joining lead

Date 08-10-2005 20:50

It seems to me that whoever you are building these boxes for would be able to give you chapter and verse on the fabrication requirements.

If it was me, I may try fasteners. If it has to be perfectly sealed, you'll have to wait for someone else to describe how to heat it up.

Good luck.
Charles

By n5uzt

Date 08-11-2005 02:06

you can join lead by useing oxygen and hydrogen
works like a regular gas flame but smaller
i used to be a lead welder in a textile mill in n.c.
or as they called it lead burning.
we had to lead line all large wood boxes with sheet lead
and all chemicals were in lead pipes.
the torch consists of a double valve one for ox and one for the
hydrogen then off of that was a long 2 ft. rubber
hose with a small what we called finger pipe.
which was a small copper tube 4 or 5 in. long with a small hole
around 1\8 in.
very low melt point welds together like soldering with lead filler material.

By billvanderhoof (****)

Date 08-11-2005 07:16

This is an occasion where one is inclined to warn- really, really keep you head out of the fume plume. Pay good attention to ventilation.

How thick is the lead?

Can you just fold the corners?

You can soft solder lead, but make sure that the customer approves. Design a joint where the solder is not required to provide shielding. The tin dilutes the lead in the solder and surely increases the permiability.

O/A should work. Pure lead kind of melts all at once so it might be helpful to support the joint with something so it doesn't suddenly fall on the floor.

I bet you can TIG it but will wait for one of the TIG experts to confirm that.

Bill

By swnorris (****)

Date 08-11-2005 10:10

Lead is welded primarily by oxyfuel gas welding, but it can be joined by other welding processes. Acetylene, natural gas, or hydrogen may be used as fuel gas. Oxyhydrogen or oxyacetylene mixtures can be used for welding in all positions. The hydrogen flame gives better control of the molten weld pool because of the lower heat input. Oxynatural gas welding is recommended for the flat position only. A neutral flame should be used with acetylene or natural gas fuel. A reducing flame tends to deposit soot on the joint. Excess oxygen in the flame will oxydize the lead and inhibit wetting. Manipulation of the welding torch and the flame intensity depend on the type of joint being welded as well as the position of the welding. In general, the torch is moved in a semi-circular or V shaped pattern. The molten lead is controlled and directed with the flame to produce a circular or herringbone appearance. Be advised that lead and its components are toxic, and exposure to these materials can present serious health hazards if proper precautions are not taken to keep fumes to a safe level. Lead exposure can be a result of not only welding, but from handling or cleaning surfaces with an abrasive.

By workingguy247 Date 08-11-2005 21:24

Mr Bill the lead plate is 1/2" thick I have not seen the planes yet to know about the corners. I was tring to get some ideal of my options before i got to far the wrong way.

By billvanderhoof (****)

Date 08-12-2005 06:48

Well that's a little thick for folded corners. It wouldn't be out of the question to cast these as a single piece.

Just the lead will weigh around 650 lb. If the box sits on its largest side (24x30) that comes out to about 130 lb/sqft. Over the 100 lb/sqft usually used to design commercial buildings (residential buildings use smaller numbers). Somebodies engineer needs to check to insure that these boxes will remain in the spot desired and not suddenly leave for the basement.

Bill

By G.S.Crisi (****)

Date 08-12-2005 13:10

Bill has calculated the box weight and came up with a very large figure. Wouldn't it be possible to make the box in carbon steel, say 1/8 inches thick and then line it up with lead 1/16 inches thick?
Radioactivity of medical appliances is low, and perhaps 1/16 inches of lead is sufficient to contain it.
Sulphur trioxyde absorbers in sulphuric acid plants are made that way.
Giovanni S. Crisi

By G.S.Crisi (****)

Date 08-11-2005 20:13

I would use the good old soldering process, that has rendered good services for decades and decades.
The method uses the good old soldering lamp, fueled by LPG (many years ago it was fueled with kerosene) and "tin" sticks, actually an alloy of tin and lead.
There are also soldering pistols, heated by an electric resistance, used with "tin" wires. This procedure is better for small and more precise jobs.
Giovanni S. Crisi
Sao Paulo - Brazil

By jackal Date 08-26-2005 01:48

Something you might try is a large soldering iron. We use these in 200 to 600 hp electric motors where we can't use a flame. The tips are 1" dia. copper and really put out some heat. You can buy them at Grainger, and the fumes aren't real bad. I always put a fan in back blowing on me so I don't breathe in the fumes, and it won't cool off the tip too quickly.

We solder 1/8" copper wire to a large copper ring and it conducts heat up rather quickly so there isn't much waiting . Sometimes a motor can have as many as 400 of these connections.

Hope this helps,
jackal

By storts Date 08-29-2005 11:14

Morning,,Im and a Lead Burner,,and have been for 27 years,,I Dont quite undersrand,,But the fellow that was a lead burner,,,Knows where Im conming from,,,why not take a 1/8 steel box,,or tank,,,and I would line it with 3/16 or 1/4" thisk Lead,,,Im in the process of fabing Lead annodes as we speak,,,Have 8 more to do,,,You can e mail me,,Being new here,,I hope Im not breaking any rules,,,But i was told over at tool box talk that there was a wuestion on lead,,and its really uniqe process,,,so its stortsweldingco@sbcglobal.net Thanks,Jack