(Part 4 of Clamps and clamping)

Here is a rack that is easy to build and will efficiently store parallel-jaw clamps.

Almost all of the racks for this type of clamp that I have seen, including commercial versions, store each clamp facing forward in an individual slot, a design that wastes space and is harder to build. This rack, like most shop-made woodworking fixtures, is likely the progeny of multiple sources but credit should at least be given to Andy Rae, who described such a rack in his book The Complete Illustrated Guide to Furniture and Cabinet Construction (The Taunton Press, 2001). The version that I built adds modifications, particularly some safety features.

As seen in the photos of the rack in my shop, the clamps are stored sideways. Two of the bins have been emptied to show the construction. All of the main components are good quality 3/4″ plywood. The back panel is 8 1/2″ high.

Each bin is made with two support pieces 8 1/2″ in height – same as the panel height. These are glued and screwed to the panel from the back with three or four #10 x 2 1/2″ deep-thread, square-drive, flat-head wood screws. An 8 1/2″ horizontal dimension for these pieces will accommodate five Jet clamps. The jaw of the clamp furthest to the back will actually overlap the back piece. You can work out the horizontal dimension for your brand of clamps and how many you want to store in each bin. The front of each support piece is cut at a 45° angle, 2″ from the corners, as you can see in the photos.

The distance between the two support pieces should be 1 1/4″ for Jet clamps, which have 1 1/8″ wide bars. The Jet jaws are 1 7/16″ wide. Thus, this spacing is wide enough for easily placing clamps in the bin but narrow enough to prevent clamps from sliding about or falling through.

For added safety, I attached with two screws a 1/2″ thick x 2 1/2″ long hardwood stop on each support piece to extend 3/4″ above the support surface.

4″ between bins allows plenty of room for the jaws of the Jets. Based on this, adapted for your brand of clamps and the desired number of bins, you can work out a width for the back panel, keeping in mind the extra width at the ends.

Attach the rack to studs with appropriately sized screws or with fasteners suited for the wall in your shop. Use your judgment, keeping in mind that it will bear a lot of weight.

The rack works best when the clamps are hung by the upper jaw only. The moveable jaw of the Jets has a clutch so it will not move inadvertently. Bessey and others do not use a clutch but instead use a tilt-grab system, which perhaps can slip if you happen to bump the handle, causing the lower jaw to suddenly slide down. It is probably better to store those with the lower jaw all the way down.

After the posts so far on clamping, there have been more inquires regarding clamp racks than clamps. Emails are always welcome but keep in mind that I will respond to inquiries made in comments on the blog and that way more people will share and may contribute to the response. As always, thanks for reading.

More quick tips to bring the total to 65 in eight posts.

Placing and removing heavy boards while reaching overhead to high lumber racks is a danger we do not need. I feel a lot safer on the large platform of this very lightweight stepladder. With a platform height of 21″, it folds flat for storage, securely locks into its open position, and has a top crossbar that you can hold on to. It now comes with a tool tray at the top and taller models are also available.

Tongue depressors can be handy glue applicators but only if the rounded ends are sawn flat. It is easy to clamp a bunch together and saw the ends square or, if you like, at an angle. When I need a narrower applicator, it is easy to split one lengthwise with my fingers. For smaller work, the craft picks are good. For small, multiple joints like dovetails, glue up goes faster by filling up one of these little cups with glue and withdrawing blobs rather than repeatedly fussing with the glue bottle.

For vacuuming furniture parts between grits while hand sanding, as well as for certain other intermittent vacuuming tasks, I got tired of over and over reaching for the switch on the shop vac. Now I love this rig made by FastCap. The receiver plugs into the outlet and receives the shop vac plug. The small remote with an unobtrusive yellow button slips into a hook-and-loop collar that can be secured anywhere you prefer near the vac nozzle. The shop vac main unit stays out of the way and the work goes faster.

