62-Racer Transom Help

[strick]

Good advice so far. I would epoxy one layer of biaxial on the old skin first and then with your core already pre made and ready next cabosil that to the still hot biaxial/cabosil on the old skin. Clamp that sucker in place so the cabosil gets squeezed out around the edges of core. I like 2x4's thru bolted into the transom then fillet all the voids around the core were it comes in contact with the hull. Let this all set up and then remove the clamps and start laying up the inside. I would use use biaxial and make the inner glass approx 1/4-3/8 inch thick. As far as how to work with large pieces of glass I usually cut it so it will drape over the transom and kinda hold itself up. Anyway you go about it it's still gonna be messy. I like to use OB sleeve (fingerless) with 2 latex gloves over my hands as that will keep the epoxy off your arms.




strick

[JohnB]

Be careful when you clamp/tie stuff down, that if epoxy gets on any of the clamps or through-bolts, you will learn exactly how strong epoxy is. This time, I put contact paper on the outer skin (had some laying around), and it was nice to not have to worry about spills/etc. I just peeled it of, and everything came off fine. Expoxy will soak through some of the masking tape that is out there, and you have to grind it back off.

[65Bowrider]

This thread has been incredible!
I still need to check to make sure the mat does not have styrine.
Otto - won't be ready for the job this weekend, so you're safe ... but hopefully by next weekend we'll have all the material & be ready.
Vinegar is a good idea ... Costco sells by the gallon.
Disposable suits is also good & cheap. Already picked up 100 latex/powdered gloves
And I have plenty of contact paper ... I like the idea of easy cleanup.
Strict - OB sleeve? I like the idea ... can I use the plastic bags newspapers come in? How did you protect the thru-bolts from getting resin on them & sticking?

We've heard of the technique of making huge clothespin type clamps & using about 6 to slide over the transom to push it all together. Using 3/4 ply approx 12" wide & long enough to reach the transom bottom & then notching out the expected thickness of Coosa & fiberglass layers. If it doesn't work, want to be prepared for the thru-bolt method.

Our total planned layer of construction is: on skin, 1.5 oz mat, 2 layers 1708, 1.5oz mat on Coosa, Coosa Board (clamp & let all set up), then 1.5 oz mat on inside Coosa, 4 layers of 1708. Let set up.
Hopefully that's enough to beef up for twin engines. (basic layer construction recommended by Hermco)
But he didn't provide a video of the "how to"... so all your tips have been tremedous and I really appreciate your taking the time to post & share. Thank you.

[JohnB]

I would find someone with expertise in clamping the coosa, and do what they did. I came close to using coosa, but went with plywood on the last one. I think that stuff has more flex to it when you clamp then plywood. Also, I don't think it has the compression strength that plywood does. I got away with clamps on the top, boards through the bracket holes, and then a bizaare seriese of bolts and boards through the drain plug. I don't know, but my guess is you will need a little more clamping contact area with the coosa.

[htillman]

I used a layer of 1708 then Coosa. Then two layers of 1708 and then extra tabs of 1708 in all corners. A layer of woven roven will be applied over all this. Plus I added some additional knees in the bottom made out of the Coosa material.
When I removed the old plywood transom. There was only a layer of woven roven, the plywood glassed directly to the skin.

[strick]

Sorry Carla OB is short for Obstetrics. I can send you some if you PM me with your mailing address. It would be easier then trying to use plastic bags. The bolts should pound out with a hammer and punch. You can coat them with wax if you want but I have never had a problem removing the bolts. The more I see that 21 hull the more I like it.

strick

[65Bowrider]

I've sent of an inquiry on clamping Coosa & hopefully will get a reply.
Stick - I thought those sleeves might have something to do with your "paying" profession. The disposable suites have sleeves, so I should be fine...thank you for offering.

Standing next to the 21, she is impressive & the sheer lines awesome ... you should have one!

[65Bowrider]

The transom is DONE ... yea!
I've learned so much on this forum, and understand why "others" say ClassicSeaCraft forum is the BEST!
Thanks so much for all the tips ...
Thanks to Dan of FIBERGLASS1, here in North Palm,Fla and a Special thanks to Denny (Bushwacker) for ALL his help !!!
Now for pictures ...
Dan came & joined us on the first day of laying 1708 to show us all the how-tos and how-NOT-tos...


First 2 layers of 1708 glassed on the transom ... then added another 2 layers.


Coosa Board dry-fitted to transom ... holes drilled in Coosa to allow air escape & cabosil to ooze out.


Our clamping system ... actually worked well! Fitted over transom, then shimmed tight. Skip & Denny cleaning up extra Cabosil mixed with glass bubbles, making nice radius.


After clamps removed


Transom shot, showing the raised transom (5" for twins) vs original height.


Denny & Skip busy laying another 4 layers of 1708, one at a time. I was in charge of all the mixing and keeping them supplied with their different mixtures.


All done ... end of day & tired.


Just one more of the transom ... "a good plan is when it all comes together nicely"
The middle dip needs a little work... but made it such that a 30" shaft single engine can fit there if so desired.


I've been playing ... making circles out of strips of 1708, with thickness from 1-4 layers ... good test for how many layers vs how stiff.


Next ... stringers.

[strick]

Looks like a great job! Solid as a tank. I like how you are planning ahead with the possibility of a single 30 inch or twins.

Question: what is the transom height in the middle (for the 30 inch motor) if you were measuring from the outside of the boat from the keel up to the top of the transom.

strick

[thehermit]

NICE! Transom looks great. Looks like you have a lot of qualified help down there. So what is the plan for the stringers? Box fiberglass filled with foam?