Jack Plane Iron Camber

[Bill Rhodus]

For many years I have had a scrub plane with a 1/4" A2 iron that is awesome. However, I have been trying to streamline the volume of tools in my shop and have chosen the scrub as a target for elimination as I believe I can get acceptable results with my jack. I have always ground my jack iron (#5 sized Millers Falls) with eased corners so that I could use it for cleanup tasks, jointing smaller objects, etc. but if I am going to use it for stock reduction I believe a full camber to the blade would be helpful. I further believe this will complicate the use of the jack as a small jointer or a plane to prep flat stock. With this in mind I have two questions; when I camber the iron, how far back do I set the chip breaker (the scrub has no chip breaker) or is it irrelevant for the rough work but negatively affects the use of the plane for jointing? Also, would it be better to replace the scrub, jack, and fore plane with the Veritas BU jack with a variety of irons as it is very easy/quick to replace the iron? What are your thoughts?

[Steve Friedman]

Love my BU jack,but if you decide to have a dedicated cambered jack blade, I would also have a matching cambered chip breaker. It resolves the chip breaker placement problem and lets you switch out the blade as quickly as you can with a BU plane.

Steve

[Jessica Pierce-LaRose]

I don't have much to add other than I started with a 7" radius on my bevel up LN jack for roughing work - it's flattened out quite a bit in the middle from repeated sharpening, as I found it a hair too much for work in harder wood. I'd tend to start with something fairly rough, as I find it easier to flatten out the center by if the radius is too much as opposed to regrinding the radius (although neither is too difficult with a powered grinder.)

Derek has covered this on his site - I believe he went with an 8" radius, but I could be wrong. Chris Schwarz also went over this on an episode in the current season of the Woodwright's Shop.

For the chip breaker, I don't think it matters too much for this coarse work - make sure the mouth is open enough to let the chips pass, and have a go. When I used a bevel down plane for this, I set the breaker fairly close at the corners, but they don't do too much cutting, so it's not a huge deal, and it leaves the center of the iron pretty far from the breaker. With the aggressive camber on the blade, you're not going to get the breaker very close to much of the cutting edge as it is.

I really like a nice blade that holds a decent edge for this kind of work. Razor sharp isn't as important as a blade that doesn't round over or dull quickly. Slamming through big bites like this, a thicker blade might be nice - that's just my sense though, I haven't tried it with a thinner blade.

[Jessica Pierce-LaRose]

Steve brings up a good point - and while I don't know if I'd bother with a cambered chipbreaker, on planes I have multiple blades, I like to have multiple chipbreakers, if the plane needs them, to make blade swapping easier.

[David Weaver]

I don't like the BU jack for rough work. I really like having the BU jack as a shoot board and end grain plane, and just for general use sometimes with a straight iron.

I've used a bailey jack and a bedrock jack (someone gave me a deal I couldn't resist). I don't know what the radius is, because I do it by eye, but I wouldn't be surprised if it was shorter than a basketball radius. I sharpen it with a belt grinder with a 1200 grit trizact belt and set the chipbreaker pretty much right up to the edges of the camber. It's obviously not effective at breaking chips from the middle of the iron when set like that, but it works OK.

I also have a cheap fuunji japanese plane (a type that JWW no longer sells) that I use from time to time. Sometimes because of mood, but also because a lot of us don't do a lot of dimensioning every day and it's another option that works different muscles. You can get in a situation where you need to dimension larger boards for an hour or two and run out of steam to push, or find yourself needing to do more the next day with elbows or joints that hurt from the day before. So I have a setup to push and pull - total excess indulgence, but whatever.

I haven't used the scrub plane in a long time.

A millers falls 14, btw, would be a fine jack plane. I think you'll find a slightly eased radius of a jack preferable for the first -go around on most rough lumber, including stuff that's somewhat twisted and cupped, and even less than that on really good straight rough lumber.