Most slick varnished wooden tool handles make no sense and are a pain. The hockey stick handle wrap is an excellent remedy, demonstrated here by a real hockey guy. For tool handles, I found it better to precede the raised helical wrap with a base flat layer. The cloth friction tape that I’ve mentioned in other posts works well for this. He saws, he scores!

When you don’t want friction, this spray beeswax is a pleasant, natural alternative and very handy to apply. Thanks to saw maker extraordinaire Mark Harrell of Bad Axe Toolworks for this idea.

Woodworkers need to cut things besides wood, often fairly heavy things like brass shim stock, cork sheet, plastics, and so on. A tough pair of scissors with one lightly serrated blade manages this work without being overwhelmed and slipping like kitchen scissors with smooth blades, and are still fine for light work. These by Fiskars are old but Wiss model #W912 appears similar.

Remember, 65 quick tips in 8 posts can be found in one place, via the Series Topics link list.

Again emerging from the sawdust and shavings of my shop, here are eight more quick tips that I hope you will find helpful.

Pictured above, the Big Gator drill guide is great for accurate perpendicular drilling when use of a drill press is impractical, which is surprisingly often. There are cheap tools for the same purpose but this one is nicely machined to tight tolerances and feels solid. This model has holes for 1/8″ – 3/8″ in 1/64″ increments and others are available. Big Gator – they must be in Florida right? Nope, Kansas.

Next to it is a mini ratchet driver that takes 1/4″ hex bits. Whew, this tool has saved the day in tight quarters numerous times. I’ve used it not only with short driver bits but also with short hex shank drill bits. You can probably find one at a local hardware store that’s inexpensive enough to buy before the day you need it.

Below, cork sheet is probably the handiest shop material that comes from trees that isn’t wood or paper. Having just the right balance of firmness and resilience, without a slick surface, it is useful for clamp pads, sanding blocks, pads for metal bench dogs, and so forth. Find it in craft/hobby stores in various thicknesses, with or without PSA backing.

When I bought the transfer punch set four years ago, below left, it vaguely seemed useful but I had nothing specific in mind. Time and again since then, however, I’ve realized, “Oh, I have those, this will be easy.” The set includes 3/32″ – 17/32″ in 1/64″ increments. You could use brad point drill bits for the same purpose but these are more suited to the task and most of us don’t have all those sizes in brad point bits. My set runs about .001″ – .0015″ undersized, which works out fine.

Lee Valley sold me again with the feeler gauge set with unusually long 5 1/2″ fingers. I have a standard length set but this is the one I reach for when tuning machines. The extra length usually proves helpful and, unlike most sets, it goes down to .001″.

Gauge blocks are usually more accurate to use than a rule when making settings at the router table, table saw, and bandsaw. There are more complete and clever sets available but I usually get what I need by combining 1/16″, 1/8″, 3/16″, 1/4″, 3/8″, 1/2″, 1″, and 2″. I suppose I could use a metal 1/32″ instead of the caliper-validated piece of wood I use now.

I’m not sure if I’m on board with all of these silicone gluing accessories but I do like the little textured roller and tray. It is just under 2″ wide but really speeds application on moderate-size open areas. Wait until the glue is dried before cleaning and then it’s amazing how it peels off.

Accept no look-alikes; Sharpies are awesome! They write on just about anything – router bits, jig hardware, storage units, and on and on. I write lots of notes on jigs, templates, and tools to save head scratching later on. Oh, and be sure to keep at least one handy in the shop in case anyone stops by with an autograph request.

The Metallic Silver Sharpie is a great all-around lumber marker that shows well on planed and rough wood of any species. It doesn’t tend to bleed in like the regular colors. I wish they also made it in the Super size point.

More tips coming soon.

Whenever possible, I would much rather use parallel clamps than long F clamps for gluing up work. With parallel clamps, pressure can be applied more accurately and, if needed, readjusted more reliably. That also means faster, which is important when the “pressure is on” during glue up.

