Workbench Finish Question

[Tom Vanzant]

Gunstock wood is quite dry to start with, so the penetrating polymer process is primarily to prevent intrusion of water in the future. It doesn't fill the pores as much as coating all the surfaces within the pores. In walnut, the penetration of a 50-50 mix of varnish and naphtha is about 1/8" (3mm), probably much less in any conifer. On a WB, any finish should be to prevent "instant" staining due to a spill. Think of it as ScotchGuard for wood. Immediate attention to spills makes a world of difference. As I said in an earlier post, Danish Oil works well straight from the can. On a WB, I stop there. As for re-surfacing, I flatten, then wipe on, wipe off. Done.

[Stanley Covington]

Ernest:

Thoughtful comments. Thanks.

I have not measured how deep the finish penetrates the wood. It would be difficult to state a number because it varies with species, location, tightness of the grain, and endgrain versus face grain. Because I can see it happening before my eyes, I do know that the wood soaks up the finish, which strongly suggests it is actually penetrating.

I disagree strongly with your observation that conifers have no pores, and when planned smooth, are not readily penetrated by a finish, "thinned or not." Allow me to remind you that all wood is composed of hollow tubes (various designs) designed to convey water from the roots to the leaves. Get out your microscope and take a gander. No exceptions to this rule. Trees are big water pumps. When the tree is cut down and dries, these tubes deform, but do not collapse entirely, and continue to admit water into the wood's interior. It will also admit other liquids so long as they are not too viscous. Thinning the polyurethane allows it to penetrate. The degree of penetration varies with each variety and piece of wood.

Rather than writing "sealing the grain," I should have used the term "filled the grain" as used by professional finishers. That is, the sliced tubes at the surface of the wood, which form visible pits, can be filled with various substances. These typically include a binder such as oil or varnish, a bulking agent such as silica, quartz dust, sawdust, or even gypsum, and a solvent. These products are often a paste or putty which is spread onto the wood"s surface and forced into the open tubes where it dries. This is repeated, and then sanded down creating a smoother surface that can be finished to higher gloss if so desired. An ancient technique still used today.

The London Finish I have described fills the grain in exactly the same way as pore fillers used for high-end furniture finishing does. However, the polyurethane and sawdust slurry mixture is quite waterproof even without a topcoat, so the grain is also sealed so water cannot as easily penetrate the wood. Sanding with wet dry paper forces this slurry into the cut tubes where it hardens. It also soaks the ends of the fibers, making them more or less waterproof. Is this a perfect seal? No, but it does slow the movement of liquid water and water vapor into and out of the wood. Before you scoff, give it a try.

The original London Finish was BLO, sometimes with driers, sometimes with rottenstone, sometimes with a tad of alkanet root, rubbed into the gunstock by hand (bare) with lots of friction. Time-consuming work, very expensive, quite beautiful on some woods, and used on the best bespoke custom guns. With force, BLO can reach deep into the wood's fibers but it does not readily harden, does not effectively slow water movement, and must be renewed annually. Well documented fact. American custom gunstock makers used this technique for many decades too, but their customers wanted something more durable, so they replaced the yellowing, smelly, dirt-attracting, dark, ineffective linseed oil with tung-oil-based varnishes, and later the tougher synthetic urethane resins. This American technique has become the world standard for custom gunstock finishes, even in London where they still call it the London Finish even though it is not the same method or materials used back in the days of the Raj.

There is an old saying used by finish carpenters which is a pun on the term used in drawings: "Cut to fit, paint to match" becomes "Cut to match, paint to fit." But the method I have described is not intended to compensate for "inattentiveness" or sloppy work. And I never said it would make nasty work look pretty.

Your most salient point is "No doubt some inhibition will result but how significant?" Now that you have asked the question, test it for yourself. I have been using it for a long time with excellent verifiable results, as have many professional woodworkers in the gunstock industry. BTW, gunstock wood is very very expensive pound for pound, and a top-quality shotgun blank can sell for multiple thousands of dollars, so a finish that looks good but does not protect the wood is totally unacceptable. Shellac finishes are beautiful but as unsuitable for a gunstock as it is for an axe handle. BLO has not been acceptable for seriously protecting wood commercially for a century (although BLO varnish mixtures like WATCO Danish oil are used in some cases). Only hobbyists or recreationists still cling to it.

Before you scoff, give it a try. I promise you will be impressed.

Stan

[ernest dubois]

Stanley, Really when it comes to the best, as you claim, finish for gunstocks along with the implication that there probably is no more demanding case for a finish than this, who am I to say you're not on the mark? But can you really mean that when it is the best finish in the one instance, this will be the case every time? Let alone that finish is always better than no finish? Can it be so simple once we accept the premiss? This would be revolutionary and perhaps if that is your meaning, this is what leads to the claim that in order to be considered a serious woodworker, (humm), London's Finest must be on the finishing shelf and top off every last woodworking project. Maybe what prompted the tone in my reply begins to reveal itself, maybe not.

