DIY copper bus bar

[Muddydogs]

Alright after my last post about messy battery cables http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/28283107.cfm and seeing Westend's pic for his DIY wire box I figure I will do the same. Like Westend said finding copper bar stock locally is not easy so I'm thinking about taking a 3/4" piece of copper water pipe and making it flat. Final size should be about 1/4 inch thick by what ever 3/4" round flattens out to be. I'll then use 1/4 x 20 stainless bolts as posts for the battery cables lugs.

What do you guys think? Good idea?

[MEXICOWANDERER]

Never take chances with lead. A painter's mask is cheap and easy respiratory protection. Goggles and gauntlet (welder's) gloves and long sleeve shirt is a plus. Fumes from the overheating flux is an excellent carrier of lead. But the results are worth the hassle. A dipped copper bus will last virtually forever in a marine environment if stainless steel (316) fasteners are employed.

[Muddydogs]

Well ya it does harden it but as you can see by the pic's it didn't crack just from being smashed, now maybe if I tried to open it up or hammer it the other way it would crack. Heck rifle brass can take lots of stretching and resizing before it starts to crack. Yes if I was worried about it cracking I would have annealed the pipe before I smashed it.

I was just wondering what the guys in the know thought about using copper pipe as a bus bar. Kind of along the lines of if 1/4" is thick enough to handle the amp's. Its obvious from my pic's that I smashed it just fine. Since I am doing a custom job I didn't want to spend $ on a bus bar and get it to fit, buy making my own I can make it fit into the space I need it to fit and have a few options to attach cables to it. Not everything has to be store bought. It wasn't that hard to whack the pipe a few times with a single jack to make it flat, probably took a whole 5 minutes to smash a foot of pipe. Cut to length, drill a couple holes and put in a few bolts is easy.

[Gdetrailer]

Muddydogs wrote:
Smashing 3/4 pipe flat ain't going to work harden it.

Actually it DOES "harden", hardening changes the molecular structures and crystallizes them. This makes the metal harder to bend AND MORE BRITTLE.

You can soften it but that requires reheating to specific temperatures for the metal you are using..

Metal working 101 basics..

[whiteeye42]

why not just contact an electrician and get the copper bar stock from him that way you are using the right stuff

[Muddydogs]

MEXICOWANDERER wrote:
Heat copper with a propane torch. Then plunge it into cool water. This is called annealing. Makes the copper softer and highly crack and fracture resistant.

If you have a steel container you can melt enough 100% pure lead to dunk the finished terminal in. Slop on the plumbing paste flux. S-l-o-w-l-y lower the terminal or bus bar into the molten lead. Examine your finished piece for holidays, and re-flux and re-dip if necessary.

Electroplated terminals and lugs, suck. The plating is too thin, and tin is used only because lead is tough to electroplate.

A pure lead hot dip battery terminal is a dozen times more resistant to sulfuric acid attack than a tin/lead electroplate.

WATCH THE FUMES!

Use a painters mask and this is not optional. Do not hot lead dip around children and clean every bit up when you're finished.

If you're after acid resistant and oxide resistant terminations this is the way to do it. TIN is not an optimal metal for this, Gold is the best but, you know...

Are you saying to coat the copper bus bar in lead?

By the way lead melts at 600 to 700 degrees but needs to be way hotter to produce gases, like 1000+. The only way to get lead poisoning is to breath lead dust, fumes or eat it. Melting lead is not generally hazardous to ones health like the gov likes use to believe.

Now what could be hazardous is coating something in pluming paste and then lowering it into a lead pot. Moisture under lead, even a small pin head drop of water will cause the lead to blow out of a pot like there was a grenade in the bottom of the pot. Chances are if you lower something wet in a hot lead pot it will burn away the moisture before it becomes a problem.

Lead and melting it is something I know something about as I am a bullet caster and have handled 1000's of pounds of lead to make my own center fire bullets as well as drip my own shotgun shot. I do have the doc throw a blood lead test in every couple years when I need a blood test just to make sure but nothing ever comes of it.

[mpiety]

that's too much work for me

http://www.speedymetals.com/pc-2892-8204-38-x-1-ca-110-copper.aspx

[MEXICOWANDERER]

Heat copper with a propane torch. Then plunge it into cool water. This is called annealing. Makes the copper softer and highly crack and fracture resistant.

If you have a steel container you can melt enough 100% pure lead to dunk the finished terminal in. Slop on the plumbing paste flux. S-l-o-w-l-y lower the terminal or bus bar into the molten lead. Examine your finished piece for holidays, and re-flux and re-dip if necessary.

Electroplated terminals and lugs, suck. The plating is too thin, and tin is used only because lead is tough to electroplate.

A pure lead hot dip battery terminal is a dozen times more resistant to sulfuric acid attack than a tin/lead electroplate.

WATCH THE FUMES!

Use a painters mask and this is not optional. Do not hot lead dip around children and clean every bit up when you're finished.

If you're after acid resistant and oxide resistant terminations this is the way to do it. TIN is not an optimal metal for this, Gold is the best but, you know...

[time2roll]

Just order a copper bar or bus on-line already.

[Muddydogs]

Smashing 3/4 pipe flat ain't going to work harden it.

[Gdetrailer]

Golden_HVAC wrote:
Hi,

I had plenty of 1/2" diameter ACR tubing, that comes on a roll, and is filled with nitrogen at the factory, to keep it clean inside. The soft copper is easy to bend, and will not crack when you try to flatten it. I used my 6" bench vice, it worked well!

