1970 20ft SF Rebuild

[RoomToMove]

Is there any down side keeping my bulk heads a couple inches below the tops of the stingers? Should they be tied into the bottom of the deck? I am only putting in two and would like some acess to the top of the tank and airflow through the gas tank cavity.

[jorgeinmiami]

In the front portion of the deck I found that the span between the stringers curved some flex (soft) area up there. It was thea area in front of the console and right behind the raised deck. I used nidacore for my deck and I had it taken up and and that area reinforced.

I would raise it just to be safe and not have to do it over again.

[flyingfrizzle]

remember you want your boat to be able to flex some when in ruff conditions. A lot of people will over build and get a boat to the point it cant flex which creates hard spots sometimes. I would want to be able to spray off the trash off the top of the tank or make it where it could drain naturally and not hold water around it. On the bulk heads I do, I cut out notches or half rounds near the keel to allow water to drain from front to rear of the bilge area to drain. Looks like you have a PVC pipe glassed in to allow the front to drain to the rear but what ends up in the tank cavity wont drain out. I would do a small void on the rear bulkhead only so that the water in the front wont enter the tank area threw the front bulk head but what builds up (it will get in there somehow) will be able to exit the rear one. If you build both high and don't have a way for them to drain they will just end up holding water around the tank. You want air flow around it and for it to drain and dry. Most bulkheads Carl originally put in these boats had little glass on them and were not super strong the way they were installed. If the deck is done right it should not need support from stringer to stringer. That's my 2 cents, You would think if sealed off you wouldn't get water in there they way you have it but I haven't seen one yet that hasn't found water into it somehow.

[RoomToMove]

Thank for the input Frizz and Jorge, always much appreciated.

Slowly making some progress. Got two bulkheads in on either side of the tank, with drainage holes on the aft bulkhead. The PVC pipe took the place of the old center stringer and allows for drainage from the forward compartment.

We stole a page directly out of Billy the Kids build, and went with balsa core on the hull sides with csm and 1708. Balsa was bedded in with none other than Joe Merton's "Hull & Deck" The hull sides stiffened up nicely! This job was a lot of work but really happy with the way it turned out.

[Vezo, Part II]

This is a photo showing the “soft spot” forward of console, aft of casting platform. The plywood core was flexing for the single reason that the stringers do not run full height forward. Had to build up with core, then replace deck and finish. Solid now. Hope this helps.

Vezo

[Kithogue]

On to the cap!!! Need a mold for extending bolster like Billythekid did below.

I guessing wood is worst potion. Thinking some type of composite would be least likely to stick. Have a piece of scrap azec i'm thinking of using any thoughts/recommendations? Havn't worked with any molds yet.

Cheers

[uncleboo]

If you use Azek, better wax it good. Resin sticks nicely to it! I wondered if the masonite bathroom paneling would work well.

[dirtwheelsfl]

1/4" ply covered in formica. Itll take a nice fair curve and the formica will act as the release. Coat of wax wont hurt though...

[uncleboo]

Originally Posted by dirtwheelsfl

1/4" ply covered in formica. Itll take a nice fair curve and the formica will act as the release. Coat of wax wont hurt though...

I forgot the formica surface in my description.

[flyingfrizzle]

That's what I use also, formica. The big box stores sometimes sells it off cheaper if it has cracks and broken corners. I always look for the discounted stuff. Melamine board works well too for molds but the formica will form well to the curves.