What wood would....

[Kitlani]

I wish to laminate deck beams using two different woods, for a lined appearance below decks. Can anyone who has already done this suggest two woods, of good strength, which would glue well together, using epoxy or wood glue? Weight is not a concideration here but the woods should have similar movement rates. Maple and purpleheart? Fir and cedar?
-ray-

[sv Lorelei]

Being on that coast I'd opt for Port Orford cedar and Doug Fir if you can get 'em clean.

You don't want to put maple where moisture can get to it. Purple heart doesn't glue up all that well IIRC. Mahogany is a good dark wood that glues well. WRC is another candidate, as is Yellow Pine.

[Mike Keers]

I'm kind of partial to mahogany and ash myself .


http://www.emkaywoodcrafting.com/011004_4.jpg

Edited to add: Hey Tim!

[Bob Smalser]

... but the woods should have similar movement rates.

For the best longevity in your climate, selected woods should be durable, rates of seasonal movement should be close, and moisture content should be an exact match. As the best practice is to spring flatsawn strips over the lamination form, both species need to be flatsawn and you should be looking at similar tangential shrinkage rates.

Two of the prettiest in color when combined are Black Walnut and Black Cherry at 7.8 and 7.1% Black Locust also works at 7.2, but White Oak at 10.5 has too much movement.

This table shows the shrinkage rates of most commercially available species for comparison:

http://www.woodbin.com/calcs/shrinkulator.htm

This is a list of domestic species having decay resistance:

http://www.fpl.fs.fed.us/documnts/fplrn/fplrn153.pdf

According to the USDA, imports with some decay resistance suitable for laminating include. Khaya, H. Mahog, Meranti, Spanish Cedar, Tanguile and Sapele.

[paladin]

and I can pretty much gaurantee he ain't agonna get any Tanguile....:D

[Stiletto]

In looking at Mike's photo I found myself wondering if there would be much difference in strength if the laminations were vertical instead of horizontal as in the picture.

Any ideas?

[ishmael]

Purely a matter of taste, but please reconsider the project. Contrasting woods get tacky in a hurry.

[capt jake]

In looking at Mike's photo I found myself wondering if there would be much difference in strength if the laminations were vertical instead of horizontal as in the picture.

Any ideas?
Might be stronger, but they are laid horizontal to allow for the curvature of the beam. If laid verticle, you wouldn't be able to bend it to the desired shape. ;)

[paladin]

...a beam laminated of light wood and then capped with a dark wood looks better...at least I think so.......

[Mike Keers]

Well Ish,
I guess it's a good thing I'm only building my boat to suit my tacky sense of taste, and not your obviously superior one, eh? Different oars for different longboats, as the saying goes. :rolleyes:

Actually, I agree with Chuck on the light wood capped with dark, but I was using what I had around here for ash and mahogany, and the alternating woods allowed me to make six or seven beams from the stock on hand. Plus, I actually like the look! :eek:

[Bruce Hooke]

One problem with ash is that it has no rot resistance...

[Bruce Hooke]

I agree with Ish on the aesthetic question, but its your boat. A lot of people clearly like the laminated look...

[JimD]

Purely a matter of taste, but please reconsider the project. Contrasting woods get tacky in a hurry.

I agree.

[Bob Smalser]

I wouldn't worry over it.

A whopping 75 cents worth of paint solves the problem if you grow to dislike the look.

[Mike Keers]

And I don't anticipate a great deal of rot happening on the underside of my cabin roof. Don't they make oars from ash?

[Peter Malcolm Jardine]

Thanks for those tables Bob... very useful.

[Bruce Hooke]

And I don't anticipate a great deal of rot happening on the underside of my cabin roof. Don't they make oars from ash?
Yes, but unless grossly abused oars are unlikely to remain in dark, wet places were rot is likely to develop. Rot usually seems to develop where fasteners penetrate the wood or where joints in the wood allow water to get in and sit next to the wood. Neither applies to oars.

