Oak, or Iroko?

[Clyde_Wanderer]

I am going to renew the rubbing strake on my boat during the winter and dont want to use teak as I dont like it.
I have priced ordinary oak and American white oak and Iroko
all much the same in price, but what I am most concerned about is, as least knots as possible, and ease of bending, as it will have to be bent to suit the curve of the hull and I wont have access to a means of steaming.
Also I want to ba able to varnish it to a good finnish.
Anyone advice on the best of this three choices, considering the above?
Thanks, Clyde_wanderer.

 

[nordic_ranger]

Possibly posting this on the Classic boat forum would give you better advice as a lot of these guys have wooden boat building experience.

 

[Alrob]

as far as I am aware teak is the widely used timber for this purpose which makes me think that this is the best material for the job. Iroko is very similar in colour & grain to teak, oak is heavy & hard to work with plus it can can get a bit brittle. others to consider are merranti/majau (easy to work & bend)
sapelle like mahogany but heavier

good luck

 

[Roach1948]

I would imagine oak to be the bendier of the two woods but it is less durable and can stain if not varnished regularly. Oak also tends to go black around fastenings and in time it has been known to crack (although this does not affect strength). Iroko is very hard to work with if you are splinning lengths but it is very durable and will come up nicely when varnished - it is also practicaly indistructable. As for steaming, really depends on lenghths. I have a 22 footer and used mahogany from Robbins timber. I needed 3 8ft lengths each side and this bent to the hull without any steaming at all. I am sure there are others with more insight into the virtues/pitfalls of either woods.

 

[tillergirl]

You won't have a problem bending iroko - my entire hull, gunwales and rubbing strake are all iroko. You can get a wild grain with iroko but if you get a chance to view before you buy, this shouldn't be a problem. The key to the bending is plenty of clamps and chamfered edges.

 

[cerro]

I have some mahogany that would be Ideal I think it is 30'x5"x1/2" but come and have a look at it I am only at Saltcoats Its well seasoned I have had it 26 years and its cheap Gordon

 

[srp]

Teak is the very best choice - I don't understand why you don't like it. Iroko is harder to steam bend and is seldom straight grained or free from internal stresses. American oak is not as durable as English, so I wouldn't even consider it. English oak will steam bend very well, especially if you buy it green from a local sawmill. Contrary to what others have said above, it works beautifully (much better than iroko or any of the substitute mahoganies). Avoid anything with sapwood in and it's very durable, but will go black if it's in contact with steel.
Clamping is the biggest problem when steam bending a rubbing strake. Don't try pre-drilling or fixing it as you go, as it will just snap. Its probably best to set up a jig by screwing some blocks on a scaffold board. Steam the timber (1 hour per inch of thickness) using a wallpaper stripper and a 4" plastic sewer pipe, then clamp it to your jig and leave to 'set' for at least 24 hours. You should only need to steam the bow section where the curve is sharpest.
If I'm steaming any sort of wood I leave it out on the grass for a day or so first, to get the moisture content up a bit.

 

[paul_williams]

iroko, as long as sharp tools are used and the right timber is selected. it finishes beautifully, the boat who's rubbing strake was replaced still looks supurb now, five years later. and if your going to steam it, don't do as i did, and borrow someones sewer pipe... plastic doesnt like that much heat if you want to re use the pipe for its origianal purpose.

 

[DeeGee]

I would advise against iroko - speaking as a carpenter, not with a marine hat on - iroko grows with a wild grain, there is no such thing as straight grained iroko. Once it has been machined, and as long as you dont try bending, it is OK, but it is difficult to machine. It is used extensively in marine construction, but on commercial machinery. Teak is easier, if you can get it. Idigbo is the wood used mostly in marina decking.