impressioning knife edge

[davidgjr]

I will probably get blasted, but I can take it . How many of you put a knife edge on the keyblank before impressioning ? I was just wondering because As a beginner, I was having a little trouble, but when I put a knife edge on the blank I have been getting consistent results. I just kind of want everyone's thoughts or inputs on doing it this way.

[pointofview]

I've also been having some trouble with impressioning. I'm currently taking a correspondance course, and I'm trying to impression a key as per the practical exercise, but I can't see the marks at all.

Does the knife-edge work for you? What kind of angle do you file to get the edge? Do you file on one or both sides of the blade?

Any insight that anybody can offer into my dilemma would be greatly appreciated....

[S3rratedSp00L]

Making a knife edge is not a bad idea, but still make sure you rough up the surface with some fine grit sandpaper or you still might not see marks!

When you rough up the surface, then insert your key and wiggle it, you will be left with little shiny impression marks where the pins (or wafers) have polished the surface a bit.

I hope I am not just repeating something that you already know.

Impressioning can be a lot of work! Good luck to you guys!

[locksmistress]

The only problem with the knife edge is - depending on your brand - you have to be very careful not to go beyond your zero-cut.

For example, a Corbin zero will work with a little shaved off the blank. A Schlage zero is actually a completely un-cut blank. It's very tricky to sharpen a key and not remove any depth.

It won't make so much difference on residential locks with low tolerances and it's a good place to start out - but flat dressing is more precise when you move up to commercial.

[Varjeal]

I would agree with locksmistress. Knife-edging on commercial locks with tight tolerances can be problematic, while on simple sloppy cam locks, etc. it can actually speed the process.

Once I figure out how to use my wife's digital camera, I'm going to take some intermediate shots while doing some simple impressioning so you folks can have a better idea of what your looking for. In the meantime, I'll try and describe it in words.

I'll mention first off that it's extremely important that you prepare your keyblank properly, and I would HIGHLY recommend that you use colored brass keys rather than the silver nickle plated. The brass keys are a smidge softer, and will show impressioning marks much better. (IMHO)

The marks you are looking for will appear to be (on a shiny surface) either fine scratches, or possibly even "dots". It's also vitally important that you have the best lighting possible. After manipulating the blank in the keyway, look at the blade from many different angles and vary the lighting if possible as well. This will help you tell the difference between file strokes and impressioning marks.

Hope this helps.

[pointofview]

Thanks for the help! A few more questions (if I may)...

When impressioning using the normal method (that is to say the non-sharpening method), would it be best to prepare the blank with fine-grit sandpaper, or leave the blade with its original finish? If sandpaper is best, should the blade be re-sanded after each layer removed with the file?

I ask because this is more of a nuance that isn't normally covered in how-to's, as it would probably vary from locksmith to locksmith. I'm just trying to figure out what I'm doing wrong, as I'm following all of the directions from many different sources, and I'm still turning up with no marks (that I can see) on the blade. It's a little frustrating, as I can't go any further in the course until I complete this assignment...

As a footnote: Thanks to the regular posters on LP101 for all of the tips as I go through this course... I've been lurking for a while slowly learning, and I hope that I can start to post more now that I'm getting more experienced...

[Romstar]

I find that preparing brass keys with a fine grit sandpaper or a very fine flat file removes any random marks that could confuse the marks made from the pins.

This results in all the starting marks going in the same direction.

The "polishing" action of the pins across the newly preped blank allows you to pick them out much easier.

If you are lucky enough to have the depth and space guides for a given lock, you can file the marks in full depths and work from that. Although, this is a more advanced method of doing this.

I almost always use the file very lightly before every putting the key in the lock.

Romstar

[MrB]

Well I have never impressioned a key, so I can only create a thought experiment here. Feel free to judge my contribution in whatever way you see fit.

But maybe it would help to put all the "do it this way's" and "do it that way's" to one side for a moment and try to think first hand about how the key is going to get impressioned.

When you put the blank in the lock, all the pins are going to be resting on top of the key by spring pressure, so they should be evenly and firmly in contact with the key surface. Now when you turn the key hard to the right or the left, the pins or drivers are going to get clamped at the shear line as if in a vice, but still touching the key. Next, while still turning the key hard, you are going to wiggle it around a bit. All those clamped pins are going to press back against the wiggling and scratch/polish/mark the key blank. The marks of course are going to be tiny, since the pin tips are blunt and made of soft brass.

OK, so important item number 1: The top surface of the key blank should be slightly roughened (matt would be a good description) so it can rub against the pins and get polished by them. (A mirror finish might also work and show up scratches, but that will be very hard to achieve in practical circumstances.) Secondly, the surface must be completely uniform without scratch or blemish, so the marks made by the pins will stand out as much as they can. Whether you use a fine tooth file or sandpaper should not matter so much as whether the resulting smooth matt surface is good.

