Spot welder

General tips/tricks/tools that could be utilized on any platform.

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Ol'fogasaurus
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Re: Spot welder

Post by Ol'fogasaurus » Mon Nov 16, 2015 3:15 pm

Well, that was an interesting mid-day. I decided to make some coupons to see what I would be able to do with the spot welder.

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Besides a portable work bench and 4 "C-clamps" I used pneumatic shears, a combination pneumatic flanging and spot welding punch tool, a body hammer and anvil to ensure the coupons were flat and a marker.

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I am not sure what gauge the flat stock is but it is fairly thin. After cutting off a wide piece of stock and two narrower pieces I flanged two ends of the wider piece. I then took one of the pieces of flat stock, laid it on the flange, clamped it in place then spot welded it to the coupon. None of the spot welds were held more a second long.

I then punched holes in the other narrow piece and clamped it in place then rosette welded it to the coupon. I was not welding for beauty, just for comparison and in a hurry.

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The next coupon was a butt joint. It feels strong but I didn't try to break it... yet. I got a bit of a crown in it (probably too much heat too fast) and I was able to use the hammer to flatten it out.

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Next I tried to spot weld three pieces together. The back piece is much thicker than the front two but it did weld up and did not come loose when I tried to move the pieces. I did not try real hard but it felt firm.

Anyway, for what it is worth.

Lee

Ol'fogasaurus
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Re: Spot welder

Post by Ol'fogasaurus » Mon Nov 16, 2015 9:22 pm

Today when I was cleaning up in the garage and putting stuff way I tried to see if the spot welder nozzle I had bought years ago would fit so off came the old nozzle and i tried to slip the spot weld nozzle on the mount; it wouldn't fit. I had been told when I got it you just pull the old nozzle off and slip the new one on.

I got looking closer at the new nozzle and ther was a recess in it then threads.... whoh!!!! I unscrewed the mount for the stock nozzle and then tried to thread the new one on and Crapola!... it worked! Damn, all these years I had been fighting spot welds and irked over the nozze and all I really had to do was look at it and use my brain. :roll: Sometimes following instructions doesn't work then the brain should!

It still would not have worked on the black buggy as the flange where the bottom of the tunne and the tunnel itself were spot welded togeher had been trimmed back at some time in the past so there was a short edge margin.

Lee

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Re: Spot welder

Post by Ol'fogasaurus » Tue Nov 17, 2015 6:51 pm

Thanks for being so patient with me on this. It has become kind of a search to just what and how far I can go on this.

After looking at the one video (that has already been posted) I still went out and got the 120v spot welder as I have tried spot welding before with mixed results. Today I thought I would try it again after discovering that I was taking the advice of the tech literally rather than figuratively when I bought the spot welding nozzle.

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I started out today making a coupon. I spot welded the ends just to make sure of no gaps which could mess up what I was trying to do.

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I used a magnetic grounding piece to not only make a good ground connection but to keep the coupon from sliding around/

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The nozzle of my Hobart 120 MIG welder as I usually use it.

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The mount sans the nozzle.

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The gun minus both the nozzle and the adapter.

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The spot welder nozzle installed.

Ladies and germs! Normally, if I don't do a good job or make a mistake, I usually don't have a problem showing it or at least noting it but what I did was so embarrassing and such a piece of crap that even a septic worker in bib-waders with a inflatable buoy under his arms to keep from going in that deep would not allow him to wade through what I did. :oops:

Even the proverbial 4 1/2 inch grinder could not make this look better than power puking! I even tried to fix it by removing the adapter and putting the rest on which just make it worse. :shock:

Those guys who make up the videos need to have a first class enema for not showing that mistakes can be made. They always look so good but no body is that good all the time! 8)

I think I need to build a pair of those $75 pliers to allow me to keep the welder centered over the hole/area to be welded.

I hope someone learns something on this besides me. :lol:

Lee

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Piledriver
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Re: Spot welder

Post by Piledriver » Wed Nov 18, 2015 3:05 am

Take two pairs of cheap vice-gripish devices and weld a spacer in between if you must.
(or just clamp either side of the nozzle, using the nozzle as a jig)
That will be stronger and a bit more flexible that the pricey Eastwood piece.

You can even get wide vice-gripish clamps for sheetmetal and perhaps cut some notches in them for same use.
Done right you can then use a std nozzle as the clamp could set the spacing.
I, for one, regularly embrace our new robot overlords, as I am the guy fixing the robots...

Ol'fogasaurus
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Re: Spot welder

Post by Ol'fogasaurus » Wed Nov 18, 2015 10:36 am

I got several similars idea so check back later today. I think there might be better ways than just the locking pliers which have limitations. 8)

We survived the storm of last night but I have to go out and get some things and the wife wants to get some X-mas stuff for her great grandchildren (2).

https://www.bing.com/videos/search?q=sp ... A586D6574D

This is the Eastwood video that was posted.

http://www.eastwood.com/spot-weld-kit-w ... {MatchType}

Apparently there are a couple of these from Eastwood at different prices.

http://www.ebay.com/sch/i.html?_nkw=spot+welder

A lot of these look just like the one I bought.

https://www.bing.com/images/search?q=sp ... ajaxhist=0

I had forgotten about this one.

https://www.bing.com/images/search?q=sp ... ajaxhist=0

Some lengths and styles shown.

