Read stickies and searched, still have questions about what I need for HT etc.

Fitzhugh

Fitzhugh

Joined
Feb 5, 2013
Messages
194
This is similar to the first thread I posted a week or two ago, but I ordered a 48" by 2" piece of .187" 1084 from Aldo and continued to read.

I've read the stickies and spent a lot of time searching and reading both here and the internet in general. I've looked at the many forge designs and the endless similar questions already asked. Maybe I'm dense, but I feel I'm on information overload and still not clear on what I need for simple heat treating, not forging, and because the plane blades I'm making only need to be heat treated on the sharpened end, not a long cutting edge like a knife.

I plan to make blades for the wooden hand planes I make, as well as random other woodworking tools I need. For the most part these are simple: a rectangular piece of steel with a simple bevel ground and honed on one end. They're 1/4 to 2 inches wide at the cutting edge, usually 4 inches long, some will be 6 to 10 inches long. All will need only the end with the edge heat treated. I hate to say it, but I need to do this as cheaply as I possible can. Normally I like to get the best tools or supplies I will need right off but in this case I need to start at the lowest cost. I'd love any advise in addition to any answers to my questions...



As I'm only looking to heat treat, not forge, can I get away with a BBQ, charcoal and a blower for hardening and kitchen oven for tempering? What is it called if not a forge, a heat treating oven? Kiln? Ruined BBQ? That seems the cheapest possible setup as I have all that already. I'm unclear on whether I'd need to add refractory material to the BBQ, in which case I might as well make a smaller, more efficient forge.

How important is normalizing in my case? Do you only do it when you've forged a piece, or will I need to do it with the cut and ground pieces of 1084 I'm going to use?

In any case, what is the most economical way of knowing the temperature? I can check the magnetism of the blade, but I'm quite colorblind and can't do it by color. Can I get by without a thermocouple since I don't have to soak the 1084, just reach critical temperature? As best I can tell I can't get a type K thermocouple probe and instrument for less than about $60, which eats up a LOT of the money for this project.

How do I check to see if the blade is no longer magnetic? This might be a silly question, but you pull the blade all the way out to check, otherwise the magnet itself can be demagnetized, right?
Here's stupid for you: I was playing around with some unknown high carbon steel before I found this site. I had trouble holding the small magnet I was using so I stuck it to the most convenient large piece of metal on hand. Luckily I realized what was going to happen before I actually tried checking the magnetism of the hot metal... I'd stuck the magnet on the free standing propane torch. Imagine: burning torch on bench, metal being tested stuck to it and pulled off, torch flying into lap...

Will a two brick forge handle a 2" wide blade? I'm concerned the blade will take up enough space that the flame doesn't circulate properly.
Why wrap brick forges with chicken wire? Is it a safety thing? Or is it just to keep if from falling apart?

Is there anywhere I can order a small amount of refractory cement, inswool, etc? So far I've only seen larger amounts (well, a lot more than I'd need for a tiny forge - remember, every penny counts in this case).

I had no idea there were so many types of torch burners for sale. I like the idea of making my own venturi burner - seems cheaper/I get to make it - but I can't figure out what design would be appropriate. Also, how do I plumb it to the MAPP or propane tank? If I go off the shelf, what burner would you suggest for this use?

Propane vs MAPP? I've read Mapp's additional heat is not necessary and can lead to hot spots, elsewhere I read "use mapp, it's hotter". I've got a normal small propane tank/torch setup with a few tanks.

I've read about using a deep fryer to temper since you can use a frying thermometer and control the temperature better than a home oven or toaster oven. Lacking a deep fryer, how about suspending the blade in a cooking try of oil so that the temperature is more stable and controllable? Worth it? A bad idea?

I have an ancient hand powered 5" wheel grinder. What grit wheel would you use? I want to replace the ancient black one that came with the grinder. I have a diamond wheel dresser coming. Can I use that with the old black wheel, or just newer types? I fear it would just shatter the diamond, this wheel is hard (to my totally naive eyes) and very porous. I was going to order one from McMaster Carr, can't afford the $40 blue norton 3X stones.

Thank you!
 
Probably, the simplest charcoal forge I have read about is a hole in the ground with a pipe running in to the bottom to provide air to increase the temperature. Use a hair dryer to provide the air flow. You might be able to determine the right temperature to quench based on the brightness of the heated metal. You will need to do a little trial and error to optimize your process. Your quench will benefit from a faster oil, I think Parks 50 has been mentioned. This is costly so many use heated vegetable oil (canola) with good results. Again you may need to do a little trial and error to optimize your results. You can suspend your magnet with a chain and see if it is drawn towards your hot blade.

