Polishing a Siler lock

[rich pierce]

There have been some inquiries about lock polishing and tuning.  I will show how I polish and lightly tune a lock that works great out of the box.  The goals are to present a lock with polished surfaces inside and out, ready to use, case harden, brown or blue, and to reduce friction. 

This show and tell is for newbies.  Nothing here to see for experienced builders.

There are many approaches.  This one uses few expensive items.  It will take me a while to get this done and maybe it will be a tutorial.  Please limit replies to questions and critique to save space.

Hippocratic oath of lock polishing and tuning:  First, do no harm!
This means we will strive to not ruin the fit of parts by over-filing or polishing and will not make any lock less safe. 

Lock disassembly

Here is the lock.




Remove the mainspring using a mainspring vise with lock on full cock.


Remove the mainspring vise.



Use the mainspring vise to remove the frizzen spring next.



Remove internals: sear spring, sear, and bridle. Now see the fly.


Remove the fly and know it is an escape artist.  I tape it to a piece o& paper and fold it up.



Now we will drive the tumbler off the cock.  I lay the plate across open vise jaws with a catch cloth beneath. Then I punch it with a quickly made brass punch.




There we are, all disassembled and parts in a container.



Polish plate and pan

Do no harm.  There is a great fit of pan to plate.  You can make it a lot worse by over-filing or polishing.  Below in pencil I am showing where we have to be careful to not remove any more than necessary to remove pebbled, as-cast surface.



Lock plates are never perfectly flat and do not need to be. But we are using flat files for first step. A coarse and fine  side. 




To remove as little as possible, protect where the pan will fit, and get the plate reasonably flat I file the outside of the plate in 3 directions. Angling 10 o’clock to 4 o’clock, 2 o’clock  to 8 o’clock, and 9 to 3 to sort of blend. There will always be a dish somewhere to file down to.  Also be careful up where the frizzen pivots. Remove as little as possible there to reduce polishing-induced slop. 


Showing directions I file.


First I file.  Then I polish with successive grits of 150, 220,and 320 paper backed by files.  Might as well go to 320 on whatever piece I am polishing and call it done b

Next we will file then polish the edges.  I use a #2 half round file and needle files.






On the pan assembly, do not mess with the area that engages the lock plate, or risk a loose fit.


Ok now we have plate and pan polished.



Tomorrow: the dreaded frizzen. 

[SingleMalt]

I'm glad you're posting this, Rich.  I'm in the process of cleaning up TRS castings.  It's always good to see how someone else does it.

[rich pierce]

Singlemalt, thanks. Just a note on projects like yours: when assembling a lock that needs drilling and tapping, of course, we would polish all the guts and fit them before drilling to keep tolerances tight. I’m thinking of final sear thickness matching tumbler thickness inside the plate and both determining height of bridle, etc. 

[SingleMalt]

That's the plan.  Remove the casting lines and polish the part, repeat.

[Cory Joe Stewart]

Thanks for taking time to show this. 

Cory Joe Stewart

[Dwshotwell]

Just in time for me... I was wondering how to tackle this task on my first rifle. Thank you.

[Tim Crosby]

"This show and tell is for newbies.  Nothing here to see for experienced builders."

  Watch us old Dogs learn a new trick:)

   Good stuff Rich, Thanks for taking the time to document and post.

    Tim

[n stephenson]

Rich, Taping the elusive fly to paper is a HUGE tip for all !!!  I started putting them in a folded piece of masking tape about ten years ago , and it has saved me MUCH FRUSTATION since then . It really is a pain to have to hunt for a fly , especially when your on final assembly.  Great Tip!!      Nate

[Chris Evrard]

A good start! And this is priceless advice:

"Hippocratic oath of lock polishing and tuning:  First, do no harm!
This means we will strive to not ruin the fit of parts by over-filing or polishing and will not make any lock less safe."

My dad used to say, "if it ain't broke.....Chris will screw with it until it is...."

The only thing I'd add at this point is that I refrain from removing the frizzen if it can be avoided at all. Sure it is easier to polish both plate and pan that way, but in my experience I never get the pan back quite where it came from and I end up with gaps beteween the frizzen and pan. This is a total pain to fix!

Can't wait to see the rest! Thanks Rich,

CE

[Scota4570]

Rich, Taping the elusive fly to paper is a HUGE tip for all !!!  I started putting them in a folded piece of masking tape about ten years ago , and it has saved me MUCH FRUSTATION since then . It really is a pain to have to hunt for a fly , especially when your on final assembly.  Great Tip!!      Nate

https://www.harborfreight.com/4-inch-magnetic-parts-tray-90566.html

[n stephenson]

Rich, Taping the elusive fly to paper is a HUGE tip for all !!!  I started putting them in a folded piece of masking tape about ten years ago , and it has saved me MUCH FRUSTATION since then . It really is a pain to have to hunt for a fly , especially when your on final assembly.  Great Tip!!      Nate

Scota4570 , I use one to put my small parts in . What I don't like about them is that the magnet gets covered in steel shavings , and I have had flies escape from them as well. The tape trick is my go to fly treatment , it saves me that much angst!! I can pop it out of the tape or tape it up MUCH quicker , than I can crawl around looking for it.  JMHO  Nate

https://www.harborfreight.com/4-inch-magnetic-parts-tray-90566.html

[retired fella]

I like your idea of taping the fly.  My last build from a Siler kit I spent a lot of time on hands and knees sweeping the shop floor with a magnet to retrieve the little bugger.             