I'll tell you what I like about linseed oil, the boiled stuff I'm not keen on, First of all it's simple and direct. It's slow for sure but that is part of its effectiveness. Because it can take up to 80 years to cure it means it has that long to get down in the structure of wood. It doesn't mean it will take that long to be serviceable, by the way. Will that have consequences otherwise? Of course but that's why we have invented the concept, maintenance, not something insurmountable or that need be avoided, as I see it, but then I am surely out of step. Because of the long curing process the linseed oil is doing its business, maybe we can say, along with the way the wood is reacting over time instead of in opposition. Here it is a matter of compatibility, one simple material taken from nature in combination with even a similar material - I envision a scenario; the nut tree standing on the edge of a flax field is felled, the wood cut and seasoned and the oil pressed from the flax seed in that field gets used as a finish. Sound fetched? It's not so different from how I have worked from time to time.

It's clear we come from very different perspectives and who knows if I will ever have the chance of trying out your number one finish or not but I don't scoff at it out-right in any case.

Regards,

Ernest

[Curt Putnam]

Took me awhile, but I finally found these recipes from Howard Acheson:

"

This is what I recommend for a workbench top treatment. A film finish (lacquer, shellac, varnish, poly varnish) is not the way to finish a workbench top. A workbench is going to get dinged and film finishes will crack or craze or be otherwise damaged. Once a film finish is penetrated, it looses its effectiveness and adjacent areas begin to fail. No treatment is going to make a soft wood benchtop harder. I much favor an "in the wood finish". Here are two that lots of folks find effective. First, is an boiled linseed oil and wax finish. Sand the surface to 180 grit. Mix paraffin or bees wax into heated boiled linseed oil. USE A DOUBLE BOILER TO HEAT THE OIL. The ratio is not critical but about 5-6 parts of boiled linseed oil in a double boiler with one part paraffin or beeswax shaved in. Take it off the stove. Thin this mixture about 50/50 with mineral spirits to make a heavy cream like liquid. Apply this mixture to the benchtop liberally and allow to set overnight. Do it again the next day and again the following day if the top continues to absorb it. After a final overnight, lightly scrape off any excess wax and buff. This finish will minimize the absorbsion of any water and you can use a damp rag to wipe up any glue excess. Dried glue will pop right off the surface. Renewal or repair is easy. Just use a scraper to remove and hardened stuff, wipe down with mineral spirits using a 3/0 steel wool pad (a non-woven green or gray abrasive pad is better), wipe off the gunk and apply another coat of boiled linseed oil/wax mixture. My personal preference is for an oil/varnish mixture treatment. Either use Minwax Tung Oil Finish, Minwax Antique oil or a homebrew of equal parts of boiled linseed oil, your favorite varnish or poly varnish and mineral spirits. Sand the benchtop up to 180 grit. Apply the mixture heavily and keep it wet for 15-30 minutes. Wipe off any excess completely. Let it dry overnight and the next day, apply another coat using a gray non-woven abrasive pad. Let it set and then wipe off any excess. Let this dry 48-72 hours. To prevent glue from sticking apply a coat of furniture paste wax and you're done. This treatment is somewhat more protective than the wax and mineral oil as the varnish component adds some protection from not only water both some other chemicals also. The waxing makes the surface a little more impervious to water so you can wipe up any liquid adhesive. It also allows hardened adhesive to be scraped off. Repair and renewal is easy. Just go throught the same scraping, wiping down with mineral spirits and reapplication of the BLO/varnish/mineral spirits mixture and an application of paste wax. Both of the above treatments are quite protective but are easy to maintain and renew. They do not fail when the surface takes a ding.

"
Seems to be about what you are recommending - and what I plan on using.

[Mark AJ Allen]

How flat is flat? I don't feel the need for a machinist's granite reference plate. I get some dye on the bench. Fine. I get some varnish / shellac on the bench. Fine. I get some glue on the bench, it dries, I grab a chisel and it pops right off. Fine.

Having said all of that, most of my finishing, and glue-ups for larger pieces, takes place on my TS - 6' x 6' all told, with cardboard I put on the top.

But using the bench is my first option, if it fits.

How flat is flat? As flat as you can make it I would say; The flatter a benchtop, the better able a person will be to detect non-flat lumber. I think it's it safe to assume using flat lumber is a best practice so this leads to conclude flatter is better.

Maybe this is a bad assumption on my part: If someone cares enough to clean up a bench after using it for assembly and finishing, they care a great deal about benchtop condition, including the key attribute of flatness. That leads me to wonder why anyone would use their bench to assemble/finish work when other options everyone has are available. This also makes me wonder how finishing a top affects the flatness of the top. Those factors are my own reasons to not finish a top, in addition to the advantages of an unfinished top for hand planing, etc ...

I don't believe it's a forgone conclusion to put any finish on a bench. I believe the motive to finish should be aligned with what kind of work a person does and how they do it. The basic question is how much work do you want to do to maintain a flat bench? If a person doesn't mind more work beyond flattening to maintain a flat bench, they can finish a bench whatever they want.

[Daniel Rode]

My bench has a finish that consists of 1 coat of thinned poly. I think it was thinned to about 1:1. I wiped the top, let it sit for a couple minutes and wiped it thoroughly with a dry rag. It leaves a surface that feels grippy rather than smooth. The only reason I put any finish on was so glue could be cleaned up easier.

It's a workbench, not furniture, so I do everything on it, even assembly.