Making my first plane blade --- suggestions appreciated

I am planning to make a blade for a handplane. It is my first time making a blade, so I have looked through Google and other resources and developed the following plan. I hope I have the sequence right; I would appreciate any wisdom, critiques or suggestions anyone can offer.

I have already purchased O1 tool steel from McMaster-Carr. It is 1/4" thick x 1-1/4", which will be the blade dimensions. It is cut to length at 4-1/2" (it can be shortened if necessary, that's not a critical length.) I have put a bevel on the blade with a grinder and belt sander.

I am planning to build a "coffee-can forge" based on Jim Wilson's economical design ---

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For safety's sake, I'll probably set the forge up on my ashphalt driveway so it's outside.

I'll stick the blade in the forge and heat it all up until the blade turns cherry red. I have read that wrapping it in stainless steel foil can reduce scale, but I really have no way to tell whether the steel is to temperature other than to look at it, which the foil would prevent. So unless someone says otherwise, I'll leave the foil off. Once it's cherry red, I'll use a magnet to ensure there's no pull. I'm not sure what kind of magnet to use --- I have one of those telescoping magnets that you use to retrieve nuts and bolts from tight workspaces; will that work? I could pick up a more substantial magnet cheap from Harbor Freight, but I am concerned that it will attach to the hot metal and I'll have a project trying to get the magnet to separate from the blade.

As soon as there's no magnetic pull, I'll dump it in the quench, blade tip first and straight down. I'll probably pick up a one-gallon metal bucket and fill it with used motor oil or some canola oil. (I know it needs to be heated to about 120 degrees; can I just do this on a stove top with a candy thermometer?) I know I need to move the blade around in the oil --- should I swirl it around, or just dip it up and down in different places?

I know I need to get the blade down to around 120 degrees; how long will this typically take?

Once the blade is cooled down, I'll clean off the oil and then stick it in the oven at 400 degrees for 2 hours. Then cool. Then rinse and repeat (the oven process) a couple more times.

I have read that the scale can be removed at that point by boiling some vinegar, from heat, and letting the blade soak in it for a couple hours, then brushing it off.

Then it's down to sharpening and honing.

Does that sound about right? Also, where's a convenient place to get a set of tongs? I know, I know, I should probably make some myself, but unless they cost a lot, I'd rather make blades than tongs.

Thanks much.

Reply to
The Dude on the Corner
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There's anti-scale compound you can get that'll keep the cleanup down. If you use the long temper time that you say you will, you should only have to do it once. The only reason to use that long a time is to allow the steel's structure time to change. Once it's done, it's done, no need to revisit things. A toaster oven works for tempering small objects.

Some experimentation may be necessary to get your initial quench to return you a flat piece, it's likely to warp. Plunging straight down, edge-on, usually works for me, I've not found that shaking about is really helpful with thin stock. Unlikely you'll get a perfect job first shot, make more blanks than you need.

For tongs you could maybe use some barbeque tongs or reshape same. I've used some cheapy needle-nose pliers on occasion, one use for cheapy-chink stuff. For small parts with holes or slots, I've used gas welding filler rod bent up for hanging stuff on before using a torch on it for heating. Just have to be careful to heat the part, not melt the filler rod.

I've never heated quenching oil and my button dies have always come out fine.

In any case, go get some long welding gauntlets and a leather cape and/or apron before firing stuff up. Face shield recommended, too. No bare body parts exposed is my rule. High-top leather shoes, too. Keep a lid around to cover your oil, just in case it stays on fire. Real quenching oil has a high flashpoint, hard to say what makeshifts will do. I've used motor oil myself with no problems but the smoke.

Salt and vinegar is the old-timers descaler, just don't leave high-carbon steel in it too long or it'll pit. It makes kind of a dilute hydrochloric acid solution and will remove scale. Don't expect a mirror finish afterwards, though. You have to work for that.

Have fun!

Stan

Reply to
stans4

Think about just heat treating the last inch or so.

Reply to
Tom Gardner

Without the foil, you'll get some surface decarburization. How much I can't say. Unfortunately, one side of the edge is formed by an outside surface. You'll just have to experiment and see if you can get a hard edge.

