I just went out and bought a Harbor Freight spot welder, the 240V version. I am trying to spot weld two 3/32 steel wires together. The welder is rated to weld up to 3/16 uncoated steel. Both wires were ground down slightly to a flat spot so that they would not move as much, and both were clamped using a vice grip. For whatever reason I cannot get a good weld on this. It heats the wires up to orange and I am pressing the button for 5 seconds like it says. Does anyone have one of these spot welders and if so is there some sort of trick to make it work better? Thanks.
HF 240V spot welder help
- Thread starter Codyyy
- Start date
Just a quick update. I managed to weld a paper clip without any problem, but there shouldn't be a problem with that anyway. I still cannot get the wire to weld, I can heat it until it glows and it just won't weld it. The few times I have gotten wire to "stick" I can tap it with my fingers and it pulls right apart and doesn't appear to have any "weld" on it. I'm not sure if I should try to return this or try a different method. MIG welding this wire is not a very good option for me as it will end up being a gas tank sending unit, but that may be the only economical way.
Lx460
Well-known member
Spot welding is typically used for sheet steel. I've never heard of using it to connect wiring. Doesn't mean it can't happen though. Are the wires stranded? Why can't you solder and shrink wrap? That's a lot of cash to plunk down to,connect two wires, I hope you have other uses for it down the road...lol.
rsanter
Well-known member
A couple,of things to try
You say you put a flat on the wires. Is that for the tips or,for where the wires make contact?
I would say to try to make a little flat where the wires meet.
Next. How much clamping pressure do,you have on them? I would say increase it a little.
Try making a larger flat spot on the tips. I have a miller and it welds better wi the tips flattened out a bit
Bob
You say you put a flat on the wires. Is that for the tips or,for where the wires make contact?
I would say to try to make a little flat where the wires meet.
Next. How much clamping pressure do,you have on them? I would say increase it a little.
Try making a larger flat spot on the tips. I have a miller and it welds better wi the tips flattened out a bit
Bob
The wires are 3/32" steel rod. I put a flat spot in on each wire where they meet, thinking that may help. The steel wires, or rods, are uncoated mild steel. I may try to file down the tips or buy some flat ones. I watched a Youtube video with what looked to be a big spot welding machine welding some sort of wire shelf, that machine had flat tips, not tapered.
I tried increasing the clamp pressure, almost to being a c-clamp but that didn't help. The heat is enough to bend the rods but not enough to weld them together. I looked on Miller's site for their spot welder to compare. They say that there should be an "intimate" amount of pressure applied before welding, and not to use it like a c-clamp. They say it will lower the resistance of the weld. I'm going to try to adjust it all the way out, flatten the tips a bit, and readjust to it not being as much force and try again.
I tried increasing the clamp pressure, almost to being a c-clamp but that didn't help. The heat is enough to bend the rods but not enough to weld them together. I looked on Miller's site for their spot welder to compare. They say that there should be an "intimate" amount of pressure applied before welding, and not to use it like a c-clamp. They say it will lower the resistance of the weld. I'm going to try to adjust it all the way out, flatten the tips a bit, and readjust to it not being as much force and try again.
I tried it with my HFT 240V spot welder with 0.080 steel wire just as an experiment to try to replicate what you were doing. This wire is zinc plated and I rubbed it with steel wool to clean. I put a flat on the weld area of wire by tapping it with a hammer on a small anvil. The first weld I tried blew through both wires, but I was able to get the wires welded in subsequent trials by flicking the trigger on the welder.
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454ragtop
Well-known member
Is this for the arm for the float? Don't really see why you couldn't mig it, but tig is probably the preferred method. Me, I'd mig it, since I've never tig welded, although I do have one of those little 110 volt inverter stick/tigs I scored on Ebay that I've never used.
Jim
Jim
Is that outlet used for another 240V appliance so you have proof that it works correctly? Can you check the outlet with a multimeter? Maybe you're only getting 120V (only one hot wire, and not two)?
This outlet was actually put in mainly for another project I had, a buddy used his Hobart Handler and needed an outlet for it to weld a different project for me. It worked fine for that. I will test the outlet out.
I have a 110V Lincoln MIG welder that I have used to weld these wires with before, but the welds are a bit ugly and very hard to set up. I'm also afraid the heat might cause problems with the sending unit itself. Seems the spot welder does not heat the metal as much or in the same way.
