Molding plane blade sources

[Ben Johnson WI]

So, I'm looking to make a couple of molding planes (and maybe even a skew rabbet if I get ambitious) for some upcoming projects. As best I can tell, my options for making blades are:

1) Buy a bar of O1 steel from [insert supplier of choice] and do all of the cutting myself. No problem with actually forming the profile I want, but cutting the long tang, etc. would take a fair amount of time with Ye Olde Hacksaw(e)

2) Buy blanks from Lie-Nielsen cut to size at a pretty substantial markup (I can get an 18" bar and get 4+ blanks for 2/3rd the price of a 1" wide blank lovingly crafted in Maine).

3) Some other supplier?

(#3 is the cue for the knowledgeable Neanderthal to chime in and come to the aid of the aspiring Neander)

[Pam Niedermayer]

I dislike blacksmithing, so my first route will be CPM 3V, cut and ground by me, tempered by others. If that doesn't work out, the LN route seems real good. Their blades don't seem all that expensive to me; but then, I wouldn't buy a set. At least they're O1. Ultimately, I don't expect either way to be more or less expensive by any drastic amount.

Pam

[Jessica Pierce-LaRose]

The one nice thing about the LV blades is that they're tapered, which in my experience, is a nice thing to have in a wooden plane.

Another option is if you peek around, you can occasionally stumble across vintage molding plane irons that have long ago separated from their planes, or pick up some used molding planes with salvageable irons, but bodies that have long succumbed to the ravages of time (and improper storage)

I wonder if you supplied the material, and where planning on making quite a bit of them, if having a machine shop cut you quite a few blanks would be cost-effective?

[Tony Shea]

That is the biggest selling point of LN blades, they come tapered. Not an easy task without the proper tooling.

[Ben Johnson WI]

The one nice thing about the LV blades is that they're tapered, which in my experience, is a nice thing to have in a wooden plane.

Another option is if you peek around, you can occasionally stumble across vintage molding plane irons that have long ago separated from their planes, or pick up some used molding planes with salvageable irons, but bodies that have long succumbed to the ravages of time (and improper storage)

I wonder if you supplied the material, and where planning on making quite a bit of them, if having a machine shop cut you quite a few blanks would be cost-effective?

Good thoughts on all three ideas. As I was browsing online, I heard mixed opinions about the value of tapering irons and how well they actually secure in place.

As far as having the basic sizing cuts done by someone else, I'd considered that as well. I'm on the management staff of a food manufacturing plant as the day job that allows me to dabble in this, and just a few short steps away from my office is our machine shop, which naturally has a big metal-cutting bandsaw, a couple of milling machines, lathes, etc. Lots of 304 and 316 stainless steel as well - aside from specialized stuff in pumps and more generic materials in utility piping, 316 is the metal of choice. Our maintenance manager sits across the hall from me, so I might just see if he's OK with letting me use the bandsaw a bit to get the blanks roughed out on a quiet day. (the bandsaw isn't too highly utilized). At least with O1, I can do the rest of the work at home in terms of the heat treatments.

[David Posey]

I've considered using Lee Valley's replacement blades for their wooden rabbet plane found here:

http://www.leevalley.com/us/wood/page.aspx?c=&p=46324&cat=1,41182

I realize they just say high carbon steel instead of specifying O1, but will your moulding planes see enough miles that it's worth the hassle to get that extra edge durability? I think for me it would depend on what profiles I was making. A simple hollow or round wouldn't be that difficult to sharpen, but a complex profile wouldn't be so much fun. At only $5, it's no great loss if it doesn't work out so great.

[Andrae Covington]

I've considered using Lee Valley's replacement blades for their wooden rabbet plane found here:

http://www.leevalley.com/us/wood/page.aspx?c=&p=46324&cat=1,41182

I realize they just say high carbon steel instead of specifying O1, but will your moulding planes see enough miles that it's worth the hassle to get that extra edge durability? I think for me it would depend on what profiles I was making. A simple hollow or round wouldn't be that difficult to sharpen, but a complex profile wouldn't be so much fun. At only $5, it's no great loss if it doesn't work out so great.