[smylee grouch]

Great topic Rich. I too have been tapping the fly to a old plastic bullet box that I store the rest of the parts in. It can be frustrating looking for that little bugger when you have lots of wood shavings on the shop floor that you should have cleaned up. I have one of those magnets with the extendable handles that will find it most times!

[rich pierce]

The Dreaded Frizzen

Now we are on to the dreaded frizzen.  Dreaded because it is already hardened and fitted.  It takes me an hour and a half to polish a frizzen.


In the Do No Harm category: take care to not reduce the width of the toe where the frizzen pivot bolt passes. This is a somewhat critical dimension.  Also do not polish the pan lid part of the frizzen beyond a tiny amount, on the edges where it seals against the pan.


My tools of choice include needle files if the toe and spur are tempered enough to use files on them, a 600 grit diamond stone to lightly polish the sides of the toe and the pan lid, an old school farm scythe carborundum stone on a red handle, and the usual 150, 220, and 320 grit wet or dry sandpaper.






One can really bear down with that big red handled stone and it should be good for about 500 frizzens I guess.




Now you will discover there are some stubborn pits here and there. When that happens I use some very inexpensive, coarse, diamond coated needle files. I’ve seen jewelry with smaller diamonds on it. 




Then I polish successively with finer grades of sandpaper. The frizzen will have a different appearance than the lockplate. It’s different steel and it’s hard. 

And, about an hour and a half later, done.

[rich pierce]

Finishing up

Now on to small parts. This is all pretty  straightforward.  The top jaw can be tricky to hold so I screw it down to a piece of pine for filing and polishing.




I like to make some little teeth to help the leather wrapping the flint from slipping.  A graver or even a center punch can be used for this.



Bridle:  Not much to show for filing and polishing the bridle. The Do No Harm rule says remove next to nothing from the bottom of the  “legs” so when screwed down, it doesn’t bind the bridle. 

Mainspring: cleaning up inside the arms is tedious but contributes to a clean look.  Never significantly reduce thickness of the working arm.  A 10% reduction in thickness results in a 20% loss of force.  So regardless of any tiny pits you may find, don’t get carried away.  The only tuning needs you might encounter on a mainspring are to relieve the working arm if it is scraping the lockplate and to polish the nose where it rides on the tumbler. Not needed with this lock.  So all polishing was cosmetic. 

Frizzen spring: same rules. It’s all cosmetic except if the working arm is scraping the plate or if the top of the arm where it presses on the frizzen toe  needs polishing. Not needed here, so just filed and polished for cosmetics.

Sear: Do No Harm rules include not reducing thickness, and leaving the nose of the sear completely alone. Do polish the top of the upper arm where the sear spring presses on it.




Sear spring: all polishing is cosmetic except where the arm presses on the top of the sear arm.


Tumbler: Do No Harm rules include: leave the notches alone, do not polish either axle, and do not polish the sides so as to not reduce dimensions.  Do polish the top of the foot where the mainspring tip rides. Any other polishing is cosmetic.







Top jaw and tumbler screws: I open the slots with a slitting file and hand polish to 320.  You could chuck them up in a drill and polish them that way if you like.

Ok, before re-assembling, clean all the grit off your parts and use a-tips to clean grit out of all screw holes and the tumbler hole in the lockplate.

[D. Taylor Sapergia]

Nice job, Rich.  And great tutorial.  I like the idea of using the big stone to dress the frizzen.  I have four such stones and it never occurred to me to use them for this purpose.  I always wear out a few miles of expensive aluminum oxide and silicon dioxide cloth getting the frizzen down to a uniform smoothness.  Thanks Rich!!

[SingleMalt]

Thanks for this, Rich. 

[oldtravler61]

  Rich thank you for doing this. Very much appreciated....!

[JNG3]

Thank you very much for this tutorial.

[smart dog]

Hi Rich,
Well done!!  This should help a lot of folks.

dave

[B.Habermehl]

Ya know i've seen those big stones with a handle on them at flea markets, cheap, now I'll never find one again. Now that I have a use for one.  BJH

[Fiftyfour]

Is it typical on siler locks for the pan to be a separate casting from the lock plate?

[B.Habermehl]

Yes the Siler lock design always was a two piece, plate and pan design. BJH

[ddoyle]

If the lock did not come from a Chamber's shop assembler or if it was required (i.e oval , as cast, already undersize, canted) I'd polish the axles and any parts of the tumbler that bear on the plate/bridal/mainspring, If that resulted in too much slop then the lock needs a bushing and or or a new bridal.   Ignoring a problem out of fear seldom makes the problem or fear go away

I find it kind of misleading to polish a mechanical device to a point that suggests a high degree of atttention while not attending to any issues that may exist in it's unseen heart. 

I'd replace "do no harm" with "consider the totality of your actions"

[rich pierce]

Good point, ddoyle. This demo is for less experienced builders and a good Siler lock.  Maybe over time we will add “fixes”.

Safe fixing of a rough tumbler axle or tumbler lockplate hole or both

Toothpaste. Yep, make your lock minty fresh and smooth at the same time.  Toothpaste is a very fine polish. It’s not going to change dimensions.  Smear the lockplate hole, bridle hole, and tumbler axles with toothpaste. Install the tumbler, bridle, and cock.  Go watch some TV or read a book and rotate the cock back and forth a few hundred times.  This is an old bicycle mechanics trick from the old days. They’d take a wheel with rough bearings and bearing races, pack with toothpaste, and go ride 10 miles.  Of course now we throw stuff away.

When done polishing with toothpaste, the toothpaste should look grimy gray and you should feel a difference in smoothness.  Remember to rinse.