Plane iron question - longwinded!

[Joel Goodman]

I recently picked up a Stanley#7 from the 30's. I would like to replace the iron with a thicker one - preferably thicker than the Hock (.095") --both to close the mouth while maintaining blade support on the back of the mouth and for rigidity of the blade. I understand that two things limit the thickness of the blade -- the size of the mouth opening and the height of the metal thing that pushes the blade in and out (as it has to clear the iron to engage the slot in the cap iron). I tried the iron from my ECE Primus smoother and although way narrow it worked well -- amazingly the slot worked fine -- it is a scant 1/8" about .120".

In that thickness range I have found four possible irons. (The LN jointer iron is .140 -- too thick.) 1) The Clifton -- expensive ($66) - I believe it is .120. 2) Ray Iles (.115) , either Carbon steel ($40) or D2 ($50) or #3, an ECE jointer iron ($32) which is 60mm wide or about 1/75" narrower than the stock 2 3/8th. I'm assuming it's the same thickness as the smoother iron.

Any thoughts from the experts? Has anyone used any of these irons?

PS - Thanks for all the previous advice on jointer planes. The magic of an old Stanley got to me!

[Jim Koepke]

I recently picked up a Stanley#7 from the 30's. I would like to replace the iron with a thicker one - preferably thicker than the Hock (.095") --both to close the mouth while maintaining blade support on the back of the mouth and for rigidity of the blade. I understand that two things limit the thickness of the blade -- the size of the mouth opening and the height of the metal thing that pushes the blade in and out (as it has to clear the iron to engage the slot in the cap iron). I tried the iron from my ECE Primus smoother and although way narrow it worked well -- amazingly the slot worked fine -- it is a scant 1/8" about .120".

In that thickness range I have found four possible irons. (The LN jointer iron is .140 -- too thick.) 1) The Clifton -- expensive ($66) - I believe it is .120. 2) Ray Iles (.115) , either Carbon steel ($40) or D2 ($50) or #3, an ECE jointer iron ($32) which is 60mm wide or about 1/75" narrower than the stock 2 3/8th. I'm assuming it's the same thickness as the smoother iron.

Any thoughts from the experts? Has anyone used any of these irons?

PS - Thanks for all the previous advice on jointer planes. The magic of an old Stanley got to me!

I have one LN plane, a small smoother and I do like it. I have one Union plane, a No. 4 size. It has a blade .110 thick and is a nice plane to use.
One of my Stanley No. 4s has a Hock blade and the others have Stanley blades.

How did you determine the .140 blade would be too thick?

There are slight differences, but to my way of thinking, all of these planes can do a great job if the blades are sharp. All of them are a struggle if the blades are dull.

Another factor is these planes have all been "tuned" to various degrees. The Union plane is on its third or fourth generation of family care taking.
The Stanleys were all acquired as junkers from eBay and an antique store.

When taking a thin shaving, it is likely all of the blade support is coming mostly from the frog. This is somewhat dependent on the angle of the bevel on the cutting edge of the blade and the position of the frog.

With the mouth closed, one is mostly going to be taking light cuts anyway.

A #7 joiner can take light cuts, but it is usually for more aggressive wood removal.

Have you experienced problems closing the mouth by adjusting the frog forward? If so, what kind of problems?

Do you have a way to check the angle of the bevel on your current blade?

jim

[Johnny Kleso]

i MADE SOME a-2 BLADES FOR MY PLANE .125 thick..

On a few I had to file the mouth a hair bigger..
You can buy custom blades from LN .125 for no extra, change at least was that way 2 years ago..

I have bought some LN for LN blades .140 thick and plan to file the mouth the .015-.021 (5-7 pieces of paper) to use the stock blades I bought on sale from Highland WW

The hardest thing is to find a file that fits the mouth space well and is not tiny..

