16' Aluminum Deep & Wide Transom and splash pan fix

[EvinrudeForDays]

Alright guys new to the forum and boating I have a couple questions, appreciate any advice!

I bought this boat 3 years ago. It's a deep and wide 16' aluminum, it had a 85 hp Evinrude on it.

I ended up selling the motor because I didn't really want one that big. I picked up a 1975 25 hp Evinrude tiller recently because the price was right.

Do you think it will get the boat on plane?

So basically the guy that did the transom before me didn't put any drain holes in and it's rotten. I plan on replacing it with 2 sheets of 3/4" marine ply, glueing it together with titebond III, finishing it with polyurethane and and bolting it from the outside through the aluminum to in the inside.

There was a sheet of 5/8" on the outside too that was bolted through all the sheets to the inside. Problem is the 25 hp motor mount is too tight on it.

I'm converting it from steering to tiller and the splash pan is pretty deep. I think it will be uncomfortable to use as a tiller.

Can I cut the splash pan back so it's more like 12"?

Is the splash pan supporting the transom?

Is the outside sheet necessary if I'm downsizing motors by over 150lbs?

Should I still bolt it together from the outside to the inside (where the outside sheet is). I plan on fastening it where the wood isn't

Do you think I need to screw the sheets together? I think glue would hold up perfectly fine

Is the polyurethane good enough for a finish on the inside of the splash pan? I was thinking about putting aluminum flashing from the top of the transom down past the drain holes.

https://imgur.com/jFYolWc

https://imgur.com/4Zjs6fG

https://imgur.com/zDk5END

https://imgur.com/cMTpj6Y

https://imgur.com/HcZxv89

https://imgur.com/VYbNlJR

Appreciate any help

 

[GA_Boater]

Welcome aboard.

Is that a Starcraft? It sure looks like it. No idea about performance with a 25 horse motor, Probably rated for up to a 75 and 25 will be weak.

The splashwell is part of the structural support for the hull. Shortening can be done as long as the structural support is kept.

The 5/8" hunk on the outside can be made from 1/2 or 3/8" ply or a piece of heavy aluminum sheet. It is more cosmetic than anything else and protected the transom from scratching when installing a motor when new.

So basically the guy that did the transom before me didn't put any drain holes in and it's rotten. I plan on replacing it with 2 sheets of 3/4" marine ply, glueing it together with titebond III, finishing it with polyurethane and and bolting it from the outside through the aluminum to in the inside.

Install the drains, I see the splashwell drains used to be through the transom.

Don't quite understand the last part. The transom ply should be installed and bolted up the way it is now with the line of machine screws/nuts on the outer edges, machine screws/nuts through the knee braces and the 463 wood screws in the flange against the transom ply.

Plenty of members have replaced transoms in tin boats here and it isn't a real tough job.

 

[EvinrudeForDays]

Yeah it's a Starcraft. So basically if I don't install the sheet on the outside, there's holes in the aluminum from the previous one... so can I just bolt through the aluminum (without the outer sheet) and silicone it? I don't want to buy any other ply lol it's already $150 for the 3/4"

And will coating it in polyurethane be good enough? For sure putting in drain holes, but just seems like it should have more there to protect it

 

[Watermann]

You can paint the transom too with something like Rustoleum pro enamel.

When you plug the holes up you should use 3M 5200, not sillycone.

A 25HP on a 16'r is way under powered.

 

[EvinrudeForDays]

I've seen a ton of 16' aluminums with 25 hp motors. The only difference is my boat is deep and wide. It's just a fishing boat and if gets me from point A to point B and can troll then I'm happy

 

[Watermann]

I've seen a ton of 16' aluminums with 25 hp motors. The only difference is my boat is deep and wide. It's just a fishing boat and if gets me from point A to point B and can troll then I'm happy

Alright.

On the transom pad you can use aluminum like I did, back buttered with 5200.

 

[EvinrudeForDays]

You can paint the transom too with something like Rustoleum pro enamel.

Why enamel paint though? Isn't that water based?

 

[GA_Boater]

Rusto Pro is oil based enamel. We paint our boats with it. It works well.

 

[Watermann]

The Rusto is easy to source, I use the same paint (alkyd enamel) in a different brand, Van Sickle because it's easy for me to source at a near by farm store where they have primer, paint and hardener all in one stop. https://www.vansicklepaint.com/tractor-equipment

 

[EvinrudeForDays]

Ok gotcha. So I'm seriously considering cutting my splash pan back so it's more like 12". Do you think as long as it's riveted through the sides and screwed into the transom the way it is now it will be good? I will never have a motor bigger than a 40 on it

 

[EvinrudeForDays]

And does anyone know what model Starcraft that is? Kind of looks like Starcraft 79 SS?

https://imgur.com/HUKTlR6

 

[Watermann]

No not an SS, there were a few different SC side console boats made, the Kingfisher which has no splashwell, the Mariner V and then yours which is a Star Trek-V which has a SW, side console and bow rails.

Yeah that 85 was way over the rated HP for your boat, a 40 will be just fine with your SW plans

 

[EvinrudeForDays]

Apparently it's a 1979, but can't find any pics on what they used to look like. Apparently the 71s were 15' or 18'

 

[Watermann]

Yeah have you measured the boat's beam and length yet? It's relative to total length with these old SCs, my 18' SS is 17'9" and my Chief is 18'11".