[dave andrews]

I really like the bevel down jack with a thick a2 cambered blade for hogging off material. It has made me reconsider my scrub plane, maybe in 6-12 months I will consider selling off the scrub. I could see having a second straight blade for other work but what I have found is that I dislike changing blades. might be just me on that one. cheers.

[David Posey]

The fact that you're thinking about getting the Veritas BU jack with differenet irons raises the question of why you're getting rid of the scrub at all. I understand if it isn't used, but I can't imagine going to a fair amount of expense just to replicate its function in only a slightly smaller footprint in your shop.

For what it's worth, I have two jacks that I use regularly. One is an old woodie set up with a heavily cambered iron, something like a 4-5" radius. It gets used rarely, mostly when I need to take a fair amount off the edge of a board when it's too short of a distance to saw. I also have a Stanley 5C that has about a 12" camber that I use for lighter cuts, and it is usually the first plane that rough lumber sees. For me the 5C and the fore plane would do the same roles, and if I were to get rid of one out of the three you mentioned, I'd get rid of the jack. I realize I could use one plane for both roles, but I find it a lot easier not to have to adjust them and be able to grab the plane and go to work. No system of changing irons is going to be faster or more convenient than having multiple planes.

[Bill Haumann]

If you're doing a significant amount of milling by hand, I personally couldn't deal with stopping to change blades between fore, trying, and jointer. My personal favorite fore plane is a 17" marples woodie with an 11-12" radius camber. New old stock the plane with iron was $80, and I've seen several others for about that price since.

[Bill Rhodus]

Thanks for the replies guys, but I would like to further refine my issue. I fully agree that the jack can be used to prep rough stock with a cambered blade and I have a 2nd jack in my traveling box for this purpose. This plane has the chipbreaker set just shy of the cambered corners and is very rank in the middle of the iron. Works great to prep rough stock; of little use as a small jointer as the tearout causes a lot of smoother plane work. What I am looking for input or ideas on is the feasability of using one jack to both rough stock and finish plane small items in preparation for smooth planing. Are these functions incompatable without an iron change? I suspect so. I currently own the Veritas BU jointer and have several irons of different angles and with the set screws to center the iron and the lack of a chip breaker, it is nearly as fast to swap out the irons as to grab another plane off of the rack. This is what leads me to believe the BU plane with multiple irons is the only way to replace the scrub, jack, fore plane combo with one plane. I would not argue with you that it is convenient to have a multitude of planes set up in each manner and in fact is what I have in my shop now, however, I have two nephews sliding down the slippery slope and would like to minimize my list of tools (anarchist tool chest? not really, just minimizing) and pass some of these planes to them as I have had them their entire life and they mean something to them.

[David Weaver]

Yes, totally incompatible without iron change, unless you want to just bull stock with a straight iron. As cheap as a #5 is, I would just buy a second #5 and use it as a jack. You can get a rough one if you're not going to use it to smooth.

You don't need a multitude of planes (I don't even like changing irons in the single iron LV planes, it's a pain), but I wouldn't want to try to make one plane function as a smoother and a jack, with or without changing the iron.

There is only one plane I have used that I would consider from rough to smoothing, and that's an infill panel plane. That's not exactly a sensible expenditure, but it's heavy enough to bull a pretty thick shaving with an iron with very little camber. It's a violent experience to bull a thick enough shaving even with that, but it can be done, and the plane can still leave a nice surface when the depth is backed off.

[David Posey]

Is there also a fore plane in the mix here? I seemed to understand that there was. If so, let the jack do the rough work and the fore do the finer work, or vice versa if you prefer.

[Bill Haumann]

<scrub, jack, fore plane combo>
I don't think it would be too big a stretch to have one plane handle these tasks, I don't think you even need different irons.
Getting that same plane to be a smoother, IMO, would require a different iron and a tighter mouth, however.
If you're not working on large pieces, however, you might be able to get by with one plane, but I wouldn't want to tackle milling very much rough lumber without a cambered iron.