Update - Can a lock plate screw hole be filled and then re-drilled?

[hmccaskey]

This is my first build.
I managed to drill the lock plate screw hole poorly.  Very poorly.  The  hole angles up from outside of the plate to the bolster.  Comes out even with the top of the bolster.
And yes I know what I did wrong, so a learning experience.

Is the lock plate salvageable?  If so, how?

Thanks

[smylee grouch]

Weld the hole closed and redrill

[Bob Roller]

Weld the hole closed and redrill

What are you using to drill this hole?Drill press or hand held electric drill or
cordless or??.

Bob Roller

[Mike Brooks]

You can soft solder a section of threaded bolt into the hole and re drill.

[bama]

This method is not as good as welding it up but it works and if done right you will hardly see the old hole. Lightly counter sink the hole on the face of the lock plate. Flux the threads in the hole and on a threaded section of the lock bolt cut to a length just longer than the plates thickness. Thread the cut off bolt into the plate so that it protrudes just enough to peen the end so that it fills the counter sink. Then reflux the bolt and hole from the inside of the plate and silver solder the bolt to the plate. Dress so the bolt ends are flush with the plate. You are now ready to re drill your hole.

[Mike Brooks]

I'm not arguing….but soft solder will do the job. I don't know if that is what bama had in mind or not. no reason to go to silver  solder temps if you don't have to.

[mountainman70]

Welcome aboard friend. We learn best by fixing our boo-boos. Lord knows I have my share of em. Have a goodun, Dave F

[bama]

Mike, Brownells Hi Force 44 has a melting temp of 475 degrees. A Map torch easily gets you to that temp. Regular soft solder will do the job but I find the Hi Force 44 very easy to use and has many uses around the shop.

[James Wilson Everett]

Guys,

Jiust plug it up and re-drill.  Here are photos from an old original from Ligonier Pa.  The old timers did the same, don't worry about it.

Jim

[Goo]

Brooks is giving you the best advice.    There's no way  to know what the  steel is in that casting. If you weld or silver solder you'll harden the steel and you won't be able to redrill.

[G_T]

At the low temp of Stay-Brite silver solder (6% sliver) you'll even be below the annealing temperature of the steel. It is liquid at 535F. That should be about a thousand degrees below the hardening temperature of the lock plate. You won't harden the steel unless being really careless with the heat - and then quenching it! If the plate isn't hardened, you probably won't soften it much either.

I prefer to avoid filing or sanding lead alloys. So I prefer a silver bearing lead free solder when it is reasonable to use as a substitute. I think this would be such a case.

However, no solder or brazing method is a reasonable choice if case hardening is intended. Then I think you are stuck with welding as the best method.

Gerald

[Dale Halterman]

I did one maybe 15-20 years ago by peening over the end of a screw like Bama described but without soldering or welding. I was afraid that the browning solution wouldn't take if there was any solder showing. Just relied on the mechanical bond of the screw being expanded into the hole. Still seems to be tight after all these years.

Dale H

[Bob Roller]

I did one maybe 15-20 years ago by peening over the end of a screw like Bama described but without soldering or welding. I was afraid that the browning solution wouldn't take if there was any solder showing. Just relied on the mechanical bond of the screw being expanded into the hole. Still seems to be tight after all these years.

Dale H

THIS method described by Dale is the only method I have ever used to cover a boo boo of
this kind.It's not uncommon so don't beat yourself up over a mistake.Mistakes are why a
pencil has an eraser.

Bob Roller

[Mike Brooks]

Mike, Brownells Hi Force 44 has a melting temp of 475 degrees. A Map torch easily gets you to that temp. Regular soft solder will do the job but I find the Hi Force 44 very easy to use and has many uses around the shop.

 That's perfect. I used to use that stuff all the time, then ran out and never got any more. I just wanted to point out you don't have to use the real high heat type silver solder stuff.

[Ed Wenger]

I do what Dale described, no solder, peen both ends into a counter sink.  The threads will swage together, and when the ends are filed flat, the repair disappears.



           Ed

[hmccaskey]

Thanks to all for the help.   I have the hole tapped now.  Will try filling with a screw.

Bob - it all started with a hand drill making a starting hole with a pilot bit in a very hard plate. Was going to use a free standing jig to drill a to b.   Broke the pilot bit off in the hole. Proceeded to try and drill out on the drill press running at too high a speed ...... 

This a pre-shaped stock - not one good square corner to use for reference.  I got lazy/impatient and decided to use the jig instead of clamping in and squaring up on the barrel in the drill press.  Lesson learned.

Some of you I met in Knoxville.  Brooks and Bama for sure.

Thanks again,

Hal

[jerrywh]

The method described by Dale and Bob Roller usually works pretty well. Tig welding always works 100% of the time but how many people have a tig welder? 

[45-110]

if it is easy to find a tig welder in montana (which it is) surely the rest of the country has the resource close by......a couple of phone calls to a weld/fab shop should do it.

[hmccaskey]

Success!

I tapped the bad hole and beveled both sides.  Then peened a portion of the bolt into the hole.  It cleaned up nicely.  Finally got the courage up to drill again today.
After a lot of "measuring" to decide where I wanted the hole on the opposite side of the stock I used the drill press with a centering pin.  It worked well.
I have the new hole tapped and the bolt in place.  Would take someone with a very good eye to see the repair on the outside of the lock plate.  I am pleased with the result.

Thanks for the help.

Hal