With my first experience using hand planes, I became more and more interested in the hand tool side of wood working. I took a week long course in using hand tools taught by Chris Gochnour at the Marc Adams school of woodworking (an excellent school that I highly recommend to anyone looking for formal instruction). It was there that I was introduced to molding planes. Since then I’ve acquired a few but none came with sharpening instructions. What recommendations do the more experienced woodworkers have for this task?
Neil
Replies
Neil,
Basically sharpening of plane irons, molding plane irons, chisels, carving tools and just about everything other than scrapers should be exactly the same process. The abrasives for shaping and sharpening are different, you don't sharpening on grinding stones. Proper sharpening, though, depends on proper shaping.
You start by deciding if you need to refine the shape or profile. If so, you need to grind. Easy success in grinding or refining the shape comes from defining the new location of the edge and creating a visual reference to grinding to that point. You do this by marking the shape on the tool and grinding at 90º to the face of the tool. This step defines the new location of the edge and creates a flat to show what must be ground away on the bevel. I like to mark that flat with machinist's red layout fluid as an aid in seeing the flat as it is ground away to just a hair-line.
Sharpening is done with stones or perhaps an abrasive medium in a hand held grinder--I prefer a flex shaft grinder with rubberized abrasive points for profiled molding planes. You still need to follow up with slips but the flex shaft grinder makes things a little easier. Like all sharpening, each sharpening should also prepare the tool for future sharpening. To do this you need a flat face on the tool and flat sharpening stones. If you dub the edge or create other problems these problems mean you have to start over every time you sharpen. Avoid this, it makes sharpening hassle. Most people don't seem to understand this basic idea and it leads to foolish short cuts like the now common "ruler trick." Dubbing is a problem, even if it's intentional.
I believe paraphernalia like honing guides only do the easy sharpening of straight chisels and plane irons. If you're going to sharpen gouges, molding plane irons or other curved edges you need to learn how to sharpen without all the unnecessary crutches. If you can freehand a complex molding plane iron, free handing a straight chisel or plane iron is pretty simple. Why add the extra steps and hardware to your sharpening procedure when it only works with the easy stuff?
If you're looking for a step-by-step guide to sharpening a molding plane I can do that but I'm not at that point with what I'm working on at the minute. I wish you had asked this question a week ago. I could have shown a real sharpening challenge. The next guy that sharpens the planes shown below needs to figure out how to do it without removing any steel from the iron. I don't know of a way to do that.
View Image
View Image
Those are stunning planes, Larry.
Neil, to hone I glue sandpaper to sticks, round (dowels) or flat, or use waterstone slips. I will also run the molding plane over a piece of soft wood, like pine, create a profile of the bevel, and charge this with green rouge. This can be used to "freshed" the edge.
Hope this helps.
Regards from Perth
Derek
Larry,
Beautiful plane! If I may ask, what would a plane with that profile be used for? It looks like it will refine an inverse schmoo shape, but what type of project would need an accurately profiled schmoo-shaped groove?
Or is it to work on a edge profile using half the iron and it is symmetric so it an be used coming and going, depending on grain?
David C
David,The planes actually cut a circle and the irons are elliptical because of the bed angle. They're gunstockers' planes for letting barrels and ram rods into gun stocks. These are rare for a reason, they cut an arc of more than 180º sharpening is a real problem without re-profiling the sole with each sharpening. The cutting geometry has to be everything from the 60º bed angle plane cut to a negative relief scraping cut when the cut is made above the halfway point on the sole. While old ones are very rarely found they do exist. I think they're rare for a lot of functional reasons.I didn't mean to hijack this thread with the gunstockers' planes but they'll prove useful in explaining the importance of flat irons in molding planes.The quality of the edge depends entirely on the surface quality of the two converging surfaces. In use, both of these surfaces wear and become rounded increasing the angles making up the edge. When you sharpen you have to address both these surfaces. You have to get those surfaces dressed and the cutting geometry restored.If you've dubbed your iron you have three choices--grind the iron back past the dubbing, flatten the iron (which becomes more difficult with each improper sharpening), or dub the iron more. Further dubbing your iron becomes a hit-or-miss operation because dubbing isn't uniform. It's also very difficult to tell when or if you've dressed the surface. Maintaining proper bevel angles can't easily be done without keeping a flat face.The irons in the gunstockers' planes are elliptical because they meet the profile at an angle. If those planes had been made with lower bed angles their elliptical profiles would be elongated in length. If the irons were set at a steeper angle the length of the elliptical profiles would be shortened. Dubbing changes the profile just like changing the bed angle. If you dub your molding plane iron, you change its profile so that it won't match the profile of the plane's sole.If you maintain flat faces on your plane irons and keep your sharpening stones flat, all the problems go away. You really don't have to remove much steel to remove dulling wear on the face of an iron. A few passes on your sharpening stones will do it. If you maintained a good flat face in your iron's previous sharpening, it'll be very easy to sharpen the next time. If you don't keep it flat you introduce time, effort and guess work into your next sharpeningWe, like a lot of other tool makers, go to a lot of trouble to send our planes out with flat irons. You pay for that because it adds to the cost. Many of our customers know the importance of flat irons and want their tools to come with flat irons. We can't dumb our planes down for those who don't know the difference or don't know how to sharpen.
