Need advice - flattening small bench top

[kfitzsimons]

I've got a 20" wide x 48" long x 2.25" thick maple bench top, which was part of a very large bench from a school shop. Of course it's got a a dozen or two brads in the top, some of which are hidden. No really large nails that I can detect with a metal detector. It's not attached to legs yet nor are vices installed. The middle 4/5ths of the top are pretty flat. The breadboard ends seem to slope off at the ends about 1/16 - 1/8" so there's a lot of surface to get flat. I can't use a plane to flatten it because of the brads. I could use a RO125, but I'm afraid of making it wavy. Any suggestions? Would a Performax like sander do the job? I don't know anyone with a large "table" sander in central Ohio. Suggestions welcome.
Thanks, Kevin

 

[Ken Nagrod]

Make sure to get all the nails and any metal out of it.  Then get a professional cabinet shop with a wide belt sander to run it thru for a small fee.  So much easier, faster, smarter... [wink]

 

[Tim Sproul]

I used a small electric hand planer to flatten my benchtop - it is 24 inch by 10 feet.

It was pretty flat after lamination but still needed a little work.

The short length of a typical 3.25 inch wide electric planer means you have to be judicious when using or you may make the benchtop worse than before.  The cost of those replaceable blades is dirt cheap and I bet they'd eat many nails before their death.

 

[PaulMarcel]

I agree with Ken.  Around here, there's a drawer factory and they have a massive 48"+ wide-belt sander that does multiple grits before dumping the product into a UV finish bath.  They can take it out before that (although, that finish is amazing for durability).

That would be the easiest.

Another way is to make a router sled to joint that face using a bowl planing bit; the router marks you'd have left would easily come out with a quick sanding pass.  Still should do the nail check, but you could get that bit with the idea that you'll toss it out and you wouldn't be out too much money; it likely would clip the small brads/pins you missed pretty easily.

Here's a bowl planing bit from EA. I know Rockler has an inexpensive version in blue.

 

[upscale]

I've got a 20" wide x 48" long x 2.25" thick maple bench top, which was part of a very large bench from a school shop. Of course it's got a a dozen or two brads in the top, some of which are hidden. No really large nails that I can detect with a metal detector.

First, get rid of the nails, ALL the nails. A halfway decent metal detector will find them all. Second, build yourself a simple router sled. Should be a relatively simple job.
http://www.highlandwoodworking.com/flattenaworkbenchwitharouter.aspx

 

[BMH]

Fine Wood Working magazine has a good article on how to make a router sled. You are probably not going to be able to find all of the small nails but the router bit will. I don't know how keen a shop would be to put it through their sander knowing there is some left over nails in it.

Bruce

 

[nickao]

"Would a Performax like sander do the job?"

Go to a cabinet shop for a 20" wide piece?

Heck yes a Perfromax/Jet drum sander will make that thing flat as a pancake. To bad I don't live near I would toss it through for nothing and in a few minutes it would be perfect. You have to know a hobbyist nearby with a drum sander, no? If no this is the greatest excuse ever to buy one. I could not live without my Performax drum sanders.

Once people get a Drum sander they usually scratch their head and say, "why the heck didn't I get one years ago"!

If there are little brads I would just run it through with a 40 or 60 grit first pass, I have done it loads of time, it does not effect my drum sander at all(as long as you get them flush to the surface to begin with). Now larger nails could hurt the drum, but little brads, they will just sand flat.

 

[mouppe]

This may be not what you want to hear, but I would not use this benchtop. If you need it dead flat, or flatter than it is now, I am assuming you intend to use hand tools. If so, any leftover nails will damage your blades and your wood. I think you will be cursing a lot whenever this happens.

Also, the bench is small. 4 feet by 20 inches. Not really big enough for a workbench, especially if you intend to add vices.

I would use the top for something like a finishing table, or a sharpening station, but not a workbench. Laminate a piece of 1/4" plywood on the top first.

Richard.

 

[Wim]

How is the underside? Can you use the table upside down? I don't think you will find much nails there.

 

[ScotF]

I would work to get the nails and brads out and then use a sharp jack or jointer plane to flatten.  It is really not that much work and great practice flattening by hand.  Work it 90 degrees to the face first, then work diagonally one direction, then switch and go back the opposite direction and finally lengthwise.  When you get full width shavings for the length of the bench, you are flat.  If you have plane tracks, a light sanding with a Rotex, ETS or RS2E will have the top in great shape.  Of course taking it to a cabinet shop with a wide belt is another option that might be easier.  Personally by the time I would load it, drive to wherever and get it processed and back home, I could have the thing flattened by hand.  Just my $.02.

Scot

 

[-The Dutch Guy-]

Like Scott said, jack/jointer plane, smoothing plane a pair of winding stickes and a long straidedge would do the trick.
It might take a while but costs are are next to nothing.

Succes with your flattening!

René