Stair treads for bench top

[Irvin Gomez]

First thing: get the idea of gluing solid wood to plywood out of your head. It just will not work, no way, no how.

honest question (not arguing because I don't know the answer): if the stair tread is made of finger-jointed small pieces of hardwood sandwiched between two layers of 1/8" solid oak, how much expansion, if any, should occur on an 11" X 36" unit? Why won't there be damage when gluing the 1/8" thick layer of solid oak to the finger-jointed composite material?

I'm in no way denying that wood expansion is very real and I'm not disputing the rule that says something bad will happen when gluing solid wood to plywood. I'm only pondering if there is enough expansion (by the hybrid-wood stair tread) in this particular case to merit worrying about the well-documented problem. Is the rule applicable in this particular case?

I have a particular interest in using the stair tread because it solves a big problem for me: how to easily and reliably do cross cuts on 7/8" (or less) thick stuff without a table saw or miter saw. That's a big part of my plans for this bench top.

Any ideas?

[Chris Hachet]

honest question (not arguing because I don't know the answer): if the stair tread is made of finger-jointed small pieces of hardwood sandwiched between two layers of 1/8" solid oak, how much expansion, if any, should occur on an 11" X 36" unit? Why won't there be damage when gluing the 1/8" thick layer of solid oak to the finger-jointed composite material?

I'm in no way denying that wood expansion is very real and I'm not disputing the rule that says something bad will happen when gluing solid wood to plywood. I'm only pondering if there is enough expansion (by the hybrid-wood stair tread) in this particular case to merit worrying about the well-documented problem. Is the rule applicable in this particular case?

I have a particular interest in using the stair tread because it solves a big problem for me: how to easily and reliably do cross cuts on 7/8" (or less) thick stuff without a table saw or miter saw. That's a big part of my plans for this bench top.

Any ideas?

Buy two clamps, take a piece of construction grade lumber, and use it as a fence for your circular saw. Or for that matter, buy a cheapie cross cut saw with hardened teeth and cut it by hand. Cutting a straight line by hand is not that difficult, and it will be good practice for all of the other cutting you will do as you progress as a wood worker.

[Chris Hachet]

Buy two clamps, take a piece of construction grade lumber, and use it as a fence for your circular saw. Or for that matter, buy a cheapie cross cut saw with hardened teeth and cut it by hand. Cutting a straight line by hand is not that difficult, and it will be good practice for all of the other cutting you will do as you progress as a wood worker.

Or for that matter, have your plywood cut at the home center or lumber yard you buy it at. Glue up two pieces on something relatively flat, and you should be off to the races. You way want to watch a you tube video on Winding sticks so you know if you are nice and level if you laminate two pieces of plywood together.

[Chris Hachet]

Go to recycle store and get a solid core door. Cut to size, glue & screw 1"" MDF to this. Double sided tape a 1/8" hardboard for the top and trim it out with pine. When the top gets damaged change it out for another hardboard top. Build the base out of 2 by material. This will last you a long time and give you a solid flat surface to work on.

...or...pretty much this as an alternative to the wood flooring option.

[Irvin Gomez]

Buy two clamps, take a piece of construction grade lumber, and use it as a fence for your circular saw. Or for that matter, buy a cheapie cross cut saw with hardened teeth and cut it by hand. Cutting a straight line by hand is not that difficult, and it will be good practice for all of the other cutting you will do as you progress as a wood worker.

I have a decent circular saw (Makita) with a rail guide. I mentioned it in my initial post - one of the reasons for considering the stair tread is that by leaving a 5" groove between them (as in those workbenches with a center groove for tools) I could easily do cross cuts on 7/8" (or less) thick stock.

I'm still interested in knowing how much wood movement cab be expected from a 12x36" stair tread that consists of finger-jointed hardwood sandwiched between 2 solid pieces of 1/8" thick oak. Enough to cause problems when glued to plywood?

[Frank Pratt]

I'm still interested in knowing how much wood movement cab be expected from a 12x36" stair tread that consists of finger-jointed hardwood sandwiched between 2 solid pieces of 1/8" thick oak. Enough to cause problems when glued to plywood?

Is the grain direction of the oak parallel or perpendicular to the finger jointed wood in the middle?

[Erik Christensen]

Irvin - re solid wood expansion - it exists and it will break things - it does not matter how the solid wood is built up - why is plywood different is the question to ask - the answer is because each layer is 90 degrees to the layers above/below - wood expands in width not length so the alternate layers keep things from moving - solid wood (even if assembled from smaller parts) does not have such 90 opposing grain so there is nothing to resist the change in size

[Phil Stone]

One other factor I have considered: even if I bite the bullet and order a laminated top for like $400 including shipping, I read a lot of guys claiming they had to flatten them upon arrival!

This is an important consideration. The Bally Block tops that Woodcraft sells are beautiful and generally flat, but they are laid up with blocks of alternating grain direction -- very hard to hand plane to flatness (although a router/sled might work).

[Irvin Gomez]

Is the grain direction of the oak parallel or perpendicular to the finger jointed wood in the middle?

parallel, Frank

[Frank Pratt]

parallel, Frank

All wood expand & contracts with moisture change much more across the grain than with it. Those stair treads will act as a solid piece of wood as far as movement is concerned. If glued to plywood, it will either cause the assembly to bow or cup as the humidity changes.

Plywood is a bit of a different animal. It's made of alternating cross grain, very thin layers. As a result, it only expands & contracts about as much as solid wood does in long grain direction.

If you start with a couple of layers of 3/4" ply, MDF, or a solid core door, then you can still add a 3/4" layer with a gap to give you the groove for clearance with sawing. You can probably build the whole bench for less than the cost of the stair treads & it'll be a much better bench.

Good luck with your build & be sure to share the results with us.