Element broken at pigtail

[caracelles]

I had to replace a broken element and some brick,  and of course when doing so, I broke a pigtail off of another element. Is there any way to splice it? Or do I have to buy a new element?

[JohnnyK]

Since you've had to replace one element already and broke a second in the replacement process, it would be a good idea to replace ALL the elements because they are all probably the same age and condition as the first...

[caracelles]

The one I had to replace was broken in the middle due to vandalism. I was told that the kiln had only been fired a few times after new elements were installed, then porch stored for several years. I've read that they become brittle even after one firing, and the pigtail join seems like the weakest part. I'd really like to test these before replacing all. I am thinking of taking the entire ring to a welder.

[JohnnyK]

Just what, exactly, are you dealing with here. Pix would help. Include  as much info regarding your situation as you can. I'm guessing it is an electric kiln of some sort. Brand & model would help...What were you doing that caused the pigtail on the other element to break?

[caracelles]

I am not aware of any kilns that use elements other than electric and I have never come across an installed or replacement element that didn't have a coiled body with a pigtail leader. Surely pictures, kiln brand, model, and specifics would have no bearing? As I described, in replacing a broken element, I inadvertently snapped off a pigtail on a subsequent element. It's not a very interesting or particularly funny story, but I included some helpful details. Like elements become brittle even after one firing and the pigtail join at the bend is clearly the weakest point.  I am only asking if someone has ever had experience repairing such a break, what methods were tried, any successes or failures of note, and other avenues to pursue. Of course replacing all elements is preferred. I didn't ask that question because I already have that information. But thanks for your help.

[GEP]

After one firing, or even a few firings, an element is not yet brittle enough to break the pigtail off by accident. Even when I’m replacing elements with 130+ firings, the pigtail bend is still flexible and takes a targeted effort to cut it. @JohnnyK‘s questions are legitimate, in that the situation you’re describing needs more explanation. Element broken due to vandalism also doesn’t make sense. I suspect these elements are much older and worn out than you have been told. 

I’ve never heard of trying to weld a pigtail back onto an element. It sounds like that would be an obvious weak spot, and bound to fail. My advice is also to replace all of the elements, so they are all of the same age, and you know their age first hand. 

[neilestrick]

@caracelles Different brands of kilns can have different solutions to your problem. They're not all built the same. That's why we need to know the brand and model. We're not trying to be difficult. Where's the break-inside the kiln where the pigtail meets the coils, inside the brick in the middle of the pigtail, or in the control box where the feeder wires connect?

Welding won't work. But there are other possible solutions depending on the info you give us.

The best way to check the condition of the elements is to measure their resistance with a meter.

[Magnolia Mud Research]

31 minutes ago, neilestrick said:

Welding won't work.

Neil,  Please explain why welding won't.     My industrial experience is that the right welder with the right welding rig can do wonders.  

LT

[caracelles]

To GEP, direct quote from the accompanying paperwork on my new element, provided by Paragon Industries. And I quote, once an element has been fired, it becomes brittle and will break if bent while cold. I am working out on my back porch, and it is cold! The remedy for cold is to plug up the kiln and Heat the elements, but I can't do that. I'm not in a situation where I have power. I did bring some of the pieces into my kitchen, and heated both element sections and pigtails in a 500 degree oven. That makes them flexible enough to work with, but I can't keep them hot enough to continue to do that work, I don't have that equipment. I'm not trying to be difficult either, I know--  let me repeat, I know replacing all the elements is the best solution! I don't need that information anymore, any longer, I know that already, and I have been told not once, but twice in this forum! but I thank you! I am primarily interested in knowing if anyone has heard of or knows of a solution to a splice or a weld or a repair. Thank you again!

[caracelles]

50 minutes ago, neilestrick said:

@caracelles Different brands of kilns can have different solutions to your problem. They're not all built the same. That's why we need to know the brand and model. We're not trying to be difficult. Where's the break-inside the kiln where the pigtail meets the coils, inside the brick in the middle of the pigtail, or in the control box where the feeder wires connect?

Welding won't work. But there are other possible solutions depending on the info you give us.

The best way to check the condition of the elements is to measure their resistance with a meter.

