heating element spliceing question

Some time back, I managed to scrounge up another Thermalyne heat treating oven. Cute lil thing, about a 5x5x8 cavity.

Checking to see why it wouldnt heat, I found that one leg of the heating element had broken.

This particular oven has three sides made of the element embedded in a ceramic, so three sides come out at one time. The leg from the switch broke off flush with the top of the ceramic. I carefuly chipped away at the ceramic until I got about 3/8" of the lead exposed. It needs about a 3" piece of some thing spliced to it, to make the run to the terminal strip. The original was just a long piece of the heating element. Ive tried crimping a wire connector to it, but it seems to not grab very well and pulled loose while reinstalling the unit. I gave it a quick shot with the mig welder using regular welding wire and gas, and it held for a bit, but was still a bit fragile and broke free while installing it.

Ive since installed the heating unit, and have a new lead run and overlapping the stub.

How do I splice them together? I do have temporary use of a mig with gas, and stainless wire as well as regular. I also have a tiny bit of silver solder, regular brazing rod, etc etc.

Any suggestions? Its possible I can excavate a bit more wire for a nut and bold mechanical connection...but would rather not break out any more of the ceramic.

Thanks in advance.


That rifle hanging on the wall of the working-class flat or labourer's cottage is the symbol of democracy. It is our job to see that it stays there. - George Orwell

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I would think a small "split bolt" electrical connector (sometimes called "bugnut") would work fine in a situation like this. They can be tightened up with wrenches to be very secure, and many are made of brass or copper. Don't think soldering will hold up due to the heat involved. Ken

Reply to
Ken Sterling

Reply to
David Billington

Deffinetly need a mechanical connection! Try a small dia. thick walled copper tube and crimp in on with a visegrip. Is ther room for a split bolt? Either shop-made or purchased?

Reply to
Tom Gardner

Hey Ken and Gunner,

On Fri, 25 Jun 2004 10:51:00 GMT, snipped-for-privacy@netzero.net (Ken Sterling) wrote: Big SNIP

I think in the trade, the items Ken describes would be called Burndy connectors. The come in quite a variety of sizes, some quite small. You may be able to do similar with the "guts" only from the smallest of the old Marr wire connectors (not the Marrette wire nuts).

And Gunner, just remember that the most heat is generated at the point of highest resistance, so if it's possible to get more than one connector on it, do so to decrease the resistance there. Be sure that the nichrome is well cleaned, and if possible "double-up" the end of the wire into a little loop to clamp on, but be careful if it's brittle. Then just do a quick heating of the element and then re-tighten everything. Some Alumatrox anti-oxidant will help during "assembly", even though it will burn away quickly.

It's also possible that the switch you mention is what started the problem, so check it as best you can too.

Take care. Good luck.

Brian Lawson, Bothwell, Ontario.

Reply to
Brian Lawson

The only right way to repair a broken element is with a new element. If this requires new "ceramic," you can patch or make a complete new one with castable refractory or possibly furnace cement. It is not a daunting task. People make metal and glass melting furnaces every day.

Ron Thompson On the Beautiful Florida Space Coast, right beside the Kennedy Space Center, USA

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The ultimate result of shielding men from the effects of folly is to fill the world with fools.

--Herbert Spencer, English Philosopher (1820-1903)

Reply to
Ron Thompson

There are a couple of different types of heating element wire. One is Nichrome and the other is Kanthal. The Kanthal elements are used in pottery kilns and other places. Kanthal can take higher temperatures than Nichrome. The Kanthal is a iron aluminum alloy that depends on the aluminum forming a oxide coating over the wire. So it is hard to splice and also hard to weld or solder. Hard as in pretty much impossible.

Nichrome however can be silver soldered. Don't know what you have, but I would try silver solder. If all else fails, you can replace the entire element reasonbly cheaply. Seattle Pottery sells Kanthal elements but maybe not ones for as small a oven ( unless your diamensions are in feet ). IIRC They also sell kanthal wire that is not already coiled. If the element is Nichrome, I might have an element that would work.


Reply to
Dan Caster

Gunner, I've had reasonable results brazing some of these things, although I would prefer spot welding if I had a rig to do it.

Mechanical pressure connections just don't work for very long.

Harry C.

Reply to
Harry Conover

Spot welding is the only way to connect to the wire and it needs to be completely imbedded back into the ceramic as otherwise it will get too hot and just fry. In addition, the wire is extremely brittle after it has been heated good once so any mechanical motion may break it off again in a new spot.

-- Bob May Losing weight is easy! If you ever want to lose weight, eat and drink less. Works every time it is tried!

