Plane Sole Conditioning with Sandpaper

[Christian_C]

Hi,

I've read that using sandpaper to condition the plane bottom is not recommended as grit dislodges into the plane, this gets transfered to the piece being planed and it nicks the plane blade. While this seems like a perfectly logical answer, I couldn't help but notice how many western wooden plane users advocate the use of sandpaper and how western wooden plane makers, such as Knight Toolworks, suggest using a reference surface and sandpaper as well. Is sandpaper a truly viable option or is a scraping the bottom of the dai the only way to go about it?

Thanks for your time.

[Sheets]

I've never tried sandpaper. Its possible that the tradition in Japan (using dai naoshi kanna) still persists today since it originated long before the invention of sandpaper. Also, the sole of kanna are not really flat, but have a wave pattern to some degree. This requires the application of selective wood removal and this might not be as accurate if using sandpaper(?).
I know there are some who use paper and don't seem to have a worry about grit remaining behind and it may in fact not be a problem in actuality. Never heard of anyone pooh-poohing sand paper prior to finishing wood - you'd think that grit in the finish would be a similar problem.

Steve

[Christian_C]

I am aware of the gliding surfaces on the sole of the plane, but those can be recreated with sand paper so I'm just looking for an alternative to the traditional method. I recall reading people argue over the problems related to sandpaper on the japanesetools.com message board. Many people echoed the same reason, Harrelson Stanley I believe as well, although don't quote me on that. There is an article in Fine Woodworking by Carl Swensson, Japanese Planes Demystified, where sandpaper is advised against due to grit embedding.

It just seems odd to me that western wooden plane makers suggest the use of sand paper for sole conditioning, but then it is a no no for the Japanese dai. I just want to know if the reason given holds any water or if it is a wives tale to preserve tradition.

[Sheets]

Only one way to find out (I don't think it will ruin anything). Let us know if you encounter any problems. It could be one of those "myths".

Steve

[yojimbo]

Christian -- if you're not fully comfortable with the naoshi kanna, Swennson's suggestion of using a card scraper to create the relief areas seems excellent, though I've never tried it -- might now, though.

[Des.K.]

Hi Christian

3M adhesive sandpaper (100 grit) on a perfectly flat piece of hardwood was the preferred method of flattening and conditioning the bottom of plane dai at the college I attended in Toyama (naturally, conditioning with the dainaoshi plane was also taught). Sandpaper was used by my instructor (40 years in the business), and the furniture and carpentry instrutors and most of their students. I have a dainaoshi plane, but the sandpaper method is much faster and gives just as good a result. Make sure you wipe the dai off at the end (mineral spirits if you prefer) and there should be no problems with grit marring the work.

Des

For clarification: The sandpaper and backing board is secured on the workbench and the plane is first pushed lengthways along the sandpaper to get a perfectly flat bottom, then perpendicular to get the relief areas.

[Christian_C]

Thanks to all who responded, I have nothing against the dai naoshi kanna, I in fact own one. Having another way to go about conditioning just gives more power to user and I something wasn't exactly clicking when I read about reasons against sand paper.