by nostromo » 7 Mar 2010 23:35
I teach a nondestructive entry course and have tried all kinds of bump hammers, trying to settle on the one hammer that seems to work for most people. Since the classes have 24 students and I have to schlep a lot of other stuff along, size and weight are a consideration. Some students have brought various commercial hammers with them, like Petersons and Tomahawks. Improvised hammers are offered, too, like batons and clawhammer handles.
In the class, about 30 minutes is spent on 'inertial picking' like picking guns and buymp keys. One horizontally mounted Titan deadblot cylinder with 5 pins is clamped to the table in front of each pair of students and they take turns.
Observations on effectiveness after about 15 minutes of practice:
- Carpenter chisels with tips blunted work 50%, lots of smacked fingers.
- 10" lengths of duct-tape wrapped 1 x 2 lumber work 50%
- Tub stopper on length-trimmed wreath hanger works 50%
- Thin plastic handle with light PVC rectangle end works 25%
- Commercial hammers work 75%
Success rates go down if the lock is handheld, not mounted or is loose in the frame- like a KIK that's been beaten on as a demo. The students tend to be aggressive.
Now, the commercial hammers are used by the folks that brought them and have SOME practice with them already. There's a lot to be said for using the right tool for the job. If you have the money, I'd say go for a Peterson. And use bump keys made specifically for the job, like 'minimal movement' ones. That way you know you are working with the right tools and can focus on your technique.
Schuyler, as always, is 'bang on' about screwdriver handles. Pun intended. Once people get enough practice to avoid smacking their fingers they get confident, start delivering the proper hit, and apply the right amount of tension, and their sucess rate improves.
My class is an overview that covers three days worth of spp, raking, bypass methods, non-destructive entry, legal aspects, and vehicle entry - so we can;t spend much time on any one subject. I'm sure if you took more time than they get (15 min) for practice you would do well.
After trial and error, the chisels offered for practice are fairly lightweight and have rounded one-inch thick wood handles with thin blades. Any kind of unusual shaping such as is used to improve grip and torque for screwdrivers will present a variety of contact surfaces as a hammer. Which makes it hard to be consistent unless you hold it the same way every time with the handle at the same position.
If you don;t go the commercial route, get the cheapest screwdriver-like tool at the dollar store or Harbor Freight that you can, and wrap some duct tape around the handle.
Let me say this, though. After the first few locks what are you going to do? It's like using a powered pick gun. Yes, the locks open, but the skill required is much less than single pin picking or even raking.
What is your purpose in bumping, what are you going to pick next? You'll need more tools and skills to deal with non-residential locks. When you order your keys and hammer, get yourself some picks and tension wrenches, too. You'll graduate to them pretty quickly.