Secondly: The received wisdom is only to file away one mark at a time. The file that you use (very softly, only one or two strokes at a time) should leave behind a smooth, matt surface. So no further sanding ought to be required, perhaps. If you feel it is, maybe you need a better/different file?

Thirdly, any marks made at other pin positions that you are not presently filing are still valid marks. You don't want to remove those marks with sandpaper, because you will be coming to those pin positions later.

Fourthly, the conclusion: After you have filed down just enough at a given pin position, the key pin will be entirely at or just minutely below the shear line. So now when you turn the key hard to the right or left, the key pin and driver pin will separate and neither pin will be clamped. Since the pin is not clamped, it cannot press against the key when you wiggle it, so it will no longer leave a mark. At the point, you will be leaving this pin alone and moving your attention to the next strongest mark on the key. With all the previous wigglings, the other marks that you have not been touching should hopefully have been getting more and more evident.

So like I said, this is purely my mental model of what is going on. But my experience in life has always been that things work better when you can really picture for yourself what is happening and you are not just following other people's instructions by rote.

Perhaps if you can really picture what is happening inside the lock, you will make a breakthrough.

One other note: everyone says that the marks are going to be almost imperceptible. Maybe you could get and try one of those jeweler's eye loupes (a magnifier that sits in your eye socket like a monocle). That should give you a much better chance of seeing the marks you are looking for.

Hope this might help.

[Romstar]

Good grief.

Now I have two days to write a mini book on impressioning. I don't know if I can get that done.

MrB pretty much has the idea though. He's right in that you should image what you think is going to happen.

The biggest thing with this is that the more you do it, the better you get at it.

Come to think of it, I don't even know if I still have the pictures and diagrams I used to use for this stuff.

I'll see what comes up though.

Romstar

[davidgjr]

On the Foley Belsaw Course, The impressioning lesson really in my opinion isnt that good. The file they give you is a piece of garbage.

[randmguy]

Gripe...gripe...gripe...What do you expect for $700 ?
Seriously, if you're really having trouble getting it try some magnification. No, I am not advocating the $30 visors you see them wearing all through the Foley-Belsaw catalog. I have a Radio Shack Lighted magnifier that costs around $10 US. It does a great job for me and its a real plus when you're trying to impression at night by street lamp or dome light.
Other advice on impressioning can be found here:

http://www.lockpicking101.com/viewtopic.php?t=3285

And here:

http://www.lockpicking101.com/viewtopic.php?t=1396

[Chucklz]

Anyone have any thoughts on the UV/marker system?

Does anyone have a source for anything like this?

1.) GM blanks, but with depth etchings on the side of the blank. I saw these on Ebay years ago, and I wonder if something similar is available for non-auto locks.

2.) Seen in LSS. Blanks with a lead blade, so marks are very very easy to see.

[HeadHunterCEO]

Anyone have any thoughts on the UV/marker system?

Does anyone have a source for anything like this?

1.) GM blanks, but with depth etchings on the side of the blank. I saw these on Ebay years ago, and I wonder if something similar is available for non-auto locks.

2.) Seen in LSS. Blanks with a lead blade, so marks are very very easy to see.

1. you culd prolly make one with not so much trouble

[Varjeal]

The goal you going for when preparing the blank is to indeed leave as close to a mirror finish as you can. This means 3 things:

1. Use a very fine cut file. Chain sharpening files (and their like) are FAR to coarse. If necessary, use the files found in those popular 4 & 5 piece el-cheapo hobby sets. Another word about files that I just thought of. Make sure you're not using the entire length of the file in your stroke (if you're using a full size or tapered round/half round file). You may be widening the cuts to the point that you're actually crossing over into the area where another pin normally rests.
2. File in one direction only, and keep your file level and perpendicular to the key's edge at all times (except when cleaning the valleys and ramps to allow smooth key operation). The original finish is most often too rough to be able to accurately guage the marks your looking for, make a habit of cleaning it always. I've never used sandpaper to do this, but there's no reason why it shouldn't work, I just don't find it convenient to carry with the other 50lbs of gear in my toolbag.
3. File LIGHTLY, and straight without a rocking motion, which can leave "marks" on the position that you don't want.
4. Regarding the "wiggling" motion. Here's what I personally do, you'll have to try it and see if it works for you...:
Each time the key is inserted into the lock, push it in fully and smoothly as possible. I then apply CW first (no particular reason why) and then in varied intensity rock the blank up and down. I then stop, allow the cylinder to return to it's neutral position, and then do the same CCW. Each side five times, then removal in one smooth pull for examination. This for me allows the cleanest method of marking the blank.

Regarding the use of lead, you only need one of those pieces to get jammed in a lock before you cease using that method hehehe..after all there's no reason why brass keyblanks in themselves are not adequate for the job at hand.

The marker system does work, I just personally find it a bit messy to work with.

[davidgjr]

Lockmasters has the UV system. It looked like at night it would be real helpful.