Finish straight on to planed surface?

[Paddy Roxburgh]

Reading the endless back and forth of Charles and David on the cap iron thread something occurred to me that I have been meaning to ask. Assuming that you have hand planed your surface successfully with no tear and a shiny surface would you go straight to finish or would you give it a quick sand with 240 to key the surface? I do the latter because Paul Sellers told me to, but it always seem like a bit of a shame. Does it depend on choice of finish? Also if this is the correct strategy the does the same apply to glue surfaces? I have never keyed hand planed boards for edge jointing but would this give a better key for the glue?
In all of this I am only talking about a quick rub with fine paper not sanding that involves any appreciable stock removal.
Thanks, Paddy

Mods, I have posted this in hand tools rather than finishing as I am primarily interested in what hand tool users do. Hope that's ok

 

[Zeddedhed]

I seem to recall that James Krenov once suggested that a burnished surface from the plane, especially a nice woodie was NOT the best surface for glue to adhere to.

Logically this would see right as I assume that glue relies on penetrating the surface of the wood by a very small amount, so opening that surface by a quick flash over with 180g or 240g would seem wise.

I await my inevitable rebuttal, since thats all just guesswork/instinct.

 

[Cheshirechappie]

Interesting question. I've finished many a surface straight from the plane, with no detrimental effects I've noticed. I do find I often have to sand lightly after the first coat of finish has dried to remove the stubble of raised grain, but that's not quite the same thing.

I've never sanded before glue either, again without detriment as far as I know. Mind you, I may have been getting it wrong all these years!

 

[D_W]

I seem to recall that James Krenov once suggested that a burnished surface from the plane, especially a nice woodie was NOT the best surface for glue to adhere to.

Logically this would see right as I assume that glue relies on penetrating the surface of the wood by a very small amount, so opening that surface by a quick flash over with 180g or 240g would seem wise.

I await my inevitable rebuttal, since thats all just guesswork/instinct.

I don't know if that's true for hide glue, but you can always sand a glue joint if you want. I've generally not done that and thus far I've not had a glue joint fail in anything.

I believe Franklin (Titebond) has rebutted krenov's statement.

 

[JohnPW]

I have read that pro "hand made" furniture makers sand before applying a finish, but only because it saves time, presumably it's quicker than planing or scraping.

I definitely apply a finish straight on a planed (or scraped) surface. I don't see why not.

And no sanding on a planed surface for gluing either, eg, gluing the two halves of a violin top.

 

[D_W]

Reading the endless back and forth of Charles and David on the cap iron thread something occurred to me that I have been meaning to ask. Assuming that you have hand planed your surface successfully with no tear and a shiny surface would you go straight to finish or would you give it a quick sand with 240 to key the surface? I do the latter because Paul Sellers told me to, but it always seem like a bit of a shame. Does it depend on choice of finish? Also if this is the correct strategy the does the same apply to glue surfaces? I have never keyed hand planed boards for edge jointing but would this give a better key for the glue?
In all of this I am only talking about a quick rub with fine paper not sanding that involves any appreciable stock removal.
Thanks, Paddy

Mods, I have posted this in hand tools rather than finishing as I am primarily interested in what hand tool users do. Hope that's ok

50% of the time, I use shellac and wax, and I've never done anything to the surface, except to actually burnish the surface further in some cases (especially if there's something post assembly I notice that can only be scraped). You use less shellac with a planed or properly scraped surface (I've seen charlie allude to what I'm talking about before, where you finish scraping with a very fine shaving from the scraper). I usually put two coats of shellac on before I address grain raising, there usually isn't much on a planed surface.

Uniformity, promoted by sanding, is more important if you're going to stain, especially if you have wood that doesn't take stain well in the first place.

(the other 50% of the time, I use shellac and spray lacquer - sanding only if it's requested - my wife requested kitchen cabinets that look manufactured, and "not too wooden". I sanded them because they have plywood sides and the ply absorbs shellac like a sanded surface due to the abuse the veneer takes, I guess. If you plane the solid parts, the sides take on twice as much shellac and color match isn't very good).

 

[Phil Pascoe]

I wonder with regard to finishing how a planed surface works with Osmo - where they actually advise you not to go beyond a certain grit (180 iirc)? This would imply (to me at least) there needs to be a key.

