Flattening a plane blade back

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Forum topic by mandatory66 posted 04-13-2015 01:45 AM 2432 views 0 times favorited 19 replies Add to Favorites Watch
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202 posts in 3186 days

04-13-2015 01:45 AM

Topic tags/keywords: plane

Just spent 2.5 hrs. flattening the back of a Woodriver 4 1/2 plane blade. My fingers are numb and black and my back aches. Started with a course 325 diamond stone then a 1200 fine diamond stone and a 6000 water stone. There has to be a better, quicker way. The iron had a slight hump about 1/4 inch from the edge, I had to use the ruler trick on the back to help get rid of it. Without the trick I probably would still be flattening the back. I am hoping some one here has a better process.

19 replies so far

View TheFridge's profile


10863 posts in 2541 days

#1 posted 04-13-2015 01:56 AM

Not that I know of.

-- Shooting down the walls of heartache. Bang bang. I am. The warrior.

View upchuck's profile


540 posts in 2720 days

#2 posted 04-13-2015 01:59 AM

The initial flattening of the back of plane blades new or vintage is a pain. For the hard-core out-of-whack examples I use 80 grit zirconium sand paper on a flat surface to just grind it down.
Also remember that for some planes the backs do not need to be perfect. With a scrub or jack plane that will be followed up with other planes the first pass over the wood does not have to be perfect. Following passes with other planes will shave off any imperfections.
Also remember that all of your efforts only need to be done that first time. After the blade is flat only minor touch ups when sharpening will be needed to maintain your blade.

View Tugboater78's profile


2796 posts in 3247 days

#3 posted 04-13-2015 02:02 AM

Id return it.. and get another..

say rob cosman only spends 2 minutes getting his WR blades ready out of box, i deserve that quality too!

If you got it flat already id still take it and maybe demand another that they make sure if flat before you left.. and take both home

But.. well i can sometimes be an ass.

-- "....put that handsaw to work and make it earn its keep. - summerfi" <==< JuStiN >==>=->

View BurlyBob's profile


8715 posts in 3321 days

#4 posted 04-13-2015 02:14 AM

Bill, work on your Zen, mind over matter, you don’t mind and a little work don’t matter. Become one with the process. I’ve spent hours and like you, gotten totally frustrated, but once the job is done and done right the results are so worth it. I can’t think of a more satisfying sound in the shop than a sharp plane sliding down the edge of a piece of board. Hang in there, it’ll get better!

View Mykos's profile


103 posts in 2850 days

#5 posted 04-13-2015 02:25 AM

For a brand new plane that is unacceptable to me. I’d return it and buy Veritas instead.

I’ve never spent more than 10 minutes on a vintage Stanley plane blade.

View DocBailey's profile


584 posts in 3415 days

#6 posted 04-13-2015 02:37 AM

I have a partial, but important, solution.

Discussions of how things should be, may be appropriate in reference to new irons, but there is many a vintage blade that needs extensive work.

After years of finger-numbing work, I finally smartened up and started using a hunk of wood.
bolt the blade to it and you’ll find that you can apply a great deal more force at no cost to your joints.

Others have used a big rare earth magnet for the same purpose.

have a look here, about a third of the way down the page.

View ColonelTravis's profile


1976 posts in 2949 days

#7 posted 04-13-2015 02:51 AM

I’ve had a few blades in bad shape but never spent 2.5 hours flattening any of them. You started way too high a grit for big work like that, I’ve tried flattening blades or chisels on my coarse Dia Sharp, which is 325 – just insane. Never again. Get a granite stone and 60 grit sandpaper – massive metal remover.

View WayneC's profile


14359 posts in 5152 days

#8 posted 04-13-2015 03:01 AM

Only the cutting edge needs to be flat… So you may have polished more than you needed to. Also, there is a trick known as the ruler trick.

