building new boat

[tabasco]

Starting to dry fit some of the sides. Still shaping up forward but just wanted to see how the slight flair would go into the tumble home. Figure if I can lay a single 8' long piece like this it should go not too bad....

[gottaflylee]

looking good there...

[tabasco]

Was able to fit a long solid piece from transom forward to just forward of mid. Now dry fitting first layer. Will be more work at stem as i have an exposed stem/keel. How tight are these joints supposed to be? Got it with only a rare mm space right now. Anything stand out as wrong? Just good to have all the experience/advice on here and it helps. This is 4mm okoume and will be two layers and bottom double 6mm.

[billschwabe]

Plank it!!! Only question is there a particular reason you are you planking the sides first? Most every cold-molded builder I know does the bottom first then the sides.

[tabasco]

Two reasons, one i want the bottom plank to overlap the side so the end grain is outboard and not on the bottom (it'll be covered in glass but just paranoid). Second the side is gonna be the most work and i want to make sure i don't shoot screws and split any battens so i want to look at the back of it as i go. Course this will make cleaning up the run out from the bottom planking a ***** as i gotta crawl under. Any reason to do do bottom first before i get too far along? thanks, tom

[Tarbaby]

I would do the bottom first because it is easiest..... It will get you used to doing the planks... If there is a learning curve for you..... well you will be a pro by the time you do the sides. You dont see the bottom so mistakes can be made. You will see the sides so it just makes sense to do it that way.... Like Bill said... Most all boats that are coldmolded are done bottom first. Don't worry about cleaning up the inside too much. It is about 3 hours with a chisel and a shopvac. Looks great.

[tabasco]

Numbered and marked the side planking and took off. Bottom started. Gets slow up toward stem to fit it into the keel/stem well.

[billschwabe]

Wow! I never noticed from earlier pics you had rabbited the keel/stem for the planking. That sure makes fitting the planks a much harder job doesn't it. By the looks of it it is going to be an external keel for grounding and help steering I presume? That should work but you should be VERY careful to seal, fillet and glass the cra* out of it with several staggered layers of heavy cloth and NOT just finish cloth! That fir is definitely strong but if any water ever got through there is a path for water to get inside through the wood and it will quickly swell and pop the cloth off.

I wouldn't change it now but you might think about on the next one just planing the keel/stem to shape then planking and glassing over it. You could then add the strip externally and it could be a sacrificial part, able to take the abuse and just be replaced periodically when it got too beat up. Thay way the hull's integrity would be preserved and you wouldn't have to be quite so vigilant in maintaining it.

I don't think you will have any problems with it as is since you have some framing in her too but cold-mlded hulls by nature are going to flex and any "hard points" like framing and keels are a potential place for it to "work" where the hard frames and hull planking move against each other and open up stress cracks. I have seen several 60' boats done like that develop cracks along the hull/keel joint where the keel went through the hull. Most of them didn't have nearly enough glass over the joint which led to the problem.

Anyway, it IS looking great! Keep up the good work (and pics)!
Bill

[tabasco]

Yep,
its exposed for grounding. Does make fitting bottom planking a B*TCH but for my use i thought it would hold up better. I would worry about just glass over planks on the keel anyway. Like the idea of an external one that sacrificial--maybe next time. what is your thought about what / how much glass on the bottom and sides? tom

[billschwabe]

Yep,
its exposed for grounding. Does make fitting bottom planking a B*TCH but for my use i thought it would hold up better. I would worry about just glass over planks on the keel anyway. Like the idea of an external one that sacrificial--maybe next time. what is your thought about what / how much glass on the bottom and sides? tom

Glassing over the bottom planking works just fine as long as you use enough that is! I am amazed at the different opinions and practices at every boathouse I've been in. Some like it real heavy, two layers of 3408, some real light, one layer of finish cloth. I have been sticking middle of the road I guess but, knock on wood, I haven't seen any problems so far either!

We long ago stopped using cloth with mat (the '08 part of the number) which is only required for polyester resin not epoxy, and instead use two layers of bi-directional weave with layer of 0/90 and another with +/-45 fabric orientation. The main reason is I HATE using just one layer which leaves a potential weak spot at the joint no matter if it's scarfed or overlapped, you always have an ending of the fibers that doesn't transfer strength across.

If it were me I'd use two layers of 1200 biax on the bottom and one on the sides, running lengthwise with staggered seams. Overlap the keel and knuckle with each layer giving you four layers on the keel and three on the knuckle. I'd start with three additional strips on the keel, each two inches wider than the previous one, maybe 6,8 and 10" wide. Then add your bottom layers. The weight will be the same as if you used one layer of 1208 or 1708 and it will be MUCH stronger with no weak seams!

On our boats (even the 60'+ ones!), I use a Kevlar/eglass hybrid for the first layer (1200), and a 1700 biax for the second and it is more than enough.
Bill