Laminating quarter-sawn to flat-sawn douglas fir?

[Phil Stone]

On a past project, I ran out of enough dry flat-sawn douglas fir to make some built-up legs for a workbench, so I was delighted to find some kiln-dried DF at the local lumber yard. However, it was "vertical grain" (i.e., quarter-sawn) DF. I'll confess at the time, it did not occur to me that the two orientations of wood might have differential movement, so I happily laminated the two types of DF together to make the leg. Two years have passed, and the leg is holding together fine, but I'm curious if this is a really bad practice.

I think one thing working in my favor is that the local climate doesn't have a big seasonal indoor humidity swing. But, aside from theory, has anyone ever seen this type of lamination (quarter-sawn to flat-sawn) actually fail?

[Mel Fulks]

It'll be fine. It's a bench. Someday ,when you are gone, joint might open just a little. The bench as fine furniture is a modern unnecessary , but harmless, indulgence.

[Phil Stone]

It'll be fine. It's a bench. Someday ,when you are gone, joint might open just a little. The bench as fine furniture is a modern unnecessary , but harmless, indulgence.


Thanks for the reply, Mel. I worry more about structural failure than looks in this case. Do face glue-joints between different orientations of grain tend to open up?

[Mel Fulks]

I think so, but that doesn't mean it WILL open a little. Manufacturers usually pay NO attention to such small things. The fir might possibly have been a little less dry than cabinet woods and therefore a little more prone to open, but there is no reason to use cabinet material for a bench.

[Andrew Hughes]

My silly rule for table top boards is never ever glue the flat sawn to quarterd.Most of the time it just looks bad or wrong.I also stay away from glueing the inside of the tree to the outside.
For your bench I agree with Mel.
its good that you are thinking about it.

[Robert Engel]

Keep in mind once acclimated, movement is directly proportional to the width of the board.

In your example, a 3 or 4" wide leg your probably looking at movement on the order of 100th's of an inch, assuming the wood is acclimated.

There is a FWW video featuring Phil Lowe where, mimicking the craftsman of yesteryear, he pegged the corners of a 24" wide one-board top with no glue and no other fasteners to keep the top flat. Apparently this is how the old craftsman did it even though it violates the most basic tenets of ww'ing. He says the pieces built in the 1700's like this are still intact and not cracked but I wonder if he's just looking at the "survivors".

What I am saying is I think we overthink wood movement sometimes. Me - anything less than 12" wide board I generally don't worry much about it.

[Brian Holcombe]

Depends on location as well, if you are in an area similar to mine with huge seasonal humidity swings combined with something like forced air heat....you'll find out what doesn't work.

If you are in a place where it doesn't change much, then you can probably get away with a lot of stuff that won't fly elsewhere.

That being said, a 5" wide leg is probably not going to show any issues especially in a place with low humidity swings.

[Phil Stone]

Thank you all. I feel somewhat reassured.