Spot welders......

[Mike K]

I live in a rural location and the mains voltage drops down each afternoon , around 4-5pm. Welding jobs after 5pm are hopeless.

Has anyone successfully spot welded aluminium sheet panels ? I've seen it done by a chap here who makes new Land Rover body tubs.
Mike

[cantankrs]

Oooooohhhhhh, might explain some issues I had many years ago on a job I was doing using a spot welder Dad had dragged out of his shed and got insulation tested before he'd let me touch it. Need clean clean metal on all surfaces. I also noticed there's not much time between a smick spotweld, and something that looked like a rough impact crater.

BTW, on a side note the welder had no arms or points so I first tried making steel arms and copper points but too much resistance (from the steel) of course. So Dad to the rescue again when we were visiting my late Grandfathers place and he ducked into the old garage and from some hidey hole brought out two offcuts of almost 1" brass rod about 15" and 20" long that Grandad had 'rescued' from the scrap wagons at the submarine base at Albany during the war! He saved them for a rainy day...

Regards

Alex
--
M3 Grant, Val, Ferrets, WM20, CMP's

[Bob Carriere]

Well Mother's day reduced my barn time but the progress was NIL !!!!!

I sheared a whole bunch of one inch wide strips in 18 guage...14 gauge ... and some 40 thou satin coated......

I cleaned the surfaces and held them tight at 90 degrees with wisegrips....
...also cleaned the tips...... readjusted for exact alignement and flat filed the contact to mate perfectly.....

Blah...... sparks all over and another crater.....

Seems that the top electrode erodes and throws out a perfect circle of sparks... the result is a cratered top weld and a smooth bottom surface where the spot weld is clearly visible but not distorded.

I tried various combination of light gauge together and mixed thickness.... same results....... and I am just cycling the switch on/off for what can't be more then half a second if not shorter.

also to be noted...... I have to twist the sample sheet metal as they are held fast fuzzed to the top and bottom electrode.

when I twist the spot weld to see the penetration the top peice being more cratered shears of on the outside of the button leaving apecfectly round 1/4 hole in the top piece.....tips at 3/16 at the tip......

According to the Miller "tekkie support" in Wisconsin ( he was more like an athletic support)..... his suggestion was to use a longer extension cord to reduce the amperage to the spot welder.....

Pictures..... I was so p****d I never bothered with pictures.....

The local distributor has offered to line up the travelling Miller sales person to lookover my spotwelder and run some demo in the Linde Gas training centre....... awaiting news....

I cannot understand why Miller would sell a spotwelder that needs to have the power cycled so fast that it becomes almost physically impossible to do.

Phil claims that he can literally see/feel the metal welding so I assume that he is holding the switch and counting "one thousand an one...." "one thousand and two..." and getting good results.....

Unless my China made Miller is defective or needs soya sauce....

Bob C.

[Phil Waterman]

Hi Bob

What you are describing sounds like something else is going on. Tomorrow I'll video some spot welding and post so that you can see how my unit works maybe from that we can figure whats up with yours. Almost sounds like it is putting out to much power.

If you can get a demo out of the Miller rep using your gun it might be worth the time and effort in tricks of the trade.

HTP has (with my permission) referred prospective equipment purchasers to me to actually see their stuff in operation. Results in a sale for them in the three people who have actually come out. Funny thing is the people always seem to buy equipment one or two notches up from what I have.

Cheers Phil

[cantankrs]

Hi Bob,

Sure doesn't sound right. I'd be testing it at some power source elsewhere just to eliminate that (like across town, or in town - depending where you are), and then get it checked out by a service person unfortunately. I seem to recall about 2-3secs on the switch on our old model.

Regards

Alex