However, little of my work is fully rectilinear with nice flat contact points and with all the surfaces at 90° angles. Therefore, a key additional ingredient is usually required to use parallel clamps: glue blocks. I consider glue blocks to be a standard work component of most projects. Because almost all of my work is one-of-a-kind, the glue blocks usually get discarded when the project is done, but that’s OK, they are still well worth the effort.

This approach is easier than trying to guess where the swivel-head sliding jaw and fixed jaw should contact opposing curved surfaces to properly direct pressure across the joints. Even after a dry assembly trial, there are likely to be too many uncertain adjustments to deal with during glue up crunch time when the meter is running. For similar reasons, F clamps are far inferior to parallel clamps for edge joint glue up.

The bottom line is that for table legs, curved case components, and so forth, I’ll do whatever I have to do to make the glue up a more predictable operation. Most clamp blocks are easily made from the bandsaw cutoffs produced during building the piece.

When a moderately long F clamp is useful, it is usually in support of parallel clamps or when the vault of the jaws is helpful to clear an element of the piece. For those occasions, the economical and widely available Jorgensen #3700 series work well enough. They also make the heavier duty but much more expensive 4500 series.

For long F clamps, I like the clutch system on the Jorgensens. When the head is set in place, it is sure to stay there throughout all the maneuvers during glue up that precede final placement of the clamp on the work.

I replaced the orange Jorgensen pads with red Bessey pads that fit perfectly on the swivel end of the sliding jaw. Bessey pads do not snugly fit the fixed jaw so there I attach thin cork sheet.

More to come on clamps.

For the other clamps in my shop, I’ve taken down one of each from the racks and have offered comments on their utility. These choices are largely matters of personal preference and very dependent upon the work being done, but hopefully readers will find some useful information and ideas.

These little 2″ and 2 1/2″-deep Bessey F clamps, 4″ and 6″ length capacity, respectively, are used almost exclusively for stop blocks, fences, jig setups, and the like. Sometimes the clutch type is easier to place precisely. Almost any decently made brand will do for these tasks.

The Bessey Varioclippix 4″ spring clamp has a sliding arm that greatly expands its capacity, flat pads that make clear contact with the work, and hand-friendly grippy inserts. These features make them preferable to the original Pony steel spring clamps. I store them gripped to pieces of brass sheet screwed to the bottom of a clamp rack.

The 2″ C clamp is sometimes just the ticket for tight quarters in jig setups. The Japanese mini bar clamp is useful for very small work where a parallel clamp is needed.

The Bessey 4″ deep x 8″ long F clamp (TG4.008 “Tradesman” 1″ x 5/16″ bar), below left, is a sturdy, reliable workhorse for a thousand tasks. The replaceable pads have never marred a work piece in my shop but they are not squishy and they stay in place. The key rigidity features are the I-beam bar and the corrugations in the malleable cast jaws. They are available in many sizes with different force ratings and handle features.

The very heavy and strong Gross-Stabil 12″ parallel clamp gives a broad, ultra-reliable hold down force. The lightweight Bessey UniKlamp is useful when the precision of a parallel clamp is needed on a small scale. The rectangular heads work well as stop blocks themselves. The balky engagement of the head is typical of Bessey parallel clamps.

I don’t know when I’ll next need this 7″ deep, heavy F clamp but I’ll be glad I have it then.

It is hard to overstate the versatility of the venerable wooden handscrew. Much of the magic of this tool derives from the ability of the rectangular wooden jaws to clamp as well as to be clamped. This allows creative arrangements that can solve lots of work holding problems. Final tightening is done with the outer handle, so the cloth friction tape is a big help there.

Excellent quality handscrews sold under many different brand names are made by the Dubuque Clamp Works in Iowa. Maybe I am the only person who finds the non-drying oil “finish” on their clamps annoying. It can transfer to some woods when the clamp is tightened hard, and in any case, seems unnecessary. I like the Besseys, which don’t have this issue and seem to work as smoothly as the ones from Iowa, though the latter are available in a larger range of sizes.

More clamps coming up.

