Can spalted maple be used structurally?

[Carlos]

That's the basic question, much of it seems like it would break easily. However I see "common uses" include furniture. Maybe just not in structural parts?

My specific use is for a bed frame that people might sit on.

[Popeye]

Just my two cents but I'd never use spalted (read rotten) wood on anything structural. You might overlay it on solid wood to have the look but I'd not use it to hold any weight, especially a bed. Pat

[Uncle Cracker]

That depends. If the spalt is "hard" spalt (that is having the black staining, but no rot), I have seen no difference in stability in my turning pursuits between that and non-spalted maple. "Soft" spalted wood, on the other hand, can be very punky, and cannot be trusted to hold together on the lathe without stabilization, which might include casting in resin, soaking and finishing with cyanoacrylate glue, or pressure injection of some other sort of stabilization agent. Other factors are the nature of the wood (hard or otherwise) before the spalt sets in, and whether the spalting took place while the tree was standing, or lying on the ground.

Spalting obviously adds a unique look to the wood, but this can also result in figuring that is not uniform, making larger pieces difficult to carry the character of the material throughout. I might suggest for furniture that you look instead at ambrosia maple, where the staining occurs in much more stable wood, and adds a multi-colored component often not found in spalted maple. Unfortunately, it also adds insect holes, which some folks highlight as part of the character, but others do not like.

Either way, I'd recommend that your bedframe design include stringers and other structural elements of a more stable (and probably cheaper) specie, if you can swing it by keeping those elements hidden. Remember that we gotta see pictures of the results...

[Carlos]

The style of this part would be a platform, where about 10" of horizontal wood rings the bed. The bed "floats" in the middle of the platform. So there wouldn't be any ability to add unseen supported (or only a very limited amount). Someone sitting on the edge would put a great deal of force on it. I originally started with hard maple in mind, possibly 8/4, but there's a sale on spalted and I love that look. Other parts of the bed set will be in bubinga for accent.

I should probably stick to hard maple for stability and strength.

Hmmm...hard maple, and pull veneers off that spalted...?

[Uncle Cracker]

If you got ways to cover the edges, then go with the veneers. It'll look like solid pieces.

[SARGE..g-47]

Uncle Crack has you covered Carlos. I also would not use spalted maple in key structure for the reason he mentioned. I wouldn't build a deck from rotten wood either.

But the ambrosia maple would be fine but as Crack mentioned it has beetle holes around the spalting which was caused by fungus carried on the feet of the Asian ambrosia beetle. The young larvae feed on the fungus but the fungus gives it a unique character and in certain cases the holes don't distract but add IMO.

For that matter I have some laying on my work-bench to be used as a lid on a small, decorative box (my first small box ever) but a lid on a small box is not going to have someone standing on it. My wife and niece may stand on it and stomp vigorously after they see my first attempt but... that is just the way it is and I don't expect collapse under normal conditions.

[Carlos]

That's the primary thing holding me back from that idea. The outside edges are visible, and would probably show a grain transition terribly. I like the look of thick seamless edges, hence the thought of using 8/4. Maybe I'll buy some and do a piece a couple feet long and see what it looks like. Wonder if I could miter the veneers... The thinnest I've pulled before are about .16", and that should be able to hold a miter edge.

[Uncle Cracker]

You could use thicker material for the edge banding, and still miter the top edges. Also, have you considered a radiused profile, with the veneer bent and glued to a substrate? With the edge thickness you are talking about, it's not really needing to be a sharp radius... Then there would be no miters needed, except on the corners of the platform. (No chance of splinters in your butt, either...)

[Carlos]

The radius profile is an interesting idea. I wonder how thin the veneers would have to be to do that? Never tried it.

[Uncle Cracker]

The thinner the better, but you could also kerf the backside of a thicker veneer to help you around the radius. Wetting and bending around a temporary form is also another method. Do not wet it and do a final glue up, as it will split as it dries.