Lee

Up-dated for some information.

L

Ol'fogasaurus
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Re: Spot welder

Post by Ol'fogasaurus » Wed Nov 18, 2015 9:29 pm

So... Eastwoods locating tool looked pretty nice but so was the price so I decided to try to make one. I went up to my nearest tool store (HF) and bought a couple of things including an inexpensive locking plier.

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Using some scrap I had I made a practice attempt at it. I have several hole saws so after measuring the outside dia. of the spot weld nozzle I got a dia of .875. I have a 7/8's hole saw and a .99 (1") hole saw so, thinking I needed some extra room I used the 1" hole saw. Too big and it slipped off-set a bit even with a pilot hole.

Looking at Eastwoods again I decided I needed a top and bottom so, using the 3/4" hole saw I stacked two pieces of scrap stock (1.25), clamped them together with a Tee-bolt clamp setup and had at it. It turned out OK but I had to do some finish work on the hole as I had not put it at the end but inset it a bit. It didn't take much to open the front of the hole so the nozzle slipped in and fit well.

I then welded the pieces to the pliers. The tack looked great and I should have stopped there but ego said finish it.

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I got some warping and some crummy welds but it hammered back into the correct position. I wonder if Eastwood re-tempers their pliers.

The pliers are OK for edge work but what about deeper.

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I plan on making another locating piece and use either a magnet like above or I also have a couple of very deep throat locking pliers to hold the locating piece in place.

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How many times have you laid your MIG welder gun down and had it start to travel on you. Maybe this will work OK for me. Under $10 as I remember.

Lee

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Re: Spot welder

Post by Bruce2 » Mon Nov 23, 2015 11:55 pm

Ol'fogasaurus wrote:I got the arms aligned and everything adjusted. The arms are only 6" long; I asked my friend if the arms were standard and interchangeable and the answer is no! I did find out that the max length of the arms is ~18" and after that there is a big drop in working ability.
I don't know about the spot welder you have, but the Miller that I have has tongs that can be swapped out.

I know it's hard to believe, but the 3/4" dia copper tongs increase in resistance as they get longer. Best is to use the shortest tongs you can to ensure maximum current through the spot. The reduction in current from 6" tongs to 12" tongs is the same as from 12 to 18". IOW, the current loss is linear, and there isn't a "big drop in working ability" after 18".

Here's a question:
I was at a friend's shop and he has a Harbor Freight 240V spot welder. It is deceiving to look at, because it is exactly the same physical size as my 120V Miller welder.
A spot welder is simply a transformer.
Why can't I just take the plug off mine and install a 240V plug? The resulting voltage at the tong tips will be double, as will the current. I would expect the heat buildup in the transformer to be faster, but if you let it cool between welds shouldn't it be ok?

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Re: Spot welder

Post by Ol'fogasaurus » Tue Nov 24, 2015 12:47 am

Bruce2 wrote: "I know it's hard to believe, but the 3/4" dia copper tongs increase in resistance as they get longer. Best is to use the shortest tongs you can to ensure maximum current through the spot. The reduction in current from 6" tongs to 12" tongs is the same as from 12 to 18". IOW, the current loss is linear, and there isn't a "big drop in working ability" after 18"."

Good to talk to you again Bruce. I agree with the use of the "shortest tongs you can get".

The 18: length dimension (I'm pretty sure it was 18") I got from someone who sells spot welders and has for many years. He also use to repair welders as part of his job at a welding supply house. I assume he knows more than I do, on many things, but what I wrote is what I was told when I asked about it.

The main reason I asked about the length was could they be used with installing new pan halves; the distance from the side of the pan, at the rear bend of the body mount tunnel, at the back of the door including the stiffening flange, to the flange of the tunnel you weld to. I just went out and measured it and it is a hair more that 21"; the deepest throat locking (vice) clamp I have has a throat of a bit over 16".

When I was buying the 120v spot welder but still trying to make a decision between 120v vs. 240v, the guy at HF said the two spot welders were the same other than the innards of the welder (windings?) were a bit heavier duty (not exactly his words but close) to accommodate the heavier load that could be applied. For the light weight material I would be playing with the 120V would could do more than I need and I got the same answer from HF and the other guy I talked to.

"Here's a question:
I was at a friend's shop and he has a Harbor Freight 240V spot welder. It is deceiving to look at, because it is exactly the same physical size as my 120V Miller welder.
A spot welder is simply a transformer.
Why can't I just take the plug off mine and install a 240V plug? The resulting voltage at the tong tips will be double, as will the current. I would expect the heat buildup in the transformer to be faster, but if you let it cool between welds shouldn't it be ok?"