 

[Cheshirechappie]

I wonder with regard to finishing how a planed surface works with Osmo - where they actually advise you not to go beyond a certain grit (180 iirc)? This would imply (to me at least) there needs to be a key.

That's a point - some finishes form a film ON the surface (and may therefore benefit from a key) and some sink INTO the surface, so keying wouldn't be so important.

 

[Beau]

I always give it a light sand for the simple reason that other parts of the piece will have joints with grain going in different directions and it's very hard to get these right straight off the plane so they get sanded anyway. I don't want the final finish to look different on different faces. Also I don't use a plane prior to the sanding on anything with tricky grain preferring a scraper plane as you know you are going to get a tear out free face instead of hoping you will.

Not sure I agree with Zedhead about a light sand as a key for glue. Would sanding not block the pores in the grain when a sharp plane should leave them open allowing penetration of the glue? Just speculation but have glued straight from the plane on most occasions without problems.

 

[D_W]

I just tracked down a titebond-based suggestion from franklin. They say a smoother surface is better as long as it's not burnished. I guess then the question is what is burnished. Larry Williams always tells those of us who use a common pitch plane that we've burnished the surface by using the plane, and that it's not necessarily the result of a clean cut (not sure that I believe that, but I'm still waiting for the first glue joint failure on a planed surface like everyone else here).

Franklin's specification for what a smooth surface is - sanded with "200 grit or higher".


no clue what that implies for other glues.

 

[ED65]

Does it depend on choice of finish?

Yes I think so. The surface straight from the plane may not be ideal if you're using full-strength varnish or a heavy lacquer, but with anything thinned enough that it could be considered a penetrating finish it should pose no problem. And any purpose-made penetrating finish is okay as well of course.

Also if this is the correct strategy the does the same apply to glue surfaces? I have never keyed hand planed boards for edge jointing but would this give a better key for the glue?

If there has been burnishing you'd be best sanding lightly. If there hasn't been burnishing straight from the plane is the perfect glue surface because it is about as smooth as you could hope for and that's very good for most woodworking glues.

However, that said I think this is really only an issue if you're either a) particularly anal about joint strength or b) you need to rely on the glued joint being as strong as it can possibly be, as on an unreinforced butt joint in thinner material.

 

[AndyT]

I think there's a risk of over-thinking things here.
As far as I can recall, across the various things I've made out of wood, I've not had any problems of finish or glue failing because the wood was too smooth or not smooth enough. Most domestic woodwork is pretty undemanding.

 

[Racers]

I never if I can help it sand anything so I all ways finish on a plained surface, I do tend to Scotchbrite the surface after a coat of Danish oil.
I would never sand a planed edge joint, it would spoil the fit.

Sanding is time consuming, dusty, repetitive and has no benefit on the appearance of the wood.

IMHO obviously, you are free to sand as much as you want.

Pete

 

[custard]

Reading the endless back and forth of Charles and David on the cap iron thread something occurred to me that I have been meaning to ask. Assuming that you have hand planed your surface successfully with no tear and a shiny surface would you go straight to finish or would you give it a quick sand with 240 to key the surface?

It's not about keying the surface, you don't have to key for finishing. Personally I don't believe you have to key for gluing either but I know outstanding craftsmen who follow both gluing practises so I wouldn't get too excited about it.

The more relevant issue is the question of finishing directly onto a planed surface. I guess I've met well over a hundred craftsmen who earn all or the majority of their income from furniture making, but I can only think of one who routinely finishes direct onto a planed surface.

Why isn't it more common?

Chiefly because a planed surface is never flat enough to receive a surface film finish (varnish, shellac, lacquer, etc) that will require subsequent sanding. The minuscule ridges that planing always leaves will get cut through by the subsequent sanding, so it's simply a non starter. In addition the most economical solution to tear out is a drum sander!

However, with finishes like Danish Oil or Osmo ridges aren't a problem. I have tried persuading clients to go for a planed finish and drawn their attention to the unique tactile attraction of a "tooled" surface. I've been pleasantly surprised how positively they've responded.

 

[D_W]

I think there's a risk of over-thinking things here.
As far as I can recall, across the various things I've made out of wood, I've not had any problems of finish or glue failing because the wood was too smooth or not smooth enough. Most domestic woodwork is pretty undemanding.

