Sunday, December 27, 2009

A Wee Table Repair

The sorry looking little item pictured is a small, black-lacquered and stencil-embellished table that must be sixty years old if it's a day.

My wife was using it for a plant stand and the plant's pot leaked, which did a fine job of ruining the table's top. That was years ago. (I hope my mom's gotten over it by now.) I mean to make a new top for it. I don't have the graphic arts skills to recreate the pattern on the original, so I'll have to settle for a plain, glossy black top. (I also don't want to make a career out of this thing.)

I'll leave the rest of it as is, except to clean away the years of grime that have accumulated while the thing languished in my basement. The finish on the legs and shelf is not in great condition, but I want to retain the piece's 'antiquity', such as it is.

An interesting feature of the table is those little studs you can see at the corners of the shelf. Those are threaded wooden 'screws'. I recall as a boy thinking that they were just the neatest things.


While disassembling it, I marked each leg's position with respect to the top's skirt in a concealed location with a letter punch. I also marked the shelf's orientation on its underside. The components of an item like this table, even though mass produced, may not be perfectly uniform, and had best go back together exactly as they were originally assembled.

The shelf comes away simply by unscrewing the four wooden screws. Each leg is fastened at its upper end by a flat head screw driven through the skirt's corner bracing from in behind.

Separating the top from its skirt looked a bit daunting. I scored through the paint all around, inside and out where the skirt and the top's underside meet. I took a piece of oak 4x4 to use as a hammering surface and hammered at the top's underside all around, the oak block taking the hammer blows and passing them along without harming the top. The top came away fairly nicely. It had been glued and nailed in place. Thankfully, the gluing job wasn't the best. There are places on the upper edge of the skirt that will have to have adhered splinters trimmed away, though.

I can see now how the top was made. It's solid wood, just over 5/16" thick. The top surface is covered with a thick sheet of glued-on printed paper. That's how they did the graphics, and that's why the water did so much harm where it got into a crack.

The Skirt

Trimming the adhered splinters from the upper edge of the skirt looked like a tricky thing to do with a chisel; too easy to pull up a splinter from the skirt rails themselves, and difficult to maintain a dead straight result. I rigged the table saw for ripping, and found a length of baseboard footing molding with a very thin upper edge. I set the rip fence so its distance from the saw blade was exactly the width of the molding, plus the original finished width of the skirt rails. I set the saw blade's height to just a little more than was needed. That setup made short work of the task. (The reason for the intervening length of molding between the saw's iron fence and the skirt was that the skirt's corner braces protruded slightly lower than the skirt rails in places. The molding's thin edge got around that by referencing only to the skirt rails themselves and no higher.)

The Top Blank

The closest I can come with material I have on hand is some plywood that's just over 3/8" thick. If I chamfer the underside edges slightly, I can approximate the visual impression of the original top's thickness. I'll have to veneer all the edges with birch. It's impossible otherwise to get a smooth finish on plywood edges.

The plywood is salvaged stuff with a darkly finished hardwood veneer on the face side. I can't make out the species, but it's close-grained and should finish well with careful preparation. The plywood may have been a wall covering, because the back side has evidence of adhesive all over it. The 'sheet' that I have is about 33"x38".

The original top is 11 1/4" square, with the corners lopped off 3/4".

Following is the procedure for obtaining the 11 1/4" square blank:

1) On the bad side, lay out an 11 1/2" square at a good corner of the sheet. One edge will be a dead straight factory edge. That will be my initial reference edge. The other three edges will all be roughly jigsawn edges.

2) With a portable jigsaw, cutting from the bad side to cause no splintering on the good side, make the two cuts required.

3) Put away the jigsaw. I mention this to raise a point about work habits. I know that there are those who can work effectively in the midst of atrocious clutter, but I'm not one of them. Clutter causes my brain to seize up. Consequently, I'm a great believer in the value of putting away things that are no longer needed. There's also a safety consideration to this. The less that you're having to shove stuff aside, the less likely you are to do harm to a tool, to the work itself or to you. Sermon's over.

4) This was a good time for me to get after the adhesive muck on the plywood's bad side with lacquer thinner and a putty knife for a scraper. With virgin material one would be spared this, obviously. This sort of thing is one of the drawbacks of working with scrounged, salvaged material but, hey, the price of it is pretty attractive. Anyway, the lacquer thinner and putty knife worked to quite good effect. The blank is ready for final-sizing.