A differential temper might be difficult for you, but you could look for a change in the brightness of the metal. Your oven might be better but some have complained of the odor of burning oil. If you use your oven, get an in the oven temperature guage and place a deep pan of sand in the oven. Heat the sand to the tempering temperature and place your blade in the hot sand during the temper.

Any piece that you mess up (unless you break it) can be heat treated over.
 
If you can access an O/A torch it would be the easiest fix for what you are trying to do.
 
I would skip the whole BBQ concept and use what is called a one brick forge, you will be better off with 4 or 5 bricks. Just stack the bricks to form a small tunnel and cut a hole one brick for your torch. I never put the end of the torch inside the bricks just the flame. You can use your propane torch to do the HT of 1084 if you contain the heat in a small area. This should work fine these small blades. I would not bother to heat the entire blade, just the working 2 inches or so. You would probably only need a gallon of canola oil for the quench, and can use your kitchen oven for the temper.

Do some test runs with some scrap 1084 to get the magnet thing down and you will be able to see the color you need when the temp gets close. My only worry would be in this method on 1084 will give a edge worth all the effort, If I were doing it I would use A2 and send out for heat treat.
 
Thank you all for the responses. It sounds like it can be done with a simple setup. I'll get some bricks because I should be able to make a more optimal little oven than BBQ and they won't break the bank.
I don't have access to an O/A torch, just the propane one I have or what I make/buy. The O/A torches I've seen are all way above my price range.

Any suggestions on a torch model? I know there was one that seemed universally recommended in old threads here that is no longer on the market. I see some recommendations for Mag-Torch MT245C, I like that it can use propane or MAPP, but do I really want pencil tip? I thought the idea was a large spread of flame. Or does the pencil tip help it swirl?

Patrickknives said:
Do some test runs with some scrap 1084 to get the magnet thing down and you will be able to see the color you need when the temp gets close. My only worry would be in this method on 1084 will give a edge worth all the effort, If I were doing it I would use A2 and send out for heat treat.
Click to expand...

I'm colorblind. Is color vital since I'm not trying to soak (since 1084) and tempering in oven? If so, I'll enlist my wife, take her to dinner in exchange.

So, I guess I'm still not entirely clear if 1084 is a poor choice or just not an optimal one. I forgot to explain my intention clearly: I don't expect to make superb blades, I just hope I can make better ones than the super crappy blades that modern low end stanley planes come with. Those I'm sure are made with the cheapest steel and processing possible. I'm under the impression that 1084 is close to the common high carbon steel you'd have found in edged tools from late 1800's - early 1900's. Is that right? If so, I'd be fine. The blades from then often perform great. I don't mind having to sharpen a bit more often. I also understand I'll have to learn from making mistakes. Seems 1084 gives me the most control since I have no experience at the expense of a lesser best-possible outcome. I also like the idea of home HT. Otherwise it is just as simple as cutting a rectangle and hollow grinding an angle on one edge. Not much fun in that.

Unless you still think I should switch I'll try the 1084. If I end up finding I can do this but the steel isn't up to it I'll pass on any left over steel to another newbie and get a more appropriate steel.

Thanks!
 
You can get a tempilstik heat indicating crayon for 1450 degrees. You would then have to pull your blade out periodically and
touch the temp indicating crayon to the steel to see when it melts if you can not see the red orange colors to heat treat by eye.

Are you familiar with The Crucible in near by Oakland? thecrucible.org is their website from your questions you could use someone to show you how at first.

I know what you mean by present day mediocre factory plane irons. Although I make my own I also just bought a Japanese laminated blue steel plane iron for my block plane from Japanwoodworker to try out.
Hock is another company that makes high carbon aftermarket plane irons.
 
For a propane burner, you can make a venturi style with stuff from lowes or home depot for pretty cheap. Also, if you have a tractor supply or Ace near you, they sell refractory mortar for fixing wood stoves. It is like $3 for a pint or quart, I can't remember, but it does withstand heat up to 2700 degrees, which is more than suitable for what you want to do. As far as tempering with a deep fryer, I'm not sure what rockwell you are after, but the oil would need to be somewhere between 350-450 degrees, and working around that just sounds like a bad idea.

