Looking for some help - W.I.P.

[Double Y]

I am not a knife maker, but I had a piece of cable that I had been playing with and had welded into a billet...so I did some playing yesterday while waiting for some other pieces to heat in the forge.

Here is my first attempt at a blacksmith knife.

My question is now what? I haven't hardened or heat treated and would like a smoother finish. Oh yeah and would like to try to bring out any grain possible from the welded cable...

Lots of wants I know!

So tell me if I am on the rigth path. I will sand/buff the knife smooth - hopefully - then heat to non-magnetic and quench. Should cable be quenched in oil or should I use super quench?

Then buff again and etch? I use muratic acid a lot so I have that on hand. Neutralize the acid with Windex. Then buff a third time?

Then thermal cycle a couple three times to heat treat in the oven and then finish with a light oil.

Will any of that work?

Thanks for your advice in advance.

John

[ThomasPowers]

Well if it's a mild steel cable neither quench will do anything; if it's double improved plow steel cable, warm oil will work great and supper quench will cause it to shatter. So what is it?

If you don't know, try warm oil first and if it's not hard enough try brine and if it's not hard enough try superquench and if it's not hard enough it's a letter opener.

Remember the edge should be as least as thick as a dime before quenching and don't do a full finish on it as heating and quenching will scale it up again; but make sure that no coarse scratches are left to promote cracking during quenching

and remember TEMPER AS SOON AS IT'S QUENCHED!

[Double Y]

Thanks Thomas...I will give it a whirl and see what I end up with.

The cable is mistery cable so it could be anything, though it sparks well when I tried it.

How long do I want to hold the knife at temperature when tempering?

[ThomasPowers]

Traditionally about 1 hour per inch of thickness. It's more the bring up that does the work than the sit so you are generally better off to temper cycle it 3 times than to do it once and let it sit for a long time.

[Frosty]

Try spark testing the cable first, that'll give you a much better idea of how to heat treat it saving you some experimentation.

Frosty the Lucky.

[Double Y]

Okay I hand sanded till I didn't want to do anymore...to take out any deep scratchs.

I heated to non-magnetic then quenched in warmed motor oil.

I then heat treated twice.

This is what I have so far.

Will buffing take out the remaining scratchs or do I go back to hand sanding?

The second knife is a piece of roller chain that I welded up a while back. Again just threw it in the forge as I was making some hooks last evening for another project.

Is vinegar, lemon juice and salt the best etch? I tried muratic acid last evening and didn't get a deep etch. You can just see some patern as a shadow.

Thoughts? Comments? Should I go back to rodeoing?

Thanks,

John

[dlpierson]

Buffing is not a good way to remove scratches. Hand sand (or use stones) until no more scratches, then go to the next finer grit in a different direction until you're happy with the scratches.

Since you're etching for a pattern you probably don't need to go finer than 400 grit.

The most common etchant is fairly dilute ferric chloride (a.k.a. Radio Shack PC board etchant). Vinegar, especially hot vinegar is also used by a lot of makers. It's slower than ferric, but
that's actually an advantage. One problem you're having with the muratic is that it's too fast so it etches all of steel too evenly.

[ThomasPowers]

You won't get topography with vinegar. And as mentioned you want a weak acid rather than a strong one as you want a differential etch and strong acids eat *everything*. You may want to try diluting your acid or your ferric chloride. Note that different alloy mixes work better with different acids, you may need to experiment to see what gives you the topography and colouration you want. Also buffing can "smear" the lines, you usually go to etch after grinding with sharp fresh belts.

And finally this is one of my quirks: please don't use the word BEST! Or to put it another way you tell *me* what is the best temperature for *my* tea---kind of hard not knowing what I like isn't it. Best for one person may be one of the worst for another. Also "Best" might cost several million dollars; not very helpful to most of us!

[Double Y]

Best is different for everyone, I am looking for the "best" advice and I thinking I am getting it. So thank you for that.

I will get some ferric acid and give that a whirl.

Thanks for your comments and willingness to help.

John

[Double Y]

Okay, I didn't get to Radio Shack instead I used the recipe for a vinegar etch that I found here on IFI.

2 quarts vinegar/15 oz lemmon juice/5 pounds table salt

I boiled to mix and then set the knife in the brew for about 15 minutes. I took the knife out at about 8 minutes but it wasn't a deep etch so I dunked the knife again for another 7 minutes.

I washed with soap and water and oiled with olive oil.

Not the prettiest pattern, but it was my first try with cable and I am sure I over folded the cable.

Thomas thanks so much for your comments. I appreciate your willingness to help.

John

[Double Y]

Thanks again for everyone's willingness to lend your thoughts and comments.

I went to Radio Shack and picked up some Ferric Chloride. I used a recipe that I found here on IFI.

10% sulfuric acid - 20% Ferric Chloride - 70% distilled H2O.

I etched this blade for about 10 minutes and then sprayed down with Windex. I then rubbed the blade with oil.

I am very happy with the etch.

Now to work on my forge welding some more!

Thanks,

John