I would grind the bevel after heat treating. A thin bevel is too likely to burn and decarburize during hardening. Even better would be to grind the surfaces with a surface grinder, after heat treating.

You might also try a case hardening compound. You don't need more carbon, but it may make up for any you lose.

You are worrying too much about 120 degrees. Room temp should be fine for the oil, and when the blade is cool enough to handle it will be fine.

Any small magnet will do.

John Martin

Reply to
John Martin

Thanks, everyone! This has been extremely helpful. I'll report back with my results!

Reply to
The Dude on the Corner

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Reply to
Barryvabeach

Suggest you just make a big Reil burner or Turbo Torch and some porcelain tiles to make a small forge enclosure, for one-time use.

Why would the foil prevent that? The foil will be (nearly) the same blackbody temperature as the blade, and will emit the same cherry-red color, assuming you have it out of the flame or forge.

Reply to
Richard J Kinch

The foil prevents oxygen from creating scale. Often times the old timers would put in a piece of cotten ..say a rifle patch, and when it burned inside the foil envelope long before scale formation temps..it burned out the oxygen in the foil and added a smidge of carbon as well. Similar was done by adding a piece of bone to the envelope for color case hardening.

I did a knife blade last year, folded an envelope out of stainless steel foil, then filled it with argon from my tig tank. Came out pretty nice, no scale noted.

Gunner

Political Correctness

A doctrine fostered by a delusional, illogical liberal minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a turd by the clean end.

Reply to
Gunner

Ive always used a commercial lock. They are a bitch to get right, so stick with doing everything else except the lock.

Political Correctness

A doctrine fostered by a delusional, illogical liberal minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a turd by the clean end.

Reply to
Gunner

I made an electric pistol when I was a pup (apprentice). I used the riffled barrel from an old .22, and shot .22 cal pellets. I used batteries in the grip that lit a glow plug used for model planes. The plan was to take it out to dad's farm, clamp it into a vice, and fire electrically from a safe distance to see what blew up. He sold the farm, so I never got a chance to test fire it. That was 20 years ago. :(

Reply to
Dave Lyon

Thanks again, everyone!

Richard, your comments suggest I may be going a little over-kill here, which is exactly what I want to know.

If I pick up some porcelain tiles or fire-bricks and build a little box for a quickie-forge, can I just use an ordinary hardware-store-style cheapie torch and a small can of propane to heat the inside of the box to the right temperature? Or do I need some other sort of torch?

Reply to
The Dude on the Corner

Reply to
Barryvabeach

On 13 Nov 2006 13:08:59 -0800, "The Dude on the Corner" wrote: \

snippage---

The old farmer way was to heat the end to critical then plunge in the quench. But only quench the bottom end maybe .5" or so. Quickly polish the end and watch the color as the residual heat moved down to the end and requench the entire blade (or tip) at the desired color.

I know this is crude by the standards of some on this board but I have had much success doing this to homemade wood working steel. Chisels, gouges, plane blades ect.

Shown to me by an old time blacksmith.....

ED

Reply to
ED

On 13 Nov 2006 13:08:59 -0800, with neither quill nor qualm, "The Dude on the Corner" quickly quoth:

Perhaps you'd like to run your ideas past Steve Knight.

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He makes excellent planes and nice, thick, stay-sharp blades.

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Reply to
Larry Jaques

Depends on the mass and geometry of what you're heating. Any forge is a leaky bucket you're trying to keep filled with heat that you produce only so fast. With enough heat you can do it in open air. A little tent of tiles would be better, fire brick better still, a lightweight refractory tent still better, etc. Based on my experience with similar sized things, a big Reil style burner and a tile tent would do it for you. Fire brick is better if you can get it. Sodium silicate and perlite is superb for a short-lived small forge; this is what the coffee-can item approximates.

Reply to
Richard J Kinch

That's probably a good idea. Building a lock would be alot of work. Karl

Gunner wrote:

Reply to
kfvorwerk

Here's one that is made entirely out of firebrick:

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While the builder used a custom-designed burner, a Propane or MAPP torch might also work well.

Reply to
RAM³

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