1974 21' Supersport Rebuild

[GA_Boater]

Re: 1974 21' Supersport Rebuild

That is a serious crack, eck. Also explains the monster ply motor pad the PO stuck on her. Did the PO ever replace the transom wood or just slap that over-sized pad on her?

How wide is the diamond plate? What I'm thinking is it might be best to have the AL plate extend below the rivets under the crack. Might have to dimple the plate so it sits flat on the transom skin. And maybe some plate on the inside so you make a good solid sandwich with the new ply. And of course plenty of 5200.

How is the knee brace, any cracks? The K/B often suffers when the transom goes. It looks bad but I think she's fixable.

 

[ezmobee]

Re: 1974 21' Supersport Rebuild

That crack is in a real bad place. Right above the knee brace. Lots of forces being applied there that need to be spread out well across the transom. I really don't think a simple patch is appropriate here. I'd prefer to see you remove all the fasteners going from the knee brace through the outer skin and everything else at least a foot wider than that crack in all directions and re-skin the transom from the inside or the outside with a fairly large piece of tin and then re-fasten everything. I'm normally pretty laid back on this type of thing but that's literally the most critical spot on your whole boat.

EDIT: posted same time as GA above. Great minds

 

[eckhoffb]

Re: 1974 21' Supersport Rebuild

The knee brace is in good shape and transom wood has been replaced. The top 3 bolts in the knee brace will go through the new diamond plate. The diamond plate is huge, almost 4 feet wide. So it will spread the load out a long ways. Will also have bolts going to through the very bottom of transom wood where there is some heavy angle inside. To me this should be every bit as strong as new skin back there.

 

[ezmobee]

Re: 1974 21' Supersport Rebuild

The knee brace is in good shape and transom wood has been replaced. The top 3 bolts in the knee brace will go through the new diamond plate. The diamond plate is huge, almost 4 feet wide. So it will spread the load out a long ways. Will also have bolts going to through the very bottom of transom wood where there is some heavy angle inside. To me this should be every bit as strong as new skin back there.

Sounds good to me.

 

[eckhoffb]

Re: 1974 21' Supersport Rebuild

Would 5200 be your choice for sealing purposes or is there anything better?

 

[ezmobee]

Re: 1974 21' Supersport Rebuild

Would 5200 be your choice for sealing purposes or is there anything better?

I can't think of anything that would be better apart from mass quantities of an epoxy like JB Weld which isn't really a practical solution. Perhaps Marine Tex? Regardless, I'm sure 5200 will be fine.

 

[GA_Boater]

Re: 1974 21' Supersport Rebuild

I would drill stop holes at both ends of the crack. When 5200 sets up, it's like concrete but still maintains some flexibility.

 

[eckhoffb]

Re: 1974 21' Supersport Rebuild

Awesome, thank you guys. Hopefully I will have that mounted up tomorrow evening then finish up my sanding. I'm ready for this thing to hit the water, but it seems there is no end in sight

 

[barato2]

Re: 1974 21' Supersport Rebuild

b, i know it's overwhelming at times. but just think: you have the "Best Save" award nailed down for saving THAT hull from the crusher
:encouragement:

 

[eckhoffb]

Re: 1974 21' Supersport Rebuild

b, i know it's overwhelming at times. but just think: you have the "Best Save" award nailed down for saving THAT hull from the crusher
:encouragement:

Thanks I know it will come together soon enough. Last year I rebuilt a 17 footer so once I get to the interior I know it will go quickly. Its just all this painting and trailer rehab I had to do. But its almost complete and I pretty well have everything I need for the inside.

On another note, not sure if any of you guys have Dollar Tree stores nearby but i got on their website and can order pool noodles for a buck a piece. Sweet deal I think.

 

[barato2]

Re: 1974 21' Supersport Rebuild

my local Lowe's also has em for that price, and they're the thicker ones. the ones i got at dollar store were smaller in diameter and had bigger hole in the middle, so less foam for your $.

 

[GA_Boater]

Re: 1974 21' Supersport Rebuild

my local Lowe's also has em for that price, and they're the thicker ones. the ones i got at dollar store were smaller in diameter and had bigger hole in the middle, so less foam for your $.

When you said Lowes, something clicked. Pool noodles are just colored, un-slit pipe insulation. Both Lowes and HD have 6 ft. lengths of black 1/2" (the center hole) for 97 cents. That's against 4 ft. noodles for a buck at the Dollar Store

Is my thinking all wet? Are no rainbow colors a deal breaker?

 

[boatnut74]

Re: 1974 21' Supersport Rebuild

When you said Lowes, something clicked. Pool noodles are just colored, un-slit pipe insulation. Both Lowes and HD have 6 ft. lengths of black 1/2" (the center hole) for 97 cents. That's against 4 ft. noodles for a buck at the Dollar Store

Is my thinking all wet? Are no rainbow colors a deal breaker?

You might be on to something.....

 

[barato2]

Re: 1974 21' Supersport Rebuild

the stuff we get here as pipe insul is more "hole" than foam,i think pool noodles would do better. but worth checking into given low cost of experimenting

 

[eckhoffb]

Re: 1974 21' Supersport Rebuild

Thats an awesome deal on the noodles. now if the closest lowes wasnt 150 miles away. I guess thats what i get for living out in the boonies

 

[GA_Boater]

Re: 1974 21' Supersport Rebuild

the stuff we get here as pipe insul is more "hole" than foam,i think pool noodles would do better. but worth checking into given low cost of experimenting

Experiment. Did I hear experiment? Do you still have wood soaking?

EDIT - Eck, you gotta move closer to town. Although I wish I was further out of town myself. :joyous:

 

[64osby]

Re: 1974 21' Supersport Rebuild

I picked some of the black stuff for pads on my sons go cart. It's not the same material as pool noodles. It's softer and tears pretty easy. It don't think it's closed cell foam.

 

[GA_Boater]

Re: 1974 21' Supersport Rebuild

I picked some of the black stuff for pads on my sons go cart. It's not the same material as pool noodles. It's softer and tears pretty easy. It don't think it's closed cell foam.

I was calling up memories. That's bad. Shoulda gone up the road to HD and checked. Case closed. Thanks 64.

 

[bob johnson]

Re: 1974 21' Supersport Rebuild

you know I was cleaning up our stock room at work, we have all kinds of metal and some plastics, and I have saved some plastic tube for various projects and shipping 'containers" and I saw one piece of pipe that is drain pipe..it is about 4" in dia and very thin walled and had a cap glued on the end...A light popped into my head....you could easily seal up at least four 15ft pieces of that pipe and lay in on either side of the stringers for sealed air bouyancy...sort of like closed oil cans. the name of the game is TRAPPED air...with as little weight as possible..neat and clean and easybob

 

[64osby]

Re: 1974 21' Supersport Rebuild

I was at one of the big box stores yesterday, 4' x 8' x 2" sheet was $32 and change.

Bob yea the pipe would work, but an errant screw could cause a leak. In a puncture of the hull the plastic could crack. There is a lot of potential unused space, round shapes in a rectangular location. Would the tubes make a thunking noise as you bounce over waves.

It would be interesting to see a comparison of which would float more weight. A tube of air or a tube of foam.