Upcoming Transom Redo
 

Not too surprisingly I discovered moisture in a baggy left in the sun with wood chips from drilling small holes in my 42 year old Seafari transom. Then while bouncing on the AV plate I measured about 3/8” deflection of the transom near the engine, between the upper and lower engine bolts. Flatness checks horizontally across the transom confirmed distortion and particularly compression of the transom at the bolts for the ETEC. Therefore with a few months of winter coming, I am planning on a transom redo.

As there are no cracks in the aft sheet of the transom and the boat is cosmetically pretty nice and doesn’t need a repaint yet, I will probably use a Seacast pour as done by Skippertee and others. The 20” transom with the Seamark splashwell tub made by Don Herman has served me pretty well. But with heavier (than the old days) guests sitting too far aft, the waterline is slightly above the splashwell drain hole allowing in a little water to coming over the transom at times. I could raise it to 25”-27”. However, due to misalignment of the mechanical steering cable that would drive me to hydraulic steering and complicate the Seacast repair a bit. Probably more later, but a couple questions right now. I have until April to contemplate and complete this effort.

1- Has anyone used the Seacast method and simultaneously raised their transom? How? I have some ideas, but surely there are some good tips among the CSCers.
2- With the raised transom was the splashwell drain hole and splashwell floor raised as well?
3- I am suspecting that those who raised their transom are happy with their decision. Were there any surprises?
Thanks all

Hey Terry, I did mine with Arjay and to this day I wish I had went to 31" on my transom. in hindsight it would have been easy to do. While I had the transom skin off I would have made sheets of fiberglass with five, six layers or so of 1708 cut it to fit in the old transom beveled the edges and glassed in in place. All you are looking for is a taller mold to pour in to. You are going to fair and sand anyway, which as we know is fun!! I found non-stick aluminum foil is the way to go when making a sheet of fiberglass, lay the foil non-stick side up, flat on plywood, pre-cut your 1708 and keep wetting and stacking until 3/16 to 1/4" thick.

Thx. Don
A good tip about making fiberglass sheets. Will save it!

When I am doing small sheets and I want them smooth or pre gelcoated, I start with a 2'x4' sheet of dry erase board from Home Depot for $10.
Wax it or spray PVA.
Spray gelcoat on it, let dry for a few hours (not several days!!!!! - I learned that lesson)
Lay up glass, put peelply on back (great bonding surface & no blush w epoxy, allows full cure w polyester or VE) and let harden
Pops right off and glass smooth (unless the wax or PVA is too thick/uneven)

Old sliding glass doors work great for making sheet glass.

My Transom Redo Thoughts
 

Thanks Moose, Mitch and DonV for your suggestions-
Right now I am leaning towards increasing the transom from 20” to 22” Why 22” and not 25”? In my 42 years of use, with a Hermco splashwell, and particularly only lake-usage now, the 20” has served me quite well. I only anchor from the bow and keep the stern towards the beach. I have about 2” of clearance now from the ETEC to the transom. A 22” transom with the splashwell drain plug installed, would provide more margin when the heavies are sitting in the stern at anchor. With 22” I can also keep my mechanical steering and avoid a 5” ETEC driveshaft extension.
The next step is building or locating an engine stand for the 418# ETEC.

Hey Terry

Get a couple of 2x6s and 2x4s with some nice HF casters, two 1/2" bolts with washers and nuts and you can make a stand in 45 minutes. Use 3" wood screws, easy to take apart when done. I've made four or five for motors up to 600#, no issues.

When I was replacing my transom, I planned on raising it 2-1/2". When I cut the core, I left an extra inch at the top with intentions of trimming it down to 2-1/2". Didn't get trimmed so I have 3-1/2" more than before. All is fine except the hydraulic steering fittings will hit if I try to raise it all the way. I have another inch to raise the new motor, (old one took a fatal crap), and that should correct that issue. You'll like having the extra height whatever you end up with.

Engine Cutout Trim
 

My ‘76 Seafari has extruded aluminum trim on the transom cut out. Has anyone found a similar replacement?

Glass it, dont put that crap back on

I glassed and faired mine as well.

That is where ingress of fresh water ruins transoms.
5200 is a friend here and not many other places.

Avoiding Transom Aluminum Trim
 

Thx Uncleboo, GFS and Chris for your comments on eliminating the aluminum trim on my transom cutout during my transom resto. There were some CSC suggestions on how I could make some fiberglass sheets to raise the transom 2’’. After seeing the "leave the trim off suggestions" I thought about temporarily forming the height increase with plywood or something, pouring the Seacast, removing the plywood and then wrapping the top and sides of the exposed Seacast with 1708 to get the bullnose appearance that Dirtwheels and Uncleboo have on theirs. Comments? Thx again guys.

Terry , I found aluminum flashing worked really good for a barrier with the Arjay. After the Arjay cured the flashing pulled away no problem and the finish was very smooth. If you use wood to make the form add the flashing and it will save you some work.

Thx Don, the flashing is a good idea. Are you suggesting my entire 2” high dam above the current transom could just be Seacast without fiberglass over it? The engine mount bolts would be lower and not in that zone.