What task produces some of the tensest moments in woodworking? Gluing up, right? And what are the main tools we use for that task? Clamps. Yet there usually is not much discussion about them, many woodworkers skimp on them thinking they’re not real tools, and they generally just don’t get much respect.

Let’s start with long clamps – bar clamps, carcass clamps, whatever you want to call them – that are mostly used to edge glue boards, clamp post and rail assemblies such as for a table, and glue up carcasses. This discussion refers to clamps where the contact part of the head starts right at the bar; not F style clamps.

I used 3/4″ pipe clamps for this for a long time – too long. They have the advantage of economy, especially because longer clamps are made by simply swapping the heads onto longer pipes. However, even with special supports and pads, they just cannot be used with the same reliable precision as parallel-head bar clamps.

Precision? For clamps? Yes. At crunch time, clamping precision matters. We use precision tools like squares, pinch rods, and straightedges to accurately assess a case or leg-and-apron assembly, looking for tiny gaps and misalignments. Doesn’t it make sense to invest in accurate tools to adjust and hold those parameters at the moment when it really counts and when there’s no going back?

As with most topics on this blog, I will tell you what I use and why, hoping this will be helpful to readers making choices and solving problems in their shops. I cannot offer comprehensive comparative reviews like in the magazines, just real stuff from years in my shop.

My favorite parallel clamp is the Jet. Bessey also make excellent clamps – I have some of their older model – and there are others including Jorgensen and Irwin. An alternative is the aluminum bar clamp by Universal Clamp Company, which is a precise clamp with the advantage of much lighter weight. Though a good choice for lighter work, these eventually lost out in my shop to the more versatile Jets, which are more rigid and deeper.

To open the Jet clamp, the head is released to slide freely without catching by lightly pulling up on a lever under the handle. The head can be advanced to close the clamp without using the lever. I really like how the thread action engages immediately when the head is set into position. There is no lag or confusing need to lift or lower the handle for any of this.

The long side of the firm, glue-resistant head extends more than four inches. In some situations, the work piece can also be placed on the side of the bar or under the short side of the head where there is about ⅝” extension. I like the large diameter handles that give good moment when tightening. To really sock down, use grippy gloves.

The inch scale on the bar is handy when readying a bunch of clamps, such as in edge joint glue ups. There is also a simple moveable support for the bar.

More to come on clamps and clamping.

There are the good reasons for using a diamond stone as a nagura. This is not a novel idea – the intent here is to present a clear rationale for it. However, there’s also a significant practical problem involved.

All of this applies to synthetic finishing waterstones. I think most or all of this probably also applies to Japanese natural finishing stones but I defer to those with more knowledge about those.

The reasons for a diamond nagura:

1. It’s fast. The slurry is raised faster and the surface of the stone is refreshed faster than with any other type of nagura that I have tried. Whatever you perceive to be the benefits of these effects, as discussed in the previous post, they arrive faster with a diamond nagura.

2. The slurry consists of grit solely from the finishing stone; no new grit is added. This removes the uncertainty of introducing another grit, often unknown, from a stone nagura, along with the uncertainty of the amount of it that gets into the slurry based on the relative hardness of the bond in the main stone versus the nagura.

3. It is very capable of crushing the grit in the slurry. I first learned about this several years ago from So Yamoshito, a Japanese tool vendor in Australia and expert on Japanese natural stones. I wrote about it then. The rationale for specifying 1200 grit diamond is that it is fine enough to readily crush the loose fine grit in the slurry yet coarse enough to raise the slurry quickly. The latter effect is apparent.

I can’t directly prove the crushing theory. Furthermore, for it to be of value, the crushed particles would have to retain good cutting ability as finer particles. After working with this for years at the sharpening bench, it does seem borne out by the blade edges it produces.

By the way, what about just using the slurry created by flattening the finishing stone with a coarse diamond stone, say 220 grit? Yes, that’s pretty good but the crushing effect is better with the 1200 diamond. Also, a lot of water is used in flattening and the process tends to swipe the slurry off the finishing stone.