The only hangup I see offhand with that blade is that the tang is centered, whereas on most side-escapement planes the tang is along one side. Lie-Nielsen sells blanks in both configurations.

[David Weaver]

A couple of thoughts:

* 1/8th O1 is plenty for a moulding plane iron, especially if you're talking about the smaller planes that someone would use in cabinetmaking, up to probably the planes where the iron is an inch and a half of profile. And especially if you make the plane and it's fresh and the fit of the iron, bed, wedge etc is all tight

* 1/8th O1 is easy to heat treat at home - especially irons an inch wide or less, which can be done with a single mapp torch. Larry williams' video is helpful to see what you should look for when hardening, but you can do trial and error.

* If you have a metalwork vise of any type, it's not hard to cut annealed O1 with a hacksaw - just get a good hack saw and clearly mark your metal, cut a bit wide and then file/powersand/powergrind to the lines.

* You want tapered irons. It makes a substantial difference, saying that as someone who tried with straight irons. The taper only has to be a very small amount to be very effective in helping you get the iron out of the plane, and probably in helping the iron to keep its depth when it's set (i had such trouble getting a straight iron out of a freshly made plane that I never even got to planing with it).

If you have a belt sander, you can effectively put enough taper on the irons. Just cut a recess 1/16th inch deep in a block of wood in the shape of an iron, tack the iron temporarily into it and put the thing on the belt, always putting the tang side down first and then let hand pressure deterimine where metal is removed - biasing toward the tang. This will be intuitive - you'll want to set up the block so that the iron is butted up against the side of the recess and so that the tang is on the trailing side of the belt movement, the back end of the tang will get very hot - but it doesn't matter.

I don't see any reason why someone can't mark, cut, grind/file, taper and harden a pair of irons in an hour.

Do not buy any irons that force you to compromise on the design of your planes. I think looking at what planes I have that work the best, the type of plane construction L. Williams prescribes in his video is the best. Your first plane will likely be a better performing plane than any you've ever bought if you have that video and follow it. Save center tang blanks for rabbet planes, and buy the LN blanks, which are rather pricey, only if you decide you can't make your own, or if you have more money than time. Making simple irons from stock is a good skill to have - all of the little planes you come by with spent irons (like bullnose infills and little shoulder planes, etc) can be had cheap and a good iron made quickly.

Avoid any steel for a moulding plane iron that you can't finish sharpen with an arkansas slip or that you have to send out for heat treat. I can't see a reason to use anything other than O1, hardening it is like riding a bicycle - once you do it right one time, you get predictable results, and you can temper it in your oven as long as you use vegetable oil to harden it.

I like to hit my irons with oxpho blue after I finish them because they're a bit ugly after hardening and tempering, and it makes them look more uniform and pleaslingly dark.

[Dave Anderson NH]

David makes good points and the only thing I would add is pick your quenching oil carefully. My first heat treating was done in my basement shop about 8 or so years ago. I grabbed some old SAE30 from a lawnmower oil change and put it in a coffee can. It worked quite well but SWMBO stormed down the stairs very upset about the smell and I received a number of choice words which our terms of service will not allow me to repeat here. Ever since that assisted epiphany I have used either walnut oil or peanut oil for quenching. Both have among the highest smoke point temperatures of all of the cooking oils and this makes life more pleasant. It also allows the use of the kitchen oven for the tempering process afterward. I have an old cookie sheet reserved specifically for kitchen tempering.

