During my year in Japan I didn’t witness one traditional pieces that wasn’t wipe lacquered made from urushi tree sap or waxed
Tool handles/bodies were many times left unfinished by the owner if the made them but again the would be darkened by the oils from your hand, they didn’t consider them fine pieces but tools to be used.
The Japanese did not sand wood it until after it was lacquered. I am baffled where you found that? Pull plane with small white oak bodies akin with a small high angle blade gave similar results to an English scraping plane.
The final coats (up to 30) were sanded/polished with pumice powder and then charcoal dust, but still not 4000 grit equivalent. Seen several places it was about 1200 grit equivalent.
The bare wood itself if sanded with pumice powder would fill the pores and cause immense issues with repair and refinishing for the next generation which they wouldn’t do.
This part I am really baffled by.
It is correct that sanding and scraping "CAN" make a surface non level if piss poor technique is used. But if they have a piss poor technique on the final scraping or sanding why would they have any better technique on the initial sanding???? The statement in relation to the OP is illogical.
And the last part about showing if something next to it is flat, is the main reason you finish sand or scrape after assembly.
The human hand can easily perceive a difference in height between two surfaces as small as .001". There are few wood workers than can complete the machine work to the wood at that level of accuracy and then assemble it as well. Finish sanding/scraping makes sure that those steps are not perceived by the end owner.
The other thing is that the human hand and even the eye (by itself) cannot perceive a surface flat at even 10 fold what it can feel a step. We need tools like straight edges and light to perceive something being out of flatness by 0.10 or less.. Many cant even perceive that.
When scraping machine tools in its always humorous to see people come up and feel the surface and say flat it is. Only to blue it against a master and show how unflat it is.
Are you kidding ?
Traditional Japanese architectural wood is routinely finished with hand planes, and then left unfinished.
It’s a standard technique mentioned in numerous books on Japanese architecture and woodworking.
Tool handles are tool handles, and it doesn’t matter if they’re finished, although all Japanese tool handles I’ve come across with imported Japanese tools have bern finished with some sort of lacquer (no clue if actually Urushi or nitrocellulose), except saw handles.
Traditional fine carpentry work is only finished with a scraper plane if absolutely necessary.
Traditional angled plane blades are usually used, and there are one or more Japanese stationary power tool manufacturers who even manufacture powered versions for finishing large pieces of lumber.
The widest Japanese scraper hand planes I can find are 54mm, or about 2”.
Japanese planes with angle set blades can be found in significantly wider widths.
Bare wood would not be finish sanded with pumice or charcoal in Japan, but the lacquer once applied is, at least on the highest level work.
Pumice “grit equivalent” doesn’t matter as much, and the same goes for charcoal grit, since both will break down and become finer as they are used as an abrasive, similar to how Japanese waterstone sharpening stones have the grit become finer as a tool is rubbed against the surface.
Incidentally, mixing a fine powder like calcium carbonate or plaster into linseed oil, creating a fine translucent paste, is a grain filing method used in Western Woodworking for woods with coarse grain like oak.
I don’t know if there is a similar technique used for Urushi, but it wouldn’t surprise me.
As far as flatness goes, the eye in a decently sighted person can easily discern non-flat surfaces, since light will not reflect of a non-flat surface evenly, and knowledge of this likely goes back millennia.
Highly polished surfaces exaggerate the effect.
Finishing wood surfaces so fit is less than .0001 of an inch isn’t some new skill, it also likely goes back 1000 plus years, and was likely needed in certain situations, or used to show skill, although plenty of items likely weren’t finished to that precision unless made for a discerning client, or absolutely necessary.
Finish scraping and sanding only really works well if planned for, and sanding out a single spot either leaves a divot, which us usually noticeable,
or requires surfacing an entire piece, which can also screw up dimensions.
On fine furniture or specialty work, such as with veneer, and luthier work, sanding or scraping out a bad spot because of leaching from a clamp pad would simply not be possible, due to the thickness of the veneer, or the fact that changing the dimensions can screw with the tone.
Using solvents may also not be possible, since the solvents can leach thru the veneer and screw up the underlying glue.
Replacing the veneer, or removing and regluing is likely going to take hours, with a huge chance of screw ups.
I can fully believe a soft padded clamp of this sort is going yo get used for veneer or luthier work.
) then figure out where/how to get them that just work like they should.