No Sir, when you pull everything apart I would still put at least two layers of 1708 over the "raw" Arjay/Seacast. I would go more to the "lets overbuild this thing" side of the project. If you build your mold 1/8" less thickness of the final inside/outside measurement then you can add the 1708 and fairing to even everything out. Let's say your inside transom thickness is 1 1/2" and outside of the fiberglass transom is around 1 3/4" thick, you want to make you pour 1 1/2" and make up the difference to the 1 3/4" with glass. Make sense?

Yes DonV, makes sense and whst I originally expected. Wanted to make sure. Hoping to remove engine in the next couple weeks. Just thinking through the gameplan. Thx.

Yeah Terry, kinda one of those measure twice, or in my case four times and cut once!! Go in with a well thought out game plan and you'll be good!! :)

I also agree on the removal of the aluminum trim for the notch. The glassed top looks fine, and then there are fewer holes into the transom. That's what the fiberglass guy did on my Seafari when he raised the transom for me.

Hey Terry, he's the latest engine stand I made out of wood. Maybe it will be of help if you decide to make one. It's on casters and I could move it around easily. I had some extra wood so I made a few extra braces....just in case. The guy who bought the engine rolled it up on a trailer just as you see it, strapped it down and off he went.

Engine Stand
 

Thx DonV-
Your stand resembles what I completed a week ago. Awaiting good weather to pull the ETEC. Like jet engine or gas turbine design, nearly every new design relies heavily on its predecessor. Maybe I'll add that forward brace like yours.

http://www.classicseacraft.com/commu...pictureid=2921

http://www.classicseacraft.com/commu...pictureid=2920

Naw I think you're good!!!! You went above and beyond with metal corner brackets. My Merc was 505#, I used the same bracket for a neighbor's Honda which was 610#, I don't think your eTec will be up there. 3" wood screws are bad to the bone, take it apart, save the wood and you can use over and over.....cheap bastard I am.

Uncle Boo's Jackplate
 

Hey Uncle Boo-
Was going through this thread and printed out some of the great tips, when I saw your transom cutout again. Maybe it is the camera angle, but don't think I have ever seen such a thin jackplate. What is the depth of it and manufacturer?
Thx

Vance Mfg. It's a 3" setback.
https://www.vancemfg.com/searchresul...etback&Submit=

Capt Terry Transom Redone
 

Many details are omitted to keep this story shorter. As a daily user of CSC, thanks to all who provided tips directly or indirectly with particular thanks to Dirtwheels, Flexpat, DonV, NoBones, Bigshrimpin, KMoose, and my longtime friend Bushwacker.

After watersports season last year I confirmed my ’76 Seafari transom was compromised. There were no fiberglass cracks, but the aluminum trim cap was askew, flexing was apparent while bouncing on the AV plate, and moisture in the wood chips from my exploratory drilled holes. Over Thanksgiving the ETEC 150 HO was removed and installed on a wood engine stand. Then wood removal began for a Seacast pour. The wood removed easily in a few areas, in others it took hours and hours with the drill, chain saw and scraper/chisel made from a sharpened 3” wide, thin steel bar. Next was repairing/replacing the chain saw damage to the fiberglass. I also raised the transom 2” to 22” (engines and boat guests are heavier than 43 years ago). I stayed with 22” to avoid a longer driveshaft, hydraulic steering, and jack plate. I also raised the engine about .75” inches and found that position duplicated holes drilled years ago by Brown & Hauptner Marine in PBG, Fla. Frank Brown was Moesly’s race mechanic and Mark Hauptner drove some of the race boats. Sure wish my ETEC installer had followed their lead, as this is the fourth time the engine has been raised since the original installation.

Due to a vacation trips to Fla and Israel plus SC winter weather the transom rebuild took much longer and more work than I expected. It was completed and ETEC reinstalled (with final painting postponed) just before our grands annual July visit. My efforts were well rewarded by the huge smiles on the faces of the boy 5 and girl 7 when each solo kneeboarded for the first time!

So far I am pleased with the results and appearance of this intensive, long-term task. Many of you have done much more extensive and expensive projects resulting in better than new condition (like Bill V’s Billsseacraft and KMoose). Frankly, my intent was more like the ’68 Corvette I had for 30 years; have it nice enough to enjoy it, but not compete in any Saturday classic car shows at the burger stand.

Some points to ponder if redoing a transom:
1- I might not use, but would consider other methods of getting to and removing the wood, maybe Dirtwheels’ termites! Maybe cut out the aft fiberglass sheet, remove the wood, reattach aft sheet and then a Ceramic pour (using 2” x 4” braced plywood to support the aft sheet during pour).
2- While I believe I achieved a satisfactory Seacast pour, the 7.4 amp drill was smoking and nearly caught on fire while mixing the end of the first thick pour. For the second and third pours I used two drills, switching to the cold drill as the mixture thickened. I recently have seen some samples of Arjay Ceramic which appear much more homogeneous than Seacast. When I was looking for someone to paint the transom, a local boat restorer told me he had used Seacast, but switched to Ceramic because it poured more smoothly thereby less likely to have voids.[IMG][IMG]http://www.classicseacraft.com/commu...pictureid=3002[/IMG][/IMG][IMG]http://www.classicseacraft.com/commu...pictureid=3000[/IMG]http://www.classicseacraft.com/commu...pictureid=3001