Red Cedar for stringers?

[Boomyal]

Re: Red Cedar for stringers?

Originally posted by BillP:<br /> Pursuit layed a foam spacer under the stringers so the load was absorbed totally by the glass holding the stringers down. The wood didn't touch the bottom skin.

Sounds like an excellent water trap to me. If any moisture breaches the glass tie to the hull, it would allow that plywood to wick that water up like a sponge.

 

[Barlow]

Re: Red Cedar for stringers?

dimensional lumber members are only as strong as the section of continuos 'through' grain .. thats grain that runs end to end - you'll have a good time finding it or any for that matter ..<br />it's natures way.<br /><br />for this reason the counter graining in multi-layered ply is structurally stronger ... compare it to fiberglass woven mat and multi single strand mat ... the choice is obvious.

 

[petrolhead]

Re: Red Cedar for stringers?

My choice would actually be a laminated stringer, several laminations with the grain all running lengthwise, of a species like Douglas-fir. The chines and sheers on my boat were done that way and they are immensely strong, not to mention much easier to bend to shape than solid timber would have been. I wouldn't even have considered the use of plywood though.

 

[BillP]

Re: Red Cedar for stringers?

Originally posted by Boomyal:<br />

Originally posted by BillP:<br /> Pursuit layed a foam spacer under the stringers so the load was absorbed totally by the glass holding the stringers down. The wood didn't touch the bottom skin.

Sounds like an excellent water trap to me. If any moisture breaches the glass tie to the hull, it would allow that plywood to wick that water up like a sponge.

I don't get your drift on that one...If glass lets water in the stringer will get wet no matter if it has a spacer or not. That's why everyone is going to pt ply or composite.

 

[hoot22]

Re: Red Cedar for stringers?

It's not that hard to laminate marine ply for use as stringers. Thickness depends on boat rtype and size. I am using BS1088 merrante.<br /><br />Very strong...encapsulate in epoxy.<br /><br />HOOT<br /><br />Use epoxy and filler for fillets and glass to hull with fiberglass tape.

 

[Philip Stone]

Re: Red Cedar for stringers?

When it comes to cedar (and I'm in BC land of cedar, douglas fir and sitka spruce) I'd suggest looking into yellow cedar (cypress) this tree is closely related to the red cedar but the wood has much stronger structural characteristics and its longevity in wet conditions is as good or better than red cedar. It carves for example like I would think soapstone would in chips instead of splitting as red cedar is prone to do. The grain is tight (they grow at higher elevations in short growing seasons) but the wood is still light. Of course it depends on the boat, a canoe is a far cry frm a 24' skiff.<br /><br />Some of the above waterline finishing on my boat is yellow cedar and it is as solid as the day it was installed. For non-structural finishing red cedar would be great too. It needs sanding and a thick finish on handrails and the like though because it can splinter.<br /><br />No one on the west coast would ever use spruce in a damp environment it is way too prone to rot.<br /><br />Douglas fir is definetly the structural wood of choice for home building construction but you'd want tight grained, check-free, pitch rich old-growth for anything like boat stringers.

 

[PW2]

Re: Red Cedar for stringers?

Alpine,<br /><br />You are correct about Alaskan Yellow Cedar (sometimes called cypress in BC.) It is very easy to work with, light, and extraordinarily strong with very good rot resistance. And an unmistakable pungent aroma. Probably hard to find in the SE US, however.<br /><br />Red Cedar is a very attractive wood, but unsuitable for any structural requirement.<br /><br />Marine plywood is probably as good or better than anything readily available and at an affordable cost. It will be as strong as anything you can get if you maintain it and keep it mostly dry. Trap moisture in it, and it won't perform any better than any other wood product.

 

[Mark42]

Re: Red Cedar for stringers?

How about laying up the stringers out of solid glass/resin? Never need to worry about any water problems in your life time.