Is spot welder worth it?
- Thread starter Lizer
- Start date
Lizer
Mad Scientist
Then there are other who make tips without the Eastwood price or the kit. I got mine on Amazon and it’s actually made in USA.
Lizer
Mad Scientist
I’m not sure I follow. You mean wire feed speed or ?
I’ve been replacing sheet metal for more years than I care to keep track of anymore. I always try to replicate the spot welds as it is the first thing I look for while evaluating a car’s condition. What I usually would attempt to do is crank the amps up and lower the wire speed to create more of a depression with my welds. A few years ago I picked up this lenco which has various attachments for spot welding. Not much of a duty cycle as I burned the transformer up doing a rocker panel. I have since added fan, but not as easy to use when you have gaps or old metal your attempting to weld either.
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Chris_Hamilton
Trying to be the best me, I can be
What wire size are you using Lizer? I don't know if I mentioned but since I use .030 nowadays those settings would do that with .023/.025. Turn the wire speed up until it stops doing what you described see if that helps. Every machine is a little different I've noticed over the years. Even the same model. One will weld slightly differently than another. Keep practicing on scrap till you find a setting that works.
Lizer
Mad Scientist
I'm using .023. I bought some .030 wire but the tips I bought weren't for my gun so I couldn't use the 030 wire. If you think it will work better I have no opposition to trying it. It was my intention to do so anyway.
If people have a small 120V/230V single phase input GMAW welder for short circuit transfer--they can work well for plug welding 20 gauge mild steel automotive sheet metal adequately. Most only have a 20% duty cycle (2 minutes welding at rated output for every 10 minutes) and do not have enough output for spray arc transfer in the smallest product offerings. Many of these welders--it's about 60-80 amps max. and a couple of preset voltage taps--maybe 16 to 22VDC. That's okay for short-arc on low carbon sheet metal replicating spot welds by plug welding. But you need to prove it to yourself and do a "procedure qualification" and a "performance qualification" for yourself.
I use a good old AC/DC buzz box and 5/64" diameter E6011 or E6012 electrodes for sheet metal plug welding. "Puddle welding" galvanized steel pans for concrete to structural steel is still done today using stick and electrodes E6024 and use the current of the arc to poke through the sheet metal and fuse into the beam flange below.
Using any "MIG" ER70S-6 or ER70S-3 wire made in AWS specification A5.18 in diameter 0.020" to 0.030" and any shielding gas 75Ar/25C02 to 95 AR/5C02 is good although higher Argon mixtures require higher arc voltages that may not work well for a welder with perhaps a high and low tap or switch for open circuit voltage for plain jane 20 gauge low carbon sheet metal. For something running on 120 VAC--0.020, 0.023" is better if the welder maker offers drive rolls in that size. Your gun whip liner can be sized for 0.035" so you can run multiple sizes through it. Your wire speed adjustment controls how many short-arc cycles per second happen and is your current control. How "long an arc" you have is your arc voltage. you could try straight C02 but it is more mess and trouble than the cost savings even in an industrial setting.
I suspect you are having problems with two things--your feed rolls and the diffuser set screw holding the liner to it may be loose or down at the feed roll output end. The diffusers in the gun head are brass and liner cable steel and that set screw is prone to loosening over use. Whatever wire diameter you use--match the feed rolls for that. Too big or too small on the choice of feed rolls is the single biggest source of problems with any wire feed welder. Solid wire uses smooth feed rolls--self-shielded flux core uses knurled. Cranking down the tension on the top feed roll can flatten the wire slightly and cause issues feeding. Try blowing your liner clean with compress air. Knurled rolls scrape the solid wire and get shavings in the liner causing a feeding issue. The tapered copper contact tips are okay--but I like the heavier straight tips. They handle heat better. I usually go one size up on contact tip size for the heating issue and feeding.
The one lb. spools of wire are both a savior and a problem. The cast of the wire is so pronounced when wound on a small spool. The wire is drawn and yielded well as it is extruded and must be made stiff enough to feed and consequently will "cork-screw" coming off the reel though the drive rolls and into the liner. That's a problem to adequately straighten it out in a short distance inside the welding machine. The wire may be stiff and hard when wound on the spool but the resulting welds however are dead soft--all the welds I test with the wires listed are less than way down on the Rockwell B scale whether done with short-arc transfer, globular or spray arc. The spread between the weld's yield and breaking tension strength is good--even with relatively low heat input short-arc welding
As other posters have mentioned--turn your wire speed up full, let it "noodle out all over" and hold your contact tip back about 3/8" or so from the surface. Throttle back on your wire speed until you get some good short-arc action. Maybe about 20CFH on your gas flow. You can drill a 1/4" hole into the top piece and practice filling that up--but with 60 amps coming off an electrode tip say "0.030" in diameter--that's 85,000 amps/square inch in the spray-arc mode. Discounting 90% for doing short-arc welding and you are still using a welding process with an enormous amount of potential heat energy to weld 20 gauge low carbon sheet steel adequately by poking through the top piece without a hole and using the bottom pieces as a containment backing that in all likelihood will be penetrated though well with about a 3-4 second count when things are set up right. These small footprint machines are out of the box all set-up reverse polarity on the current so flat, out of position etc... no problem--should work well overhead, flat, horz. vertical.
