Spot welders......

[Bob Carriere]

Hi Phil.....

1. I wouldn't run out and buy the timer unit. Think the problem is not lack of auto timer. Half the time I do the welds almost by ear and eye. Sound of welder changes as metal heats.***How long do you leave the power on...?
2. Try some sample welds after cleaning all four sides of the metal and post some pictures (or e-mail them to me)....that maybe my problem...I used scrap metal with some surface rust bloom......
3. Do you have a AC volt meter that one of the guys could read the voltage of the 220 voltage going to the welder. I had problems with mine when I built the barn as it was fed from the house to garage to barn to much line drop. While your at it check both legs of the power panel. I have to turn off the halogen shop lights when I'm weld sheet metal to angle iron with the spot welder.....I have a 200 amp service dedicated to the barn as a seperate service.......
4. Can not over empathizes need to clean/polish the steel........ will do new samples with new clean steel....
5. I've made up some sample combination sheet metal thicknesses to put between the tips when setting the tip pressure. On them I've written the weld time and heat setting......Good suggestions....
6. Just as with any other type of welding when you have not done it for awhile you have to practice, I have to force myself to practice until I get good again time.
7. The manual is correct about shape and size of tip contact area being important.....I have new tios and spare tips.... how often do you redress..as in how many cycles/spot welds between dressing
8. Holding the pinch pressure until the metal is no longer red hot is also important and a problem that I had trouble with until I remembered that you have to hold the pressure after releasing the trigger. Some thing like a three count should do it. .....never had to do that..... I barely cycle the switch on for a fraction of a second and it burn a hole and throws sparks all over... the metal prep may be my single biggest problem

Will cut some new strips in new clean metal....degrease.... various gauges primarily 18 G and 14 G at this time...

Stay tuned...

Bob

[Phil Waterman]

Hi Bob

Sounds like good starting points, after you try some more experiments and send photos we should know more.

I'll check the actual cycle time on mine welding at different settings.

When you take your pictures include on of the tips. I have differ size tips and the small ones will burn through more easily than the big rounded ones. I'll take some photos of the tips I have.

Glad to here you have a separate power service to the barn, when I redid ours to install the generator transfer switch I separated house, garage, and barn. Which solved a lot of my problems. I've still got a problem in the barn that I've got to shift around, all the lights ended up on one side of the circuit.

Cheers Phil

[Anthony Main]

The metal you intend to spot weld needs to be clean, No rust or paint
as this stops the welder making a proper electrical conection between
the metal & Blows holes instead of welding!

[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