[delraydella]

I'm biding on a job where I have to cut apart some old safety deposit box doors from their frames. The frames are most likely high carbon steel so i want to use a plasma cutter, but my problem comes in where there are decorative brass pieces mounted to the front of the doors.The brass is highly polished and most likely coated. I can't eff these up. I need to cut as close as possible to the brass, so my question is how will the heat of the cutter affect the brass or it's coating? I'd like to cut at least a minimum of an inch away.
and....
I can't take the brass pieces off until I cut the doors off.

Other Steve

[Otto Nobedder]

OMG! A "Bank Job"???

[Otto Nobedder]

You'll need to keep a stock of fresh tips... any "washing" you do will damage the tips quickly. This may be a job where you can justify dry nitrogen as your cutting gas.

[delraydella]

The wife wants a new house.....I want to cut out the middleman on a bank "loan"


Same air line and regulator setup for dry nitrogen? The guy I'm quoting this for has megabucks so the sky's the limit, but I have to do this job right. I can't damage the brass in any way, shape or form...

[Otto Nobedder]

Get a nitrogen bank, and the dryers and filters become redundant.

You'll get more mileage from a "dewar" of liquid nitrogen.

No oxygen, no moisture. Nothing to damage what you don't want to damage, or tear up your consumables early.

Just keep the tips fresh, and aim carefully.

Hell, if money's no object, get a Dewar of liquid argon... Even cleaner a cut.

Preserving the brass is on you, keeping the cut steady...

[delraydella]

I'll be cutting behind the brass, so I'm not going to touch it at all, but i'm worried about the heat from the torch affecting the brass or it's coating. Is that something i should be concerned about and move my cut line further away from the brass? I'd like to go in about an inch behind the brass plate, but if that's too close, I can go back further.

I can post a picture of what i want to do, if i'm not making any sense.

[Otto Nobedder]

As long as you're careful and watch the arc, you can get quite close. The heat in a "clean" plasma arc is very focused.

I assume you want to cut the last fraction with a zip-disc or similar?

[delraydella]

I was thinking about cutting a 16th over and running the frame though a horizontal mill or some sort of rotary grinder, but if i can get a nice clean cut by doing what you said, cleaning it up with a zip disc should be fine.

Thanks!!

Other Steve

[Otto Nobedder]

If money's no object, err on the side of caution at every step.

[noddybrian]

Wow - I'm doing this all wrong - your " legally " opening safety deposit boxes & I'm trying to rehab a trackhoe bucket that is'nt worth the effort !

If these brass pieces are all the same how about making a sheet metal "mask" to fit over to protect them - or if the job justifies it, plasma them out with a good leeway round the brass then take them to someone with a water jet profiler & get him to do the final cut - there's a guy near me got one & the accuracy & finish it leaves are amazing.

[BenJackson]

As long as you're careful and watch the arc, you can get quite close. The heat in a "clean" plasma arc is very focused.

I assume you want to cut the last fraction with a zip-disc or similar?

I'd think you'd want to use settings high enough to ensure a clean through-cut. That way the metal heated by the plasma is separated from the base and blown away, carrying the heat with it. If you don't cut through you've heated the remaining metal *almost* hot enough to melt and then left it attached to the work piece.

[krazziee]

I like the water jet approach, money being what it is, blow them off and water jet .... jmo
good luck

[Otto Nobedder]

Yeah, Steve,

A pic or two might help here... Hate to find I'm making bad suggestions.

Steve S

[delraydella]

A picture of it would be impossible at this stage, the boxes are still embedded in the wall of the vault. I'll draw up a top view of what I'm trying to do once the boxes are freed up. That should help answer a lot of questions. If it means anything, I didn't know what the h--l they wanted from me either when they first started talking to me about doing this!

A brief explanation of what they want...There are a bunch of old safety deposit boxes in a basement vault that have decorative brass plates on the doors. They want to save the doors and brass and make tables out of them, but no one has the keys to the boxes. If they could just open up the boxes, they could simply pull the screws that hold it all together. So now the plan is to somehow unembed the box units from the walls they are in and have me cut off the back of them, thus exposing the inner side of the doors. To make matters even more difficult about pulling them out of the wall....when the building was built some time in the 1920's, they dug a foundation, poured the basement, put in the vaults and then built the rest of the building over it! So up to this point, no one has a clue how to get these things out of there short of destroying them. They have brought in locksmiths and safe people, but so far no answers. I suggested bringing in machinery riggers to look at getting them out.

A drawing will help make a lot more sense out of this, I'll try to do one tomorrow.

