idea!

Steve

DonV · #9 08-07-2014, 03:10 PM

I think it would work from the outside quite well, which Jorge as doing. With a lot of "pre-fitting" it should work....especially with lots of his new best friends....fiberglass and fairing compound. After pouring Arjay when I did my transom I don't know if I would go back to wood ever again. I wish Jorge well and remember sand paper is cheap!

Capt Mako · #10 08-08-2014, 10:23 PM

Love it! If u were in mass I'd say back it in my bay and I would help u. I'm assuming you are just raising the transom height. That being the case my only experience is -w- a full transom so I would follow the advice of the sc guru's here. If u change your mind I'll shoot u the measurements and build images on mine. Good luck enjoy!