frames timber

[alienzdive]

Hi there,

I am replacing 2 rib frames in a 30 foot yacht, they were previously about 6 foot long 2 pces of laminated Miranti soft wood. 5" x 2" making a total of 5" x 4" after lamination.

I know that oak is common, but can also get Iroko, Miranti and teak for a good price. The frames involved also support the wieght of the keel although there are about 5 frames in total spreading the load.

It has got me thinking, price not being the main issue as 2 of 6 foot laminated frames are not going to have dramaic price variations, ie approx £25 - £50 per length. What are the benefits disadvantages of each timber? are all suitable? what other common hard wood timbers are readily available?

At the moment I am more inclined to be using teak as it is readily availbale but asking around I have been getting varied and mixed opinions on what best to use and what would or would not be suitable.

 

[Joe_Cole]

Personally, I wouldn't use Teak for a laminated fabrication. Being oily it is not the easiest of woods to glue and a laminated component relies on well glued joins. Oak would be very strong. I've never worked with Miranti so I don't know anything about it, but I'm sure that others will be able to tell you. However if it was satisfactory before then why change?

 

[chippie]

I think sticking with what was there is probably the best option, if only to seem more harmonius when you sell the boat.

 

[tillergirl]

Well oak is the best (except I don't know miranti) but bending 5" x 2" will require some steaming! In my boat, these are sawn frames, but if you cut down the oak to more steamable sizes, I think that will work ok. Don't use teak for the reason given, also iroko can have a wild grain so doesn't take to bending well. It is also a little oily but nothing like teak.

 

[kds]

Your profile doesn't give much away !
I have had great success with meranti - it will steam and take a bend and glues well - but that was years ago. I have not seen any good, dark, hard meranti about for ages. There is plenty of porous, pinky softwood meranti, which I would not consider using for anything structural. I think the name covers a multitude of mahogany-like timbers. Can you get the good quality stuff ?
Oak is so easy to steam, but ash would also do a good job. 2" is thick to bend - surely 1" would give a fairer curve and a stronger result ?
Ken

 

[alienzdive]

Hi KDS,

Miranti is cheap and readily available, it is my belief that all Miranti is soft wood.

There is no bending required as the boat is a 30 ft chined ply construction, however 2 pieces of 2 " thick require lamination and then the shpe cut by saw.

All teh Miranti I can find is not so much pink in colour but usually oak coloured and the occasional length I have seen in the past ahs been dark but I think it is whast ever gets sent out on the day with that stuff. Is the light oak coloured stuff what yopu mean by pink?

 

[kds]

Hi Alien,
I should be honest and say that I was building in Africa at the time and could get what was called meranti of a mahogany colour - hard and easily worked. The local stuff in the West Country is much lighter - yes sometimes like an oak colour and you can push your thumbnail into it.
Have you considered using layers of 12mm ply - you can make a very strong chine joint that way ?
Ken

 

[Spuddy]

Ther seem to be two subvarieties of meranti at least, with an alternative name of lauan just to confuse things. I used to use the dark red meranti for cheap furniture - stringy texture, glues well, reasonable density and strength and probably got adequate durability for your purpose but use some preservative.
Lately I've only had to handle the paler orrible stuff - softer than pine sometimes and less durable judging by some of the "hardwood" window cills I've repaired.
Local timber merchants are probably no good. We used to use Fitchett and Woollacott for the good stuff and like you say for your quantities it would only cost a bit more.
regards...spuddy