Thanks Larry,
I have a hard imagining how the plane would be used if it cuts more than 180º since that would prevent you from plunging into the profile from the top.
Is most of the shaping done with a gunstock float and then this used to chase a final profile from one end to the other?
If that is the case, it probably (thankfully) doesn't need sharpening too often.
Of course it's likely I'm missing something obvious. Fascinating though, I've never seen or heard of such a thing.
David
David,Sorry for the delay. The stocks aren't cut at more than 180º. The barrels are tapered so they want to be able to tilt the planes and closely fit sides and other parts.Gunstockers' planes are very rare and, until recently, all those I'd seen in dealer sales, auction catalogs and such looked as if they'd been made from converted rabbet planes.I've made a number of gunsmiths pretty angry by telling them I wasn't interested in making a plane I didn't think would work. I've now seen photos of two actual gunstockers' planes--made and marked by known plane makers. I've uploaded the one I worked from to go with this post. It's a late 18th Century plane by John Green. I did put chamfers on those I made that were more common a few decades earlier than this old plane has. I don't think the iron in the Green plane is original but I never had it in my hands so I'm not sure.After making the two I made, I'm just as convinced as before that these planes have some fatal flaws. I don't think the people I made those planes for will get much, if any, use out of these planes. I did try to talk them out of ordering them in the first place. There are a lot of hobbyist and professional gunsmiths out there interested in reproducing the old guns. One of the difficult woodworking tasks they face is accurately inletting the barrel. I believe almost every article about making gunstocks in the last 50 or 60 mentions gunstockers' planes. These planes are so rare I doubt the authors have working experience with them. A lot of the gunsmiths I talk to believe these nearly mythical planes are the magic bullet. Many of the gunsmiths I've talked to don't take kindly to someone who has no gun smithing experience telling them what works and what doesn't. I did the best I could at giving the gunsmith what he asked for and I'm confident it worked when it came out of the box. Time will tell if I'm right or wrong about gunstockers' planes.
Neil,
Mike Dunbar has a good section on this subject in his book "Restoring, Tuning and Using Classic Hand Tools". You may find it at your local library, but I'd buy it as it contains many things you may find interesting down the road.
The trick to getting old molding planes to work is dealing with the sole to iron mismatch. I'm pretty sure that's what Larry was talking about. So here's the deal- In general, wood shrinks. It goes through a seasonal shrink swell cycle, but each cycle makes it a little smaller. When you encounter a wooden molding plane, you'll typically find that the body has shrunk in thickness (across the profile). Now you must bring the iron and sole to match, but there's a reasonable question as to what to fix. If the profile is complex, includes boxing etc, it can be very difficult to fix the sole. You may have to take off more material than you'd like. In this case, fixing the iron is the right thing to do. On the other hand, if you have a fairly simple profile (like an ovolo), fixing the sole brings the plane closer to the planemaker's original intention.
I used to flatten every plane iron and chisel I had. I no longer do this. Molding plane irons are often quite far out of flat. I don't think its worth flattening them. I'm not convinced there's any real functional benefit in use. In fact, the dubbed edge may function like a back bevel, raising the effective angle of the plane, which may help it work difficult grain. Flat irons can be easier to sharpen because you have a reference surface to go back to. Let's say it this way- try it first, and if you have time, flatten one and try it that way. See if you notice a difference.
You can often use needle files to correct a molding plane iron's profile. They are often tempered higher than other blades, so they are soft enough to work with a file. Despite the higher temper, I think you'd be wise to avoid powered grinding unless you are an expert like Larry. Unlike normal chisels and plane irons, if you blue a corner, you'll have quite a bit of work to do to remove it.
I think planemakers may make molding plane irons that perfectly match the soles. I don't know for sure. But woodworkers don't always want this. Without experience with a specific plane, its hard to say when and where to deviate from the sole. All I can say is that we don't always want a perfect match. On hollows and rounds for example, we sometimes make the iron taper off to one side (typically the right side). I'm just saying this to bring it to your attention. Its something to think about as you sharpen your planes. You may chose to not fuss quite so much over perfecting the profile. A "perfect" profile often is necessary and may not even be desirable.
I guess I'd sum up my comments as - be sure to try it before you fix it. Let your observations of the plane's deficiencies guide your restoration instead of shooting for some theoretical perfection.
Lastly, know that most planes we encounter second hand are carpenters' tools, never intended for curly cherry. If curly cherry is your goal, put those molders on ebay and start saving for Clark and William's silver bullets.
Adam
Adam,
You wrote: "wood shrinks. It goes through a seasonal shrink swell cycle, but each cycle makes it a little smaller. "
Guess that's why old planes and antiques in general, are so scarce; they first become miniatures, then eventually disappear.
Ray
This forum post is now archived. Commenting has been disabled