How to connect copper wire into carbon block ?

Crimp an eyed terminal onto the end of the copper wire, Drill and tap a hole in the graphite block and bolt the terminal to the block!

This is a good idea, is the graphite brittle enough to break in the threaded area ?

If you can drill and tap a good long course thread then it should be OK! Could you drill through and put a nut on the other end?

I can just connect by the side of the plate, I can't have a screw head or nut. I am looking to put the copper wire directly into the graphite plate.

Both copper and graphite will withstand immersion in water!

Go on. I'm curious. What on earth is the application? There might be another way of doing it. Why can't the copper be attached to the graphite in the air above the water? What is this, a new type of conductivity probe?

Making the connection in the air may be a great idea, but the graphite is porous and the moisture will run to the connection anyway.

I'm still curious. What is the application? Why are you putting volts onto a piece of coal hanging off a pier?

I am using this graphite as an electrode plate into water mixed with a kind of salt to generate something else, I can't say more.

Oh, no. Another radio-frequency-burning-salt-creates-free-energy-and-saves-the-world-from-global-warming thread <groan>!

I'll be scratching about in Basildon Bus Station if you want me <unsubscribes>.

you look strangely like EC

Sounds like a project in electrochemistry...maybe an electrochemical separation of the salt?

Stinky Pete,

He is most likely doing some sort of electrolysis, such forming O2 and H2 or other gases from a salt solution.

A salt is required to get conductivity of the water, and the process attacks most metals, so carbon is used.

Platinum and other metals are usually better than C in these applications, but are expensive.

Tad

I will hazard a guess, are you making oxidizers? like potassium or sodium chlorate. Other than the above mentioned free energy thing, at the moment I can't think of much other secretive stuff with salt water.

He is separating hydrogen from water.

I've always wondered how people make electrical connections to the graphite electrodes, anyone care to fill me in?

Thanks!

STU

Dear Stu'

(in reply to 2)

Don't be blue,

just use some glue,

Epoxy will do

There are a few.

But dose it with silver, aluminium, graphite in powder form or else it won't conduct for you.

Clever, Mr. Cat, Clever!

I'm only asking because I have some fixturing that I need to solder to. I'm looking at a 1" diameter graphite rod and I want to apply solder to the circumference of the rod but not get it into the center. I'm struggling with this one.....are there any "off the shelf" graphites with post processing on the surfaces for solderability?

Guys nobody here that ever used a motor brush?

The shunt is apoxied into the carbon graphite concoction the actual apoxy I have never enquired have you tried the glue that is available to weld/ solder copper water pipes with out heating. It works for the pipes and apears to have an electrical conductivity factor as it is used where the ground wire is connected in the water system.

Just an Idea!

All depends on size, For big cable and big block or small cable and small block or any of the variations in both cable and block!

this is for a 8mm (.313'') thick graphite plate and 1.6mm (.063'') diameter copper wire

What is that epoxy glue you are talking about ?

The one I am referring to is found in plumbing supply houses and ocassionly Home Depot in the plumbing section. (You usually use it where if you use a torch you probably have a visit from the boys in the red truck with a lot of water). It serves a purpose when used right. Whether it would work in this application experiments is what we learn by!

A crocodile clip fits that description, particularly if it is made of stainless steel.

I thought they were called alligator clips

corcodiles have longer skinnier noses than alligators.

Two nations divided by a common language, Bwana.

Acquire copper barrel terminal end solder it to the wire. Remove excess solder on the OD of the terminal. Drill over sized hole for terminal in the graphite Glue it in with electrically conductive epoxy. Loctite may make a conductive instant adhesive then drill the hole to a tight fit. It can be pressed fitted in but you take the chance of splitting the graphite.

Plate, flamespray, or sputter a metallic surface onto the carbon. Braze or solder to it. Dip the whole thing in conformal coating to keep it corrosion-free. Repeat the coating 3 times.

Alternatively, buy a big honking motor brush and file it down. Live with the corrosion.

Under no circumstances should this equipment be used within 20 feet (6 meters) of hyrogen or hydrogen compounds.

I'll buy into this. Just buy a large motor brush and file or grind it to the size you require. You don't give all the dimensions for the graphite block so I'm guessing that you can get a large enough motor brush. You might want to check into various carbons made for arc lights. Some of them have a partial copper coating that can be soldered to (soft solder). Also, carbon rods made for the air-arc gouging process are pretty hard, and some of them are copper coated. Ask for them at a welding supply company. Good luck!

