Lock sparks 3 out of 5 timmes...

[jm190]

I've assembled this lock from the small Siler kit and this is the best I've gotten for sparking. When it does spark it sets off the primer just fine. Everything has been hardened/tempered according to instructions. All moving parts have been polished so there are no rub marks on any of the moving parts. The hammer and frizzen have been fit so they move freely with no binding. All springs and moving parts have been checked for clearance with the lock plate and bridles; everything has 0.002" - 0.003" clearance. Everything works as advertised; hammer falls and frizzen is pushed completely open with no rebound. It just doesn't spark all the time. I've tried several flints and that made no difference. I've included pictures so you may see how everything is set up and where the flint is striking the frizzen. Everything below the red is where the frizzen strikes.

I've tried everything suggested on this forum for lack of spark and figured you might see something that I've missed. Any and all suggestions will be greatly appreciated.

Thanks!
John

[G_T]

I'm sorry I can't see the pictures from here. That's my problem not yours!

Lack of spark generally means too soft steel or too little carbon in the steel. Or it could be oil or grease or other junk on the frizzen surface or even possibly the flint. If you don't mind my asking, how did you go about hardening and tempering the frizzen?

That is, how long did you heat it and how hot did you get it, how did you quench it and how quickly after you removed the heat? What did you use to heat it? Did you use any Cherry Red or Kasenit or similar?

After it was hardened, how did you go about tempering it? Oven, kiln, torch? Did you shine up a bit to bright metal so you can see the color temp? If you used a torch, where did you focus the torch flame? How fast did you run the temperature up? How did you stop the tempering?

Sorry for all the questions, but the details generally tell the story.

Gerald

[Daryl]

Mine was like that, only not failing as often. Taylor re-hardened it and tempered it and bingo - my best lock especially with Rich's white river rocks.

[Pukka Bundook]

That hammer face, (frizzen) seems pretty chewed up Jim.

I think it's a bit soft like others have said.

[Longknife]

I have locks that are 30 years old with ? shots fired and none of them have a grooved face on the frizzen like that!!! Your flint looks kinda blunt, is it being dulled by the grooves in the frizzen? 

[jm190]

I'm sorry I can't see the pictures from here. That's my problem not yours!

Lack of spark generally means too soft steel or too little carbon in the steel. Or it could be oil or grease or other junk on the frizzen surface or even possibly the flint. If you don't mind my asking, how did you go about hardening and tempering the frizzen?
Sorry for all the questions, but the details generally tell the story.

Gerald

Thanks for the reply! I did heat treat and temper the frizzen according to the provided instructions from Jim Chambers. I heated the frizzen with MAPP till it lost magnetism and then just a little more. It was immediately quenched in non-detergent motor oil (30W, maybe this is too heavy?) After removing all the scale I put the frizzen, face down, on a 1/2" of clean sand in a tuna fish can and cooked it for 1 hour at 375 verified with a thermometer.  I let it air cool and then used a propane torch to heat the base of the frizzen till it turned light blue and let it air cool again.


I'm sure the steel has lost some carbon because I heated treated the frizzen twice. I tempered the face too much and it was definitely too soft so I started over.

[rich pierce]

How does the frizzen do on the file skating test?  In other words does an ordinary file skate off the frizzen face or bite?

I normally grind a few thousandths off a frizzen face because as cast they are often decarburized at the surface.

[jm190]

That hammer face, (frizzen) seems pretty chewed up Jim.

I think it's a bit soft like others have said.

I have locks that are 30 years old with ? shots fired and none of them have a grooved face on the frizzen like that!!! Your flint looks kinda blunt, is it being dulled by the grooves in the frizzen? 

Thanks for the replies! I think the grooves are from the frizzen being too soft. I don't know why the flint has rounded over.

My first heat treat/temper failed as I let the face of the frizzen get to hot (turned light blue) and it was too soft.  So I started over and what you see is the second attempt.  So, how many times can you heat treat/temper a frizzen before you have to use "Cherry Red" or get a new one?

John

[jm190]

How does the frizzen do on the file skating test?  In other words does an ordinary file skate off the frizzen face or bite?

I normally grind a few thousandths off a frizzen face because as cast they are often decarburized at the surface.

Thanks for the reply! The file scratched the surface leaving the tooth pattern but didn't dig in or remove any visible material, if that makes any sense.

John

[Ky-Flinter]

The file scratched the surface....

Too soft, me thinks.

-Ron

[G_T]

In terms of glowing, what color was the frizzen when you quenched it? Did you quench it immediately upon taking the torch off the frizzen? What did you quench it in? Swish it around as it cooled?

Carbon steel loses magnetism at 1420F. Full conversion of crystal structure is by about 1500F. So just losing magnetism only gets you in the ballpark.

If you heat till loss of magnetism as determined by testing with a magnet, then pick it up to quench, it has already cooled too much.

After doing the hardening part of the process, test with a file before tempering. The file should just skate across the frizzen. If it doesn't, it isn't suitably hardened.

Gerald

[G_T]

PS - Saw where I missed you answering my earlier questions. Sorry about that! This thread is moving fast!

An oven can have quite a bit of temperature variation. It might have been 375 when you set it, and even 375 when it is done, but when the heating element comes on the radiant heat can run the part up a fair bit more.

