So im finnally fixin up the old boat. I plan on mounting a 16-23hp GDLT on the back. Anyways i had a few question. What is a good way to attach the plywood to the bottom and how far should i mount the grab bar from the transom.

Here's a pic of my homemade grab bar just sittin in the boat.

How thick is the plywood? I am in the process of taking my plywood floor out. Added too much weight. Noticeably different in performance

3/8" i wouldn't think it would be heavy enough to slow me down, but ive never put in plywood floors before.

You'd be ahead of the game to get some aluminum sheet for the floor instead. No matter what you do, the plywood will end up wet, and never dry out from the underside, it'll get very heavy.


Is it a polarkraft hull? Looks like mine, i did the same thing, taking the seats out and welding the holes up, came out great.

Its a Grumman hull. I would have loved to put aluminum floors in it but the wallet wouldn't allow it. When the wood finnaly rots Im gonna try to replace it with aluminum

I certainly know how that is.


I used decking board ripped in strips the same height as the ribs, and sub floor adhesived them down to screw my flooring to. I didn't want a bunch more holes in the ribs, already had a few cracks welded up from the old screw holes.


You should be able to glue the strips down with liquid nails, adjacent to the aluminum ribs. I also ran some lengthwise on the outer edge, so that the edge of the floor wasn't spongy near the sides.

Best advice I could give would be to get some fiber glass resin from Walmart ad use it to seal the wood so it will slow down the water absorption. It is cheap and will make that floor last a couple more seasons.


Just my .02

I planned on sealin it with somethin just didnt know what would work best. How far from the transom would be a good spot to mount the grab bar?

i have a similar boat. a grumman 1849. in mine the foam in the seats was saturated. I cut the tops of the seats out, ripped all the foam out and put pieces of plywood on hinges over them for benches. i was gonna remove both benches but decided against it. i have a 25hp longtail i run. i probably do 17/18 maybe unloaded with a brand new prop though i don't think i have the cavitation plated adjusted right just yet. unloaded the boat has some serious flex when at full throttle in open water. but its super light now. i probably cut out 200lbs of wet foam. good luck with your build.

thompsons might work well to seal the plywood. i've used it on plywood on big home construction jobs over advantech plywood before and it keeps it in great shape. it is slippery at first though

Are you just gunna screw that grab bar to the floor?
If it takes a hard hit you may be in the water grab bar in hand.

I would find a more solid way to attach it.

I planned on drillin holes in the floor than bolting in on i got a 12" square piece of plate to reinforce the bottom side. The way i got it i would think the plywood would rip up before the bar came off

Cb531 is right. I pulled my floor up that I resined and sure enough it is already rotting on the ends especially(will post pics later). I think I am going to run it without the floor from now on to free up a good hundred pounds of dead weight.