Workbench - Sacrificial Top

[Steve Friedman]

I have replaced my workbench top several times - always using 4 layers of 3/4" ply laminated together.  The one I am doing now will be a couple of sheets laminated to a 1-3/4" thick solid core door that a friend gave to me. I want the thickness because of the added weight.

To make the edge look a little nicer, I'm going to frame the top with hardwood, which started me thinking about leaving the edging proud to accept a sacrificial top.  I really abuse my workbench and kind of like the idea.  Two questions:

1.  What's the drawback to using a sacrificial top?

2.  Any strong preference for the material to use?  I know lots of folks use Masonite, but I'm leaning toward 1/4" cabinet grade plywood.  It's a little thicker than the 3/16 Masonite that I can get and I kind of  like having a wooden surface.  I hate MDF.  

Thanks,

Steve

[Bibliophile 13]

Why not just go with solid wood all the way across? Even pine will hold up pretty well. Plywood has its uses, but IMO a frequently-used work surface isn't one of them. Edging it in hardwood will probably make a plywood top last a little longer, as the delamination usually begins around the edges.

[Steve Friedman]

Why not just go with solid wood all the way across?  Even pine will hold up pretty well.  

Thanks Steve,

Because I don't have the time to laminate a bunch of pine to make a top.  I have been using laminated sheets of plywood for almost 10 years and never had a problem with the edges.  I followed the suggestion by Drew Langsner to coat the edges with marine-grade epoxy and the edges hold up fine.  The damage has been to the top - mostly from using it as a general purpose bench.  It gets covered in grease, grime, oil, rust, glue, epoxy, even PVC cement.  Just about every substance you can think of.  I even drive screws into the edges sometimes if needed to attach jigs to the bench.

I'm upgrading my bench in stages.  The frame supporting my existing bench is made from poplar.  The new one is hard maple and I'm excited to have come even that far.  Maybe when it's time to replace this top, I'll be ready for one made out of wood.

Steve

[Stwood_]

My top sheet is 3/4 marine grade ply. It's been flipped once already, about time to replace it now.
I'll replace it with the same ply

[hbmcc]

You don't like MDF. I don't like ply for a surface--for the same reasons you replace yours. I can never make a solid bench do what it is intended for; it turns into a shelf. I doubt you have the same problem. 

But, I have found that Melamine covered sawdust board works well as a temporary work surface. Screw it onto your top, destroy it as usual; and then, replace. Fantastic for glue-up work. The only hassle I have is it doesn't hold an ink line very well (for layout), is slippy, and sucks if left out in the rain after a hundred screw holes.

[Steve Friedman]

You don't like MDF. I don't like ply for a surface--for the same reasons you replace yours. I can never make a solid bench do what it is intended for; it turns into a shelf. I doubt you have the same problem. 

But, I have found that Melamine covered sawdust board works well as a temporary work surface. Screw it onto your top, destroy it as usual; and then, replace. Fantastic for glue-up work. The only hassle I have is it doesn't hold an ink line very well (for layout), is slippy, and sucks if left out in the rain.

Thanks Bruce,

Every horizontal surface in my garage/shop becomes a shelf.  I even have a stool that ends up becoming a shelf.

I thought about the melamine coated stuff.

Steve

---

Rich,

I thought you meant to tack the 3/4" ply to the door.  I was planning to laminate two sheet of 3/4"ply and then glue that to the bottom of the door.  Any reason not to use glue there?

As for the thin top, I was going to use screws, but like the idea of just popping in a few brads in the corners.  I was going to pin the top down before cutting the border.  With the odd thickness of plywood and Masonite, it's the only way I would ever get the width right.


Steve

[blackhat]

1.  Looks
2.  1/4" tempered hardboard. Wears like iron. Mine is still in good shape after 6 years. Cleans easy. Butt ugly.

[Steve Friedman]

1.  Looks
2.  1/4" tempered hardboard. Wears like iron. Mine is still in good shape after 6 years. Cleans easy. Butt ugly.

Thanks. I don't mind butt ugly.

"2.  1/4" tempered hardboard. Wears like iron. Mine is still in good shape after 6 years. Cleans easy. Butt ugly. "


This^^^^^^  -   if you are committed to a replaceable top, which you already know is a compromise, but I've done that in the past over a solid core door.  

Any cabinet grade plywood (which ain't cheap)  won't wear well as the veneer is really thin nowadays, and you'll be replacing it sooner than you think.

Niece Lumber in Lambertville is a good yard, and they have 1/4" hardboard, rather than the 3/16" I see all the time at the Borg.

It might go without saying, but I'd lay whatever you end up as the replaceable top on top of the solid core door, putting the 3/4 ply under the door, pinning it with only 6 max 8 of the 3/4" brads.

Thanks Rich.  I didn't know where to get 1/4" hardboard.  And the best thing (for those of us with a huge pickup) is that they deliver.  

Buy why only pinning the plywood to the door?  I was actually going to glue it.  I'm guessing the concern is wood movement against the plywood, but this door apparently came from a hospital and still has a label dated in the late 1960s.  It weighs a ton.  Laminated strips of wood (maybe 1-1/2" square), covered with a layer of something that looks like hardboard, with the whole thing covered with a veneer.  I figured that since I was gluing to the laminate, wood movement would not be an issue.

Steve

[Admiral]

Thanks. I don't mind butt ugly.


Thanks Rich.  I didn't know where to get 1/4" hardboard.  And the best thing (for those of us with a huge pickup) is that they deliver.  

Buy why only pinning the plywood to the door?  I was actually going to glue it.  I'm guessing the concern is wood movement against the plywood, but this door apparently came from a hospital and still has a label dated in the late 1960s.  It weighs a ton.  Laminated strips of wood (maybe 1-1/2" square), covered with a layer of something that looks like hardboard, with the whole thing covered with a veneer.  I figured that since I was gluing to the laminate, wood movement would not be an issue.

Steve

No need to glue it, that's overkill for this material. I've got some on my RAS top held in by 4 brads, it sits really flat and hasn't moved at all in 8 years.  Very easy to pop up and replace when the time comes too.  And if you wrap the edge in hardwood it ain't moving sideways.  I'd pin it down first and then affix the hardwood edge flush, so if and when you replace the hardboard it will again sit flush.  One in each corner, maybe two on each edge on the long length edges and maybe two in the center depending on width (and that number of brads is over-engineering).  It doesn't take much.

[Admiral]

"2.  1/4" tempered hardboard. Wears like iron. Mine is still in good shape after 6 years. Cleans easy. Butt ugly. "


This^^^^^^  -   if you are committed to a replaceable top, which you already know is a compromise, but I've done that in the past over a solid core door.  

Any cabinet grade plywood (which ain't cheap)  won't wear well as the veneer is really thin nowadays, and you'll be replacing it sooner than you think.

Niece Lumber in Lambertville is a good yard, and they have 1/4" hardboard, rather than the 3/16" I see all the time at the Borg.

It might go without saying, but I'd lay whatever you end up as the replaceable top on top of the solid core door, putting the 3/4 ply under the door, pinning it with only 6 max 8 of the 3/4" brads.