I should mention before leaving this point that while I was scraping the bad side, I had the good side sitting on a piece of thin rubber anti-slip material for underneath rugs. It keeps the work from sliding around, and protects it from getting scratched by any particles that may find their way underneath. The method is invaluable, too, while you're sanding.

5) If you're not certain of it, check the table saw blade's squareness to the table, and correct it as required. Set the rip fence for just under 11 1/2" from the blade. The reference edge on my blank has a bit of a roundover at the good side, and I want to be rid of that; I want all the edges to end up square and sharp. Hence, this cut will be to create a new reference edge.

6) Good side up; original reference edge against the rip fence; make the cut. I now have my new reference edge.

7) At the workbench, new reference edge against the edge of an 18" aluminum level. The blade of a carpenter's square against the level as well, the square being on top of the blank. Position everything so the tongue of the square is very near one end of the blank. Making certain that the reference edge and the square's blade are simultaneously held firmly against the edge of the level, draw a line along the square's tongue very near the one end of the blank with a sharp pencil. That line delineates what's to become the reference end.

8) With a sharp plane set for a fine cut, plane to the pencil line. Work inward from both ends so as not to cause any splintering. When done, you'll have a reference end squared to the new reference edge.

If you're familiar with table saw cross-cut sleds, you know that there is a way to not have to do the previous two steps. I don't have a cross-cut sled, so I had to fall back on this method.

9) Set the saw's rip fence for the final, 11 1/4" width of cut. Make a cut with the new reference edge against the rip fence. That gets rid of the original reference edge with the slight roundover. Make the next cut with the reference end against the rip fence. That gets rid of the remaining jigsawn end. We have our square blank.

Cutting Corners

Years ago, I built an oak fern stand with an octagonal top and base. As is the case here, the top and base started out as square blanks. To lop off the corners, I constructed a sled for the table saw that presented the square blanks to the saw blade at a forty-five degree angle, the sled's left edge referencing the rip fence. (I always work with my saw's rip fence to the left of the blade.)

That sled is exactly what I need for this table top, and lo and behold, I found it.

(I never said it was pretty.)

[I suppose I should insert the obligatory words about table saw safety here before the safety police have a shrieking fit.

My saw has no blade guard, and I wouldn't install it if it did have one. I've always figured that if I can see the blade, I can avoid the blade. It's worked out for me so far, and this saw has cut a lot of wood. I will emphasize this, though: Think through every cut before you make it, and during every moment that the blade is spinning, your absolutely undivided attention must be on it and on your relationship to it. And don't even think about ever making a cut without wearing eye protection. 'Nuff said.]

So, we're just about set to lop off the four corners. Mark the cut's location for one of the corners, place the blank in the sled and set the rip fence empirically by referencing the saw blade to the mark. Three brief cautions:

a) Be absolutely certain of the blank's fit in the sled. Watch that no splinters or particles get between the blank and the sled's cleats.

b) Be mindful that the sled is always fully and truly registered against the rip fence.

c) Splintering as the blade exits the cut is very likely, especially at the two corners where the good side's grain direction is angled toward the oncoming teeth of the blade. A way to preclude splintering is to keep a small block of softwood pressed against the blank's edge where the saw blade will exit the cut. This slightly complicates the operation, but it can be safely done. Think it through and rehearse it first.

With all that in mind and set to go, we make four cuts and it's done, like so. [I know it looks somewhat rectangular instead of square. It's the camera angle. Trust me, it's square.]

Edge Veneering

I've had good results from a product known as Bennett Preglued Veneer Edging -- Iron-On. I can't seem to locate Bennett on the internet, though, so they may no longer be with us. Someone must still make the stuff.

It's a 13/16" wide, real wood veneer tape with hot-melt adhesive pre-applied to the back. It works as advertised, though I've never applied it to edges this narrow before.

I'll be using birch for this. Birch is a lovely, pale, close-grained hardwood that will give me the smooth surface I want for under an enamel coating. You'll want the blank's edges to be absolutely free of dust beforehand, and the best way to get that is by blowing them off with a compressed air blow-gun. I'll veneer the short edges at the corners first.

