How to temper a flint-and-steel steel?

[rdennett]

I forged a small striker steel for a friend and I had a great deal of trouble getting it to make any sort of sparks.  It was forged from an old file I bought at a flea market, then quenched in water and tempered to dark blue.  The flint certainly made marks on the striking face, but I only got a spark twice out of about a hundred tries.  I tried striking a spark both before and after tempering it.  I had made one for my self a long time ago and it works fine but this was pretty much a bust.

 

Thanks for any help,

Rob

[HWooldridge]

Some files are case hardened so there's not much carbon in the whole piece; in those cases forging redistributes whatever is there. On the other hand, is your flint a proven sparker? I have chert laying all over our place and some of it produces better spark than others.

[Steve Sells]

Blue is way too far, I have to wonder where you got the idea that blue was correct?  You will have to reharden and try again, do not draw back much, 300F is plenty for stress relief.

[Frank Turley]

Sometimes the surface decarburizes. After hardening and a mild tempering, you might take the steel to the grinder or sander and remove a little of the surface steel.

[John McPherson]

Going from a decade old memory here, but Jim Wilson's method was: to heat the finished iron to non-magnetic, quench just the face in water, pull up out of the water, let the heat retained in the back and curls run the colors from the ends just to light straw on the face, and then immerse the whole piece.

 

You still sometimes have to grind a few thousandths of decarb off to get a good spark, but usually all the scale pops off the face in the quench.

[WayneCoeArtistBlacksmith]

In a demonstration by Ryan Johnson when he made a striker, then started a fire on the first strike. Ryan said that the reason that so few old strikers are found is that they were brittle and broke during use. 

[VaughnT]

I have probably made a hundred strikers out of old files and cheap screwdriver shanks..... and I've never tempered any of them.  I'll bring them up to non-magnetic and then quench in oil.  That's it.

 

If I make a simple c-style, or something that has a delicate curl to it, I'll draw back the hardness on that area by simply not immersing it in the oil, but tempering the actual working face?  Never did.

[Rashelle]

Figure I'll chime in here as I do a lot of strikers for Fort Vancouver. Unless making a bright oval striker the following is the main way I do the strikers.

 

While forging I make sure I have a flat (as forged) smooth striking surface, normalize the piece after forging, edge quench just the striking surface. let a little heat bleed back in if it gets to hot to touch requench the edge (I alternately occasionally just hold the edge in water until the whole thing is cool to the touch). The arms and non striking surface not being quenched don't get hardened thus providing some shock resistance. Clean off the striking surface after treatment. With a file, a brick, sand paper whatever just to get rid of any decarburized area. Check with a SHARP piece of flint, chert, agate, jasper etc. If good sparks good if not good sparks then re harden this time more aggressively quenching more of the striking surface further up the face. No quenching the arms of c or j style strikers.

 

What you are doing with flint and steel strikers is the flint ( or whatever) is harder then the steel, using a sharp edge you shave off tiny particles of the steel which is what sparks.

 

Rashelle

 

Oh yeah I forgot to add in some people just edge quench by placing the edge edge down into a shallow pan or shovel or whatever of water. Letting the whole thing cool down while keeping the edge cool. When I do edge quench I do move the steel back and forth in line with the body/blade of the steel. Another way to do the temper is use an oven and temper the whole thing. Real important if hardening the whole thing is to temper the whole as the body and arms are hard and may be prone to failure in use.

Edited February 23, 2014 by Rashelle