Sears/Alumacraft 14' transom panel

[loose rivet]

About a year ago I was given a 14' Sears row boat which appears to be identical to and made by Alumacraft.
The last owner had a 40hp Gale on it, which took a toll on the transom panel. Upon removing the rotted wood, I can see where the smaller inside panel has indented the transom quite a bit. There's crease about 15" long about mid way and the outer plywood panel has taken a curved, permanent set.
What I'm thinking about doing it making the inside and outside panels the same size.
Basically I'll cut the outer panel to stock size, then cut the inside panel about an inch taller to bring the wood to the very top flush with the transom. I'll wrap the very top with aluminum incorporating a clamping pad in the bent inside metal.
I'll be using pressure treated 3/4" plywood since when this is in the water, the lower half of the outside wood is submerged. I'll drill, sand and epoxy coat the plywood and paint the transom panel in and out to help protect it against corrosion from any thing in the wood. The plywood has aged about 4 years in the garage, so it's pretty dry too.
I'll replace all the rusty hardware with stainless Bolts, washers, and Nylock nuts sealing all holes with 5200.
My guess is that this panel will outlive me.

No, I won't be running the 40hp on this. I can't even imagine what it handled like. Amazingly there's no other damage or leaks. At best it'll see a transom trolling motor or my 9.5hp Evinrude. (It's rated at 20hp on the plate.)

 

[oops!]

Re: Sears/Alumacraft 14' transom panel

dont use pressure treated wood....it will cause a gavlvanic reaction in the tin....

if you put a barrier between the wood and tin you could....but all the more to interfere with a simple transom job.

the rest of the plan looks good....

lol....a 40 on a row boat....geez !

 

[jasoutside]

Re: Sears/Alumacraft 14' transom panel

Yah, no pressure treated like oops said there.

Have ya got some photos of what you are working on there? I'm scratching my head on the "submerged" part eh.

Yup, your Evinrude will be a much more comfortable match for your rig

 

[jigngrub]

Re: Sears/Alumacraft 14' transom panel

Hey LR, I understand what you're doing with the PT plywood. How many coats of epoxy and how many coats of paint do you plan on using? Since the wood is nice and dry it should suck up the epoxy well, and sealing the holes with 5200 should help protect your aluminum.

Normally the advice is no PT lumber in an aluminum boat, but it sounds like you have a good isolation plan and you're familiar with the hazards and consequences of what you're doing.

Post up some pics of what you're doing so we can take a looky-see.

 

[loose rivet]

Re: Sears/Alumacraft 14' transom panel

The PT plywood is older marine ply, it was left over from a job some time ago. I cut and sanded the pieces, oversized the holes a bit, then coated the wood with a coat of sealer/stain which gave it the color or teak, and then 6 coats of clear epoxy. The last coat is drying now. I also primed and painted both sides of the transom aluminum with self etching primer and four coats of argent silver enamel.
If any part of the wood ever touches the hull directly or causes any corrosion, chances are it won't be in my lifetime.
Besides, its CCA treated wood not ACQ, which is not nearly as corrosive. I'll get some pics once I get back to working on the boat.
The transom panel on this thing is only two small 10" wide panels, with the original inner panel being only 4x9" or so. The new wood will be the same size inside and out, with the inner panel going all the way down to the lower set of bolts.

When this boat is afloat, the transom panel on the exterior, also 3/4" ply, is submerged part way. They use the wood to give the transom all vertical support. Otherwise its just a single layer of aluminum with a rolled top edge and some minor impressions for strength. There's a 3/4" wood panel on both sides of the aluminum transom both are through bolted from the factory with 1/4" screws and claw nuts on the outside. I plan to replace the hardware with SS carriage bolts and Nylock nuts with SS washers. All sealed with 5200 sealer.

 

[jasoutside]

Re: Sears/Alumacraft 14' transom panel

If any part of the wood ever touches the hull directly or causes any corrosion, chances are it won't be in my lifetime.

Based on what you've done there, I'd totally agree.

 

[jigngrub]

Re: Sears/Alumacraft 14' transom panel

CCA plywood is da schnizzle for aluminum boat work!

My decking and transom are CCA from the factory.

 

[loose rivet]

Re: Sears/Alumacraft 14' transom panel

Once all the epoxy was dry and the panels were ready to install, I decided to go one step further. I was going to just make an aluminum plate for where the clamps contact the wood but I had a roll of 1/16" thick PVC sheeting which we used to use for air dams on the race car. The stuff bends and folds like sheet metal but don't dent or degrade with age.
Once the panels were fitted to the boat, I folded a piece of PVC over the entire outer panel and half way down the inside panel. This protected the open top edges of the two panels. The over all thickness was increased but no so much that a trolling motor or outboard won't fit.

I sealed all holes with 5200, all bolts, and all threads as well. I then coated the inside nuts with 4200. It probably wasn't necessary to seal the inner nuts but I wanted to make sure no water could seep behind the washers or nuts into the holes in either direction.
Both the inner and outer panels ended up with 7 coats of epoxy.
I'm sure this was WAY overkill for a 14' row boat but I hate doing things twice. My next plan is to polish the boat to get rid of the 80 or so decal outlines all over it. The former owner had a decal from every brand of tackle, every magazine, and every park he could find all over the boat. It took me all day to remove all the stickers and glue and to get it to an acceptable state of polish so far. I figure tomorrow if the weather cooperates, I'll take the big buffer to it.

One part of this that concerned me is that the combined width of the transom panels, aluminum transom skin, and plastic still don't make the outer panel level with the rolled top of the transom on the outside. The original transom panels were 5/8" ply on the outside and a narrow strip of 3/4" ply on the inside only where the motor clamps.
If I built up the outer panel enough to be level or flat with the upper rolled edge of the transom, I'd only be able to get maybe 1/4" panel on the inside. I have three of these boats, all are the same way from the factory. With the way these are built, with no knee brace, I felt it needed two full length panels top to bottom The result is a transom that don't budge. Before, the transom was creased across the middle just below the inner clamp panel. Partly due to the lack of support, partly due to the 40hp the last owner had on it. As you can also see, about 1/3 of the outer panel is always submerged when in the water, especially with my 300lb self and a 125 lb motor.
Of course, more than likely this won't ever see a gas engine, it'll most likely be rowed or end up with a saltwater transom mount trolling motor for crabbing.

I attached a few pics of the transom panel installed.