What's happening: Sargent mortise deadbolt

[Kheops]

I recently acquired a few old Sargent mortise deadbolts. They do not have anything special, no security pins, no sidebar, just plain old pin-tumbler with 6 pins. But, wow! These things are REALLY tough considering they do not have any special security features.

They were used on many doors in police stations many, many years ago, so when they installed them, obviously security was a big concern. They've been worn down A LOT!

Now my problems, I've only attacked one so far: I can't feel ANY pins bind unless I put A LOT of tension, and even then, when the pins bind, they will sort of make a dull click/thud instead of the loud click/snap I would expect with so much tension.

Also, even though I feel, say number 6, bind, I will then move on and find that 4 binds. As soon as I get it to the shear line, 6 will drop back down. And on top of that I can VERY easily over-set.
I've managed to pick it, more or less by accident, a few times. I don't like saying I can pick it, unless I can clearly describe what's going on, and with this one... I don't know...

I closely examined the lock and noticed that the plug is somewhat flat-topped, and the pins are all very slightly bevelled. Is this what is dampening the clicks?

The brass also seems rather soft, which I guess could contribute... and the lock is really very worn...

I've been using TOK tension with a Peterson Pry bar clone I made using an industrial band saw blade, along with a medium hook, and progressive curve hook I've made.

Any advice?

I am far from an expert, but I have picked, sometimes easily, stuff with loads of security pins (American, Guard, Brinks, Abus, Master, ...) and have managed to pick really awkward keyways like Yale or Schlage... but holy cow! This thing is kicking my butt!

[silvfox1200]

Some of those old locks need a lot of tension. Also when you set a pin and then fine another pin to set, then lighten up on you tension just enough to set the next pin. If that doesn't help, then keep tension an the one you just set and then lighten up the tension and reset the other pin. If that doesn't work then you probably need to use heavy tension and force the pin above the shear ling.

Thanks

James

[Kheops]

Alright, thanks. What I'll try is putting it in a vise to be able to exert substantially more torque. I was holding it and torquing it with one hand and picking with the other (not ideal, I know, but I'm getting used to it). I'll have to be careful not to break my picks! I might try a little more heavy duty tension wrench. I was thinking of flattening out an Allen Key and cutting the wards out (like a key) for maximum contact for BOK tension, I think that'll be pretty much the most I can do as far as a tension tool is concerned.

Thanks again.

[1mrchristopher]

Kheops, if you have a pinning kit, I'd highly suggest repinning the lock with new pins and new springs, I'd also take it outside with a can of Houdini (or WD-40, or Tri-Flow, but Houdini smells like oranges which is an added bonus if you like citrus, and won't gum up) and flush it out real well. They sound like locks that were used hard and maybe didn't see much in the way of maintenance. ie. Secretary: "My key doesn't work." Custodian: "Sure it does, you just have to pull it out a teeny bit and jiggle it while you turn." Anyhow that's my 2 copper clad disks.

I prefer hex key tension wrenches myself because of the precise control you can achieve with them, and they are very handy for those locks that require extra oomph. I just ground mine to the point that it would fit snuggly in the bottom of the plug, and didn't worry about matching the profile of the keyway. So long as you have solid contact on both sides, even if it's just a ridge on the one side, you'll have complete control over where the plug moves and how much.

[phrygianradar]

I had the same exact experience as this with an old (probably 1940s era) Schlage deadbolt that is up at the family cabin in Big Bear CA. I thought that it was just machined really well... It has not been maintained for many, many, many, (etc.) years for sure!

[cuttinedge1]

Sargent lock have no security measures but have extremely tight tolerances making picking very difficult. The problem is not the pins its that the binding is almost nothing because of the tolerances.

[Kheops]

Well I tried with more tension and it' s maybe 25% better... gonna have to practice more I think!

I had forgotten to mention that before even posting I had taken it completely apart, dumped all the pieces in a masson jar full of BBs and Acetone. I shake it all up every once in a while for a few days to really de-gunk the parts...pass it all through a sieve amd let the acetone evaporate off before re-assembling... seems to work well. It was completely full of grease, dust, and random substances.

I am starting to suspect that the tolerances are simply way more tight than I'm used to.

[1mrchristopher]

That's quite a cleaning regimen! Must have been a night and day difference when you got it back together. You wouldn't happen to have taken before and after pictures? My picking skills aren't such that I can offer any real assistance - I'd probably clear all but two cylinders, just to get the feel of what tension works well, and then build it back up, but that is in large part because I am still inexperienced.

[Kheops]

Honestly it's 'not bad' but to do a better job I would need smaller than BB sized bearings. I didn't take any before and after picture, however when I would let the gunk settle there was a good amount of gunk at the bottom of my jar. I clean this way when I'm in too busy to really do a good job with a brush. I got the idea from firearm knowledge. For reloading cartridges people use a technique like this, but much better. The bearings are thrown in to a device with the used brass. A solution is then added and the machine either shakes or vibrates for a set time. I am thinking of buying a kit to try it out on old locks.

But, nothing beats a brush and acetone, but a major problem with acetone is that it is terrible for your health. So I try not to touch the stuff. If I can let little BBs do the work for me, I prefer that.

I'm starting to be convinced that for such an old, and accurately built lock, one really needs a lot of tension.

[Raymond]

One of the facts about Sargent locks no one else mentioned is that they use a very wide range of pin lengths. From a no-cut number 1 to a 0 (10)cut, the 0 is 200 thousandths deep. The top pins are also usually very long in factory pinned cylinders. Long top pins tend to have much more stability and do not wobble or pivot. Because they do not wobble there is more frictional surface holding the top pin straight. Factory bottom pins are shaped round on the tip. They are called ball-end pins. They are just a little different to feel. They are just naturally pick resistant with no tricks.

[cledry]

One of the facts about Sargent locks no one else mentioned is that they use a very wide range of pin lengths. From a no-cut number 1 to a 0 (10)cut, the 0 is 200 thousandths deep. The top pins are also usually very long in factory pinned cylinders. Long top pins tend to have much more stability and do not wobble or pivot. Because they do not wobble there is more frictional surface holding the top pin straight. Factory bottom pins are shaped round on the tip. They are called ball-end pins. They are just a little different to feel. They are just naturally pick resistant with no tricks.

Not fun to impression either.

[1mrchristopher]

For firearm brass polishing many people are now using small pins rather than bearings. If you wanted something less detrimental to your health, but still quite effective for cleaning the kind of grime you get with locks, I would suggest d-Limonene, or a solution of citric acid, both of which are much safer than acetone. If you were to build a little rotary tumbler with a plastic tumbling container such as a peanut butter jar or something, you could put the solvent, pins and lock parts in the jar, turn it on and walk away. Search for pellet pins, and you'll find the polishing media I'm talking about. With a little shopping you can get a pound of them for $20.00 d-Limonene might be hard to come by in a quantity you want to buy, I know Amazon sells it by the gallon. Citric Acid can be purchased as Lemi-Shine at the grocery store, or in larger quantities online or at some bulk foods stores.

[Kheops]

I really like the idea of using a citric acid based cleaner. I will definitely look into finding little pellet pins, and combine that with the citric acid cleaner.

I'll post an update... eventually.

Thanks!

[billdeserthills]

I find a small bottle of 91% isopropyl alcohol works great and it won't hurt anything I have put into it. The cost is right too, you can find the alcohol for a dollar a bottle. I just put whatever I want to clean into my jar and cover it with alcohol and leave it for awhile. When I come back it is getting clean!