Bingo. It's like the argument against a hollow grind. We never actually see chisels that broke because they were hollow ground. We don't see glue failing because of how a joint was prepared, and there is no great time difference doing it either way.

 

[woodbrains]

Hello,

I'd be interested about the thought that Krenov keyed the surface from the plane before gluing. I have read all krenov's books and cannot recall that ever being written, though memory might be failing. He was anti sandpaper, in fact and wanted surfaces straight from the tool, whenever possible. He is usually misquoted for saying he never used sandpaper, in fact, though the truth is, he did use very fine paper if necessary. I attended the college of the Redwoods, and keying before glueing was never mentioned.

Water borne glue such as PVA and its derivatives bonds on a cellular level, so keying the wood is unnecessary. Resins such as epoxy, keying would be a good idea.

I've never keyed the wood for a finish, either. Keying finish for subsequent coats is a good idea, for film forming varnishes. Lacquers would be unnecessary, though light sanding for de-nibbling is usual.

Mike.

 

[Peter Sefton]

I can't remember seeing a commercial furniture maker leave his work from the plane before finishing. We deal with a solid timber in various grain directions, end grain, mouldings, veneers, laminates and inlays. Uniformity of surface preparation across the entire job is required prior to finishing. The planes sole may leave wax or other contaminates that would effect either clear or particularly a stained finish.

I do not sand surfaces prior to gluing either but I wouldn't use wax on the sole of a plane prior to jointing a pair of boards ready for edge gluing. I do sand manufactured boards prior to veneering to remove any waxed surface or finger marks.

Cheers Peter

 

[D_W]

I think finishing from the plane is something that's never been suggested done by anyone other than hobbyists and the occasional period woodworker (there is someone in the states who does it commercially).

The overwhelming majority if commercial answers I've seen rely on safety (defined as not having to do something over) and uniformity.

It's interesting to me as a hobbyist because I'm sensitized to the dust of my favorite wood, but sensitivity is not so bad yet that I can't plane it. If I sand, and dust extraction isn't very good (so sanding anything by hand without downdraft would count here), I get symptoms like bronchitis for a while and need to use an inhaler.

Planing or scraping don't cause that.

Since hand tools is the theme, and since I'm not much of a historical reader, I'd be curious about what was done in a commercial shop 200 years ago. Any idea?

 

[Jacob]

I think there's a risk of over-thinking things here.
As far as I can recall, across the various things I've made out of wood, I've not had any problems of finish or glue failing because the wood was too smooth or not smooth enough. Most domestic woodwork is pretty undemanding.

Bingo. It's like the argument against a hollow grind. We never actually see chisels that broke because they were hollow ground.

Yes we do

We don't see glue failing because of how a joint was prepared,....

Yes we most definitely do.
You can't really plane a surface (wider than the plane) unless the plane is cambered, or you end up with tramlines. On the other hand a cambered blade leaves shallow scoops. This may be OK as finish - if you cast a strong light over a bit of old handmade furniture you often see plane scoop marks - quite OK. Or it may have been sanded and/or scraped

 

[D_W]

I think there's a risk of over-thinking things here.
As far as I can recall, across the various things I've made out of wood, I've not had any problems of finish or glue failing because the wood was too smooth or not smooth enough. Most domestic woodwork is pretty undemanding.

Bingo. It's like the argument against a hollow grind. We never actually see chisels that broke because they were hollow ground.

Yes we do

We don't see glue failing because of how a joint was prepared,....

Yes we most definitely do.
You can't really plane a surface (wider than the plane) unless the plane is cambered, or you end up with tramlines. On the other hand a cambered blade leaves shallow scoops. This may be OK as finish - if you cast a strong light over a bit of old handmade furniture you often see plane scoop marks - quite OK. Or it may have been sanded and/or scraped

The only glue joint failures I've ever even heard of second hand are those that occur after someone has glued a board (pair of boards) and then adjusted the joint with a hammer under clamping pressure, presumably not immediately. That failure was reported to have occurred before any piece was finished.

I've never heard of a chisel breaking up into the hollow due to the hollow. It certainly is possible that a chisel would break because the primary bevel is too gradual, but that would seem to be a different issue.