I have a retired steam-iron that I use for a heat source for applying the veneer tape. It's kept set at near its high setting. Always cut the tape pieces about 1/2" over-length; a pair of light tin snips cut it nicely. Set a piece of tape in place and press the iron down on it squarely. Heat it till you can see that the glue is going molten. Take away the iron and press down on the tape squarely and firmly with a smooth sanding block. Keep pressing for about 10 seconds to ensure a sound bond.

When you take away the sanding block and examine the job, you should see no evidence of any voids in the bond at its edges.

To trim the tape, you'll need a sharp block plane set for a fine cut, and a small, sharp utility knife (I use an Olfa Model 180). You'll also need something to serve as a cutting block, and some 150-grit aluminum oxide sandpaper.

With the veneered edge hanging out over the edge of your workbench, trim down one side of the veneer with the block plane. Stop just before it's flush with the surface. Do the same on the other side. Trim the ends by pressing the veneered edge firmly down onto a cutting block surface, and running the point of the utility knife over the tape's underside repeatedly until it cuts through. (The forty-five degree angle complicates this a bit. It's much easier to do this at ninety-degree corners.) Sand the edges and ends flush. It's ok to use an orbital power sander for sanding the edges. When properly applied, the veneer is absolutely secure. The ends must be sanded by hand with a small sanding block.

Do the preceding steps at the three remaining short edges. Repeat for the long edges. Long edges are a two-handed job. I start with the iron from the right, moving fairly quickly to the left just to get the tape 'tacked' in place. I then slowly move the iron along from left to right, following along with the sanding block in my left hand. When you're all done, it will look like this.

The image doesn't do it justice, but I hope it gives you some idea of why I think quite highly of this veneer tape.

There's still much to be done. I'll update this post as I make progress.

- - -


There was some unavoidable splintering at the underside when I did the sawing. I've filled that and sanded it. I had thought of chamfering the underside edges to create the illusion of identical thickness to the original top, but I've thought better of it. The extra 1/16" thickness of this top is not disproportionate, and I'd be begging for trouble were I to go ahead with the chamfering idea. So, the next thing up is --

Top/Skirt Attachment

The original attachment method of glue and nails is not on. I need an entirely mechanical fastening method. The skirt is just shy of 1 7/16" high. I'm going to use eight No. 6 x 1 1/2" round head wood screws, two at each corner brace. By counterboring 1/4" deep for the screw heads, I'll get almost 5/16" of effective screw projection into the top, and the screw heads will be hidden. With eight screws, the security of attachment will be adequate, in spite of the very short screw engagement with the top. Pictured is a view of one corner's screw hole layout.

(The masking tape is concealing the 5/8" square mortise that accepts the top end of a leg.) I wanted to point out the usefulness of masking tape as a layout aid. I use it for this sort of purpose a lot. Whenever you have a surface that's difficult to mark or that lacks contrast for a pencil mark, or that you don't want to mark on directly, apply masking tape and you're away.

Now I need to drill through eight places 9/64" diameter; clearance diameter for a No. 6 screw. Then I'll counterbore 17/64" diameter to a depth of 1/4".

- - -

Done. Now I have to install all eight screws to the point where their points are just about to emerge from the top of the skirt, position the skirt squarely on the top's underside, hold it firmly in place and tap each screwhead to mark its spot. Before taking away the skirt, I'll want to key the skirt to the top with a letter punch. On an assembly like this, there's no way it's going to fit together any other way than that established at first assembly.

With the eight pilot hole locations marked, I'll chuck a 3/32" twist drill in the drill press and set the depth stop for about 1/16" from the drill press's table surface. Eight pilot holes later I'll put it together.

And here it is. One screw at the lower right hasn't been run in all the way yet.

That turned out well, but if I can digress for a bit, I should mention that few things in the workshop are so fraught with peril as axial dimensioning; blind holes and counterbore depths being just two examples. Be it in woodworking or machine shop work, few things are so easy to miscalculate or err in the execution of than axial dimensions. I've even seen an example of the problem in mass produced high-tech equipment. There's a model-line of Hewlett-Packard laser printers that has a design flaw that can become troublesome as normal wear-and-tear progresses. There's a place in the machines where a pair of gears exhibit marginal mesh, even in new machines. Eventually, the gears begin jumping out of mesh. It's an axial dimensioning error that got put into production without ever having been caught. So, axial dimensioning even snags the big guys occasionally. Take great care with it.