Other than the potential wire size of the plug (load capability) cord between the two could be a problem; we never got into that. Otherwise you are over my head now (remember that my electrical shop was in '58-'59) but I did burn up a electrical reciprocating saw when I accidentally plug it's 120v plug into a 240v supplied outlet in just a few seconds (a lot of sparks visible via. the cooling vents); I can only tell you what I was told and I am trying to be honest with what I found out.

I think I have also seen what could be described as two piece spot welders that are used for deep throat applications (like on assembly lines) but I also think they were of a are very specialized design (robots mostly).

Again, I was told that 18" was the longest made; I did a search on the web and based on what I saw that looked to be very possibly true. I did see other design tongs than what you and I have. Some of them looked like they were for special applications such as getting in and around things but the longest dimension I saw was in the 18" range. Do a search and you might be surprised at some of the shapes.

By-the-way, I Bing'd for spot welders (looking for pictures) and it is surprising how many look just like my HF unit but with different brand names and maybe even colors (I wasn't looking that hard for color though).

I don't think I helped with your question though. Best to really talk to someone who knows much more about it. I still think they are more useful to the average hobbyists' than they are given credit for.

Lee

Ol'fogasaurus
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Re: Spot welder

Post by Ol'fogasaurus » Tue Nov 24, 2015 5:25 pm

Quite a few years ago I was leant a Miller 240v spot welder, stand and all but I couldn't get it to work (silly me). I did have to make a special power cord for it as it took a 20 amp receptacle.

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For those of you that don't know or have never seen one, this is the power cord I made up. Notice the set of the prongs for each leg of t he 240 v.

Also, as a fun/silly side light I bought this:

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The heavy spacer rolls around but laying the spacer flat the magnet held it OK. You don't have to wear it on your wrist as the elastic band w/Velcro could be attached to many things. Much better than taking off fasteners, putting them down, knocking them off and having to chase them on the floor.

http://www.harborfreight.com/catalogsea ... 2&q=magnet

Lee

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Re: Spot welder

Post by Piledriver » Tue Nov 24, 2015 11:09 pm

I was thinking for pan halves, (esp if you had a shop and did it regularly) it might be sane to fab a long reach spot welder set of interlocked arms and hook a TIG power supply to the ends only.
Run the welding cables to the ends, just make it so the copper electrodes hit true.

You could do it with a cracker box stick rig (is technically a TIG supply stick uses constant current too, just with zero bells whistles or gas valves) and a contactor you could remotely operate, perhaps using a timer relay.
I, for one, regularly embrace our new robot overlords, as I am the guy fixing the robots...

Ol'fogasaurus
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Re: Spot welder

Post by Ol'fogasaurus » Tue Nov 24, 2015 11:56 pm

Based on the picture I posted showing my drilling of a hole in a piece of scrap I was thinking about making a strap with end long enough to go from the end of my long locking pliers to the area of the plug weld (in this case) to hold things tight, top and bottom to make the plug weld. It might not work well but it might be worth a try. Not a thing of importance right now... more of just musing.

Lee

Edit. The other option I already alluded to and that was to make a strip with a locating hole in it and use one or two of the 3 inch, 95# magnets to hold the pieces tight together.

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Re: Spot welder

Post by Ol'fogasaurus » Mon Apr 18, 2016 9:32 am

raygreenwood wrote:You can also get a spot weld kit for a mig welder from Eastwood. It has a pair of forked vise grips to clamp the parts and allow welding between the forks. It has a special nozzle with a leg on each side to gjve an exact standoff distance. The nozzle fits on the pliers which holds it still and at the exact distance. After you set voltage abd wire feed....its pretty simple and works well. I have used one I borrowed with my mig welder. Its about $75 for the whole kit. Ray
To add to the previous post which Ray was referring to (previous post I had made): to show how well the guide works: I drilled a small hole in a piece of flat stock and clamped it in place to another piece of material to see if it would affix the two pieces together.

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I did make a second piece of flat stock with the half hole but a longer end on it. Since the pliers do not have that long of a reach so if, lets say, you were looking at welding something in deep from a side of a panel then the tabbed piece could be held in place with a magnet and you have the same steady plug/rosette welding guide as the pliers.

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Lee

dragvw2180
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Re: Spot welder

Post by dragvw2180 » Sun Apr 24, 2016 11:47 am

A long time ago I worked in a shop doing restorations. One of the tools I used was a Lenco dual spot welder . It had two hand held electrodes , one had a button to start the timer which was adjustable for the thickness of the material. The other thing we used was a grey spray primer specifically for the spot welder so that the metal being spot welded would not rust between the welded panels , you sprayed both panels between the panels you were going to weld, it actually conducted the current for the spot weld. I have no idea if any of this is still available but it did work perfectly for me at that time. Mike McCarthy

Ol'fogasaurus
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Re: Spot welder

Post by Ol'fogasaurus » Sun Apr 24, 2016 12:41 pm

My local parts store stocked a weld through primer, I wonder if that is what you are talking about. I'll have to see if that is what it is for.

dragvw2180
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Re: Spot welder

Post by dragvw2180 » Sun Apr 24, 2016 12:43 pm

exactly the product

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