-Adam
 
Carcara,
I'd love to hear more about the blades you make and anything you might share that you've learned. Have you posted any photos?
It sounds like tempilstiks are a good solution. I didn't know anything about them.
I'm near the Crucible but hadn't remembered it was there. Another good idea.
I have only a few hand planes so far: A few year old stanley cheapo - AWFUL blade, a modern stanley SW block plane - good blade, a small Japanese smoother with a wonderful laminated blade and a plane I made around a Hock O1 blade. I love both the Hock and the Japanese blades. They're very different, the Japanese seems to take an insanely sharp edge but both work great.

Adam, I'll look at the burner designs. I prefer to make things myself simply because it is fun and occasionally cheaper or even better.
How would I use the refractory mortar? Would I use it to make something like a coffee can forge?
I have no idea where I read about using oil that way since I've read a lot recently but you're right, that could be a disaster. Any benefits not worth the risk. I'll just use an oven thermometer and keep an eye on it.

How stable does the temperature need to be when tempering? Kitchen ovens - especially ancient POS like mine - rise and fall by large amounts.
 
Aldos' 1084 is significantly better than the older 1084. The older 1084 was pretty much carbon, manganese, sulfur and phosphorous. Aldos' has, additionally, a small but significant amount of chromium and traces of vanadium and something else. These should help you make a better blade.

The deep pan with sand in it will help to moderate the fluctuations in temperature and prevent radiative heating of your blade (both good things).

One smith would take a 4' rod of steel and forge out blades until the bar was too short and became to hot to hold with a gloved hand. He just welded another rod to it and kept on forging. You could do the same with your bar. Bevel the end. Heat and quench the end. If it doesn't break, carefully and quickly cut the end off to length and temper.
 
Don't have a way to show pictures on this forum. I make Japanese style plane irons with wrought iron bodies with W2 or Cru Forge V steel cutting edges. Have you been to Hida tool in Berkeley?
 
Quite honestly, if I were doing what you are doing I would use A2 and send it out for HT. You need a pretty tough blade to cut wood like you want to do. I have a number of planes and chisels and I would be doubtful that you I could HT and temper 1084 to hold a better edge than a current stanley with your skill level. 1084 is not a high grade steel and probably not much better or worse than the current blade, the difference in performance will be up to you. If I was really serious about getting better performance I would step up to CPM S30V or another high tech steel.

If you choose to use 1084, you only need to stack the bricks to hold the heat in, there is a propane torch that can connect to a 5 gallon bottle, I have one but dont recall the brand or model. I alway do test pieces in scrap side by side with the steel.
 
Bo T, the pan of sand makes great sense. I tried to harvest some sand from the old sandbox in the back yard. Bad idea. We have dogs, but the neighbors all have cats. I think I'll buy a bag of sand.

Carcara, Yeah, I've been to Hida - got my one good purchased plane and chisel there. The rest are either crap, or hand-me-downs, or a few planes I've made. Do you sell yours there? You're making something a world apart form what I ever hope to make, I'm impressed, or jealous, or in awe - or all the above. That one laminated Japanese blade is fantastic. Each time I sharpen it I feel like I'm working with a piece of art and it's not even a high end one.

Patrickknives,
Thanks for the warning about using 1084. In all honesty, I don't expect to get anywhere near a fine blade. I figure I'll get a better chance of making something OK with 1084 than a very poor chance at making something great out of a better, more difficult, steel, if I home HT until I learn more.
Aldo shipped the 1084 a day earlier than the lady I spoke to thought, so 1084 it is. In looking around, I see a lot of references to both 1080 and 1095, or sometimes 1080 through 1095, being used for plane blades in times past. I'm assuming 1084 has characteristics that fit between the other two.

I actually think the Stanley I complain about wasn't properly heat treated. The edge rolls, even when ground with a high angle. If the body of the plane was decent I'd get/make a better blade for it. It isn't, so I'll make a better blade and make another wood plane instead.
 
No I don't sell through Hida, and as a non paying member I can't talk about my wares here. But Hida tools has sponsored events of bringing tool makers from Japan to demo in the Bay area and helped coordinate tours to Japan. So they are a good resource for net working. Have you looked at Daikudojo.org? You live in civilization with master craftsmen, might as well take advantage of it.
It can be argued 1084 from Aldo will yield a sharper edge as a simple steel if heat treated right than a highly alloyed steel
with large carbides in it's grain structure so I am sure it will be fine. I only made one attempt years ago to reheat treat a
soft Stanley blade but cracked it. Oh well...
 
You must log in or register to reply here.
Back
Top