Question for you lock specialists out there

[Paddlefoot]

I found an old Large Siler lock kit that I screwed up big time back in my teens when I didn't have much access to good tools and little understanding of precision fitting.  The screw holes for the pan bridle and the frizzen spring were misdrilled and then welded up. I dressed off the nasty welds but the plate has acquired an bit of a bow from front to rear.  The area right aft of the bolster is relatively flat but a straight edge from tip to tail shows maybe a .020 bow right under the bolster. Is this tolerable? I know some of you case harden these lock plates and the heat does warp them some. I'm looking for suggestions based on any experience you have had with this. 

[Tom Cooper]

I'm no specialist

With that said I square up my lock plates with a press when needed and am a fanatic when it comes to blocking for case hardening.

If by some strange coincidence I end up with a warped plate out of the quench tank I anneal and start the process again.

[P.W.Berkuta]

Do as Tom suggested or --- just buy a NEW plate and start over - problem solved.

[Paddlefoot]

Yeah I sort of suspected that this one will become a practice plate for engraving.  No point in trying to make candy out of excrement.

[Jim Chambers]

When I receive lock plate castings from the foundry they are almost always bowed in one direction or another.  I simply open the jaws of by bench vice about three or four inches, lay the plate on top of the jaws and use a rawhide mallet to correct the bow.  It's amazing how little force it takes to move that metal.  When you've corrected several thousand plates you learn just how hard to hit and exactly where to hit to make them absolutely flat.
Jim Chambers

[frogwalking]

I managed to bend one.  (I am just talented that way.)  I called Jim and followed his instructions and the repair was easy. 

[Paddlefoot]

Thanks for the good suggestions. I put the plate in the vise with dowels to focus where I wanted the pressure applied and cranked it down until I could see it straighten out. Another 1/4 turn and it was pretty close when I took it out of the vice. I'm going to learn a lot before this one is ready.

[David R. Pennington]

I case hardened a plate once and then found it had warped. I took a big chance and tried staightening it and lucked out. I wasn't exactly sure what kind of steel it was, but knew if it had hardened more than on the surface it could break. I used some heavy leather shims in the vice and sqeezed it back straight.

[Mike Brooks]

Bowed lock plates are common. Lay it on something flat and give it a whack. Isn't anything about building muzzleloaders that can't be fixed with a good whack with a hammer.

[Paddlefoot]

I like this Brooks feller. Very practical advice.

[Dennis Glazener]

Isn't anything about building muzzleloaders that can't be fixed with a good whack with a hammer.

Mike this reminds me of my dad. He was a mechanic and his belief that if a good whack with a hammer didn't fix it then he needed a larger hammer! It was interesting to watch him, thinking he was going to break something he was trying to get loose or straighten up. I don't ever remember seeing him breaking anything with a hammer but 9 times out of 10 whatever it was came loose or straightened up
Dennis

[Bob Roller]

Bowed lock plates are common. Lay it on something flat and give it a whack. Isn't anything about building muzzleloaders that can't be fixed with a good whack with a hammer.

Years ago when I was making the Chet Shoults lock a straight plate was a rare thing.
I was told the foundry that cast them used an air hose to eject the wax from the die and then made up
the "tree"make the castings in.Warped plates were standard and not hard to fix.

Bob Roller