Advice Request...Converting a Bench Plane to a Scrub Plane ?

[Derek Cohen]

Lowell

Anything can be made to work.

The issue is whether it is an efficient tool, or not. And if not, what is better?

Regards from Perth

Derek

[Allan Speers]

I have a #3 that is normally a straight forward #3. It is my favorite bench plane.

I purchased narrow replacement iron at one of the box stores and ground a severe camber in it. When I need a scrub plane, the narrow, highly cambered blade goes in it, and Voila!, it becomes an aggressive scrub plane. .

This is a good idea, since the OP will not likely use a scrub much. Who does?

Everyone covered it, a narrow, highly cambered blade with an open mouth is the whole point. - but I'll add one more thing about usage:

The typical use for a scrub is when prepping raw lumber, or when taking down a lot of width in a completely non-powered shop. thus, the blade projects a significant amount and one hogs off large strips. For that, I prefer a plane that has a front handle which can be PULLED, such as the Swedish types. (ECE, Ulmia) - And these also have the advantage of being light weight.

However, a converted plane can work great for prepping tough lumber, such as figured hard maple & some burls, before the final planing. For this, you keep the blade VERY shallow, and make a series of light passes in all directions. Even with this job, you want a very narrow blade and a very high camber. However, a slightly longer body & more weight can actually be helpful.

[Michael Ray Smith]

Hi All,

At this point I don't know how a #3, with the iron sharpened like a fore plane, would work and how useful it would be. Right now I have that Dunlap that does me no good at all, and I was thinking about what I could do to make it useful.

Stew

I converted a No. 5 1/4 to a scrub plane. The 5 1/4 is the same width as a No. 3, and I wouldn't want anything wider than that.

As for the radius on the blade, I think you want something that's not as tight as the radius on a No. 40 just because your blade is wider than a No. 40, but I could be wrong about that. I honestly have no idea what radius I used on mine. I simply started out with something that looked about right, erring on the side of something that was too wide, tested it out, and then adjusted it a time or two until I was happy with it.

After you're happy with what you have, if Paul Sellars or anyone else tells you you're not doing it right, tell them to take a hike. Well, unless it's George. If George tells you you're not doing it right, give serious consideration to the possibility you're not. And then if you still think what you're doing is okay, stick with it.

[steven c newman]

Working down some rough pine planks I had glued up
scrubbing pine.jpg
Plane is a Corsair C-5. 14" long scrub jack. Iron is at about 8-9" radius. Trying to flatten a wavy top. Lots of scallops. Have had this plane for quite a while, might have had to sharpen it once....

[steven c newman]

Have a Harbor Freight Windsor #33, converted into a #3 sized scrub plane
IMAG0173.jpg
Radius is about 3", hungry little beasty
IMAG0172.jpg
BIG thick shavings. As for that Corsair C-5 Scrub jack?
IMAG0168.jpg
may it is by Great Neck, and maybe it was designed with a single bolt to hold the frog in place. But, grind a 8-9" radius on the edge of the iron, and we have a fairly decent wide mouthed scrub plane. Might have sharpened both of these once in the last year or so.
IMAG0166.jpg
Had just cleaned and candle-waxed the sole today, even...

[Tom M King]

I don't know that a scrub plane is any faster at removing stock than a Jack is. We use a scrub plane for scrubbing old beams and boards before putting a good iron in the wood. Look at the picture I posted that shows the iron edge. It's dull as can be, but was still working at the end of that day. I never understood why people started using a scrub plane on clean lumber. An 8" radius Jack iron might not take as deep a bite, but the width probably takes about the same amount of wood. If I'm knocking a high corner off a board to save time before running it over the jointer, I almost always reach for the Jack. An sharp iron is always easier to use, but the scrub iron doesn't stay sharp long cutting dirt and grit.

[Barry Dima]

Thanks all for this conversation. I've been kicking around the same idea—and with the same plane—as OP. The pictures are especially helpful; I have 0 idea what I'm doing, so the visual references are really helpful. Dang, those open mouths. Although the opening isn't as important as a rigid chipbreaker or wedge—albeit one not bedded too closely to the end of the iron, yea?

[steven c newman]

To quote Herr Schwarz....you want to be able to see the corners of the iron.

Just keep it close to the corners of the cambered itons. Close as in maybe 1/32" or so back