Now for the problem. When you rub a 1200 grit diamond stone, even an Atoma with its surface made of tiny dots of grit clusters, on the wet finishing stone, it sticks like crazy. This is very annoying and then it tends to carry away much of the slurry when you remove it.

I tried using smaller continuous surface diamond stones but they were no better. Then I tried a DMT 6″ x 2″ inch 1200 diamond stone with the “polka dot interrupted surface.” This reduced the sticking but still not well enough. It needed to be smaller.

The little DMT polka-dotted pocket stones were too thin to grip in my fingers. So I hacksawed a 2″ x 2″ section off the 6″ x 2″ stone, which you can see above. It works pretty well. The small size and the perforations eliminate most of the sticking.

Note that I do not consider flattening to be a function of the nagura. In fact, a reasonably evenly-distributed rub of the small diamond nagura should not significantly change the flatness that has already been established well by a coarse diamond flattening plate. I flatten stones at the end of a session when they are fully wet and so they are ready to go for the next use.

The best solution, I believe, would be a 1200 grit diamond nagura, about 2″ x 2″, with narrow channels extending to the edges that would reduce sticking and allow the slurry to flow away from the nagura and remain on the finishing stone. I am working on prototypes using 1″-thick ABS plastic for the base and various applied diamond surfaces. I’m hoping this results in a nagura that is the bee’s knees, but in any case I will report on this soon.

Several reasons are usually given for using a nagura on fine grit waterstones. These include: to raise a slurry, to remove unwanted deposits in natural Japanese stones, to refresh the cutting surface of the stone, and to flatten areas of the stone.

Let’s think about what’s going on when a nagura is used, recalling what we can directly sense at the sharpening bench.

The slurry

When the little nagura stone is rubbed on the finishing stone, a paste, or slurry, is generated. It is sometimes claimed that the slurry actually does the sharpening, but it seems questionable whether loose abrasive particles in the slurry are really cutting steel. There are microscopic photographs of blade edges and stone surfaces, but to my knowledge, no direct visual recording of the actual cutting action at a microscopic level. We can observe the effects but not the actions that produced them.

The thin edge of steel plows most of the slurry but perhaps some loose particles are held by the stone’s surface texture, enabling them to cut. Maybe it burnishes the steel. Maybe it creates a variable grit surface on a synthetic stone somewhat like in a natural stone.

In any case, we can sense that the slurry improves the feel and ride of the blade on the stone and reduces sticking, all helpful effects. So, whatever it is actually doing, the slurry at least feels good.

The next issues are what composes the slurry and what happens to it.

Are there particles of the finishing stone, the nagura stone, or both in there? Particles of the softer (more loosely bound) of the two stones will presumably predominate. This should be considered when the two differ in grit size. For example, a nagura that is softer and coarser than the synthetic waterstone with which it is paired will be probably be counterproductive.

With fine natural Japanese waterstones, nagura selection is an art unto itself. Consult a knowledgeable purveyor of these stones. The nagura also is used to remove defects in natural stones that can damage the blade edge. This function is, of course, not relevant for synthetic stones.

So, what happens to the particles in the slurry? Are they left intact or crushed to some degree? If the nagura could crush loose grit to a finer size, that would seem to be an advantage assuming these crushed particles retained their cutting ability.

The surface of the stone

We can see and feel that a nagura refreshes the surface of the stone by removing metal and glazing. Much like dressing a grinding wheel, cutting particles are better exposed at the surface, ready to cut steel.

As for flattening, there are better ways to do this accurately than with a nagura, though with natural stones a nagura might be helpful for some local flattening as it is used intermittently for its other benefits in the course of sharpening.

A solution

There may be more questions than answers here and you may be thinking that this is all a little bit interesting but enough already. I agree, I’d rather get back to woodworking. However, at least restricting the matter to synthetic waterstones, which most woodworkers use, there is a simple solution to all of this, to be discussed in the next post. The background discussion of this post will support why I think the solution makes so much sense.