A Krenov plane with an adjustable mouth

I promised to our local woodworking forum to build a plane and write a story, as there are not any good plane-building instructions on the net in Finnish. So this was intended to be just a quickie, a demo for our forum.

The basic idea is just a Krenov plane with an added adjustable mouth piece. A fixed mouth would have even simpler to build, but I wanted the plane to be as versatile as possble. The plane iron was an old 45 mm wide E.A. Berg.


On the scrap pile I had an 50 mm oak plank with a bad crack. On the other hand rest of the plank was very good and straight grained.

For the plane you need just a length of 50 mm plank twice as long as the plane. Other half is for the center parts (bed and front piece) and the other is split into three: two cheeks and a thicker middle section for the movable toe piece and wedge. I don't have a table saw, so I just cut two grooves in the oak piece with a handheld cirqular saw, finished off with a hand saw and hand plaed the parts to right thickness.




Next were the parts for the adjustable toe piece. I made a threaded hole in a 6 mm brass piece and chiselled out an opening for it on the toe piece. The edges of the brass piece were tapered so that the top was narrower than the bottom, as the brass is only glued to the toe piece with epoxy.

I drilled two holes to the fron piece and opened them with a chisel for the 6 mm threaded rod for the toe piece. The knob was just a brass drawer knob, I only had to drill and tap it for M6 threads.




I sawed the bed to 48 degrees, freehanded it straight on my shooting board and chiselled out the groove for the chipbreaker screw.





All was glued together with West Systems epoxy. The temporary toe piece that I'm hoding with my index finger is there just for measuring out the needed space for the actual toe piece.




I roughly pland out the top and bottom after glue-up. I also adjusted the toe piece and cut it to the right length. There is also a small allowance to tighten up the mouh afterwards if I have to flatten the sole sometime.

I also made the wedge from the same offcut I used for the toe piece with 8 degree taper. The crosspin is 10 mm brass.




I have always liked coffin smoothers as I have started my woodworking with one. I also have somewhat disliked the usual blocky looks of home-made Krenov planes, so I wanted my plane to look like a classic.

I had planed the sole quite straight already after planing, but I still flattened it ove a glass plate with sandpaper.




Finaly came the finishing. soaked the plane for a while in linseed oil and pine turpentine and after that put a dark shellac on top as on the old planes. And the last touch is some homebrewn beeswax - boiled linseed oil - pine tar mixture I use on most of my wooden tools.




The mouth can be opened about 5 mm, plenty for even a roughing plane. It can also be fully closed. The best surface and thinnest shavings I got with a very small mouth opening, maybe 0,1-0,2 mm.




The plane was intended to be just a demo for the local foum, but it ended up being a better smoother than my Spiers that I have considered unbeatable. And as a bonus, it is more versaile than the Spiers, as the mouth can be adjusted.




Pekka