I have a 110V Lincoln MIG welder that I have used to weld these wires with before, but the welds are a bit ugly and very hard to set up. I'm also afraid the heat might cause problems with the sending unit itself. Seems the spot welder does not heat the metal as much or in the same way.
depatty
Well-known member
Have you tried welding any other kind of wire other than the paper clip? I'd try on a couple of pieces of coat hanger. Knock the paint/varnish off of the spot to be welded and see if the welder will spot them together, if so it may be that there is something in the wire you are trying to weld, if not I'd be thinking the welder is defective.
Dave
Dave
depatty
Well-known member
I just took a look at the comments on the HF 240v spot welder. Second one down states:
Didn't seem to work right out of the box. Light welds, no penetration, poor quality spots. It basically needed to be disassembled, correctly adjusted and all contact surfaces sanded and tightened together TIGHT. The connection strap was loose, dirty and only partially inserted between its fasteners. Tongs were way out of alignment and their seating surfaces unprepared. Basically these are good welders but are less than carefully assembled at the factory so it's up to end user to do the job right. It now does a fantastic job, very happy with it but expect regular maintenance to be a necessity.
Sounds like what you are experiencing. That welder should burn the wire you are trying to weld up with a 5 second pulse.
HTH
Dave
Didn't seem to work right out of the box. Light welds, no penetration, poor quality spots. It basically needed to be disassembled, correctly adjusted and all contact surfaces sanded and tightened together TIGHT. The connection strap was loose, dirty and only partially inserted between its fasteners. Tongs were way out of alignment and their seating surfaces unprepared. Basically these are good welders but are less than carefully assembled at the factory so it's up to end user to do the job right. It now does a fantastic job, very happy with it but expect regular maintenance to be a necessity.
Sounds like what you are experiencing. That welder should burn the wire you are trying to weld up with a 5 second pulse.
HTH
Dave
Good post. I'll look into that. As an update I checked my outlet, 240 volts. I filed down the tips and tried welding coat hanger wire, it wouldn't even heat it up. I also tried loosening and adjusting the tongs all the way in as well as aligning them. I'll need to look into taking this welder apart and seeing what's wrong, I'd rather not do that but oh well. Otherwise as a last ditch resort I'll try it in a different outlet and see what happens. I wish I could find a different brand welder locally to just try and compare so I can rule everything else but the welder out.
PCO6
Well-known member
This is a little off topic but for those of you with this type of spot welder ... I built a foot operated stand that makes things a lot easier.
Sorry for the highjack but here it is ...
View media item 43752
Carry on.
Sorry for the highjack but here it is ...
View media item 43752
Carry on.
In case you want to build your own, or just see how they work, here's a link to a DIY spot welder from Popular mechanics in the 60's...seem pretty simple, so I am guessing the transformer in yours is shorted or something...
https://books.google.com/books?id=m...#v=onepage&q=spot welder works 3 ways&f=false
https://books.google.com/books?id=m...#v=onepage&q=spot welder works 3 ways&f=false
OccupantRJ
Well-known member
Read my thread on spot welding and see if it helps. All current must pass through the weld joint. Clamping will tend to bypass weld tips. Every connection must be bright and tight.
http://www.garagejournal.com/forum/showthread.php?t=145161
http://www.garagejournal.com/forum/showthread.php?t=145161
Major Ramifications
Well-known member
PC06,
You built that? It's beautiful!
OP,
Are you trying to weld two wires together end to end (**** joint) or side by side (lap joint) or ? I can't see using a spot welder for either.
You built that? It's beautiful!
OP,
Are you trying to weld two wires together end to end (**** joint) or side by side (lap joint) or ? I can't see using a spot welder for either.
joe_padavano
Well-known member
I'm assuming the O.P. is talking about overlapping steel wires, like welded fence wire mesh. The spot welder should work fine for this, there's no difference between round steel and flat steel. If the wires won't weld, despite getting red hot from the welder, check contamination and/or specific material of the wires.
OccupantRJ
Well-known member
Wires will have to cross to spotweld. Current must pass directly through the joint to be successful. Even nonferrous materials can be spotwelded, but it takes a capacitive discharge welder.
I have been dealing with spotwelders in my job for 26 years, and they can sometimes be confusing and frustrating.
I have been dealing with spotwelders in my job for 26 years, and they can sometimes be confusing and frustrating.
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Very nice! You're a craftsman!
I've used capacitance discharge welders for welding tabs on test batteries for a former employer. We used nickel plated steel tabs. I think that the benefit of CD welders is that you can control the total amount of energy that you store and subsequently dump into making the weld. Usually we adjusted the "watt-seconds" depending on what was being welded. We used old Black & Webster welders made in Waltham, MA.
