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Hull Construction

Posted: Wed Oct 03, 2018 8:27 pm
by trebot
Are the plank hulls "double planked" or is the inside plywood?
My '56 Continental has plywood inside the hull (bilge). I'm wondering if it has a "5200 no-soak bottom".

Re: Hull Construction

Posted: Thu Oct 04, 2018 6:11 am
by Matt Smith
At some point, and others can chime in, Chris Craft did Plywood inner hulls. My 1960 was that way. And I have seen others. I would assume it was earlier. I will add its better than the plank system and less soaking

Re: Hull Construction

Posted: Thu Oct 04, 2018 7:07 am
by mbigpops
My 1953 Rocket has inner plywood under the planking.

It came this way from the factory with canvas in between the plywood and planking and now that I have re-done the bottom it has 5200 between the new plywood and planking.

To answer your question it depends. Seeing the plywood layer alone does not tell you that you have a 5200 bottom as what you are looking at could be the original plywood from the factory. Without some kind of proof from a previous owner or physical evidence it is hard to tell.

Does the bottom look like old wood or new wood ?

Mark

Re: Hull Construction

Posted: Thu Oct 04, 2018 7:14 am
by trebot
Bottom planking looks original. Haven't stripped paint yet, so I'm guessing.

Re: Hull Construction

Posted: Thu Oct 04, 2018 7:58 am
by Matt Smith
Another way to tell is sometimes there is a little resedue under the frames that squeezes out. I would say that if the bottom had been done it would have been a huge selling point

Re: Hull Construction

Posted: Thu Oct 04, 2018 10:32 am
by mbigpops
Another tell tale sign of a 5200 bottom (if done properly) is that you will see a small gap in between each of the bottom planks which is filled with 5200. An original bottom will just have the planks right up against each other.

Mark

Re: Hull Construction

Posted: Thu Oct 04, 2018 6:25 pm
by Don Danenberg
Wow.., I'm expecting this current crew to come up with some answers?

The earliest CC inner bottom, in plywood (Doug Fir) that I've ever seen, was a 1953, CC, 17-Sportsman.
I believe this was a 'transitional' boat because we found ALL BRASS screws and bolts, on one side of the boat, and ALL BRONZE screws, and bolts, on the other side of the boat?

On the assembly line, one side had new barrels of Bronze screws, the other side did not yet have?
Yet, 1953 was also my first experience with plywood, inner bottom?

There were many boats still being built after that date with the slats, not yet plywood....,
They did NOT just say; Throw that wood away, Throw slotted screws away.., They took advantage of their still current supplies.

Re: Hull Construction

Posted: Fri Oct 05, 2018 7:32 am
by maritimeclassics
I agree with Don, and I think plywood inner bottom was on some models and not others. You started seeing it around 1953 but I have restored a few 1955 18' and 21' Cobra's which all had mahogany diagonal inner bottoms on them. Then sometime in 1957 you see every boat with a plywood inner bottom. That's at least the way I have see it.