Need suggestons for fixing a lock

[Dale Halterman]

I learned my lesson the hard way about buying lock kits assembled by persons unknown. I have a Siler lock on my bench now that has several problems that I didn't notice when I bought it, just made sure it sparked OK and put it in a drawer until I needed it. Don't remember where I got it anymore so I can't send it back.

The problem I am working on now is that the fabricator got carried away when counter boring the hole for the screw that attaches the pan to the lock plate. There is a paper thin sliver of metal at the bottom or the hole. It is so thin that the screw threads bind in the lock plate before the pan is drawn up tight.

My first thought was to simply solder the pan to the lock plate. I suppose I could just order a new pan from Jim, but where is the fun in that?  No, I don't have a welder so I can't weld the hole shut and start over which is probably the right thing to do. Maybe fabricate a small washer the fit under the screw head? I don't have a lathe but I am sure I could manage somehow. Doesn't seem like that would be too sturdy unless I solder it in. Any other ideas?

Thanks

Dale H

[webradbury]

Could you just shorten the screw? That’s basically all that’s happening when a washer is added.

[Dale Halterman]

Overall length of the screw isn't the issue. The problem is the very small portion of the screw shank that is unthread just below the screw head. That binds against the lock plate since the sliver at the bottom of the screw hole is thinner than the unthreaded portion.

Dale H

[Ky-Flinter]

Dale,

The counter-bore is too deep, so you are running out of threads on the screw, right?  Can you run the screw into a die to thread some more of the shank?  Or put a washer under the screw head, as you mentioned.

-Ron

[rich pierce]

The problem is the foil-thin remaining metal at the bottom of the hole is flimsy. Solder in the hole seems simplest to me. More complicated fixes include drilling the whole thing out and putting in a larger diameter threaded rod and peening the devil out of it, then re-drilling. Or putting braze in the hole and re-drilling. That would be very strong. On thin stock I use snips of sheet brass and borax stuffed into a hole or seam and get by with propane. Without oxy-acetylene it’s hard to get a lockplate that hot though.

[msellers]

If I were to try Rich's method, I would switch to MAPP gas ss it get hotter than propane. And i can get it from most hardware stores, I think I have even seen it at Walmart.

Mike

[Pukka Bundook]

Without a welder, I think I'd solder a stud in the hole and re-drill for the screw..

That, or make a rivet that fits the hole and rivet the whole thing together.

Just ideas,.... 
R.

[Kingsburyarms]

Not PC - But I have done this in the past: https://www.amazon.com/Helical-Thread-Repair-Kit-8-32/dp/B007N6T9OC it's a stainless steel insert, comes with the drill and tap for the coil. Just drill out the threaded hole with the included bit, tap with the new tap size (also included), screw in the coil and you have brand new 8-32 threads, any depth that works for you.

Jon

[Craig Wilcox]

I am with Pukka Bundook on this.  I had a similar situation, silver-soldered a piece of drill stock in the hole, and re-drilled it properly.

[jerrywh]

 You can make a screw with a larger diameter head and don;t counter sink it so seep. I have done this years ago with nothing but a dril press or a electric drill.  That's called red neck lathe.

[ron w]

easiest remedy is to put a close fitting washer under the head of the screw, with it's OD. trimmed to the diameter of the counter bore.   beyond that, just fill the counter bore with a piece of mild steel rod (no need for anything harder) and redrill it.  soft or silver solder the plug in place if you want to before drilling.

[D. Taylor Sapergia]

The threads on many machine screws have been simply made by running the screw into the starting threads of a die.  To get threads right to the head, where needed, turn the die over and run the screw into the other side of the die,  It will add about a thread and a half to the shank, and allow one to set the screw more deeply into a hole.  Breech plugs come to mind for this application.

[jerrywh]

Easiest fix is to solder a piece of rod into the hole and re drill, that's if you don't intend to case harden  the pan

[Dale Halterman]

Thanks for all the good suggestions so far.

I wasn't exaggerating when I said the sliver of metal was paper thin. In the course of measuring and general fiddling about it has pretty much folded up and disappeared. So, what I have is a hole clear through the pan extension big enough for the screw head.

It appears my best option in to solder in a washer or a solid rod and redrill using a drill press, files, patience, and ingenuity.

Failing that, my fall back will be to solder the pan to the lock plate and hope no one feels the need to remove in it my lifetime.

Thanks again

You guys are the best

Dale H

[Pukka Bundook]

Dale,

If the sliver has folded and more or less leaves a straight through hole, I'd countersink it , and solder a fitting stud in place and re-drill for the screw.
Soft solder will be fine, but the counter-sink will give it much more hold than a straight peg in the hole.

Best,
R.

[Dale Halterman]

Good point.

Thanks

Dale H

[Clint]

If you have a straight hole in the bolster now,you could cut a light counter sink on the bolster and fit a new screw to the plate. Put the pan onto the plate and run the new screw till the threads are snug and cut the screw body off, just proud of the bolster. Now hammer fill the countersink with the proud section of screw shank and file everything flush. There is no need to ever take the pan off again, so why not make it permanent?   Clint