Finish Sanding and Finish Application

I've done the final sanding with 220-grit paper, and 'broken' all the sharp edges; i.e. slightly rounded-over the edges with fine sandpaper. Sharp edges have a way of shrugging off spray paint; surface tension effects cause the paint to back away from sharp outside corners.

Ideally, I'd like to obtain a gloss black enamel finish that exhibits no evidence of wood grain or porosity whatsoever, but I doubt that I'll get that perfectly. I'll start with a liberal coat of grey primer overall. To do that in one go, I've installed four screws in the underside's screw holes. I'll set the piece on its top surface and prime the underside with the screws in it and the edges. Then, using the screws as handles, I'll pick it up and set it back down on the screwheads so I can carry on and prime the top surface. It's a delicate bit of manoeuvring, but it is doable. One is well-advised to rehearse such a sequence beforehand, and make certain that everything needed is at the ready.

I'll give that primer coat a week to harden, and then see if sanding and repriming is called for. I expect it will be.

- - -


There's nothing like a coat of primer to reveal flaws. There's more grain porosity in evidence than I expected on the top side, and some tiny splintering on the bottom that had escpaed my notice. I've applied Polyfilla to the bottom side flaws, sanded the bottom and the edges and reprimed the bottom and edges. Next week I'll see what I can do about the top side's porosity. Whatever the outcome, I'll settle for it; I would like to have this over with before 2011.

- - -


Two days ago I 'painted' the top side with a thin, overall coating of Polyfilla applied with a putty knife. Today I sanded that. It has had some good effect; I can see where the Polyfilla remains in evidence in the pores. I've just given the top side a heavy coat of primer again, and reprimed the edges. I'll recoat it within an hour, and then I think I'll leave it at that and get on with the gloss black enamel next week.

I know there are products for building a glass-like clear surface on even porous woods. I once saw some small tables in a restaurant or tavern that had been finished that way, to quite a spectacular effect. But I'm not prepared to go to the trouble and expense for this item.

- - -


'Went to paint the underside with what I had left of a not terribly old spray can of gloss black enamel, and got outrageous orange peel and fish eyes. Wiped it all off, cleaned it with methyl hydrate and tried again with a new can of paint and got fish eyes again on the first few passes. Wiped it off and cleaned it with lacquer thinner. Thankfully, the primer had had a week to harden, so a fast wipe with lacquer thinner didn't harm it. Sprayed it again and it's ok. Recoated it and it's still ok.

I don't know what to make of that fish eyes incident. I know it's said to be asking for trouble when one's painting area shares space with a mechanical shop where there's WD-40 and what have you present, but I'm unaccustomed to having painting trouble like that. Perhaps that's the downside of setting aside a primed item for a week; it has lots of time to pick up airborne contaminants. Anyway, I'll certainly keep in mind the good effect of a lacquer thinner wipe down.
Next up is to paint the top surface and edges.
- - -


Well, it certainly is black. I just gave its top surface and edges two coats of enamel, forty-five minutes apart. 'Looks like it'll be acceptable, if not perfect. What a trying thing that was to paint. (I repeated the lacquer thinner wipe down beforehand, and had no trouble with fish eyes.)

I've cleaned all the other components with Fantastic.

I wanted scratchless foot pads for the bottoms of the legs, so I cut four 9/16"x 3/4" rectangles of felt from an old hat, and attached them with double-sided outdoor carpet tape. It's tenacious stuff, and should work fine here where it will only be subjected to a straight down static load. I wouldn't use the same method on a chair or stool, though. A seated person is seldom a static load. People adjust their position and fidget and squirm, generating all manner of force vectors on the legs of a chair. The flexible adhesive provided by carpet tape will tend to yield to sideways forces and creep out of position, if not creep off entirely.

Anyway, it's done except for final reassembly. I'll stash the newly painted top in a safe place for a week to harden.

- - -


Done at Last

And just in time for Valentine's Day. You'd think I knew what I was doing.

Not perfect but not too bad, if I do say so myself. The plain black top is probably an improvement on the rather 'busy' original.

The felt 'feet' were a nice touch. I gave the top a coat of paste wax, which may not have been such a great idea; that stuff can be awfully difficult to buff to a truly streakless condition. Anyway it's as good as it's going to get.

# # #


# # #

No comments:

Post a Comment