PCO6
Well-known member
Major Ramifications - I did - thanks! I looked at a lot of different designs on line and didn't see anything quite like what I wanted to build so sketched it out and started welding.
The pedal works great and there in no slack in the mechanism in either direction. I get nice firm pressure on the sheet metal I am welding when I put my foot down and the "jaws" open fully when I take my foot off the pedal. Most of the metal came from my scrap pile. The return spring came from my kids' trampoline when I scrapped it. The box on the bottom isn't quite finished. It houses a timer that can be set to a half second. It will allow me to make real consistent welds - no guessing on the timing! I'm trying out a few hand held push buttons that will allow me to hold metal being welded in both hands and trigger the button with one hand. So far a remote auto ignition button seems to work best.
Overall it makes the welder a lot more versatile.
PCO6
Well-known member
Thanks DenisG. The nice thing about it too is that the welder detaches quickly - just a few screws - so it can be used in the conventional way quite easily.
That's a very nice stand, I wish I could make one if I used one of these more. I decided to return the welder. I was trying to use the spot welder to weld the two 3/32" rods crossways. I tested it using multiple scraps of rods, both ground flat or just cleaned up. I'm trying to find another spot welder locally but it seems more common to find a 110V machine. If I ground flats in the rod, would a 110V machine work good enough or hold out for a bigger machine? I know most if not all 110V spot welders are rated to 1/8", and I'm barely over that. Thanks.
OccupantRJ
Well-known member
What is the KVA rating on these portable welders? Think I will research that a little to see more of what we are dealing with.
Harbor Freight rates the 240V welder at 2.5 KVA while the 110V welder is 1.5 KVA at 50% duty cycle. An eBay ad I found for the Dayton 230V welder is also 2.5 KVA. The 110V Dayton spot welder says it is at 2.5 KVA at 75% duty cycle and 1 KVA at 50% duty cycle. I hope this helps.
OccupantRJ
Well-known member
With the familiarity of one of the 15 KVA spotwelders we have at work, the Harbor Freight unit sounds a little light on uhmp to get the weld done on anything but thin material. The 15 KVA unit has 5 tap settings, and it usually takes a setting of 2 or 3 to even get a good weld on thin stainless tubing through one wall. If one were to assume that the taps draw equally from the transformer, it looks like it might take 6 KVA or so to get that weld. I am surely not an expert on the electrical end of spotwelding, but I have served my time on the aggravations and mechanical aspects of it through the years. I make most of the welding tips we use from scratch.
Here is a good pdf on the basics of spotwelding that may help someone.
http://www.lors.com/pdfs/what_to_know.pdf
Here is a good pdf on the basics of spotwelding that may help someone.
http://www.lors.com/pdfs/what_to_know.pdf
OccupantRJ
Well-known member
Major Ramifications - I did - thanks! I looked at a lot of different designs on line and didn't see anything quite like what I wanted to build so sketched it out and started welding.
Most of the metal came from my scrap pile. The return spring came from my kids' trampoline when I scrapped it. The box on the bottom isn't quite finished. It houses a timer that can be set to a half second. It will allow me to make real consistent welds - no guessing on the timing! I'm trying out a few hand held push buttons that will allow me to hold metal being welded in both hands and trigger the button with one hand. So far a remote auto ignition button seems to work best.
Overall it makes the welder a lot more versatile.
PCO6, if you will install a limit switch on an over travel assembly in relation to your foot pedal assembly, you can have it set so that when the welding tongs have clamped into position, then the switch will fire the welder. If you can insert a compression spring between your pedal mechanism and the upper actuating arm on the welder, then the foot pedal can clamp the metal between the tongs. Afterwards, the foot pedal continues to travel more downward triggering the limit switch I referenced. The switch needs to be adjustable in relation to the foot pedal so the metal is clamped securely between the tips before the welder is activated.
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Rookie2
Well-known member
Try welding without the vice grips.
PCO6
Well-known member
OccupantRJ - Sorry for not getting back sooner. My plan is to hand hold the metal being welded, step on the pedal and apply the same (generally) amount of pressure that the original handle would apply and then trigger a hand held push button on switch (remote auto ignition push button?) which will send power to the welder through a pre-set timer. I've bench tested it and it works. I just haven't figured out how I'm going to arrange everything in the electrical box yet. Your way would eliminate the hand held push button and that is well worth considering.