’97 Starcraft Corroded Transom Repair using Pourable Ceramic

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CMOS
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’97 Starcraft Corroded Transom Repair using Pourable Ceramic

Post by CMOS »

Fantastic. =D>


CMOS
1982 Johnson 15 HP - in pieces, in progress
Currently boatless :(

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DaleH
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’97 Starcraft Corroded Transom Repair using Pourable Ceramic

Post by DaleH »

Thanks for the comments guys! It's been a long road, but I'm beginning to see the light, as the ...

Outside rear-most transom panel is ready!

And now I'm prepping the inside transom panel and supporting braces. The transom will be formed with 1-1/2" channel with the 2 skins or panels on either side. Across the bottom is the squared 'S'-shaped piece original to the boat, that Starcraft put in place to hold the bottom of the wood. This was stripped, cleaned, neutralized and then coated with zinc chromate and riveted back in place.

Essentially this structure will form a cofferdam that will be filled with the ceramic pourable compound. That main U-channel you see will have 3/4" holes bored all along the sides of the piece, not so much to lighten it, but to allow the semi-vicious (flows like honey or thick maple syrup) compound to not only weep through it, but around it and ALL over it to essentially mechanically LOCK it in place once the compound cures.

I'll have a hybrid transom, of aluminum outside and bracing, complete with a homegenous, synthetic compound that is totally impervious to rot or saltwater. Plus all internal aluminum will be encapsulated within it. I also plan to not cut down the height of the transom, as Starcraft had 3 heights across the stern ... full transom height, a step-down of 2" lower on each side for a good foot or more run to the center and then the cut-out height. I plan on leaving her full height, plus to narrow the OB opening.

Getting ready for the big pour :D !

P.S. - I will say either I got lucky or I'm good ... but I drew a centerline on my replacement transom piece and after riveting it permanently to the boat ... the line was not only square up and down ... but was deads nut on the money ... not even 1/32" to the left or right ... when I would have been happy with +/- 1/8" or so ... but she was dead nuts CENTERED 8) .
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DaleH
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’97 Starcraft Corroded Transom Repair using Pourable Ceramic

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Pour complete!

Well .. after a LONG delay due to pressing family matters, the transom is finally all poured ...

Once I had the area all fabricated, akin to a cofferdam if you will, i.e., a metal structure that formed a 'pool' that the liquid thickened ceramic polyester resin mix can fill (sealed for no leaks) then the entire process took less than 2-hours, maybe just over an hour, as I didn't really clock it. Plus I had a little emergency fixes to stop a small leak, just so I didn't get stuff all over the inside of my new transom.

Attached are the photos of the mix and the final result after pouring. We did not get any pictures taken of the pour, as well quite simply ... it is anti-climatic! Just mix the material and pour away!

Ideally this concept and product is NOT for everyone and only I chose it for my use on a boat to be used expressly in saltwater, as I already had to replace :shock: (not repair) the transom piece due to salt impregnating & permeating the unsealed wooden transom. Cost-wise it is more than good marine ply with epoxy coating. But the compressive strength is 7X greater than plywood, while being a tad more flexible and lighter in physical weight. As a bonus, it will never absorb water and is impervious to chemical attack once cured.

If it works ... there is also a video attached, showing the mix, where the viscosity is about that of a McD's milkshake.
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DaleH
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’97 Starcraft Corroded Transom Repair using Pourable Ceramic

Post by DaleH »

... video did not upload ...

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Johnny
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’97 Starcraft Corroded Transom Repair using Pourable Ceramic

Post by Johnny »

good job Dale. Glad you didn't have any problems or surprises.
https://www.tinboats.net/how-to-build-a-transom/
https://www.tinboats.net/varnish-vs-polyurethane/
All about Primers = https://www.tinboats.net/primer-and-paint-basics/
Paint, Thinners and Applications = https://www.paintingforpainters.com/

1959 Crestliner Commodore 14'
1958 Johnson 35 RDE-19 Sea Horse
1958 Johnson 35 RDS-20 Super Sea Horse

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DaleH
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’97 Starcraft Corroded Transom Repair using Pourable Ceramic

Post by DaleH »

Johnny wrote:Glad you didn't have any problems or surprises.
... had a little surprise with the hardening, but it all worked out in the end ... just took a little longer than anticipated.

Update:

Not the prettiest yet ... as my plan was to prime/paint enough to hang the OB motor ... but she's on and I'm getting her rigged and ready for her 1st test run with a new aluminum transom inside and outside ... whew!
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DaleH
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’97 Starcraft Corroded Transom Repair using Pourable Ceramic

Post by DaleH »

FWIW a few guys PM'd me and chastised me for not posting pictures of the final product whilst floating ...

Added the 60hp, flawless performance to 40mph
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Stumpalump
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’97 Starcraft Corroded Transom Repair using Pourable Ceramic

Post by Stumpalump »

Nice to see it in the water! Congratulations! My best buddy as a kid had a 16' Starcraft with a Merc 60. Well, his parents did but we had the keys and they let us have at it. It was a 1979 and it flew! What year is yours? Tin lasts forever so was well worth the work you did. =D> =D> =D>
1991 18' Valco Bayrunner Evenrude 48 SPL

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DaleH
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’97 Starcraft Corroded Transom Repair using Pourable Ceramic

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Stumpalump wrote:Nice to see it in the water! Congratulations!
Thanks :D ! It was much more work than I had planned for, so I'm glad I didn't pay a lot for her ...
What year is yours? Tin lasts forever so was well worth the work you did
This one is a '97. Besides the new transom, with the motor off, I tipped the hull up and checked every rivet for integrity, then cleaned the hull up really well, then coated everything on the running bottom w/ SteelFlex.

Well, no - not in the salt, as the saltwater environment can be BRUTAL on tin boats! On my '79 12-footer, unprotected (no prime, no paint, no anti-fouling) rivets started giving away due to oxidation. I lightly tapped against the rivets on the bottom this Spring and about a dozen rivet heads flicked off w/ zero effort. Luckily I now have the tooling/tools to replace them all. Next Spring I'll fix them all, then SteelFlex thst hull. As my boats are in the water 24/7.

KrazyAboutTin
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’97 Starcraft Corroded Transom Repair using Pourable Ceramic

Post by KrazyAboutTin »

Awesome job!
Thanks for sharing it