Reply to
Bob May

I once repaired the nichrome element of a waffle iron using silver solder. I simply hooked the element ends and crimped them together. Then I applied flux and soldered with 45% silver solder and a propane torch. The solder flowed readily and made a nice little bullet shaped blob over the connection. Testing showed that the connection was good and it ran much cooler that the element wire on either side of blob since it's resistance was very low. The element wire got bright red, but the blob was so cool that it did not glow at all. It was 30 years ago and the waffle iron was still working at last report.


Reply to
Randal O'Brian

Hi Gunner,

In my experience

Reply to

Given a similar situation on an electric stove, I made a new end with O/A and some #6 Stellite. This was at least five years ago and the contact is still bright and shiny. In your situation, I would weld on a piece of SS or Nichrome wire much heavier than the heating element using the Stellite as filler.


Reply to
Ted Edwards

We repair oven elements by either MIG welding the leads together using stainless steel MIG wire if they are NiChrome wires, or TIG welding if Moly


Reply to

Gunner, I have a few pieces of stellite rod that Ted gave me. If you have TIG or O/A I'd be glad to send you a bit of it in an envelope. It's .132" dia but you could always grind it down. Hammering it doesn't work; it shatters.

Reply to
Don Foreman

Hi Gunner,

I own about 10 annealing ovens for my glass work. my largest has a 10 ft long ID. So I deal with elements on a regular basis.

It's been my experience that any "fix" is a temper one. When elements get old they get real brittle and tend to break real easy. They also get thinner as they age, especially if it has been used at high temps. An elements over all length determines the heat range created with x amount of watts of electricity put to it. As they get older, thinner, or shorter, they will burn hotter and tend to burn off quicker. As mentioned by others, using a bolt to connect will also create a hotspot at the connection.

My best advise is to just replace the element. I suggest that you replace the others as well. They can't be in to much different shape. By doing so you'll be good to go for years to come. If not., you may be doing it all over again next week, or next month......or.....

If you can't find the replacement you can make your own. Just gauge the wire size, count the number of turns. Use a wood dowel or threaded rod in a drill to wrap it up. You can get nicrom at McMaster's.

Or many of the kiln manufactures will wrap them for you. You will just have to stretch them to length to fit your oven.

Thanks for the welcome. I found the thread on cutting glass and I'll add my

2 cents worth. I didn't think I would be able to contribute to much in this group, guess I was wrong . Glad to help when I can.

Randy SC Glass Tech Scam Diego, Comi-fornia

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Reply to


I just spent a half hour looking at every picture in your album.

If you wouldn't mind posting a little BIO or CV I'd be very interested in reading about your experiences.

Now I know I might be a little forward here but just how much is some of that stuff worth, how long does it take to make, etc., etc., etc.

My curious mind really wants to know.

After looking at that rather long line of pieces in for repair I thought to myself.... there's got to be a lot of money in those bottles.

And a lot of time.

Reply to
Shiver Me Timbers

There is also a Tophet A resistance wire.

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Addendum: Tophet A falls into the Nichrome group. Interesting reading, though.


Reply to

Thanks Shiver,

I've been working glass for more than 30 years. I'm a second generation glass blower, my dad got me started as an artist when I was a kid. My family had a small gift shop in a tourist town in Michigan. It happened to be close to Midland Mi. where Dow Chemicals world head quarters are. I eventually ended up there and worked for Dow as a glassblower for 13 years . At one point Dow had 5 glass shops around the country. The main shop in Midland was designed to house 20 glass blowers. When I started there they had 9 men left on the floor and all the other shops were closed already. We specialized in building what they couldn't buy anywhere else. From lab scale to production and pilot plant scale we did it all. There are 4 men left now for Dow globally. The tool & dye shop is gone along with most of the other skilled trades that used be there. Isn't globalization great!

The tool & dye shop was across the street form the glass shop. We always had a great rivalry going on as you can imagine. They were a great bunch of guys and good friends. We had lots of fun with each other, but most of all we had great respect for each others trade.

I left Dow in '93 and came to San Diego to start my little business. I guess I was tired of all the disrespect from the corporate c*ck bights that ran Dow. I didn't trust them with the future of my career anymore. I only had to look around to see what was happing all over Michigan with the auto industry. (which a lot of you guys probably used to work for one way or another) Being that I was single and didn't have a family to worry about I decided to take the risk and went for it.

It hasn't been easy, but I'm still here. In the last 11 years I have taken about 10 days off total. Just in case you were thinking that I have it made!

In an effort to keep this short and not boring the hell out you all I'll end it here. I didn't want to get to political so early. I hope I didn't offend anyone, especially any of you corporate c*ck bights, I know how sensitive you can be.

Randy H. SC Glass Tech Scam Diego, Comi-fornia

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Reply to
Randy H.

Having worked with pottery kilns - the heater is like glass or almost.

The expansion and temperature really hammers a silver solder job -

Maybe TIG - really. Or a mechanical clamp.


Reply to
Martin H. Eastburn

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