I use a good old AC/DC buzz box and 5/64" diameter E6011 or E6012 electrodes for sheet metal plug welding. "Puddle welding" galvanized steel pans for concrete to structural steel is still done today using stick and electrodes E6024 and use the current of the arc to poke through the sheet metal and fuse into the beam flange below.
Using any "MIG" ER70S-6 or ER70S-3 wire made in AWS specification A5.18 in diameter 0.020" to 0.030" and any shielding gas 75Ar/25C02 to 95 AR/5C02 is good although higher Argon mixtures require higher arc voltages that may not work well for a welder with perhaps a high and low tap or switch for open circuit voltage for plain jane 20 gauge low carbon sheet metal. For something running on 120 VAC--0.020, 0.023" is better if the welder maker offers drive rolls in that size. Your gun whip liner can be sized for 0.035" so you can run multiple sizes through it. Your wire speed adjustment controls how many short-arc cycles per second happen and is your current control. How "long an arc" you have is your arc voltage. you could try straight C02 but it is more mess and trouble than the cost savings even in an industrial setting.
I suspect you are having problems with two things--your feed rolls and the diffuser set screw holding the liner to it may be loose or down at the feed roll output end. The diffusers in the gun head are brass and liner cable steel and that set screw is prone to loosening over use. Whatever wire diameter you use--match the feed rolls for that. Too big or too small on the choice of feed rolls is the single biggest source of problems with any wire feed welder. Solid wire uses smooth feed rolls--self-shielded flux core uses knurled. Cranking down the tension on the top feed roll can flatten the wire slightly and cause issues feeding. Try blowing your liner clean with compress air. Knurled rolls scrape the solid wire and get shavings in the liner causing a feeding issue. The tapered copper contact tips are okay--but I like the heavier straight tips. They handle heat better. I usually go one size up on contact tip size for the heating issue and feeding.
The one lb. spools of wire are both a savior and a problem. The cast of the wire is so pronounced when wound on a small spool. The wire is drawn and yielded well as it is extruded and must be made stiff enough to feed and consequently will "cork-screw" coming off the reel though the drive rolls and into the liner. That's a problem to adequately straighten it out in a short distance inside the welding machine. The wire may be stiff and hard when wound on the spool but the resulting welds however are dead soft--all the welds I test with the wires listed are less than way down on the Rockwell B scale whether done with short-arc transfer, globular or spray arc. The spread between the weld's yield and breaking tension strength is good--even with relatively low heat input short-arc welding
As other posters have mentioned--turn your wire speed up full, let it "noodle out all over" and hold your contact tip back about 3/8" or so from the surface. Throttle back on your wire speed until you get some good short-arc action. Maybe about 20CFH on your gas flow. You can drill a 1/4" hole into the top piece and practice filling that up--but with 60 amps coming off an electrode tip say "0.030" in diameter--that's 85,000 amps/square inch in the spray-arc mode. Discounting 90% for doing short-arc welding and you are still using a welding process with an enormous amount of potential heat energy to weld 20 gauge low carbon sheet steel adequately by poking through the top piece without a hole and using the bottom pieces as a containment backing that in all likelihood will be penetrated though well with about a 3-4 second count when things are set up right. These small footprint machines are out of the box all set-up reverse polarity on the current so flat, out of position etc... no problem--should work well overhead, flat, horz. vertical.
'68 Coronet R/T
Oldtimer
I thought the Eastwood video was interesting since they didn't drill any holes.
My MIG has a Spot Weld setting were I can set the amount time the welder will be on. I predrill the holes in the panel I am welding, then using a tip similar to the TIG one, I set it over the hole and pull the trigger full open and hold it until the welder stops.
Now I confess that many times, I just use the regular welding tip and manually fill the hole.
My MIG has a Spot Weld setting were I can set the amount time the welder will be on. I predrill the holes in the panel I am welding, then using a tip similar to the TIG one, I set it over the hole and pull the trigger full open and hold it until the welder stops.
Now I confess that many times, I just use the regular welding tip and manually fill the hole.
metlmunchr
Member
I've got a nice Miller that will spot 2 thicknesses of 11 ga. It's suspended from a roll around boom with a gimbal mount and has air clamping and interchangeable water cooled tips. Due to the way it is suspended, it is near weightless and can be turned and twisted easily in most any direction. But, if a person was using it for extensive auto body welding, they'd still need the car on a rotisserie to get good access to a lot of places.
Chris_Hamilton
Trying to be the best me, I can be
What Eastwood shows in that video is nothing new. Didn't work 25 years ago, still doesn't work today. By that I mean if you don't drill a hole and try to spot weld from one side the nugget or fusion area is very small.
Many times trying to do that you will see the metal on the one side expand and lift up then hear a pop from the 2 pieces separating. Without specific clamping it does not work. Take a weld done in that manner, do a destructive test on it, you will find the weld nugget is small and separates easily. You gotta drill a hole and fill it for any sort of strength. Or get a spot welder like a Pro-Spot that can do OEM spot welds.
'68 Coronet R/T
Oldtimer
Comforting words.