Transom building questions

[Alan]

Hello to all;
Anyone got time / inclination / experience they want to share on building a transom?
This is not one of those easy ones that are looking right at you. This one is fully buried in my old 19′ Lund runabout. Major surgery.
I think I have a plan but would love to have it reviewed by someone with experience. The lumber and epoxy will be expensive, and the labor is a minor nightmare.
But this is a motor forum, and don’t want to be a bore.
Many thanks;
Alan

[joecb]

Pictures would be helpful.

Joe

PS, an old saying … “If man put it together , man can take it apart”

[billw]

Usually the whole deck has to come off to do it right; but I have a feeling you know that already. I did a 20 foot Seacraft one time. It was a stern drive so I was able to clamp the outer glass to the new plywood by using C clamps through the stern drive hole. I don’t know how it’s done with an outboard transom. I am sure somebody here will.

Long live American manufacturing!

[crosbyman]

are we talking glass…or aluminum ??

in any event this book provides solutions…

https://www.amazon.ca/Runabout-Renovation-Find-Fiberglass-Speedboat/dp/0071580085

Joining AOMCI has priviledges 🙂

[Alan]

Replies appreciated.

I think I can see my way through removal and installation, (although it’s not out yet, after three hard days!)

But I’m no woodworker, and will be happy for any guidance.

I’m tailoring plans I see on (https://www.boatdesign.net/threads/replacing-transom-on-aluminum-boat.36711/).

In short, I’ll use three layers of 1/2″ marine plywood, each coated twice and allowed to cure, then bonded with more epoxy plus hardener and fibers.

Thinking of using WEST systems 105 resin and 206 slow hardener. Working conditions will be about 80 degrees and low humidity.

The plans say to bed the finished transom into the boat with more epoxy. I try to work with the, “next guy” in mind, but I like the idea of strength. Opinions?

I don’t want to drill mounting holes over-sized, fill them with resin, and then redrill. I can see why this is good, but I’m not sure about the long term health of two dissimilar materials under stress. Do I need to rethink this?

Any special blind or, “pop” rivets needed? They look like the ones I’d get at the local hardware store. It’s a 1969 Lund Aluminum, 19’…

OK; please pick this plan over mercilessly and let me know how I can improve.
I very much appreciate the support, as I head out to fight with it on day #4, just the get the old one out.
Alan

[Bill Roth]

Alan,

Take a look and these YouTube videos. They should help you with your project!

https://www.youtube.com/results?search_query=how+to+install+a+new+transom+in+aluminum+boat

Bill in Minnesota

[kerry]

I have heard (not confirmed) of people using a chainsaw to (CAREFULLY) get the bulk of the old wood loose, and torching a piece of rebar, beating it with a sledge, making a long chisel to remove the rest. Not my first choice, but boats are built so differently it may be an option to “last resort”. A safer option is a long drill bit and a shop vac. Resin coating the bolt holes is proper, dont overthink it- just do it. Marine sealer on the bolts as they go in is also good insurance.

If you have too many, AND not enough, you're a collector.

[crosbyman]

these should also help you chip away at it….. after you drill in a few holes vertically…of course 🙂

https://www.homedepot.ca/product/diablo-12-inch-carbide-pruning-and-clean-wood-cutting-reciprocating-saw-blade/1001104622

Joining AOMCI has priviledges 🙂

[Alan]

All replies very much appreciated!
Yeah, I can see using a chainsaw for removal. Home made chisel? That too. It was an epic battle, but it’s out. I was glad to keep it mostly intact for a pattern Got Dad (w/ 60 years of carpentry experience) to cut out the layers yesterday.

I ended up using a 2 ton shop crane, lots of WD-40, and a thin bladed machete to slip down and free the wood from the corroded aluminum. The machete was great for this. Still was a 4 day fight!

I’m still debating; do I epoxy the new one in place when I install?

With care, this new transom should last decades, (Fresno CA is mostly hot and dry). And after 30 or 50 years, I’d think the epoxy would have deteriorated.

I very much appreciate the support.
Peace.
Alan

[outbdnut2]

You probably already know this, but don’t use waterproof-treated wood. The green treatment chemical, placed against aluminum, will corrode the aluminum.
Dave

[Author]

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