Dunlap #3726 Bench Plane - I Think

I was given this plane in pretty rough condition by a guy who really didn't know anything about planes.  One telltale sign was that the iron was upside down when I got it (bevel up).  And while I know a fair bit about planes, I knew little about this particular brand when I started on this one.

The plane as found

Something look funny here?

Maybe the upside down iron explains why the cutting edge 
was so chewed up!

It's an oddball size - it has a 9 1/2" long sole similar to a Stanley #4, but the sole's width is 2 1/8" and the iron is 1 3/4" wide, like a #3.  Initially, the only identifying mark I could find on the plane was the remnant of a DUNLAP decal on the broken tote.  From a Dunlap type study that I found online, a #3 size plane has the 1 3/4" wide iron, but the plane should be only 8" long (or 9 1/4", depending on the source of info).  Go figure.

I found two websites that were very helpful in researching this plane.  According to justtheplanefacts.com and aplanelife.us, Dunlap planes were manufactured for Sears by either Millers Falls, Sargent, or possibly at one time by a West German maker.  Some details point to this plane being made by Sargent in the 1940-41 time frame, but I think it is probably a bit later than that - maybe the mid 1950's (reference the Dunlap type study on the A Plane Life site).

Here's the plane fully disassembled, complete with broken tote
and bent tote screw/post

Initially, I could find no identifying marks on the casting, iron, cap iron or lever cap.  The only marks I could find are a casting number on the frog (5272) and a raised "MADE IN USA" mark on the main casting just below the adjuster knob.  However, since I started writing this, I cleaned up the iron and it's got DUNLAP APPROVED BL stamped clearly at the top.

DUNLAP
APPROVED
BL

Here's the iron all cleaned up, but not yet sharpened.
Note the hole for the cap-iron screw is at the top, unlike Stanley plane irons.

I had to grind back to the blue line before grinding a new bevel and sharpening

According to the sites I referenced, the "BL" and the cap-iron screw hole location are indicators of a plane made by Sargent.  So is the upside-down U-shaped lateral adjust lever.

As for the plane's casting, I took sandpaper to the sides and sole.  They looked horrible, but cleaned up fairly easily.  A wire wheel in the drill was used to clean up all the hardware.

The body was really grungy and the sole was horribly rough

But it cleaned up nicely

The tote was broken, so I cleaned up the mating surfaces and reglued it.  I'll have to see if that fix holds over time.  Originally, the tote had a decal or two on the left side.  Unfortunately, more than half of it was gone.  It looked like there was once another decal up where the middle finger grips the tote, but it was missing completely.

The still-broken tote showing remnants of a decal

Here's another interesting tidbit.  The yoke was a two-piece construction, as opposed to a casting.  It still works fine, but it's interesting that the two "fingers" of the yoke can move independently.  That's no big deal; when the plane is assembled, the adjuster nut keeps them aligned.

The two-piece yoke

Here showing how the two "fingers" can be misaligned with each other

When I finally had the parts cleaned up and the iron sharp, I put it together, adjusted the frog to get a reasonably tight mouth, and tried it out.  It made a shaving, but the shaving was like an accordion.

First shaving all crinkled up

I'm aware this could be caused by the cap-iron being too far forward.  Some adjustment helped, but not enough.  I also noticed a rippling effect when face planing.

You can see the ripples

So there was some juddering of the plane as I planed along the face of a board.  To me, that points to issues with how well the frog and plane body keep the iron firmly in place.  Here's where I really had to do some work.  The surfaces of the frog and plane body where they meet were painted or japanned, and were not level, so the contact between the two was poor.

Pointing to one of two spots where the frog sits.
These needed to be filed/sanded level and flat.

Same with the frog seat

Frog seat filed flat

After this, I was able to get a better edge shaving, but there was still a big problem.

Got a much better edge grain shaving ...

... but when planing the face grain, CLUNK!
The plane stopped in it's tracks and dug in hard!

Here's the problem with this plane and it's a serious design flaw.  And it's also why I think the plane was made in the '50's - you know, after plane makers "forgot" how to make planes that worked well.

The frog of Stanley planes has two flat areas that mate with two flat areas on the plane body.  The frog "seat" and the frog "toe" both should be milled flat and mate precisely with corresponding spots on the plane body.

Locations of the frog seat and toe

In this plane, not only is there no milled spot on the plane body for the frog toe to mate with, but the frog toe doesn't even come in contact with the plane body at all!  It's basically cantilevered out over the plane body, just behind the mouth.  Without support there, it's no wonder that the frog and iron don't have enough support to plane face grain.

This is a piece of cardboard, probably about 1/32" thick

Sliding the cardboard under the frog's toe.  I could have fit
3 or 4 of these cardboard pieces in there.  And this was with
the frog bolted firmly in place!

I've started trying to make a piece of wood that will fill that gap, but I don't hold out hope that it will fix the problem.  But for this plane to work, I believe there needs to be firm support for the toe of the frog.

Summarizing, there are a couple of details that gave hints about the maker and age of this plane, thanks to the type study provided by A Plane Life.  The position of the iron's keyhole, the "BL" on the iron, the inverted U-shaped lateral adjust lever, and the two-piece yoke all indicate a plane made by Sargent.  The lever cap had been nickel plated, though the plating was removed when I cleaned up the plane.  The nickel plating indicates a plane possibly made in the 1940-1942 timeframe.  Other details include the double threaded 12-20 rods that hold the tote and knob, the brass waist nuts holding the stained hardwood tote and knob, and the three-ridged knurling of the adjuster knob.  But even with these clues, I can't help suspect that this plane was made in the mid-1950's due to the shoddiness of the design.

This is an odd plane for sure.  If there are any collectors of Dunlap planes out there and you're interested in this plane, please let me know and I'll be happy to mail it to you free of charge.