Screws, bolts and other fasteners are often run through the deck and into deck beams to attach winches, cleats and other deck hardware (not to mention simply holding the deck in place). Such fasteners provide a very good way for water to find its way down into the deck beam, where it sits, hidden from view, rotting the deck beam from the inside out. The ends of the deck beams are often very close to the stantion bases, which are well known places for leaks and rot to get started.

[Bob Smalser]

And I don't anticipate a great deal of rot happening on the underside of my cabin roof. Don't they make oars from ash?

In Arizona you should be fine. I don't think the moisture content of any of your above-waterline woods ever gets very high. Keep your paint and varnish in good shape, tho.

Ash and other rot-prone woods just don't survive as long as durable woods after lack of care in warm, wet climates...and all boats eventually get neglected. Ash in an easily-replaced part is one thing. Ash in a part that requires dismantling half the boat to replace is another entirely.

[JimD]

I wouldn't worry over it.

A whopping 75 cents worth of paint solves the problem if you grow to dislike the look.

:D And that's exactly what I ended up doing when I tarted up one of my little boats by getting too fancy pantsy with the bright work. But it was a lot of time and effort put into a mistake.

[seo]

Maple is a nice hard wood very bright-white wood that has a very tough surface, and glues ok, not great. For this use I would prefer it to a ring-porous wood like ash.

Black walnut, black locust are very dark brown/purplish woods. Some cherries are fairly dark red/brown.

Esthetically, I would suggest two woods that vary between light and dark brown or red-brown, not white and another color, which might begin to seem a little much.

If you get tired of the look, you can stain the wood, then revarnish, or paint.

[Bob Smalser]

:D And that's exactly what I ended up doing when I tarted up one of my little boats by getting too fancy pantsy with the bright work. But it was a lot of time and effort put into a mistake.

We're all guilty of surveying the final result and lamenting that it looks more like something from a brothel than what we intended.

But for Kitlani, in a wet climate like yours, I would take great pains to use only durable woods. I've turned the air blue once or twice, and don't like the idea of a restorer cussing my work some day. ;)

[Bruce Hooke]

Maple is a nice hard wood very bright-white wood that has a very tough surface, and glues ok, not great.

Maple also has a very bad reputation in damp locations. Those wonderful sugars that make maple syrup also make great food for little beasties.

[JimD]

... in a wet climate like yours, I would take great pains to use only durable woods. I've turned the air blue once or twice, and don't like the idea of a restorer cussing my work some day. ;)

In the particular case of my learning experience I used WRC throughout. I had some boards that were very richly pigmented and some that were quite pale and alternated them, epoxy glued and encapsulated. The contrast was very striking. It taught me that when it comes to dressing up wooden boats the 'more is less' rule generally applies. A wooden boat loses its grace and dignity when you go overboard on the decoration.

[Kitlani]

Sincere thanks, people, for the thoughts and info on this. My idea was of two woods which would differ in colour by only a few shades so you could see the difference but it wouldn't be white to dark. I haven't looked into this Black Locust enough so I will. And, yes, when building a deck structure we should remember all the stresses which will end up being applied through the deck: winches, windlass, stays, cabins etc., and not just us walking around on it. Thanks again.

[Bruce Hooke]

I was not so much talking about the stresses, which obviously need to be accounted for, but rather the point that with all those fasteners, deck beams are more prone to rot than some might think, so the woods picked should have good resistance to rot.

[paladin]

Originally, all the beams in Tana Mari were laminated, coated with epoxy, sanded and varnished over.....the underside of the deck was likewise prepared but painted an off white. The inside of the boat used a Russian ash veneer that we purchased in rolls and laminated in Thailand. It has a more pronounced grain than american ash, and is more rot resistant. The wood was then rubbed with the dry varnish material used in Japan to highlight the grain....after 3-4 years.....it really was too much. The bulkheads etc, including overhead beams were done in off white, with rosewood caps on the beams. The ceiling was varnished ash, and the interior furnishings in the boat were done in rosewood. It really lightened the boat up and made the space appear larger.....