ECN Forum Forums General Topics of the Trade General Discussion Area Calling all old guys... Help with soldering K&T?'s

I made up some western union splices for a BB, either here or the home inspectors, and I just used my trusty old Weller 200w gun. It worked great on #12

Scott of course you can use it... I'm not quite done yet though, I still have to do some work on that document.

AND, I was just sent me some FANTASTIC scans of an old lesson on the matter from 1926, there is some worry about copywrites so not sure about the posting of them. So there may be some more to absorb, decipher into modern language and add later.

Anyway, I have not read the whole thing yet, but in it I found this gem.
They to this day pipe eveything, with limited use of flex...

Mark, with 394.17, if the 3" wire protection above a horizontal framing member is to keep plaster from accumulating around the wire, would there need to be protection above the top plate? There shouldn't be any plaster above the plate and I can't remember ever seeing a tube stacked over the one running through the top plate(s).
The code statement "Where passing through wood cross members in plastered partitions" sounds like fireblocking or diagonal blocking inside the wall stud bay.

394.30, "every 4 ½’ and at 6” minimum on each conductor coming to a tap, or splice." Shouldn't that be no more than 6" from the splice?
Within 150 mm (6 in.) of each side of each tap or splice

When I think of "acid" flux or acid core, I think of flux used for soldering sheet metal and those containers state not for soldering electrical connections. Should the wording be "rosin flux"?

steve

K&T wiring worked very well since the K, - i.e. Knobs, and - T, i.e Tubes, were usually made of porcelain, a very good insulator, as you probably know.

Joints are another story.

Proper solder techniques were the artform in K&T wiring.

The only real secret to doing the soldering was to use rosin fluxcore solder and not acid core stuff. Insulation of conductors was exceedingly crucial and most intsallation of K&T survives to today and has not caused a problem around my part of the world.

The only issue I've run into is the HO that wants to upgrade a now really older home to modern standards like new ranges, A/C and electric clothes dryers (although in Alberta I can't for the life of me figure out why gas wouldn't be the fuel of choice). It has always become a TOTAL rewire, with no other options available including every home run in the house.

The other folks that are just buying these homes usually can't afford that, so I am still adept and able to deal with a repair (although infrequent) to K&T stuff.

Upgrades and soldering in J boxes is a skill not learned or taught in schools much any more but only by seeing what us old farts do when going at K&T in a house built in 1925.

Hope that helps.

Steve, I have on occassion seen tubes above the top plate, but agree that in most cases not nessesary. And thank you for catching that wording use of "Minimum" v. "no more than". The early versions of flux were muratic acid and other chemicals. In the 1926 lesson Alan Nadon graciously sent me, had instructions on how to make your own, out of muratic acid, and zink from a "used dry cell". It too also suggested not to use on electrical connections. What I haven't gotten to yet, is that all joints need to be cleaned well afterwards, be it acid or rosin. Both will contain any oxides that came off the wire in the process. Rosin contains some very long named clorides that rot joints pretty good over time. And most rosin fluxes intended for electrical use also contain active acids of some type or another to react with the resins. (I learned this too long ago, but found a great explaination of it here. )And non-rosin type fluxes intented for electracal use which are acid based in various ways. Which is what I intended by the use of "Acid" in the document. (I find these type of fluxes easier to use and clean afterwards.)

Like these: http://www.solders.com/395_alcohol_based_flux.htm http://www.solders.com/802_resin_free_flux.htm
http://www.solders.com/109_water_soluble_flux.htm

Either way, suggestion taken, and I just may well take "acid" out of the final document to illiminate confussion. As there are certain types of fluxes not intended for electrical use. That is why I posted it for the valued critique. Or take a long deep dive into the chemical properties of flux... Which I just might do. It is a work in progress...

My personal prefference is to stay away from cored solder all together, they are great for electronics work, but on larger conductors just dont work very well.

Edit to add link about the acid reaction in rosin solders.

[This message has been edited by e57 (edited 05-20-2006).]

Here's some info I found. (Of course I am still a very young man) in an old American Electrician's Handbook.

Re: Flux



Re: Poured Joints



I started a thread in The Nostalgia Area, and posted the full text, which shows different ways of wire preparation, etc. and has pictures of various k&t parts.
That way I won't hog up a bunch of space in this thread, and make it slow to load for those that aren't that interested in it.

The thread in Nostalgia is Here



[This message has been edited by electure (edited 05-21-2006).]

Gent's I think I have finished my diatribe on the subject....
http://www.markhellerelectric.com/wusplice.pdf

The last K&T I encountered was in Hawaii: bare copper running within 9" overhead of anyone using a shower installed by the homeowner on Ahinahina street.

As for solder... forget it. I'd always go with compression connectors and a transition to Romex.

Greenlee Gator ECCX to the rescue.

They make a die for #14 - #12????