Thanks,  again, I'm sure that's good information, but I am not interested in any answers that don't include a potential fix or solution to a broken element at the pigtail join. The pigtail broke off of the element from the bar connector at the bend inside the Kiln just before it entered the brick.  this could have happened during the vandalism, the actual brick that held the two element ends was broken, and I'm sure I put excessive pressure on the bolts to break them, even after several applications of blaster.

[hitchmss]

15 minutes ago, Magnolia Mud Research said:

Neil,  Please explain why welding won't.     My industrial experience is that the right welder with the right welding rig can do wonders.  

LT

Not sure you'd be able to remove the oxidation from the wire, to get a clean weld, without grinding away all of the metal you'd need to weld. Soldering might be a better option, but youd still have to remove the oxidation, and likely would need to bolster the joint with another piece of wire; the change in thickness might provide a weak point where successive heating cycles will cause the element to break again. My understanding of Ni-chrome wire is that it oxidizes greatly during heating.

Ive never soldered/welded ni-chrome wire; not even sure if you could find the proper filler metal or shielding gas, but my limited metallurgical experience tells me that unless you had the very precise (expensive) TIG machine, and related materials, that it would be cost prohibitive, if not impossible entirely. Im curious to know if it is possible though, out of a purely technical query. Would the repaired section be more or less brittle after heating to soldering/welding temperatures?

[Mark C.]

I have never wielded an element pigtail but why not try it.Not much to loose. If you have enough pigtail sticking out to get to. Another idea would be if there is enough pigtail to get to on the outside you could attach to it directly with the needed wire.

If the break is where this will be done inside then welding (which I have zero experience with) is your only option. I would think its a spot wield or wire feed wilder for this job. I think welding will be a bit of an experiment but it will either work or not..

If you try it could you let us know the outcome after a few fires?

[caracelles]

when the vandalism happened, I also had a breakin, and these two incidents were likely concurrent. I have very few tools left, the only things that were not stolen were the two klins on the back porch! And all the tools that I had in my truck at the time.

[Mark C.]

If you still have that old broken element that you took out that could be a test piece to try welding on to see if it can work in terms of joining two pieces.

In terms of solder - as Hitchmass said silver solder is the hottest and it needs an acetylene touch to use (I have this setup and used it a fair amount) to work on solar water copper pipes mostly)This may work only if outside heat chamber as it will melt inside kiln.

[Mark C.]

Sorry to hear about the deadbeats that stole your stuff-I have a loss recently at my pottery booth and its never a good feeling especially at holiday time.

[caracelles]

I actually found a post pertaining to this, where an electrician took a smaller coil of element, and left the pigtail intact. He then fed the new Element Section into the old one, applied a borax paste, flux, and allowed it to seal the two wires together. I would definitely try this if I had another section of the element wire! I am looking into ordering the wire now, it is actually Kanthal, I'm not sure if that is nichrome? The breakdown seems to be fe iron, CR chromium, and Al aluminum alloy

[hitchmss]

Sorry about the losses from vandalism and theft. Just my $.02, I know you are trying to find a method to fix the broken wires, and while there may be a physical method to do this (I am not experienced or skilled enough to know of a method), but the tools and equip necessary to do any repair that I can think of, far outweigh the costs of new wires, or even a brand new kiln.
Ive seen folks who have "rewired" their kiln with feeder wires, elements, relays etc, and joined the elements to the feeders with all types of crimp style connectors. While this is how the manufacturer designs them, they need to use the proper connector, and usually there is only enough of the pigtail element wire to feed through the wall of the kiln, and connect to the feeder wire. If it broke off in the wall of the kiln, then a crimp connector may be too large to fit inside the hole for the pigtail itself, as well, being inside the "insulated" wall would likely cause, even the high temp/heavy gauge barrel/butt connectors to fail shortly.

[Magnolia Mud Research]

Part of the problem is the steps necessary to convert the materials back to the non-brittle state, aka annealing.   My question was not to challenge the decision not to weld, but to get some reliable background on the WHY, other than "aunt so and so said don't do it"

I agree with Mark,   balance the cost of learning with the value of learning, and move on.  

LT

[caracelles]

3 minutes ago, Mark C. said:

If you still have that old broken element that you took out that could be a test piece to try welding on to see if it can work in terms of joining two pieces.

In terms of solder - as Hitchmass said silver solder is the hottest and it needs an acetylene touch to use (I have this setup and used it a fair amount) to work on solar water copper pipes mostly)This may work only if outside heat chamber as it will melt inside kiln.

