resistors

[Mxx20]

So I've aquired an old airco heliarc welder, by the date xode ita a '78. I've had to do some cleaning and tune up as the guy i got it from said the ac didn't weld aluminum up to par and looked horrible. Found out it was just an adjustment and years of corrosion, but in the mix i pulled apart the foot pedal for the tig and cleaned and repainting it, the resistor has some sort of coating on 3 sides. Feels like ceramic but i am unsure. I've just read alot about the widings coming off and having to replace it, I'd rather not while i have it apart, maybe i can find a coating to re coat? I've searched and havent found much on it other than replacing the resistor.


Any ideas or suggestions?



Ps i am trying to upload pictures but my phone is not cooperating tonight... i will upload when im on the pc in the morning

[SHEEPMAN!]

I have a Lincoln Pipeliner circa late 1940's.

Lincoln Electric had new parts for it 10 years ago. Cleveland, OH. "Bill's Welding Equipment"

Different company/brand of course but this is FWIW.

[CWB]

hmmm ...

that resistor will be ok if none of the windings are loosening up .
they should be in shallow grooves , perhaps only on the corners .
you could clean up the connections of the wiper bar ... clean up the pivot point ... use some silicone grease (think heatsink compound) or *noseize* (aluminum powder in grease) .
the actual brush and holder should be cleaned out/up and inspected for *free travel* as the brush is spring loaded to maintain firm contact with the nichrome windings .
the actual purpose of the resistor should be to control the feed speed of the wire/spool ...
sooo ... the feed may be a little erratic if this resistor is not clean where the brush rides and the brush itself is not mechanically correct .
(this is barring other considerations of the feed path)

the brush can be replaced if need be ...
an electrical supply or motor/generator rewinding outfit should carry a brush that is close in size and composition (hardness and copper metal dust "lube" count) .
get one that is oversize and use a mill bastard file to take it down to the correct dimensions .

the low temp (relatively speaking) ceramic material peeling off/away is a common occurrence with those "sandy" resistors ... and has been since the 30s .
there are better quality resistors ... they use a ceramic material but it is of the "high fire" type and actually bonds to the ceramic form and of course , it costs more to produce .

with a machine that was made 4 years after i graduated , all connections are suspect .
if something needs to be soldered ... do not use acid core solder .

[Mxx20]

So, i redid all the connections, soldered and heat shrank them. Set the contacts, ran the water to it and no gas flow. Well they had the diaphram set wrong, Basically the thrid thing ive found wrong or set wrong on this. The guy i got this from had absolutely no clue lol. Welds great now

[CWB]

"ran the water to it ..."
how about that ... a fluid drive welder .

[Shawn]

Works great to weld ice sculptures.

The water replaces the "juice" used in old style welders.

[CWB]

gives new meaning to the term "spray welding" .

[Mxx20]

Lol, i deserved that one, i dont have a water pump/tank/cooler for the tig so im cheating running the garden hose over


Trying to find onr or see if one of the coke or pepsi guys i know can spare a carbonator pump, same proton the miller uses

[CWB]

that is a good source for a water pump .
you might be able to get one that needs to be rebuilt and then order up a kit for it .
to regulate the flow , restrict the inlet side .
are you going to run it as a closed or open system ?
a cooler can be made with an old heater core and a small fan .
a glycol solution with a small amount of disinfectant (the same stuff that keeps the grunge from growing in diesel tanks) will transfer heat better .

[Mxx20]

Im undecided, i was going to maybe use an evap core. Ive got several kicking around at work, for a fan i was thinking maybe just using the one on thr unit itself, it runs all the time and flows a ton of air