I have used 4" diameter rods 4' long mounted in a delta configuration which is immersed in a brine solution for load testing generators. This aplication is similar to a 3 phase salt water rheostat. The way I connected the power conductors to the carbon probes was to roll copper bus bar with an ID that will fit around the probe snug. The connector would be made in 2 halves with flanges on each side of the half pieces. The flanges would be bent on each of the 2 halves before it made the 180 degree circumferance of the OD on the probe. This gives you a clamping device that bolts can be tightened between the two halves in the flanges to create a good high current connection between the carbon probe and the copper clamp. The wire can then be connected to the bolts on the clamps with standard compression lugs. For my application I did not submerse the clamp assembly in the salt water. I hung the 3 phase assembly from an electric hoist and lowered it in the water to achieve the load desired. There are other details about how the 3 probes were hept apart but this is the basic concept.

Engineers make things soooo complicated! Drill hole in the plate, pass the wire through twice and twist the end.

JasBond wrote:

Engineers make things soooo complicated! Drill hole in the plate, pass the wire through twice and twist the end.

Not much contact area. True that sometimes folks forget to K.I.S.S. but I think wrapping the wire is not so good. If you wanted to do it that way then you could just wrap the wire around the graphite and be done with it.

I think Mr.Trumans Brain is right with the tapping, not a problem for a coarse thread just don't torque it too much. the silver epoxy work as well...you don't need to "ream " the hole hour-glass shaped just chamfer each end of the hole.

Hooray! That looks like a Stinky Pete sort of solution!

Use Silver loaded, conductive epoxy, drill hole in graphite block, "ream" out hole to roughly hour-glass shape, Strip and sort of flatten end of wire, fill hole with epoxy with syringe, insert wire and cure. Been there, done that.

All interesting ideas, however, they do not work.

1: What is the graphite you are using? Not all graphite is the same,

Poco, etc. Density, surface etc.

Also, note. Sun has a big patent on a process to make electrical connections to graphite. Look it up, tells you what to do.

Also, graphite for what you need should be a composite with a center grid (support grid) generally titanium. You make your connection to the support. This can be acquired off the shelf.

Graphite grade is GM-10 from Graphite Store.

You are talking about Sun, what is Sun doing ?

Make a "sandwich" of 3 plates, with the middle plate notched on the middle of one edge. Use conductive epoxy to attach the plates to each other. Insert the wire into the notch and fill the notch with the epoxy.

this idea will require buying special tooling but how bout taping the block and threading the actual wire. tricky but possible.

How about tapping and then using a brass machine screw with wires soldered to it? Ugly, but effective.

Pop, can you use stainless steel electrodes? I have experimented with stainless for a chlor-alkali process. The commercially available cells use some high grade stainless as electrodes.

Just curious, what grade (alloy) of stainless did you use in your experiments?

I wish I knew. It was just some scrap I found laying around the farm. I thought about trying some stainless steel cookie sheets, but haven't yet. I'm guessing they would not be of adequate quality, but I won't know until I try. I have looked at some papers (via internet) that detail chlor alkali cell design and explain what grade stainless they are using, but I don't remember the details as I was reading for concept. Try googling chlor alkali cells or something similar.

Is the 1.6mm (.063'') diameter copper wire finely stranded (flexible) or solid? This could affect your application.

I use solid copper wire

So, after doing this, have you made more energy than you have used, then?

Graphite loaded epoxy... or silver loaded epoxy.

As far as the battery build contest I have thought about the carbon block and arc light rods which were the only carbon I had any common occassion to handle and carry in the Grip Truck. They are right fragile really and after you run one you understand Lamp Operator as a credit better.

I don't have any in the house but have considered smashing up into a paste charcoal and sticking a wire in it and pouring saltwater over it.

The acrylic epoxy at the hardware store is right expensive and I have a screwgun as a normal thing to have. My meter is broken.

I suggest you look at the block and feel it. If it will take a screw connection, that would be better than a through hole wrap. If you put the material in a vice and put your drill on low you may get a good pre drill for a small screw into the eyehole connector. Otherwise use very fine to larger wire tight wrap around the stuff as I would with the arclight rod, which is round.

Possibly a bit of aluminum foil against the carbon block/plate with the fine copper wound around would help contact sans drilling?

My question is, how do they connect lead wires to graphite electrodes in a typical conductivity sensor??

Whenever I get to this point, the members, associates, gurus, or power users suggest I visit Wikepedia. Sometimes it is useful advice.

Then again you might consider taking your conductivity sensor apart to see how "they" did it.

I am sorry I did not save the parts of my Amprobe that Colin stepped on, since I imagine the mandables were attached to the current reader in a similar way as would be used to attach to the conductivity sensor.

Typically I've noticed that if things aren't soldered together, they are screwed together, though maybe since I have never owned a conductivity sensor I'm out of line suggesting you screw it.

Hello pop, I used to make carbon brushes, all sizes & shapes, grades etc.. Would have drilled a slightly bigger hole, inserted the wire, filled it with a mix of carbon and copper powder, tamped it & finally added a spot of "glue" to the visible joint. regards, Leon