What I did was flatten out about 3" of tubing, then fold back about 1/2 of that length. Drill a 3/8" hole in the flat section, and the remaining 1/2" or so, (that was not flat) I put the 000 size wire in it, and then clamped that in the vice, so it never failed (well since 1997 - it might fail someday). . .

If you are looking for a 'ground' bussbar, then flatten 1/2" tubing, and have the end open to accept the wire going to the battery. This can be any size, say #4 wire, then clamp that in the vice, it will hold forever! You can drill 1/4" holes where needed. Put in a #10 screw about 1" long and a nut right next to the copper. You can then add about 5 wires to that screw, and put on another nut, to hold all the solderless connectors to that bolt. Use multiple bolts, with 3-5 wires per bolt, or bolt a large amperage wire directly to the copper buss.

For a 'hot' bussbar, I would recommend a fuse assembly. Your local auto parts store should sell a fuse holder with 6, 10, or 12 fuses of 5 to 30 amps capacity for each fuse. Normally they also have a large terminal for the +12 battery wire.

You don't want more than about 12 fuses, as normally they have 20 amp fuses, and you would want only about 100 amps load on each fuse box, due to voltage loss over the wire between the fuse holder and battery.

Plumbing water pipe is all copper, but normally fairly stiff. The ACR tubing or tubing sold on a roll, it will have less zinc in it, and more pure copper, so it will be softer. You can buy 50' roll of soft copper at Home Depot, where they probably also sell it by the foot. 2' will make 8 each 3" long battery terminals, or the bussbar (say 6" long) and several battery terminals.

Good luck!

Fred.

Regular plumbing copper which is sold in 10ft "sticks" is known as "hard" copper. It is not the ideal choice for flattening since it is so hard and will work harden as you smash it.

The real choice is called "refrigeration" tubing (aka "soft copper"), it is much softer to flatten and is sold in rolls. It will also work harden but since it starts out very soft and pliable the hardening is no issue.

I have used refrigeration tubing to make my own copper crimp and solder terminals for 2 ga and even 1/0 wire. Find the size of tubing which just slides over the wire. Crimp then solder.. Flatten the open end and drill hole in the flat spot.. Cheap and effective.

Tried that for my 250A DC stick welder.. Worked great for 2 ga welding wires then did the same for my Inverter and batteries for my TT.. Works like a champ.

[pigman1]

Type L soft copper tubing in 1/2" nominal diameter pounded flat will work fine. Just tell the hardware store you want the bendable type. When flattening it, don't over work it as it does work harden and can then crack.

[Muddydogs]

I figure a vise and 3 lbs single jack should take care of the flattening.

[msiminoff]

I don't think plumbing pipe is of the same purity as buss-bar or electrical wiring, so it's resistance will be higher.

ASTM B88 specifies that copper tubing used for drinking water must be 99.9% pure copper...
So as long as you don't mind doing the work to flatten it, there's nothin' wrong with using is as a bus-bar.
Cheers
-Mark

[Muddydogs]

GordonThree wrote:
I don't think plumbing pipe is of the same purity as buss-bar or electrical wiring, so it's resistance will be higher.

Just how many amps are you trying to carry? What's wrong with the buss bars for sale on Amazon, Lowes, Home Depot, etc?

I'm not sure of the amp's but since I have 2 group 24 batterys I would think its around 200 amps? Want to put a couple boxes on the trailer frame to collect all the trailer wires so all I have running to the battery's is one positive and one negative lead. Trying to clean up the wires hanging under the trailer before I hook them on something and tear things up as well as clean up the battery posts since there about full with solar and inverter cables.

I can't find anything but electrical breaker box ground bar bus's at the local hardware stores.

[Golden_HVAC]

Hi,

I had plenty of 1/2" diameter ACR tubing, that comes on a roll, and is filled with nitrogen at the factory, to keep it clean inside. The soft copper is easy to bend, and will not crack when you try to flatten it. I used my 6" bench vice, it worked well!

What I did was flatten out about 3" of tubing, then fold back about 1/2 of that length. Drill a 3/8" hole in the flat section, and the remaining 1/2" or so, (that was not flat) I put the 000 size wire in it, and then clamped that in the vice, so it never failed (well since 1997 - it might fail someday). . .

If you are looking for a 'ground' bussbar, then flatten 1/2" tubing, and have the end open to accept the wire going to the battery. This can be any size, say #4 wire, then clamp that in the vice, it will hold forever! You can drill 1/4" holes where needed. Put in a #10 screw about 1" long and a nut right next to the copper. You can then add about 5 wires to that screw, and put on another nut, to hold all the solderless connectors to that bolt. Use multiple bolts, with 3-5 wires per bolt, or bolt a large amperage wire directly to the copper buss.

For a 'hot' bussbar, I would recommend a fuse assembly. Your local auto parts store should sell a fuse holder with 6, 10, or 12 fuses of 5 to 30 amps capacity for each fuse. Normally they also have a large terminal for the +12 battery wire.

You don't want more than about 12 fuses, as normally they have 20 amp fuses, and you would want only about 100 amps load on each fuse box, due to voltage loss over the wire between the fuse holder and battery.

Plumbing water pipe is all copper, but normally fairly stiff. The ACR tubing or tubing sold on a roll, it will have less zinc in it, and more pure copper, so it will be softer. You can buy 50' roll of soft copper at Home Depot, where they probably also sell it by the foot. 2' will make 8 each 3" long battery terminals, or the bussbar (say 6" long) and several battery terminals.

Good luck!

Fred.