Floor Boards on a bench top?

[Bill McDermott]

In making a benchtop... if I glue together two 3/4" sheets of MDF to get a stout, flat "subfloor" and then put maple floorboards on top - how would that work as a benchtop? The stability of the sheet goods appeals to me. The simplicity of nailing tongue and groove floorboards also appeals. Outside trim, dog hole rows, etc. would be solid. My main concern is the seasonal gaps I'd get between the boards. I think I can live with that.

Thoughts?

Thanks. Bill

[Glenn Madsen]

Bill, I have a couple of thoughts, because you asked so nicely...:)

I like the sheet goods as subfloor. I did my 'first bench' that way 6 or 8 years ago, and it's still in regular use. Mine was cabinet ply, but much the same thought.

And I like the maple as a work top, too. Unfinished, I'd think, or maybe danish oiled. But not much else. Otherwise, too slick for my use, really. Especially for handtools.

Nailed down? Well, not for me. My next bench will most likely be 24", down from 32" on this one. I don't expect massive swelling and shrinkage across 24", but then I live near San Francisco, and we don't get the major humidity changes across the seasons. Glue together would work fine for me. 6 or 8 screws, maybe, but no nails. YMMV.

Be sure the base is strong. Overly strong. Massively hugely over-engineered strong. Stout, even.:)

But have a go at it. Enjoy!

[Zach Logan]

I was searching around for uses for leftover flooring, and ended up here. Other than asthetics, would the maple serve any purpose? Two plies of MDF would seem pretty stout to me. But this was my first thought, to sheath the top of a bench with what I've got. Of course, I'd have to build a bench first...

[Andy Roeper]

A few years ago the local architectural salvage shop had a stack of section of cut-up bowling alley. Not the lightest stuff in the world as it is solid maple that is nailed every foot so you have to be carefull putting in dog holes.

[Jim Becker]

As you surmise the biggest issue is movement of the solid stock. A lot of folks who build MDF bench constructions for mass will simply top them with a replaceable piece of 1/4" hardboard held in place by a raised apron level with the field. To avoid complications with dog holes and vices, that portion of the bench can be a solid stock construction. You may be able to float the floor boards in a similar manner, but it may be difficult keeping it flat.

[Ron Brese]

I have to agree with Jim, I think you would be trying to fasten an unstable material to a stable material, if you fasten solid stock on the edge when the maple top expands it will attempt to push the solid stock on the edge outward which will break it's connection to the edge of the bench, and if it contracts it will be pulled inward which also will try to break it's attachment to the edge. I have heard of people doing this with no problems, however I don't know how much the humidity changes where these benches reside. It might work and it might be a nighmare. I would suggest screwing a piece of 3/4" maple or birch plywood to the top, this way when it becomes too banged up you can just remove the screws and replace the top piece of plywood.

I've heard of someone that used engineered maple flooring on a bench top. This material uses a thick veneer on top of a plywood substrate, which makes it quite stable and the thicker veneer would give you years of use.

There are a lot ways to do this that would create a much more stable assembly, the last thing you want is a workbench that is tearing itself apart.

Ron Brese

[Derek Cohen]

I built my bench top this way about 12 or so years ago. Not flooring, per se, but 1" thick Karri (similar to Jarrah) quarter sawn strips on top of 3" of MDF. It was meant to be a quick bench for use when we built this house, but it has remained in use in all this time (with a number of upgrades). Over the years it has developed a few 1mm gaps here-and-there in the Karri boards. Nothing that I would consider a concern, but the two materials do move differently.

http://i13.photobucket.com/albums/a262/Derek50/Workbench%20and%20Workshop/Benchstop.jpg

http://i13.photobucket.com/albums/a262/Derek50/Workbench%20and%20Workshop/lengthtoplane.jpg

It may be a better idea to "float" the solid wood top over the MDF rather than glue them, as I did.

Regards from Perth

Derek

[Mark Stutz]

Bill,
There was an article in WOOD some years agoabout bench construction using this method. They used 3/4" strips of flat sawn stock, turned on edge, giving a QS top which would at least decrease movement. They atached the strips to the MDF with construction adhesive to allow for movement.

I used this technique to do the cabinet tops in my shop, using left over oak flooring. The top "floats" on the MDF, and is glued in front but allowed to move at the back. The gap is covered by "backsplash" much like using shoe molding on the floor. This is not used as a bench as such, so does not need to be perfectly flat and so far there are no gaps after about 5 years.

Mark

[Tom Hamilton]

Hi Bill:

Lot's of good advice here and so to add to it assumes that what follows is also good advice. So, the disclaimer...just what I did, not advice.

http://www.sawmillcreek.org/showthread.php?t=50172

Lumber Liquidator's oak T&G flooring for 89 cents a square foot. Lot's of rejects...took three bundles to do my 77 X 33 top. The oak flooring covers the original 3/4 inch MDF, the second layer of 3/4 MDF and the 1 1/2 in thick quarter sawn southern yellow pine.