Was there any polished portion of the frizzen to show color from the initial tempering?

Just speaking what I like to do, I use a tiny torch to add a little bit of extra heat very gently to the foot and watch the color temp, while it is still hot but otherwise slowly cooling. Hit with torch only for a moment at a time then watch for the result. Don't be in too much of a hurry to get it hot enough or you will go way too far. Creep up on it, just don't let the colors creep up the frizzen face. Go slightly too far and you have to start again. Quench to stop it when you get there. I also am willing to place a drop of water on the frizzen on occasion to keep the main part from getting too hot while heating the foot. And make sure never to put the torch heating the main part when you are intending to heat the foot.

There are other ways of course!

On youtube videos you can watch people butcher the job.

Gerald

[Bob Roller]

The file scratched the surface....

Too soft, me thinks.

-Ron

Look soft to me. Resurface the frizzen with a grinding wheel that hopefully matches
the radius it now has.Reheat to bright orange and add hardening powder,hold it thru a good melt
and then quench it in water.Dry it and the polish it and using a Bernz-O-Matic torch,draw it to
a straw color and let it cool off.I'm assuming you have a heat source for the hardening that
gets a lot hooter than the Bernz-O-Matic.
That frizzen may be carbon deficient from new so you may have to repeat this rehardening.
In years long gone,I have been aggravated by poor quality control from a foundry that
didn't care about anything but getting paid.

Bob Roller

[Old Salt]

This may seem like dumb question. Are you using the same flint. Some flint are just not hard enough in some area's of the flint

[jm190]

This may seem like dumb question. Are you using the same flint. Some flint are just not hard enough in some area's of the flint

The file scratched the surface....

Too soft, me thinks.

-Ron
[/quote]

Look soft to me. Resurface the frizzen with a grinding wheel that hopefully matches
the radius it now has.Reheat to bright orange and add hardening powder,hold it thru a good melt
and then quench it in water.Dry it and the polish it and using a Bernz-O-Matic torch,draw it to
a straw color and let it cool off.I'm assuming you have a heat source for the hardening that
gets a lot hooter than the Bernz-O-Matic.
That frizzen may be carbon deficient from new so you may have to repeat this rehardening.
In years long gone,I have been aggravated by poor quality control from a foundry that
didn't care about anything but getting paid.

Bob Roller
[/quote]

Thanks for the input!

I tried two other flints besides the one in the photos with the same results.

Actually I used two Bernz-o-matics; one with propane and one with MAPP. The propane was aimed at the foot and the MAPP at the frizzen face. I'll try one more heat treatment/ temper and see what happens...Cherry Red is on order from Blacksmith's Depot.

John

[G_T]

At this point you might want to wait until the Cherry Red arrives before heating it again. The results should be better that way.

Gerald

[TommyG]

Here is another dumb question, but is your lock lubed properly? 

[jm190]

Here is another dumb question, but is your lock lubed properly? 

I would like to think so.  Tumbler shafts through lockplate and bridle, frizzen spring contact, sear spring contact and sear is lubed with Armorer's Choice grease. Fly, frizzen and sear pivots are lubed with CLP.

[KentSmith]

Too soft.  You got some great advice on fixing that.

[retired fella]

what kent smith said.  Your frizzen face tells the tale.

[rich pierce]

I never temper steel after hardening without knowing it is glass hard.  If I didn’t do this I’d never be able to diagnose any problem. 

[Ron Scott]

If you use oil for your Quench, make sure it is warm. Cold oil will retard the dispersion of heat. I know it seems counter intuitive but seems to be a fairly constant opinion with knife makers I know. We discussed this issue with George Suiter's tool making class last NMLRA seminar.

[Daryl]

 The vertical marks I see on the frizzen appear to me to have been made with a file (drawn vertically down the face, not made by a flint. They are perfectly spaced from one side to the other.
They are very much lighter in a few areas due to wear.  There are 2 vertical scratches, one 1/8" in from the left side, one on the right side & they are parallel as well.  The face of the frizzen does appear soft, in the picture. I would have thought it should be nice and shiny. Mine all are. Difficult to say, without having the frizzen in hand.

[P.W.Berkuta]

I've tried everything suggested on this forum for lack of spark and figured you might see something that I've missed. Any and all suggestions will be greatly appreciated.

Thanks!
John

My guess also is that the frizzen is too soft. Your hardening technique sounds good but your quench bath of motor oil is a poor choice - use warm Canola oil (about 125 degrees) and enough of it to cover the frizzen five or more times over then test with a file  - then place into a 375 degree oven to soak for one hour . good luck

[D. Taylor Sapergia]

Using a hand held propane and/or Mapp gas torcdh to heat a mainspring or frizzen is chancy at best.  A way to get a better soak with those tools is to make a little oven out of fire brick.  I have pieces of fire brick under my bench for this purpose, and when needed, place a flat piece on the bench vise, and then two more forming a "V" of 90 deg on top.  This holds your heat better and also allows you to hold the piece at orange heat.   A piece of coat hanger through a hole , as in the frizzen, allows you to remove it from the heat into the quench in a quick and smooth motion.  I move the part in a figure of eight through the quench oil.

There has been some excellent technique shared here.

Regarding the face of the frizzen shown:  it should be polished - not scored, prior to heat treat.