Other Steve

[Otto Nobedder]

So it's a 1920's safe-deposit. Unknown contents? Or known empty?

My brother is an old-school master locksmith (he taught me how to escape Smith & Wesson double-lock handcuffs behind my back when I was twelve...). Let me run it by him... He may well know a specialist. I find it hard to believe 90 year old locks can't be defeated by the right person for the job.

Can you get a picture of the face of one of the boxes, perhaps an extreme close-up of the lock, itself?

Steve S

[Otto Nobedder]

Also, what region of the country is this job? Somewhere near you, I assume?

Steve S

[weldin mike 27]

Hey,

Ahhhh we thought it was empty untill we cut it open and found the stack of first edition spider mans on fire. lol

Mick

[delraydella]

Mick.... That would be my luck!

Steve...I'll see what i can do. The locksmiths that they've talked to up here, the building is in Detroit, have said to just drill the locks out, but the owners don't want to do that because it would destroy the look of the door. They can't make keys for them because they don't have the right blanks or they can't get them anymore.

[noddybrian]

Hey - I bet there are still plenty of guys that could sort out this problem without the need for a plasma cutter - but it's unlikely they are members on this forum !!
Not that I would know anything about this - but many older safes / boxes have very shallow engagement on the locking bars so have you tried "old school" method of trying to spread the case in the area of the bolts using very thin hardened steel wedges - it should not damage the doors if done carefully - it's worked for "my friend" in the past !

[Alexa]

This string is becoming more interesting with each post.
Better than a good mystery or thriller paperback.
Waiting for the next scene.
Alexa

[delraydella]

Here's some pictures, they should help explain what I'm trying to do. The first is the wall of deposit boxes. The boxes are built in sections, each holding a certain amount of boxes. Once a section is free, i will cut off the back of them leaving what you see in several seperate 4 x 6 sections. Measurements are just guesses here.

The second and third are the locks. I didn't take these pictures so if you need a different view, let me know.

There are 2 more, I'll put them in the next post


Other Steve

[delraydella]

These two show the inside of one of the boxes. This ones locks got drilled out. On the second picture, i drew a dotted line where I want to cut. The doors and whats left of the frame will be used for table tops, the back part is scrap.


I hope this helps!

Other Steve

[Otto Nobedder]

In the second picture of the first set, I only see one strike for the locks, opposite the hinge side. If I see that right, it should be possible to use a small narrow-kerf diamond blade (Think "Dremel" size, but get them from an industrial supply) in an angle die-grinder to slice the hinge pins (with spark-paper on that beautiful machine-turned brass, of course), and pull the door off complete from the hinge side. Examine the jamb, bolt(s) and strike(s) on the "drilled" door to see if this could work.

Since it's now going to be decorative, the hinge pins can be repaired (if needed) by counterboring the "pin" side of the hinge and TIGging in a 304SS pin the right diameter, once you have the frame separated.

IF this idea can work, you can pull all the doors (matchmark the frames), and hack the frames off at will.

If, however, the doors have bolts and strikes on the hing side, or top-and-bottom, this cant work, but that's not what the picture appears to show.

Two cents...

Steve S

[delraydella]

Thanks,it's certainly a workable solution if it can be done that way. I'll forward it to the powers that be and let you know what they say.
You can see now why I was worried about effing up the brass with the heat from a plasma cut!

Other Steve

[WerkSpace]

I'm not so sure that removing the hinge pins will work. I have the safe from an old Automated Teller Machine (ATM) and with the hinges completely removed you cannot get into the safe without opening the lock first. It's all in the design of the door. The metal door wraps back around another piece of metal, so that when the exterior hinge is removed, the door still has to rotate around the interior structure in order to be removed.

In the second picture of the first set, I only see one strike for the locks, opposite the hinge side. If I see that right, it should be possible to use a small narrow-kerf diamond blade (Think "Dremel" size, but get them from an industrial supply) in an angle die-grinder to slice the hinge pins (with spark-paper on that beautiful machine-turned brass, of course), and pull the door off complete from the hinge side. Examine the jamb, bolt(s) and strike(s) on the "drilled" door to see if this could work.

Since it's now going to be decorative, the hinge pins can be repaired (if needed) by counterboring the "pin" side of the hinge and TIGging in a 304SS pin the right diameter, once you have the frame separated.

IF this idea can work, you can pull all the doors (matchmark the frames), and hack the frames off at will.

If, however, the doors have bolts and strikes on the hing side, or top-and-bottom, this cant work, but that's not what the picture appears to show.

Two cents...

Steve S