Monday, April 13, 2015

Bench maintenance

Works has slow down in the shop lately, life seems to gets in the way sometimes...


One thing I notice while taking pics for my blog, is that there seems to be a growing gap around my antique leg vise and the bench top.

About 20 years ago I re-faced the vise chops and the faces have curved, 
not getting a good grip anymore for sure.

When the bench was built. There was already a bit of a curve on the vise faces.

I was going to add a piece of leather to both faces of the vise, but I will have to flatten them first.
But first thing first, I need to investigate what is going on with the vise face and top.

And while I am at it, may as well go over the whole bench to see how it has fared all these years (the bench is now close to be 6 years old) and a long haul move. The rubber footings came off during the last transport, I put the rubber pieces under the footing of the bench, but I need to reattached them securely. They were just contact cemented in before. I find that the addition of these rubber feet, makes a big difference on the bench stability when I plane, it anchor the bench to the floor. Very sure footed grip. It is a small joinery bench, only 4 Ft X 22 inch but it is very solid and heavy, it doesn't move when I plane or bang mortise on it. No racking, no play, no nothing!

Looking at my long 30 in joiner on the bench, I thought I saw a gap under it, sure enough, the top has developed an hollow were there was a bump before. Time to re-flatten the bench and go over all connections making sure everything is OK. Interestingly, the hollow has developed at the only place were the top was exposed by planing away the previous bump. The remainder of that Maple slab is still covered in a plastic like layer, varnish or poly? Whatever they used on bowling alleys.

Oh yeah, we have an hollow!

The top rest on two hardwood pins up front and is secured by two lag bolts in an oblong hole to allow wood movement toward the back. The bolts are roughly 2 third toward the back, the one on the quick release woodworking vise is a bit closer to the rear by necessity.

The connections are solid. the lap joints are glued and lag bolted

The vise (beech) is in line with both top and middle rails (Maple)
while the vise is buried into laminated construction 2X lumber (Fir) 

On the LHS the vise stationary chop has pulled away more from the top.

In the rear back RH corner the bench top has curled up.

So obviously, I got some maintenance to do before I flatten the top again. You can see how to top has some grooving on the back side, it was a chunk from a bowling lane floor.

The front rails, top and bottom are chunk ripped of the Maple slab.
After machining flat coplanar with the top side, I still got a good 1-1/2 in thickness. 

You can see the grooving pattern from the slab behind the rail

Apparently that grooving was in an effort to stabilize the slab and keep it flat. Well that fail!
Time to flip over the bench, take off the leg vise and make some corrections.

Only one rubber foot remain stuck, but it has slipped crooked. The frame is still very stiff, no play.

With the leg vise removed, I can assess the bench framing and can work the vise legs flat.

The leg vise boards have developed a big cup.

The top is curling up in the rear corner, no wonder there is an hollow.

The vise leg has shrunk away from the maple front skirt 

Backed lag bolt, clamp closed and re-screwed.

Lots of gap between frame and top.

Loosen lag bolt, clamped and re-screwed. Will probably reinforce the top connections. 
One lag bolt on each end doesn't suffice to keep it flat.

With the two leg separated, I can assess and work on the flat faces. 
Must remember to account for the toe in.



Once done, I will re-flatten the top and make sure the leg vise chops are again made parallel to the top side rails.

Bob, who has a cleared top on his bench for a change. 




2 comments:

  1. Do you think you are leaching moisture through the foundation into the bench?
    That is a healthy hump and hollow you go there.

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  2. I don' know, but i doubt it. It has been exposed to high humidity levels,but should now be stabilized, and i run a dehumidifier in the summer. I worked on the vise parts, then slap some stain on it. Tomorrow the bench should go back right side up.
    And that slab had a curved when I got it, thats why the big section in the middle which was planed the first time.

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