Identifying wood?

I'm thinking about buying some wood on Craigslist. The seller is calling it "mahogany decking." how do I tell if it is actually mahogany as opposed to meranti or something? I would be fine with buying meranti, I would just like to be sure I know what I am buying.

 

True mahogany is a hard dark wood with marked grain and golden sparkles. The density is 41lbs/ft3.

 

There is no way to know for sure on cut lumber, density and color can vary all over the place within one species. The only way to know is to take a micro scope and examine the wood cell structure and compare it to slides of known woods. Or send a sample to a wood lab and they will identify it for you.

It might be possible to accurately weight and flex some samples and compare the density and elastic modulus to known woods, but again you need a large sample and you still can get fooled. Might be faster to see if you can trace the source of where it came from through the seller.

 

There are 40 separate sub-species of mahogany, though most are easily identified by those familiar with it. Of these 40, only a half dozen or so, are commonly available. CraigsList is a great place to get ripped off, so ask for very close pictures and several angles, then post here.

 

A shaving can be mailed. That's a pretty good identifier. Many cedar species are called mahogany and they can be good boat woods but they also should cost much less so buyer beware.

 

Cant you ask for certification so some legal responsability is applied.

 

This is CraigsList, all you're dealing with is some guy looking to off load something they don't want any more, so guess what usually happens.

 

Pig in a poke- price accordingly...

 

I went and toll some pictures today? What do you think?
www.nbehlman.com/wood1.jpg
www.nbehlman.com/wood2.jpg
www.nbehlman.com/wood3.jpg
www.nbehlman.com/wood4.jpg

 

That appears to be dark red shorea, commonly known as meranti, lauan and Philippine mahogany. It's not a real mahogany, but is quite durable and pretty when varnished up. It's an evergreen and very commonly found in many products, including plywood. It's not common to be found as solid stock in the USA generally, as native species dominate, but is available.

 

Cool. Thanks, PAR. I'm thinking about buying it. It's 150 boart feet for $250. I plan to plane them down to use for planking on a Chris craft style mahogany runabout.

 

Meranti doesn't like to bend well, though with experience you can "convince" it. Mahogany also doesn't like to bend, but is better then meranti in this regard. The meranti will fool most folks, but not anyone familiar with mahogany.

 

Looks like Ipe (greenheart) to me...

The planks are milled for the fastener-less decking clips.
You will know when you go to pick up a board- Ipe is HEAVY.

 

+1 for ipe...especially at that price. in my experience its easy to distinguish from mahogany just by pure density. ipe is wood that doesnt float. i once tossed a stick of it in the pool so my dog could cool off and she just gave me the stink-eye cause it went straight to the bottom. ive installed acres of the S4 edge-grooved ipe decking. its hands down the best wearing residential deck stock. beautiful, will not rot, nicely greys over time, stable and hard hard hard. eats up carbide tooling and flat-out destroys standard saw blades. ive been cautioned the dust and smoke are particularly toxic but have no specific info.
after extensive research on this and other forums and with several suppliers ive decided to use 6" 5/4 un-grooved ipe decking as the laminating stock for new floor timbers in my boat. i prep the wood with a good slow scratch of 24grit, then acetone wash and flare with a match strike. then build the lams with a layer of 1708 biax / epoxy that extends beyond the floor and up/out along the bilge to tie them into the hull. when the lams reach about 12" total height the entire member gets 2 layers of biax tying it to the bilge and hull and seals up the edge grain of the ipe. they make for damn heavy floor timbers and i like that each layer is tied to the hull and fanned out over several square feet. overkill ? probably. its weight below the waterline so i dont worry too much.
i dont think id use it above the waterline in quantity though.

also, being very dark the stuff gets really hot in blazing sun...no bare feet in summer.

hope this helps

 

Hmmm. I'm not sure what to do now. I looked at the properties of ipe and I don't think that is going to work. It seems to be incredibly hard and heavy, which is pretty much what robwilk37 said. I was planning on milling this stuff myself, and it sounds like it is difficult to work with. As a side note, ipe actually appears to be slightly more expensive than african mahogany, at least where I'm from.