belt axe

[Ohioan]

I purchased a small cast beltaxe. I just got done filing the heck out of it. I have a couple of questions about finishing it.

I'd like to harden it so it coud be used as a striker. How would be the best way to do that?

I'd also like to polish it up some. I was planning on sanding it with 100, 180, 220, 320, 440, and 600 grit sandpaper. Should I do that before I harden it?

I'm going to file in a design on the top of the blade I think.

Any suggestions?

 

[jasontn]

where did you get it from? i have a cast re davis axe and it came already hardened. i got mine from dixie gun works, it was made by re davis and company.

 

[paulvallandigham]

YOu will want to polish out any file or tool marks before hardening. The final finishing will be done after you harden and temper the blade. During the hardening process you will have a scale= thick and black- form on the the metal. That has to be removed, and is often done with belt sanders, or files, or both. Its at that stage you begin making that mirror finish. Do all the design work before you get around to hardening the piece. 600 grit is very fine for metal work like this. You can go finer, but finding the smaller grits may require a purchase off the internet. Its rare to find a hardware store that carries small grit papter, or cloth. If you are looking for fine grits, look for a supplier of jewelry makers, or just call a local jeweler and ask him where he gets his fine grit papers. For real fine polishing, you might also consider getting Rottenstone at a paint store. This fine pumice is often sold to polish varnished surfaces on wood. It works quite well on hard steel to produce a shiny finish. After that, you go down to buffing compounds and a buffing wheel.

 

[Ohioan]

It's not hardened. The guy I purchased it off of told me so.

Couldyou go into a little detail about the hardening process?

Do I just need to put it in a forge until that black scale comes up?

 

[davy]

You can find the finer grits at the auto supply store under body work accessories & tools! :hatsoff: I have found grit up to 2000 there before.

Davy

 

[paulvallandigham]

Th eBlack scale comes during the quenching. Its an oxidation byproduct. Since this hawk is Cast, It may be difficult to impossible to actually harden. Some of these cast steel heads clearly show that the edge of the axe is made of a separate piece of steel that is welded to the body of the axe. Look behind the edge about 3/8-1/2" to see if you can make out a faint line, where the two metals come together.

The process of hardening involves getting a good heat source and forge that will retain the heat, so that you can take the temperature up to 1200 degrees or more F., or an orange/white color, which the old time smiths tested with a magnet. When a magnet was not drawn to the metal, it was said to be the right temperature to harden.

At that temperature, the piece is quickly quenched. Some use water heated over 100 degrees. Others prefer motor oil. Others still use a salt brine that is also heated.

Once the axe head is quenched, it is Brittle as a file. A file will normally not cut metal from it, either. To keep the axe from shattering, you then need to temper it. sand, or grind, and polish off the scale that formed during the quench, to expose a bright surface on the axe head. Then heat the axe back up to about 350 degrees and let it stay at that heat for an hour. Then remove it from the heat and let it cool slowly in the air. It may form a slight yellow oxide on the surface, but this is easily removed during final finishing. Tempering relieves the stress in the metal, and allows the grain of the steel to align in strands again, make a tougher metal that will not shatter. Some smiths repeat the tempering 3 times. Others send off their blades to have them frozen in Nitrogen after hardening, and before tempering, to relieve stresses. " Cryonizing " is a viable process, and many barrel makers are now having this done to their barrels. The two axes I own are forged steel axes.

I have watched smiths make axe heads using a forge, from billet to blade, with all the hardening and tempering down at the forge. You can make axes this way, and come out with a fine working product. For that reason, I don't think I would spend the money to have my axeheads frozen. However, cast steel heads, while cheaper, may also present other metallurgical problems that can only be dealt with by special treatments. Perhaps Wicke Ellerby will see this post and come on to give better advice.

