Big layup in plank, too big?

[dmede]

So because of the plank shape and my decieding not to do a dog-leg scarph I ended up with a pretty big layup peice on the front of my middle plank. It's also got bad grain oreientation. I think I got lazy on this board.

The glue up itself is fine and feels nice and solid. The board is stiffer than the one under it but still makes the bend almost all the way into the stem without steam.

Should I reconsider using this guy? I think it's not ideal but will be ok. What do you guys think?

[dmede]

Spent all day at the "other office" yesterday Played around with fitting the new plank and clamping it in place. After putting a lot of pressure pulling the hood end in to the stem (without steam) I feel pretty good about how strong the wood and joint are. So I'm moving ahead with this plank as is.

cheers

[Bob Smalser]

So I'm moving ahead with this plank as is.

Ouch.

[dmede]

Ouch.

For which, the extra big layup, or the grain runout? Or is it a double whammy thats sure give me greif down the road?

How bad is it? It's a 3/4" thick plank. Both the plank and the layup have good rift grain (only a few of these in my pile) and the run out will be supported along the leading edge in the stem rabett and will be "glued" to the plank above the length of the gain with Sika.

[Bob Smalser]

The grain runout. No strength, is extremely liable to crack at the stem fastenings and looks like you rushed to finish.

That plank couldn't possibly have been laid by the same guy who cut this exceptional chine joint.

[dmede]

Oh man. Yeah I rushed it a little. Mostly I just forgot to pay any attention to the grain run on my layup, I was focused on the main plank and the glue up itself.

So does this entire plank become bottom planking material, or can I saw off the offending layup and glue in a peice with proper grain run?

[Bob Smalser]

.... or can I saw off the offending layup and glue in a peice with proper grain run?

The layup seams are stronger than a solid plank would be and will practically disappear when sanded.

The problem is the planking grain that's not anywhere near parallel to the shear as it meets the stem. Besides cosmetics (even under paint it will show), the resulting shortgrain at the sheer is too weak for longevity right where it counts at the stem.

Simply dogleg scarf stock onto that plank that does run as parallel to the shear as you can get it, and recut/refit the bow end.

[dmede]

So cut off the entire end, good plank and layup, and dogleg scarph on a new peice? It wont do to just cut out the layup along the glue line and put in a new layup with grain that matches the main plank (which is much closer to running with the sheer)?

[Bob Smalser]

1) So cut off the entire end, good plank and layup, and dogleg scarph on a new peice?

2) It wont do to just cut out the layup along the glue line and put in a new layup with grain that matches the main plank (which is much closer to running with the sheer)?

1) Exactly.

2) Unlike shortgrain at the stem fastenings, you can get away with this structurally, but it's not an ideal edgejoint, and won't look right either.

[dmede]

I realized as I was up last night thinking about this that I can't add a new full layup at the correct grain angle anyway, my stock isn't wide enough for the full layup if I have to cut it out at an angle.

I think for now I'll just move on to getting out the plank for the other side of boat here, use this plank as the template and come back to this problem after the other plank is hung. Probably do a dogleg scarph at that point.

Thanks for the help, and the reminder to slow down

[Bob Smalser]

Cedar and epoxy love each other....epoxy machines and sands beautifully, sticks to itself well, isn't brittle or gummy, and is all-around ideal. If my grandfather had access to it, he would have edgejoined a number of applications rather than watch wide boards eventually crack.

Just make sure your layup stock is perfectly jointed so as to not require a lot of clamping pressure to mate, that you flip (alternate) the cups even with VG stock, and that you follow the manufacturer's sequence. Unthickened on both mating surfaces, let it soak in for 15 minutes, applying more unthickened if required, then another coat of epoxy with high-adhesive thickener added before lightly clamping.

[Chan]

dmede
I see you made one of those clamps from Wooden Boat number?
How is it working out? Worth the time and effort?
Project looks like it's really coming together.
So Bob
Is it me or is the theory of bark out a myth?

[Bob Smalser]

Is it me or is the theory of bark out a myth?

From wood science's point of view, complete myth like several you'll hear here occasionally.



"Bark out" doesn't even pass the common-sense test based on how flatsawn boards shrink and swell, and for VG boards "bark out" means "edge out".

Granddad knew more than I ever will about many things, but didn't get everything right.

[ken connors]

Oh just go ahead and lay the plank, what can possibly go wrong?

[dmede]

dmede
I see you made one of those clamps from Wooden Boat number?
How is it working out? Worth the time and effort?
Project looks like it's really coming together.

The McGuiggan clamp is great. I can't imagine puilling together those 3/4" thick planks at the hood ends with out it. Now I need to make 3 more!

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