teak substitute

[my1972ih]

I may catch significant flack for broaching this topic here, but the primary joy I get from my sailboats is using them, not maintaining them.
A rubrail was added to my CAL Cruising 36 sailboat, probably decades ago. It is in need of replacement. It appears to be teak with a stainless rub strip.
Here comes the controversial part, particularly since this is a WOODen boat forum.
I am thinking of replacing it with Trex or similar. I have used the appropriate color Trex as replacement for teak on another sailboat several years ago and it has geen great. It looks like teak and only a couple folks in the yacht club have noticed that it isn't. No maintenance!
Since I am unaware of any trex-type composite lumber in appropriate lengths, I'll probably have to scarf joints. What would be the best "glue"?
I'm thinking I'll change from stainless bolts to bronze to avoid anaerobic corrosion of the bolts. Thoughts?
Recommendations for proper sealant around attaching bolts ?
Anyone know of a resource for composit lumber in longer lengths?

[BarnacleGrim]

My rub rails are white oak, and that's what I would use. Never mind the stainless strip, it's not really a rubrail if it won't rub against anything. Then again, I doubt that solves your maintenance problem.

[David G]

my,

You're not the first to have this brainstorm. There is one problem, however. Wood expands and contracts with changes in humidity. It changes a most across the grain, and very little along the grain. The composite lumbers expand and contract with changes in temperature. They are not limited to 'across the grain'. They move equally in all directions. Most of them move quite a bit.

The net result - along a long strip like a rubrail - is that the 'wood' tends to work against the fasteners. This can open up the shank clearance hole, or pull out fasteners, or force the 'wood' to buckle. I've even seen it pull the rubrail away from the hull after it's been pookied down. All in all, I'd say it's not a good material for the application.

You say you've used Trex before on a boat. I'm surprised you haven't noticed this phenomenon. Maybe it was smaller pieces?

There are any number of less expensive wood species that'd be suitable.

[Breakaway]

Search the forum for "bartender boats." One forumite built a Bartender and used trex or equivalent for rubrails, describing the process in detail. I just cant remember who.

Kevin

[Thad Van Gilder]

um.... teak is pretty mantainance free... scrub it once a year.

[wizbang 13]

Y' say the rubrail was added, why not subtract it?

[Cogeniac]

Personally, I think Trex looks like fake plastic wood. Why not just use plastic and forego the fake wood aspect?

If you want an alternative to teak, try Afromosia. It is about $10/bf versus teak at $30/bf. It is known in some circles as "African Teak". It is pretty much like a cross between Teak and Mahogany in appearance. Brown like teak, but a more uniform grain (less big dark stripes) than teak, more like a harder brown mahogany. It is a bit less oily than teak, so I am not sure how it might fare unvarnished. Varnished, it looks pretty much the same as teak..maybe a little browner, and less gray.

Anyone else have any experience with this wood species in a marine environment?

S

[BBSebens]

There are plenty of rub-rail products made out of rubber or whatever other soft squishy stuff they find suitable. Why not go that route?

I know of no way to join trex together. My suggestion would be to do the work on a warmer day than normal, but not the hottest. Make a butt joint with a gap of say 1/16th, and caulk the joint with a color-matched bedding compound, probably the same stuff you are using to put it on the boat. This should give you the wiggle room you need. I think.

IIRC, Trex is available in 16', 20' and 24' lengths from the manufacturer. Very few decks are bigger than those dimensions.

[my1972ih]

Y' say the rubrail was added, why not subtract it?

I like the extra side protection it offers, and the holes would have to be dealt with anyway, so replacing the rubrail does both. I would attach a picture of the boat if I could figure out how

[my1972ih]

my,

You're not the first to have this brainstorm. There is one problem, however. Wood expands and contracts with changes in humidity. It changes a most across the grain, and very little along the grain. The composite lumbers expand and contract with changes in temperature. They are not limited to 'across the grain'. They move equally in all directions. Most of them move quite a bit.

The net result - along a long strip like a rubrail - is that the 'wood' tends to work against the fasteners. This can open up the shank clearance hole, or pull out fasteners, or force the 'wood' to buckle. I've even seen it pull the rubrail away from the hull after it's been pookied down. All in all, I'd say it's not a good material for the application.

You say you've used Trex before on a boat. I'm surprised you haven't noticed this phenomenon. Maybe it was smaller pieces?

There are any number of less expensive wood species that'd be suitable.

the previous boat used much shorter pieces, longest being about 4+ feet. no problems. with temperature extremes from 40 below to 120 above. But you have a good point. I need more info.

[Binnacle Bat]

You might be able to avoid the expansion issue if you double the number of fastenings. That would tend to hold it into alignment better. Trex like most synthetics is much more elastic than wood, and if held in place with enough fasteners, should compress rather than bow out.

Personally, I would go with white oak, and resign my self to an annual ritual of Cetol and masking tape.

Allan

[JimConlin]

If practicality is paramount, there are extruded PVC rails that don't need finishing, will take a beating and aren't terribly expensive.

http://store.hamiltonmarine.com/prodimg/DWP-448-R.JPG

Hamilton Marine (http://store.hamiltonmarine.com/search.htm?searchterm=pvc+rail&searchmode=any&s_category=0&oper=lt&searchprice=&DoSearch=Show+Matches&numresults=100&viewfrom=1&step=2)sells a considerable variety of them. Search for PVC Rail .

[Duane Brown]

Iroko is also refered to as a teak substitute and even weathers to a nice silver/grey when unfinished.

[mcdenny]

Another good teak substitute is Garapa. Available at lumberyards for high-end decks. It doesn't have the distinct grain of teak but is just as weather resistant. $6/bf. Glues well with epoxy.

[my1972ih]

my,

You're not the first to have this brainstorm. There is one problem, however. Wood expands and contracts with changes in humidity. It changes a most across the grain, and very little along the grain. The composite lumbers expand and contract with changes in temperature. They are not limited to 'across the grain'. They move equally in all directions. Most of them move quite a bit.

The net result - along a long strip like a rubrail - is that the 'wood' tends to work against the fasteners. This can open up the shank clearance hole, or pull out fasteners, or force the 'wood' to buckle. I've even seen it pull the rubrail away from the hull after it's been pookied down. All in all, I'd say it's not a good material for the application.

You say you've used Trex before on a boat. I'm surprised you haven't noticed this phenomenon. Maybe it was smaller pieces?

There are any number of less expensive wood species that'd be suitable.

I received the following info on Trex with respect to elongation.
from 16.1 X 10(to the minus 6th) to 19.2 X 10(to the minus 6th) inches per inch of length per degree F.
My old fashioned math tells me that is about 1/2 inch in a 24 foot length. does that seem like I've done the calculations correctly?

[JimConlin]

You've done the calculation correctly.
That's the amount that a 24 foot piece would grow or shrink with 100 deg. F change in temperature if it were not restrained.
Constraining the piece to no movement would take a force in the neighborhood of 300 PSI. Select fastenings accordingly.

[Sayla]

There's a timber people use here for fence / screens (I think it will one day be seen as an incredible waste) - Belian - Class 1 durable +++ - I think I might try some for a use like that - doesn't glue so well, but fastens fine (kinda like teak).

Another timber available here is Vitex - sometimes called the poorman's teak

Sayla