Which wood for bearers?

[Volvo KAD 32 tfft]

So what is the recommended timber for engine bearers? I see in the USA they use "live Oak" don't know what that is, do they mean green?
My new bearers need to be about 6x4" and 18" long, any suggestions?

 

[sailorman]

So what is the recommended timber for engine bearers? I see in the USA they use "live Oak" don't know what that is, do they mean green?
My new bearers need to be about 6x4" and 18" long, any suggestions?

green oak will have the tendency to warp/ split as it dries out & there fore not really stable.
Iroko would be hard & durable

 

[sarabande]

I think that "live " oak is an evergreen oak, such as Holly Oak.

It's a very tough wood, and is used for barrels and wood bearings, as it has an oily texture. So, presumably water and oil resistant ?

 

[oldsaltoz]

There are some recycled plastics that will replace timber and avoid most of the problems that timber has.

 

[Assassin]

There are a number of "engineered lumber" products which are now being used, they act the same way as wood does when you work it so it cuts and shapes in exactly the same way, but does not shrink and is waterproof.
Engineered lumber comes in many forms and often comprises wood pulp, wood chips, or wood fibres compressed tightly together with a bonding meduim such as epoxy based glues to form a highly durable and stable product.

 

[Poignard]

Iroko: locked-in stresses?

green oak will have the tendency to warp/ split as it dries out & there fore not really stable.
Iroko would be hard & durable

Iroko can be unstable, though. I recently ripped a short length of straight iroko that had been in my garage for years (i.e. well-seasoned) and ended up with two curved pieces! As the bandsaw cut through it the ends just bent apart

 

[Volvo KAD 32 tfft]

There are a number of "engineered lumber" products which are now being used, they act the same way as wood does when you work it so it cuts and shapes in exactly the same way, but does not shrink and is waterproof.
Engineered lumber comes in many forms and often comprises wood pulp, wood chips, or wood fibres compressed tightly together with a bonding meduim such as epoxy based glues to form a highly durable and stable product.

"engineered lumber"

How about, 20mm marine grade ply cut into lengths and laminated together with epoxy/resin and glass?

 

[oldsaltoz]

"engineered lumber"

How about, 20mm marine grade ply cut into lengths and laminated together with epoxy/resin and glass?

Very expensive and you end up relying on the manufacturers glue.

 

[tillergirl]

Forgive me sticking my nose in (of course I don't know the intended application) but 18" long doesn't sound very long for engine bearers especially if the weight of engine requires 6"x4" section. The point is to spread the weight as much as possible. I used longer than that quite a while back for a 10hp side valve petrol engine. I would suggest that the marine ply route is a rather complicated way of doing something simple. Try some kiln dried oak from Robbins of Bristol.

 

[Volvo KAD 32 tfft]

Forgive me sticking my nose in (of course I don't know the intended application) but 18" long doesn't sound very long for engine bearers especially if the weight of engine requires 6"x4" section. The point is to spread the weight as much as possible. I used longer than that quite a while back for a 10hp side valve petrol engine. I would suggest that the marine ply route is a rather complicated way of doing something simple. Try some kiln dried oak from Robbins of Bristol.

Ok, I should have explained more clearly, the 18" long bearers are to raise the height of the existing bearers by 4" and will sit on top of them,
the existing bearers are constructed of steel box section and heavy steel angle, which is on glassed blocks and also through bolted to the stringers which are approx 8" x 2" and as you know run almost the entire length of the boat,
This arrangement has supported the Mercruiser 185hp engine for 26 years, without fault, but the new engine is 200lb heavier so needs a" little beefing up" to be on the safe side.

 

[Tranona]

Don't think the actual wood in this case is that important. It just needs to be stable and non-compressible. I have just raised bearers by about 50mm using mahogany and faced with 6mm ply as the mahogany in my dwindling stock was not quite thick enough to make up the whole additional thickness.

 

[fergie_mac66]

ASH

ash would be a good choice

Tough and flexible - Ash is one of our toughest native timbers and because of its flexibility it can withstand pressure, shock and splintering. Traditionally ash was used for weapons and the word ash comes from the Anglo Saxon word for spear 'Aesc'. In modern times it is used wherever toughness is important as in sports equipment

 

[Imperial One]

MDF from B&Q?

 

[Volvo KAD 32 tfft]

MDF from B&Q?

Is that what you use at Imperial Motor yachts? tut tut

 

[GRPrich]

Im currently replacing the engine bed in my sea ray seville and have used mahogany and will laminate that in place (if and when the weather warms up!). I have replaced and modified a number of engine beds and always used mahogany with no problems whatsoever! Hope this helps!

 

[Volvo KAD 32 tfft]

Im currently replacing the engine bed in my sea ray seville and have used mahogany and will laminate that in place (if and when the weather warms up!). I have replaced and modified a number of engine beds and always used mahogany with no problems whatsoever! Hope this helps!

Hello,Welcome! and many thanks for your reply,
Due to this weather (bored with it now) all progress has stopped for the time being, hopefully I can continue soon, I should be able to get hold of some Mahogany no trouble,
I am still unsure about the correct matting/sheet and epoxy etc that i should use to glass in the bearers, any advice appreciated?
Bill

 

[GRPrich]

Its hard to say what mat, resin, epoxy you will need without seeing the job. Give me a call if you get stuck 07888055951 Rich.

 

[nedmin]

Ash no good were water is present,it loves it! Soaks it up like blotting paper and then goes rotten.I had ash rubbing strakes on previous boat,I spent more time on them than the rest of the boat ! Needless to say I would never buy a Morgan car !