Spot welders......

[Bob Carriere]

...if I left my spot welder ON that long I would melt a hole to China....

Your is behaving like what I would expect and what I have seen in sheet metal fabricating plants......

Either something is wrong with my Unit or it is wired wrong.....

Can't wait to take it back to the dealer and have the sale rep try it out.... which will also check it out from a different power source.

The Miller came with a standard 15 amp 220 volt plug which is like a 110 plug except both spades are flat like two _ * _ the asterisk being the ground prong...... I had to build an adapter section using 24 inches of 10 gauge 3 wire rubber cable.... it has a female outlet in a metal box and the other end is wired to a standard 220 large welder 50 amp plug..... which in turn is plugged in a commercial 25 foot 220 extension cord which I use regularly with the Mig welder......

This is no good with out pictures..... will try a photo shot tomorrow evening if the political hassle at work does not keep me in til 6:30 like tonight.

???? how large are your tips contact area in the first samples....??

I am using the specified pointed/tappered coppe tips at 3/16 wide at the contact area.

Man this is frustrating....... particularly when the teckkie from Miller suggests using a long extension cord to drop the amperage.... ????

Bob

[Phil Waterman]

Hi Bob-

I'll comment on the rest of the e-mail a little later. But could not resist commenting on ".... particularly when the teckkie from Miller suggests using a long extension cord to drop the amperage.... ????" did he give you any idea of how long the cord should be? Or around whose neck it should be coiled? If it had been the salesmen saying this the answer would be easy how far to the next sales district.

If every thing is wired correctly on your unit sounds like you should be able to spot weld two sheets of 1/4 inch plate. As to reducing the amperage how about a big a variack would you need?

Tips in the first image is 15/32nds rounded these seem to last well and are less critical of miss alignment. The funny U shape tip unit is for welding fender lips they are cone shape with a flat that start off new at 1/8th but fairly quickly flatten/burnoff down to 13/64ths when they seem to stay constant and weld well for a long time. I only use the fancy shaped tips on auto sheet metal which use a fairly low power setting and time. For most if not all the CMP spots I'm using the round tip as they can take the heat and just don't seem to wear/flatten/burnoff. I'll try to post some more still photos and detail explanation on my site let you know when they are up.

[Bob Carriere]

Finally connected with the Miller sales rep this afternoon.

As can be expected I was totally "humidated" when he showed me how it worked.........

First for the tickness I was using..... it is not explained in the miller manual.... the copper tips of the are toooooo small a surface area and burn holes..... tips brand new are meant to fit the low amperage 110 and the 220 spot welders...... the tips are about 1/8 new... they need to be burned down... or filed down to 3/16 to a 1/4 inch wide.......

Next issue...... they told me I was using too much pressure.... in fact even when I was first using it I was not using enough pressure.... again the manual says.... do not pressure too much or copper rods will bend......

Well it seems that with good decent pressure.... enough to hold, compress, and see some flex in the copper rods....... you Zap the switch for a slow second and....voila..... very good welds.

I even simulated the door skin combination..... one 40 thou (19 gauge + -)
plus one 14 gauge (for the door frame) and one more 19 guage for the door skin fold over...... about 4.2mm.... and perfect welds all the way through the 3 pieces with very little surface damage.

....and this 3 layers were done without readjusting/lowering the pressure to account for the extra thickness of the 3 parts. Only difference I kept the switch on for about an extra 1/2 second...... total 1 1/2 sec.

They have recommended using a flat surface tip for the lower electrode when doing the good side of door skins.

Left with a smile..... now I know how it works and free new tips.

In time I will experiment with using a perfectly spherical copper tip as opposed to pointed to see if it will work for me as suggested by Phil W. As soon as I get a tip too worn out.......

Now the proof is in the puddin' or the doing the practice, practice, practice...

Thanks for all the help, support, comments, suggestions.....hope it can be of some help to others.

Boob

[Phil Waterman]

Hi Bob

Glad to hear you are now going to be able to use what is a really handy tool. Now the next step is to look at the original 60 year old CMP spot welds and file your tips so they will match the shape of the original worn tips used in producing the truck in the first place.

Keep us posted on any trick you learn now.

Cheers Phil

[RHClarke]

Originally Posted by Bob Carriere

Finally connected with the Miller sales rep this afternoon... In time I will experiment with using a perfectly spherical copper tip as opposed to pointed to see if it will work for me as suggested by Phil W. As soon as I get a tip too worn out...Now the proof is in the puddin' or the doing the practice, practice, practice....Thanks for all the help, support, comments, suggestions.....hope it can be of some help to others. Boob

Bob, Feel free to try welding up a few of the one gal POW can holders - they are in the barn attic (the can is on the wooden shelf nearby). Congrats on sucking it up and going to the experts for help (we were running out of scrap test metal).

[Stewart Loy]

Originally Posted by Bob Carriere

Now the proof is in the puddin' or the doing the practice, practice, practice...

Boob

Bob,

Save some pudding for me!


Stewart