I have done copper solder with MAPP gas. I bet that would work with silver as well, but I'm thinking I need more unfired material to make that work. The pigtails themselves are much more flexible because they've never carried much of the Heat, but still we're talking about a small quantity.

[hitchmss]

2 minutes ago, caracelles said:

it is actually Kanthal, I'm not sure if that is nichrome? The breakdown seems to be fe iron, CR chromium, and Al aluminum alloy

I believe Kanthal is a tradename. Ive always heard element wire referred to as ni-chrome wire. Kanthal doesnt have any Nickel in its alloy, but other heating elements are alloys of nickel, chromium, iron, etc, hence the ni-chrome. I guess really it comes down to colloquialisms.

[caracelles]

 thank you all, some very good information here! What I'm leaning toward doing is going ahead and purchasing a quantity of the Kanthal wire and making my own elements. Now I just need to know the gauge! And of course my wire strippers, my calipers, my gauges, were in the toolbox that was stolen! I can purchase the wire to replace all four top ring elements for the same price as a single element. Seems like a no- brainier!

[caracelles]

3 minutes ago, hitchmss said:

I believe Kanthal is a tradename. Ive always heard element wire referred to as ni-chrome wire. Kanthal doesnt have any Nickel in its alloy, but other heating elements are alloys of nickel, chromium, iron, etc, hence the ni-chrome. I guess really it comes down to colloquialisms.

Kanthal is rated to 2500° f, I don't think nichrome is good beyond ∆5?

[caracelles]

11 minutes ago, hitchmss said:

Sorry about the losses from vandalism and theft. Just my $.02, I know you are trying to find a method to fix the broken wires, and while there may be a physical method to do this (I am not experienced or skilled enough to know of a method), but the tools and equip necessary to do any repair that I can think of, far outweigh the costs of new wires, or even a brand new kiln.
Ive seen folks who have "rewired" their kiln with feeder wires, elements, relays etc, and joined the elements to the feeders with all types of crimp style connectors. While this is how the manufacturer designs them, they need to use the proper connector, and usually there is only enough of the pigtail element wire to feed through the wall of the kiln, and connect to the feeder wire. If it broke off in the wall of the kiln, then a crimp connector may be too large to fit inside the hole for the pigtail itself, as well, being inside the "insulated" wall would likely cause, even the high temp/heavy gauge barrel/butt connectors to fail shortly.

The first thing I considered was a connector, but I rejected it for the same reasons you mention. A thermocouple type shield -- a ceramic feeder bolt or lap screw would be worth a shot. Anyone firing ∆10 wanna make me a few for Christmas? Lol

 

PS, thanks for the sympathy. Why do they always take my tools!?!

[GEP]

We had a discussion about winding your own elements on this forum a few years ago. Not exactly a “no-brainer” or else we”d all be doing it. But if you are willing to invest the time, here’s more information

.

[neilestrick]

Like @hitchmss said, there are too many variables with type of wire, oxidation, etc. to make it work, based on what I know, anyway. I suppose a very talented welder could maybe figure it out. And even it if did work, it's not going to be worth the time and money to take the element somewhere. And if the element is brittle enough to break from movement, it can't be removed from the kiln without further breaking. And it probably won't be any cheaper than buying a new element, which is really the big issue here. There's no cheaper, easier, better fix than getting a new element.

Elements do not become too brittle to move after just one firing. More brittle than new, but you can generally still get them out. If the element broke, it had probably been fired a number of times.

Any solution to fixing the element inside the kiln will be a temporary solution. Soldering materials likely won't hold up to the heat of firing. You can try to heat the element and twist the ends together, but that will be temporary, too. I've had it last a couple dozen firings and just one firing. It depends on the quality of the twist and the condition of the element to begin with. The location of your break will make it very difficult to accomplish. No sort of crimp connector will hold up to the heat of the kiln.

To roll your own elements, you'll need to know the wire gauge, coil mandrel size, and element resistance. You can't just use any size Kanthal wire. The kiln manufacturer has calculated which size wire and coil spacing works best for that size kiln. There are, of course, variations that can work, but without a knowledge of resistance heating I wouldn't mess with it or you could end up wasting a lot of money and time. Like GEP said, it's not really a no-brainer or we'd all be doing it. It's also the difference between taking an hour to replace or elements or an entire day.