hull plank help

[brian62]

I need to scarf 3 planks on my 1960 sealancer.I just viewed on page 9 of Restorations Txcapdan posted 2 pictures(HULL PLANK RESTORATION) of how he did the exact same thing i need to do and in the exact same location.(i love this web site)I need to know how he did this.I dont know what he meant by angle cut 4 inches.Also i noticed he did not stagger every board.Should every board be staggered?what type of wood are these side planks made of on these cortland sealancers.They also seem to have a curve the width of the board. How is this accomplished?Finally are butt joints recommended in this location to give it some added strength?Thankyou for any help and/or suggestions....Brian J

[LancerBoy]

Planking is most likely 3/8 inch thick Douglas fir marine plywood.

The bevel of the scarf is 4 inches long.

I would definately recommend staggering the scarfs in adjacent boards.

I doubt the planks are curved thru their width.

You can add a butt-block at the backside of the glued scarf. Not necessary but a degree of redundancy is fine.

Andreas

[gts]

Andreas, if I'm having a problem finding marine grade Fir plywood, is substituting either ash or birch acceptable for use below the waterline? My plywood choices from Condon in White Plains NY http://www.condonlumber.net/index.htm are:

MARINE (Exterior) PLYWOODS

ASH, WHITE A/1
BIRCH A/1 Sound Lauan Back
MAHOGANY, RIBBON STRIPE A/1
MAHOGANY, Genuine Rotary Cut
MAHOGANY, Genuine Plain Sliced A/1
MAHOGANY, BRUYNZEEL REGINA
Separate Bruynzeel color brochure available on request.
MAHOGANY, OCCUME
TEAK, Quartered, G1S (Mahogany Back)
Standard face thickness
TEAK, Quartered, Both Faces G2S
1/20” veneer face and back
TEAK, Black Line PLYDEK Decking Boards
TEAK, White Line Cabin Sole Plywood

George

PS Was the original Mahogany plywood plain sliced or rotary cut?

[LancerBoy]

Do not use ash or birch. Neither have any decay resistance.

Okume or meranti marine plywood are acceptable substitutes for Douglas fir/larch. They are cousins of Philippine mahogany so they will look more like mahogany than Douglas fir/larch.

Andreas