[george wilson]

As David says,01 is plenty good enough for molding plane irons. It was also used by LN for their blades before they went to A2. I used it for many years before I got an Electric furnace and stainless steel foil wrap(which is very expensive to start off. you must buy a big roll). If you are quenching blades in the house,as Dave says,peanut oil works fine. We used automatic transmission fluid at the toolmaker's shop for many years in Williamsburg,but it can catch fire a bit when you plunge red hot steel into it (nothing serious). We were in an industrial room,with a big hood and powerful exhaust fans,though. Didn't have to worry about soot.

Dave,will peanut oil go rancid sitting around forever in a quench tub? I need to get quenches set up at my home shop,both brine and oil,and I have an exhaust fan here,too. My walls are painted white,though,and I'd like to keep them clean. Does peanut oil catch fire ? Does it start smelling bad?

[Jessica Pierce-LaRose]

If I remember correctly, the smoke point of peanut oil was around 450 degrees Fahrenheit? The flash point is higher, but I don't know how much. This is just off of memory from deep frying. I've never had peanut oil go rancid, but we've never kept it around that long. It will go rancid eventually, quicker if you've opened the original seal. I think it keeps about a year or so unopened. Like olive oil, it keeps better in the fridge. It will turn faster if it stays warm. I think once you've opened it up, you should be able to get 4 or 5 months out of it, Probably longer if you're not eating with it; there's point where something you cook in it will taste a little funky but it won't smell acrid yet either.

[george wilson]

I like a 5 gallon quench. Would be a loss if it did go bad and had to be tossed. Hey,I made a poem!! Too big for the fridge!! And,your quench should not be cold in use,or it shocks the metal too much,promoting cracking and warping.

Blacksmiths would quench some random red hot large metal in their tubs in the morning when it was cold,in an unheated shop.

[Dave Anderson NH]

Hi George,

Until I klutzed out a few months ago and knocked over the can of walnut oil spilling it all over the shop floor I had used the same batch for 3 years with no smell issues though it did get darker over time. So far the replacement peanut oil has only been in the can for about 4 months ans it still has no odor. For both a storage and working container I use one of those quart sized metal paint cans with lid you can buy at any home center for about a buck or so.

[Jessica Pierce-LaRose]

Good point there. I knew you wouldn't want to quench in cold oil. Would be a hassle to go keep it cold when not in use, and hot when in use. I figured Dave would post with more direct experience; mine is going from memory and dealing with cooking.


There's a big difference between too far gone to cook with, and gone far enough it's noticably stinky. I've heard peanut oil doesn't get nearly as stinky when turned as olive oil.

[Matt Bickford]

I have a vat of peanut oil that has been open for well more than a year. It sits in my basement. There is no smell.

Be warned, quenching irons in peanut oil will make you hungry.

[Bob Winkler]

Perhaps this may be a dumb suggestion since I'm only a Neander wannabe, but last weekend I was in a local antique shop that had a bunch of old molding planes with different profiles and their iron intact for $14 each. That seemed reasonable to me and I was surprised how useable they appeared.

Bob

[Jessica Pierce-LaRose]

It occurs to me that rancidification is an oxidation reaction; and that to packaged and processed foods often add an antioxidant to prevent this - I wonder if the use of the oil as a quenching medium, you end up adding something to it that helps this process?

I'll keep my cooking-based knowledge out of the metallurgy discussions from now on!

[Ben Johnson WI]

It occurs to me that rancidification is an oxidation reaction; and that to packaged and processed foods often add an antioxidant to prevent this - I wonder if the use of the oil as a quenching medium, you end up adding something to it that helps this process?

I'll keep my cooking-based knowledge out of the metallurgy discussions from now on!

Diving way OT...

Well, before I took this manufacturing gig, I actually did R&D work at my current company, which makes a lot of those packaged/processed foods (although my background is mostly in cheese and other dairy products). I'm not sure the mechanism that more conventional anti-oxidants work on, but it could be that if you lose any trace bits of iron in the quench, the iron would be more readily oxidized versus the oil. However, having the rust in your oil wouldn't exactly be tasty either - oxidized oils tend to have a bit of a metallic taste anyway.