Better video

-- We must guard our enthusiasm as we would our life - James Krenov

View Andre's profile


4459 posts in 2861 days

#9 posted 04-13-2015 03:24 AM

2 sided tape a small block of wood onto the plane blade, start with 80 to 180 grit adhesive backed paper on flat surface, then I go to a 1000 water stone and finish polish on a 8000! (Mirror) for bad vintage blades, about 30 to 60 min.? When the plane is a keeper/worker a PMV11 blade from LV is installed, 10min prep!
Hock blades for Krenov planes take 30 to 45 min. because of the chip breaker.

-- Lifting one end of the plank.

View mandatory66's profile


202 posts in 3186 days

#10 posted 04-13-2015 03:51 AM

Doc, hunk of wood sounds like it will sure help, so does using the 2 sided tape to attach it recommend by rad457. Will try starting with larger grit paper on a flat surface next time. Will look into the PM11 blade in the future. I did get that sucker flat my best shaving was .0005. WR not up to LN but will get the job done. Thanks to everyone for the advise, that block of wood will sure save my fingers.

View TRHeath's profile


75 posts in 2642 days

#11 posted 04-13-2015 06:41 AM

I’d return it. I bought a WR #6 and a Pinnacle blade/chipbreaker for a #4 a week ago. Between the two of them I probably didn’t spend more than 20 minutes flattening and sharpening to 16000 grit. I started the back of the blades on a 1000 grit waterstone and had them polished in about 1/8” within a few minutes. You must of gotten a bad blade. In fact, I was so impressed with them that I just ordered a #4 1/2 and a #5 1/2 a few minutes ago.

-- So much to little time.....

View unbob's profile


810 posts in 2958 days

#12 posted 04-13-2015 01:48 PM

When a thin item like a plane blade is made, its surface ground on both sides. To help keep it flat it has to be flipped several times grinding both sides more evenly. Otherwise, if a blade is surface ground completely on one side, then the other side completely ground, the blade will warp-curl….
To produce a blade that is flat, it takes more time and cost more.

View Robert's profile


4522 posts in 2536 days

#13 posted 04-13-2015 05:31 PM

My WR #6 blade took more time to flatten than I expected, but no more than 30 mins.
Even at that, the best I could do was get a 1/16” behind the middle of the edge, so its gonna need more flattening. I was a little disappointed, but since I have a Veritas blade to fit, I didn’t go any further.

As far as your plane, I would have returned it. If you have to take off that much metal, you can’t help but wonder how stable the blade is going to be. I can almost guarantee you’ll be checking it for flatness from here on out.

Cosman is full it bull making people think they will get a WR plane ready in 10 minutes.
Remember he’s tied into Woodcraft, so what do you expect?

Interesting that the WR blade is thicker than the Veritas blade of the same size.

-- Everything is a prototype thats why its one of a kind!!

View BinghamtonEd's profile


2298 posts in 3425 days

#14 posted 04-13-2015 05:44 PM

Wow, I bought a harbor freight plane just to see how they were and it took me less than that, starting at 60-grit sandpaper on a granite tile. I was able to take that lump of crap from a turd to a sharp turd in about an hour. Great paperweight.

I also agree that you started on too-high of a grit.

-- - The mightiest oak in the forest is just a little nut that held its ground.

View Fettler's profile


206 posts in 3052 days

#15 posted 04-13-2015 05:53 PM

Take it back to woodcraft. Rob says some of those blades have been defective and if they have a hump don’t waste your time. The ruler trick assumes a relatively flat back and you may run into chatter issues.

I put IBC pinnacle blades in my woodcraft planes. I’ve been very happy with my #6 and block plane but my #4 1/2 always seems to give me troubles. Make sure you take a file and chamfer the edges so if you ever nick the edge you wont be leaving tracks in your work piece. I need to hit the base again with several grits to smooth it out.

I’ve never liked the tote design on Veritas, the angle is a bit off for my height and over time leads to some sworeness in my wrists. Port Townsend school of woodworking has a lot of veritas planes.

-- --Rob, Seattle, WA

showing 1 through 15 of 19 replies

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