1975 SF 18 going under the knife.

[chuckcallahan]

Purchased this ‘75 a few months back and have been stripping her down and doing some probing.

The plan is: Replace the transom, those core samples can really smell! This will be replaced with Coosa. Not looking for a full transom, just raise it some, to ease the following-sea pucker factor, suggestions please. Then I would like to raise the deck, and re-core with Nida, somewhere around 2” graduating down to 1” closer to the stern. New 50-gallon tank moving it forward some. Rewire, re-hose, then new deck hardware and finally paint with Alexseal.

The engine per my mechanic, a 2000 Johnson 115, is good for at least a couple of seasons so that will remain as is for now. Picture is of the day purchased. Boat is in decent shape, except for the transom and what maybe lurks below deck? Hopefully no major surprises. But most know how that goes. I will try to post often with pics and look forward to critiques and suggestions from the abundance of knowledge that resides in this community.

My first question. Is there any advantage or disadvantage of going with a single, 1 ½" Coosa board vs, (2) ¾" boards for the transom?

[uncleboo]

Might I suggest reading my 'Deck replacement' thread. Mine was built in 75 and I think many of your questions will be answered. Regarding the choice of transom coring thickness, I used the 1-1/2" in a single layer. Albemarle Boats uses 1 layer in the transom of their 29'er and they hang a bracket and twins on it! As far as raising the transom, almost every boat I have ever seen will allow at least 2 additional inches of freeboard due to the mounting height of the motor, (i.e., raise it to 27" minimum). Keep us posted.

[steel686]

Great to hear it. Look forward to seeing your progress. I just finished the rebuild and repower of my 75. I went with 26.5” on my transom and could have gone another inch easily. AV plate is only 1.25” above keel and may move up. I think 2” seems to be optimal from all the results I have read. Transom was cored with 1.5” Airex. I have a few hundred pictures I would be happy to share as you move through it. Keep posting...I need some winter reading.

[chuckcallahan]

Uncleboo, I have read your post and picked up a lot of good info. I have been the dude who recently pm'd you with questions. Last was about gunwale removal.


Steel, I will take you up on the extra pics offer at some point. I have enjoyed the post about your restoration journey as well, great documentation.

Thank you both, and have a Happy New Year!

[dirtwheelsfl]

You can do alot more with 3/4” leftovers than 1.5” leftovers...

[strick]

Originally Posted by dirtwheelsfl

You can do alot more with 3/4” leftovers than 1.5” leftovers...

This is a great point as you are sure to use the coosa for other projects during the refurb.

strick

[steel686]

That is a great point. It saved me a step in the layup/glue up but now I have an expensive 12” x 8’ rip that I will trip over for years. If I did it again I wouldn’t be afraid to laminate 2 layers and maybe even layout some areas to overdrill and fill ahead of time.

[chuckcallahan]

Very valid point. First potential mistake avoided! This forum is awesome.

[uncleboo]

That is a good point! I had originally planned on using the extra 1-1/2" for raising the deck and to create a support under the deck in front of the console. I had approximately 2 square feet of material left shaped such that I couldn't use it anywhere, (slivers).

[chuckcallahan]

Making progress. Transom is close to 100% removed. Questions for the installation of Coosa, 2 ply of the 3/4"

1. Is it better to use PE and CSM to bond the two plies? Epoxy will be used for bonding the transom skin and the Coosa.

2. Any advantage or disadvantage of bonding the two Coosa plies together prior to installing? I am thinking as long as the dry fit is correct for both, bonding prior to, would not be an issue.