[Joel Goodman]

These are all good points. I haven't tuned the plane yet -- but it works pretty well. I plan to flatten the sole etc. My assumption is that it's ideal if the plane iron rests on the back of the mouth for additional support -- but I haven't tried advancing the frog. In terms of the possibility of fitting the LN .140 Iron I was concerned that the pawl will not engage chipbreaker to advance the iron and that the mouth will be too tight. With the .120 ECE blade the pawl fully engages the chipbreaker (comes almost flush with the top) and the mouth is about 1/64th (estimated). Should I get some feeler gauges and measure this more accurately? Perhaps the LN will fit? I grind my irons at 30 degrees usually -- sometimes at 25 degrees. Which is better for this plane?

[Mike Henderson]

I grind my irons at 30 degrees usually -- sometimes at 25 degrees. Which is better for this plane?
For a bevel down plane, the only thing that matters is whether you have clearance behind the cutting edge for the wood to "rebound" into. Since the blade is bedded at 45*, if you were to sharpen the blade at 45* the bevel would be parallel with the wood, which would not be good. You need to leave a 5 to 10* clearance angle, so sharpening at 35* is good and provides good support to the cutting edge.

Sharpening at 25* does not help it to cut better and only weakens the cutting edge.

Mike

[Jim Koepke]

For a bevel down plane, the only thing that matters is whether you have clearance behind the cutting edge for the wood to "rebound" into. Since the blade is bedded at 45*, if you were to sharpen the blade at 45* the bevel would be parallel with the wood, which would not be good. You need to leave a 5 to 10* clearance angle, so sharpening at 35* is good and provides good support to the cutting edge.

Sharpening at 25* does not help it to cut better and only weakens the cutting edge.

Mike

Good way of explaining this Mike. I seem to be able to say things, they just don't always get articulated well.

My sharpening system came with a book that says much steeper than 35° will slide over the wood and shallower than 30° will chatter. I have seen "grind at 25° on some blades, but maybe that was with the intent of causing blades to wear faster in order to sell more.


I plan to flatten the sole etc.

What indications are there that this is needed?

With a joiner, I would be careful before starting. I have found it is easier to mess up the sole of a plane than it is to make it perfect.


My assumption is that it's ideal if the plane iron rests on the back of the mouth for additional support -- but I haven't tried advancing the frog.

I would have to try this on a plane from the same period as yours to see how this comes out. Unfortunately, there is only one from the 1930s in my shop. It is set up so nice it would be a shame to mess with it until at least the blade needs some attention.

When setting a frog on a plane that does not have an adjustment screw, a, preferably dull, blade is held bevel up on the frog. This is done without the cap iron or lever cap. Setting the base of the plane on a block of wood helps. The frog screws are about a half a turn from being tight. The blade is held to protrude through the bottom of the plane. The frog is positioned so the blade is flat on the frog and rests evenly on the back edge of the mouth. Just now made a visit to the shop and tried this on an older plane. The frog was set back just a little more than in the method described. The lip of the mouth is proud just enough to to catch the edge of the blade going through bevel up. When the blade is turned over, enough passes through before coming into contact with the base to take a cut. The amount that comes through before making contact depends on the angle of the bevel. The blade in my example is an old worn out one. It has a bevel angle of about 30°.

On the plane used, a type 6, the casting at the mouth may actually be thicker than what is on newer castings.

Give it a try and see what you get.


In terms of the possibility of fitting the LN .140 Iron I was concerned that the pawl will not engage chipbreaker to advance the iron and that the mouth will be too tight. With the .120 ECE blade the pawl fully engages the chipbreaker (comes almost flush with the top) and the mouth is about 1/64th (estimated). Should I get some feeler gauges and measure this more accurately? Perhaps the LN will fit? I grind my irons at 30 degrees usually -- sometimes at 25 degrees. Which is better for this plane?

My tendency would be to use a bevel between 30° & 35°.

If you have feeler gauges, you may try putting different thicknesses between the blade and the cap iron to see how a thicker blade would effect the adjustment pawl's ability to engage the chip breaker over normal movement.

jim

[Jim Koepke]

The hardest thing is to find a file that fits the mouth space well and is not tiny..

If you are clumsy like me, you may want to grind the sides so that they do not mark the edges.

Or use masking tape.

jim