So the base if stable and the oak flooring has been so far...since Jan 07.

Not my idea, but a tip of the hat to Scott Grandstaff at Old Tools.


Enjoy the process, Tom, in Houston, with a really heavy bench.

[Bob Smalser]

I don't care if you use qsawn stock. Even the most stable of qsawn woods like H. Mahog or cedar will cause your ply-mounted hardwood top to go slightly out of flat the moment the humidity changes. Oak after 6 months OTOH, will look more like a cattle trough than a flat bench. ;) And sandwiching solid oak with ply is asking for the painful experience of making a new top, because if it delams...and it probably will eventually... it can't be saved.

http://pic20.picturetrail.com/VOL12/1104763/2594265/36332508.jpg

If the flooring is cheap, simply buy a enough for three layers and lam the top. Lams are best done in threes, fives, etc, and the thinner the better because thinner lams exert less power during seasonal movement. Then soft mount it using buttons on grooves in the end rails, and if you attach an end vise, then soft mount the crosscleat, too....like in a sliding dovetail. Otherwise I guarantee the top will go out of flat when the season changes, and there's no use flattening it then, because it will just go out of flat again the following season.

If you are using White Oak, the high tannic acid content can cause problems with epoxy. Use a laminating glue like one of the UF-resins, or even resorcinol if the bench will ever spend any time outdoors or in an unheated space. Use Titebond and you'll never reglue atop any part of the residue if it ever requires repair.

Also be careful with flooring stock. These days with underlfloor heating so common, it's usually kilned to 4% EMC. If the average EMC in your shop is 8% even a soft-mounted top will go out of flat. The only difference being when you flatten it 6 months after its finished, it'll remain flat.

[Derek Cohen]

I don't care if you use qsawn stock. Even the most stable of qsawn woods like H. Mahog or cedar will cause your ply-mounted hardwood top to go slightly out of flat the moment the humidity changes.

Hi Bob

I would agree with you just on logic. Fortunately I do not live in a humid climate - Perth has dry heat (>100 degree F days but minimal humidity) in summer and winter is just plain wet but not especially cold. So, while I do not get the day-to-day variations, what I get are the seasonal variations. A dozen years of using a sandwich construction has been very kind. Not much movement to speak of. I have only needed to flatten the top once in all these years. No doubt a different climate would produce a substantially different result. If I was to start again - which is finally on the cards as we are about to embark on renovations - I would only build a solid construction of the design you described.

Regards from Perth

Derek

[Bob Smalser]

....A dozen years of using a sandwich construction has been very kind.

Somehow I don't think Bill lives in Perth. ;)

I once was on a team restoring traditional sailing dhows in the Sultanate of Oman, and the wood problems there were more like yours than in the US. Set your bench out in that 100-degree sun and UV for any length of time, and see what happens. Glues supposed to be flexible cease to be so with heat and UV, the top curls as moisture distribution becomes uneven, and the glue joints break. That's why the only planking wood you ever see on an old dhow of any size is stable, sun-resistant teak, often with mango framing.

But unless Bill and the other posters live in the dry deserts of Arizona, California or Nevada, I guarantee they'll experience the problems I mention to one degree or another, depending on seasonal humidity changes.

[Tom Saurer]

I needed a heavy and cheap bench, so I went this route. I saw that the local home store sold steel door rejects for $5 or less. I then screwed MDF to the top to cover the steel. I screwed it, so that as the MDF wears I can replace it. The MDF can be flattened with a belt sander as needed. All for less then $15.

[Bill McDermott]

More great information than I expected! My first post was an unadulterated success!

I'll float solid boards, allowing for movement.

Thanks all! Looking forward to returning the favor.

Bill

PS - I am not aon a luxury yacht, not do I harken from Perth. But my basement shop in Chicagoland does demand some environmental consiederations.

[glenn bradley]

More great information than I expected! My first post was an unadulterated success!

I'll float solid boards, allowing for movement.

Thanks all! Looking forward to returning the favor.

Bill

PS - I am not aon a luxury yacht, not do I harken from Perth. But my basement shop in Chicagoland does demand some environmental consiederations.

Just think how post 3 may go :D . Welcome aboard BTW.

[Pete Ducklow]

Bill, you might want to check out Ken Vaughn's bench. He attached oak flooring strips to a solid core door with construction mastic

http://home.comcast.net/~kvaughn65/workbench.html (http://home.comcast.net/%7Ekvaughn65/workbench.html)

http://home.comcast.net/%7Ekvaughn65/bench_top.jpg