 

I would advise against trying to harden any axe head to act as a dependable striker - a good striker is HARD, HARD, in the 58-60 Rockwell B range - whereas an axe head should be relatively soft, I like in the mid to upper 40's amybe low 50's on the Rockwell B range at most, so it won't chip out, which an overly hard blade WILL do.
Second I doubt very much if you could get the blade hard enough to work well as a striker since most cast heads are made of failry low carbon steels with only about .40 parts carbon (high carbon steels are generally considered to be about .50 parts and above.)
BTW - scale is NOT formed during the quench - it is formed during the heating and is in good part
carbon, which is why it is so hard (leave a piece of steel too long at too hot in the fire and you'll have pure iron - the carbon will burn off completely). To remove most of the scale one can soak the part in vinegar - much easier than all that grinding, though some may be required.
Also steel in order to bring it to the austenizing point needs to be more in the realm of 1450-1500 and above depending on the type/alloy of steel.
In fact without knowing the type of steel in the head it is tough to suggest the best/correct hardening method as it varies by the type of steel (even every batch of the same steel alloy can vary enough for one to have to tweak their hardening/tempering process for each batch) - this would especially be true if you are a complete novice at workiing steel.
While many of us older smiths enjoy working with "mystery" steel, IMO it is not recommended for the novice, at least not without guidance by some expereinced working with it. One must learn how to do a spark test, how to test for hardness capabilites (harden it and then snap it - something not possible with your head without destroying part of it), whether to use a hot oil quench or a brine quench or a water quench, etc. Without knowing what you're doing you can really mess up - even us old timers with years of experience still get that dreaded PING! a real heartbreaker - Just ask nifeman, Mike Ameling, Wick, Loyd, and other smiths who frequent this site........

My recommendation - polish the head and use as is and then get a GOOD striker from Mike Ameling. I've had one of Pete Allen's cast hawk heads that I've used as a camp axe for better than 35 years and it has worked well in all those years as bought. A quick lick or two with a file or coarse stone and it is good to go.

Can your head be hardened? - yes - but if I were to do it I would harden only the edge - IMNSHO the poll of an axe should NEVER be hardened........

for suggestions on file work - here's some examples that I did based on originals........

as always others mileage will vary.......

afterthought: one possible option for hardening the head - get an experienced smith, somebody like maybe Mike A. or nifeman or ??, to harden it for you properly????

 

[Nifeman]

I agree with Chuck (Grey Wolf). An ax head ir any other striking tool shouldn't be hard. And he is right about the cast heads, they are usually a mild steel, because at the heat needed for a pour it loses much of the carbon. I'm sure the manufacturer doesn't add anything to the mix to replace what is lost (too time consuming and is not cost effective.
You may be able to get the head a little hard, but, it should be a little soft for ease of sharpening and safety. If you look at an older axehead,or better yet, a hatchet with a hammer poll, you'll see a certain amount of peening on the hammer end. That's due to the softness.
As a matter of safety, I'd hate to think what a piece of flint in one hand and a sharpened ax in the other might produce :hmm: :wink: .
I'd say just clean up the head and put a handle on it and use it. Hope this helps some...Bud

 

[Ohioan]

Well, I had heard someone discussing using it as a striker and thought it would be a good idea. Sounds klike it would just be a PITA, so I guess I won't. No big deal, I have a striker, just thought it'd be nice to have to pack one less thing.

 

[Ohioan]

What about using Naval Jelly on it to change the finish? I have seen pictures of rifles that have had Naval Jelly treatment on the barrel and lock and like the looks of it.

I belive the process is spray on, let sit a couple of days, then rinse off. Is that correct?

 

Any acid (naval jelly is basically phosphoric acid) will etch/color the blade. I personally haven't used NJ preferring my BC Super Blue and Bleach method - which "works" in 5-15 minutes dependent on how etched you want it, but this is an aggressive method which takes keeping an eye on (it's what was used on the examples I posted above).
Some other options are:
1) straight bleach
2) vinegar
3) muriatic acid
4) LMF Brown let go too long
5) lemon juice, onion juice, potato juice, etc.

By etching you actually create not only a patina but a rust resistant finish.

 

[Ohioan]

I applied Naval Jelly to the belt axe with a rag and let it hang from a coat hanger for about 24 hours. I rinsed it off, and the finish was VERY splotchy and didn't cover very well.

I filed off all the finish and sanded it back down. This time, I placed the head in a plastic container and sprayed the naval jelly on thick. I spreayed a bunch in the bottom of the tray for the axe to sit in. 24 hours later I rinsed it off.

I rinsed it off last night and it was a much more even patina. looked good.

 

[jasontn]

i discovered this about naval jelly by accident. if you leave it on a blade or head out in the sun all day till it dries into a hard crud it will etch the surface nicely. left some on a knife blade once on accident. looked good tho.