New Transom Using Seacast
 

A new transom for CJ ...
Skip and I have just replaced our original wood transom on our 1966 Bowrider with Seacast.
I thought I would share our findings, experiences and process, in case anyone is considering a new transom for their boat.

We chose a pour-material because 1) cutting from the inside would have entailed too much work cutting and re-attaching the engine well and 2) really didn’t want to cut the outside skin either.

In summary, Seacast is a pour-able substance with fiberglass strands. It is heavier than CoosaBoard, but lighter than plywood with multiple FG layers. It is strong, drillable, tap-able, will never rot, and floats. For more detail & specs, check out their website.

Approx 3-4 days
Step 1, removed all hardware, then removed the cap to the transom with drummel tool
Step 2, tried to use long drill & drill holes in the wood from the top. Too solid, so step 3.
Step 3, used a chainsaw & cut wood out, used long-handled chisel to finish cleaning inside skins. All wood must be removed.

Approx 1 full day
Step 4, prepped transom, putting tape over holes, putting plastic on everything else we didn’t want slopped with the Seacast. I used masking tape for the plastic … should have used duck tape around the edges of the pour area. The masking tape just broke before it lifted off the overflow of Seacast. Also made drain hole plugs wrapped with saran wrap to keep Seacast from filling the hole.
Step 5, bracing the transom to maintain its shape. Added Seacast spacers between skins. Used the 4 engine bolts and 2-2x4’s to brace the outside of the transom. Used scrap plywood & 2x4s to brace inner skin too.
Step 6, make funnel to pour the very thick (like chunky oatmeal) into the 1.5” transom opening.

1 day with a 3 hour break
Step 7, mix and pour 5 gals, then mix & pour another 5 gals. Max 10 gals per pour, then must let it cure, and it does get hot. After 3 hours, it had cooled down and we were able to finish the last 3 gals of pour. As it’s poured, hammering on the transom with a rubber mallet releases air bubbles.

Step 8, cleanup of tools, easier once cured.

Step 9 will be to add an additional 2 layers of 1708 on the transom and over the transom cap. Then fair, sand, fair, sand and add some primer & paint. Then she’ll be done & better than new!

Thus far, we have been very pleased with the results and the support team at Seacast in answering all questions.

Overall, less than a week … not bad.
Here are the pictures .... !!!

"1 day with a 3 hour break"

I sure enjoyed the beer you offered and the fine company, during the "3 hour break"!!!! It's all in the timing, I show up while they are taking a break between the first and the last pour and enjoy a Corona!! Life is good!

You guys did a great job, you should feel quite proud!!!

Excellent timing Don - great post though, very detailed

NICE job Carla, and done on schedule too! I like Skip's plywood funnel! How come you sanded the paint off the transom? I'm guessing that where you're adding the extra glass? Using epoxy or vinylester for that? Jeff said that styrene will continue to escape from the Seacast for some time, so best to use poly or vinylester to avoid bonding problems between it and the glass. Denny

A nice matrix.

Nicely done as always,
Us

As a friend of mine used to say " well planed and well executed = a job well done"


Now... if you could get working that fast on the 21 you'd be done in a few years :D

"Now... if you could get working that fast on the 21 you'd be done in a few years"

Hummmmm.........you know Skip and Carla, he makes a good point!! :) :)

Thanks for all the possitive comments and encouragement.
Don, it was good to see you too and you're timing was perfect ... 1 beer & no work... we'll catch you next time... we have the 21 yet to do!

I wish we could move as fast on the 21 ... a bigger project and a bigger learning curve.

Denny, we are doing research on the bonding issue. We are epoxy people and that's what we want to use to wrap the transom & cap, leading into the engine well for securing it all very well. The exposed Seacast is small and may not be an issue. Running tests with epoxy soaked 1708 on a Seacast sample today ... let cure, then try to pull apart.
Hands on is the best educator.

Nice job!

How did you ensure the cavity was clean prior to the pour? One of the big concerns I would have is contanimation due to bar oil coming off of the chain.

Wow. What a creative solution to a common problem! I love the mental image of going at it with a chain saw.

Thanks for sharing, and let's hear how you finish it out. Makes me want to do another SC... well almost.