Finishing hand-planed surfaces

[Patrick Chase]

So I'm one of those neander snobs who [believe that they] can create a finish-ready, streak/ridge-free surface off of the polishing plane, and I've gotten into the habit of staining and sealing from that starting point, without scuffing. Obviously stain up-take is much different from that of most sanded surfaces, but I've adapted to that and that isn't my concern tonight.

I typically seal with 1 lb shellac or (more rarely) a vinyl sealer. I've done the standard adhesion test with a grid of knife cuts and packing tape, and my finish stacks pass with flying colors so far. When I've had issues it's always been because I did something silly with an intermediate layer, and never because of the base coat's adhesion to the wood. I do sand between intermediate layers when appropriate, though always extremely careful not to cut through and disturb the planed wood surface.

My question is: Is this something I need to continue to worry about going forward, or does the "open-pored" structure left by planing provide enough mechanical bite for basically any finish? Planing doesn't provide as much "bite"/interlock as a coarse-sanded surface, but it also doesn't close off the pores like sanding (and particularly overly fine-grit sanding) does. It's sort of a different thing altogether.

FWIW my reasons for finishing "as planed" are twofold: First, I think that there is a visible difference in chatoyance etc under thin finishes like shellac (obviously if you slap on 4+ dry mils of CV you won't be seeing any difference at all). Second, it makes grain-raising with water-containing finishes a nonissue, as cleanly planed surfaces have no loose fibers to swell and stiffen.

[Wayne Lomman]

What you are doing is legitimate - it works and you have adapted your finishing regime to suit. Be prepared to relax the rules if necessary for colour matching. If a component stubbornly rejects stain, sanding will increase absorption of stain and darken more as a result. Cheers

[Frederick Skelly]

I also finish off the smoothing plane. I haven't expeeienced any adhesion issues with the finishes I've used.

[Wayne Lomman]

Adhesion will certainly not be a problem. That is more of a worry for those who glaze their work with 600 paper etc. Adhesion issues are almost without exception caused by contamination with dust, moisture and chemicals or incompatibility between coating materials which is just more of the same. Machine planed surfaces can experience problems with adhesion but that is due to glazing and waxes etc used as table lubricants, not planing. Cheers

[Pat Barry]

I'm curious if you use any lube on your smoothing plane as some espouse, for example wax or oil pot. I would be concerned that would leave residue that would affect adhesion or if you dye or stain, the absorption of the coloring.

[John C Cox]

Patrick,

What's the concern? Your finishes are working and not having issues delaminating..

All the testing on glue adhesion in the 1900's - 1940's showed that a freshly planed surface was far and away superior to every other surface for glue bonds. I would not expect this to be any different for finishes - which must bond to the wood just like glues do.

If I was a betting man - I would wager that the finish companies have worked to come up with ways to get their finishes to "take" about as well to a sanded surface as to a freshly planed surface.. But it also has to be something the average workman/hobby person will actually do... An aggressive, coarse sanding immediately before finishing appears to be what they came up with... 100-220 grit sandpaper is commonly available and this doesn't take too much time in the prep stage before you are painting on your finish...

It's interesting to note that many professional varnishers sand a surface to around 3,000 grit prior to varnishing with oil varnishes.. And they come out spectacular. But this is also a "white glove" sort of operation where contamination of the surface prior to varnishing is a real problem..

[Rob Young]

I'm curious if you use any lube on your smoothing plane as some espouse, for example wax or oil pot. I would be concerned that would leave residue that would affect adhesion or if you dye or stain, the absorption of the coloring.

It won't unless one somehow hooked up a liquid-wax-dispensing system to the plane so that the sole is constantly bathed in wax.

The quick swipe with a candle stub or lump of paraffin won't cause a problem. Same with a quick swipe over an oil pot once in a while.

It is a case of some is good but more isn't better.

[Patrick Chase]

I'm curious if you use any lube on your smoothing plane as some espouse, for example wax or oil pot. I would be concerned that would leave residue that would affect adhesion or if you dye or stain, the absorption of the coloring.

I use wax, which is one reason why I prefer shellac as a base coat.

If I know I'm going to use a waterborne or a penetrating stain on the bare wood then I often do my final smoothing "dry", as I don't mind the added friction when taking shavings that thin and it's less hassle than removing the wax.

As Rob says the amount of wax involved doesn't matter for any finish that I use, but I'm paranoid about wood cleanliness.