Thread: Japanese scraper plane problem

Hi Andreas87

A small amount of clogging during use is not unusual. When my dai-naoshi plane starts to clog up I simply use a small firm painting brush (any cheap variety will do) to clean it out.

Adjust the mimi to make sure the sides of the cutting edge don't extend beyond the mouth opening otherwise it will clog up very quickly, and become unworkable.

Also make sure your scraping action is only very light. You can extend the blade a reasonable amount, but the downward pressure on the plane should only be quite light. This will reduce the jamming problem a fair bit.

And keep the blade sharp. The scraping action damages the blade edge fairly quickly, and you will notice a big difference between scraping with a dull edge and with a sharp edge.

While the plane has been given the name of "scraping plane" in English, it is a dai-naoshi plane, and it is designed for tuning the bottom of Japanese wooden planes (which are made of white or red oak, a hardwood). I'm not sure how it would work with softwood, as softwood doesn't respond the same way as hardwood when scraping. I would also avoid using it in the normal way of a "scraping plane" to smooth the surface of a piece of timber for furniture or the like. It's not designed for that, and a hand-held scraper is more appropriate.

Regards

Des

I don't know I'm sorry, but I'm interested in the solution. Have you tried emailing stu from 'tools from japan'?

Originally Posted by johnredl

I don't know I'm sorry, but I'm interested in the solution. Have you tried emailing stu from 'tools from japan'?

I'd just cut and paste what Des said. He's right on the money all the way.

Interestingly, folks here don't always use them for conditioning their planes, resorting to sandpaper often enough to work the hollows that they actually make special set-ups to that effect.

The trick is that the 'shavings' are coming out as chunks of grain, not actual shavings. They have little integrity, and even when clogged they will usually not clog strongly enough to prevent them from getting the job done. For an actual 'scraper plane' you need a LOT more clearance for the shaving to come out, and these planes just can't manage it without a lot of modification.

In short, use a cabinet scraper or a proper scraper plane for the intended task. Leave the dai-naoshi for it's actual intended task of conditioning kanna soles and it'll work like it's supposed to.

Stu.

Sorry, I was writing my reply at the same time as des, so I didn't see his reply when I pressed send.

Adjust the mimi to make sure the sides of the cutting edge don't extend beyond the mouth opening otherwise it will clog up very quickly, and become unworkable.

is this the mimi? (pic)

Thanks for all replies I guess the problem is not the plane but my inexperience. I will start using it as was meant to be used

Thanks for the help!!

Mimi are 'ears' and in the case of a kanna, they're the angled areas at the outer edges of the blade.

Take a look here for some explanations of the nomenclature of a kanna.

It doesn't mention the 'mimi' of the blade, but there are 'mimi' on the chip breaker, and you should get the general idea.

Pretty much every kanna needs adjusting of the mimi periodically. Just the nature of the beast, and yes your blade's mimi need grinding back.

Stu.

What you've indicated there are just the sides of the mouth (haguchi) where the grooves holding the blade (osae-mizo) end at the sole.

The mimi are the parts of the blade that are angled back from the cutting edge. Mimi is the Japanese word for ear.

As you continue sharpening the blade, the length of the actual cutting edge increases as the mimi are worn back. Once they wear back too much, the sides of the cutting edge extend past the sides of the mouth, and this causes all sorts of problems when planing.

To prevent this, you need to grind back the mimi when required. One of the photos (the second one) in my explanation of the tapping-out process shows where the mimi and sides of the cutting edge should be in relation to the mouth opening.

Ah now i get it

Then i will grind the edges of the blade until the width of the cutting edge is equal to the opening of the mouth. I see that i need to remove about 2mm of cutting edge on the left side of the blade if I use the picture as a reference to what left and right is. Thanks a lot for the help!!