old UNION 4 lever padlock

[femurat]

I recently got this nice old UNION padlock.
Unfortunately my phone takes crappy pictures under energy saving lights and there were no sunlight this morning.
The padlock is open and from what I can feel without closing the shackle it has four levers.
I'm going to make a key for it and I may need some advice. Does anybody know the space and depths of this old padlock? I can insert a wire in the curtain and probe the levers heights. I may try to decode it and produce a rough key. Then I could just finish it by impressioning, rather than starting with an uncut blank. I'm going to cut my blank out of steel, so an almost working key would be quite helpful for impressioning...

Thanks

[Oldfast]

Any luck yet? Good project for a rainy day mayabe.

Looked through my files to see if I had anything helpful for you... nothin'

[femurat]

Thank you for trying to help me Oldfast, I appreciate it.



To make a key for this padlock I took some measurements.
Key hole height 11 mm. Key hole width 1.5 mm.
Total padlock thickness 12 mm, wall thickness 1 mm, estimated flag 10 mm.

Then I bent a wire getting an L as tall as the keyhole to probe how much it rotates in the keyhole under each lever. Going from front to bottom I found 5 different "obstacles", and the probe turned respectively 30°, 60°, 30°, 60°, 30°. These are eyeballed angles. These obstacles may be 4 levers and the bolt.

I decided had enough info to start filing an old steak knife. I roughly filed it with a cutoff disk on my dremel and got the shape you see over the paper sheet in the small rectangle. Then I blackened it with a bic lighter, inserted, turned, extracted and filed where I saw a mark. After some time I got what I think is the correct key for this padlock. See it on the green table? Looks like a classic shaped key

I thought I could close the padlock and try if it worked. To my surprise the padlock can't be closed. I got this padlock open and didn't try to close it before making the key because I was afraid I couldn't picked it open again, so I didn't know if it was a working padlock or not. Well, it turns out it's not. The levers may be blocked by rust. The shackle is springy, if I close it it bounces up again, without even catching somewhere inside the padlock. The bolt can be slightly moved with a piece of wire, but pulling it was useless.
I sprayed some unlocking oil in the shackle hole, hoping it'll free the levers. I'll let you know if it works, but I'm afraid it will not be possible to fix this padlock.
Well it was a nice rainy sunday anyway.

Cheers

[MBI]

If rust turns out to be the problem, there are a couple of electrolytic rust removal tutorials on the forum. As I recall they were stripping rust from disassembled items, not a complete lock, but if all else fails it may be worth a shot.

[oldbiscuit]

Femurat, Just a thought, If someone had the wrong key (one where the bit was to high), they may have gotten the lock to open. But if they turned the key back after it opened, it may have left the levers in the loaded position under tension. You might try spraying the inside with a good rust penetrant and inserting your key and try turning it counterclockwise with the shackle held closed. It might release the tension on the levers allowing it to lock. I've had this same thing happen to a couple of locks I was trying to fit keys to, worth a try. Mark

[femurat]

I saw those tutorials MBI, they are quite impressive. I don't think it would work on an assembled padlock because the current tends to be on the outer surface of objects. If you try to chrome a tube in an electrolytic bath for example, the inner walls won't be affected.

Thanks for the suggestion Mark. I've tried it immediately after trying to close the shackle, but the key didn't turn CCW: there's a rivet just above the right side of the keyway and it blocks the key before it can reach the levers. The key can be rotated CW till it reach this rivet I guess. My key can't rotate that far, but since it doesn't get marks on the side, I stopped filing.
I may try to move the levers back with a shorter bent wire... I'll let you know if this works.

Cheers

[femurat]

I really hate to cut locks. It hurts my feelings to ruin a padlock. This time I had to make an exception. I can accept not being able to open a lock, but I can't stand not being able to close one!

I took my dremel and opened a small window on the left side of this padlock. I could confirm my hypothesis: the levers are so rusted it was not possible to move them, even levering a flat screwdriver over the rivet against them had no effect. I sprayed some penetrating oil again and gently move them, while keeping the shackle closed.
After some light attempts I decided to apply more force, so one of the levers moved down a little and the shackle got trapped in its closed position. This told me I was on the right track, so sprayed some oil and moved up and down the levers a few times. Now the lock can be opened and closed with this rude method. The levers stay exactly where I leave them and are still full of rust. I'll try to remove as much rust as I can the next rainy day...

Cheers

[femurat]

So I put this padlock in a mug with coke and let it sit overnight. Then I fished it out with a screwdriver and it's nicer and cleaner, and fortunately the old patina is still there.
The levers unfortunately are still blocked, but now I can open and close the shackle without levering them with the screwdriver. When I open or close the shackle the two higher levers go up and down on their own, allowing me to open and close it without the need of a key.
Looks like there's still some rust in between the levers, I'll let it soak some more and see if those levers will be free to move or not. Now those are still hard to move.

When I'll remove the padlock from the coke mug, what should I do? rinse, dry it with compressed air and then lubricate I guess... I'll keep you updated.

Cheers