I have 125 amp Harbor Freight Flux Core welder. I bought it for $89. Weld was splattery (like dog’s slobber) and sucky. I decide to check out Welder mods. I found your site as well as other. I ordered 150amp Full Bridge Rectifier and 68000uf 63v Big Can Capacitor. Bought couple foot of black and red 6 guage wires, connector ect… I put it all together and made it neat and organize. I use old Pentuim III heatsink (4 inches silver heat sink with tiny cooling fan removed) and put thermal paste on its back, I drilled hole and bolted it to Full Bridge Rectifier. I trimmed Secondary Transformer wire that it will hold Rectifier without any contact around the welder case and cooling fin facing toward to welder cooling fan. Capacitor laid on bottom of welder and hooked up 6 gauges wires (red and black) according to its polarity to Capacitor and from there I hooked Electrode to Negative and Clamp to Positive. I haven’t add resistor to drain Capacitor yet but will do that soon. I tested welded the scrap using cursive “e” and setting #4 speed and Min setting. Weld on scrap look so beautiful, enough to make me cry. No splatter!! Soon, I will order Toroid cores and 6 Guage enameled wire to wrap around. I did not need to unsolder anything, just unscrew capacitor and re connect to Toroid and then I’m ready to weld. I will post Picture of my “design”. So it works perfect for the first time I’ve put together. (Of Course I’m electronic Technician myself).
Matt,
Why add toroid if allready beautiful? I get thats the way its usually done, but…
Rindert
LOL. Just want to have smoother DC current. I’ve built a micro DCEN experiment on breadboard. All old Electronic scraps from junks and luckily had a big fat toroid coil with 16 guage wire wrapped around from 600 watts high performance PC power supply (it had a lot of Toroids in it). I use 120v to 28v ac step down transformer, 20 amps full wave rectifier, 3 of 680uf 25v, big fat toroid, and 1k ohm resister (for draining capacitor). Fired it up and use volt meter and oscilloscope. It show that without Toroid, I can see flicker of ac on dc line, with Toroid, dc line is smooth. I posted it on YOutube. https://youtu.be/iN5UCXu79hg
Unfortunately, mini DCEN can’t weld but it put out big spark when tapping “electrode” end to ground…
(update) I just put up youtube video of my welder mod. it’s just silent video but observe! On end of video, you may see
video moved to edge of welder to see how flush the mods are. I will put thick tapes on connector so it won’t touch panel. Just my common sense…
Good luck
I have been struggling over the past year with power sources for my welding projects. I have a new-in-the-box buzz box 240 volt AC/DC stick welder and I made an extension cord to plug it into a range outlet, but I never had the opportunity to do so yet. I tried running my HFT flux core machine off of my 1500 watt inverter, but the inverter refuses to power it. So I ran an extension cord to my neighbor’s house while I wait for my 5000 watt 240 volt inverter.
But yesterday I was welding away on a stool for my gasifier and my flux core machine started buzzing loudly and lost a lot of power. It is unusable as-is. Upon examination there is either a short in the transformer windings or a bad connection at the spade connectors. So I used my deep cycle batteries to stick weld finish my stool. But I was left without a machine for welding thin sheet metal.
Today I wired four solar panels in parallel directly to the high current output of my wire feed machine before the inductor and disconnected the transformer. I was able to heat up and melt the wire, but I only had around 16 amps at 32 volts coming from the panels. I had a social function to attend so I didn’t connect more panels, but I did get a load center today and 10 circuit breakers to connect 10 to 15 panels together. After today’s proof of concept I am confident I will be welding wire feed powered by the sun tomorrow.
Here is a close-up of the guts of my welder. The two big wires on the left are positive and negative from the load center. Positive connects to the (lower) positive post of the capacitor and goes on to the ground clamp. Negative goes to the inductor through the other side and then connects to the negative post of the capacitor and on up the cables to the gun. The two wires from the secondary coil of the transformer are detached and taped off. I also removed the resistors that I had to drain the capacitor. I am now back to a hot tip gun, but I think that helps to kick start the arc.
Here is my first weld on my solar powered welder. They are water heater wire box covers. It works better on days with full sun. When it’s cloudy like today the power output from the solar panels can be erratic, but I will make do.
My solar panels are well-suited to power a wire feed welder because they are 235 watt panels that produce a steady 30 volts no matter how much sun is shining. 30 volts is about perfect for this kind of welding. Each one puts out a maximum of 8 amps or so. Therefore I can add a bit more power 8 amps at a time by flicking a switch. I feel like I have more control over the power level now than just to select min or max.
Brian,
What you are doing is interesting! Myself, I would put more battery and / or capacitors into the final stage of the system to store some electrons and average the load to the solar panels. If your panels get damaged, that’s a pretty expensive welder. Also, I think you should try out that N.I.B. “Buzz-box” welder, even if you have to take it to the 220vac source. You might like what that stick welder can do for you.
Good day, Mike. Thanks for the comments. How much more than 68,000 microfarads do you suggest? Plus I have the inductor which is a magnetic “battery.” It works pretty well for me.
I feel like if I can’t use my solar panels for what I need them for, then I might as well toss them into a landfill right now. I won’t be afraid. I really don’t believe they are so sensitive that they can’t handle short circuit welding. Time will certainly tell.
I do have a battery powered stick welder, and that is way too strong for welding sheet metal. It is hard to weld 1/16 and 1/8 inch steel with it. It pushes well over 100 amps. So anything under 100 amps I can use solar and anything over 100 amps I can use my batteries. I have a 225 amp hour 30 or 36 or 42 or 48 volt battery for welding heavy metal. It works great on the thick stuff.
Ultimately I have a 5000 watt inverter that will produce 20 amps at 240 volts coming from Taiwan in the next couple weeks and two of those babies will power my buzz box no problem. So I will get to try it out soon!
I should also mention that a friend of a friend wired some of his solar panels directly to a water heater element to heat water for bathing with solar. That is a resistor which is close to a dead short. Welding is similar; the wire acts as a resistor to create heat and melt the metal. I should be fine.
However, you are absolutely correct: if short circuit welding damages either my solar panels or my batteries, then it is a very expensive set of welds, indeed.
I am actually more concerned about the batteries. They are rated at 225 amp hours, but that is a 20 hour rating, meaning that you could draw 11.25 amps for 20 hours and they would be completely dead. Doing so would damage them, though, so a rule of thumb is to never discharge them below 50% capacity. Maybe draw 11.25 amps for 10 hours. But I am drawing 120 or 140 amps, and such a huge draw is very hard on them and reduces the overall life of the battery. But I need to stick weld right now, so do I use them, or not? What do I even have them for if I can’t use them? I try not to weld very much and then fully charge them the next day. Solar powered stick welding. Something else.
Brian, after some thought, my suggestion didn’t sound so brilliant. It looks like what you have is working. The inductor is a good thing, and 68,000uf is quite a lot of storage. I guess modern solar panels are fairly rugged if they survive direct connection to a water heater element. Lately my welding skills have been shown to be inconsistant. I am good at melting random holes in a lawn mower deck attempting repairs. We will see how long that repair holds!
Mike my memory failed me. It is an AC225 Lincoln Electric.
Well my inverter has arrived so now I can connect 18 of my solar panels up and also connect to the grid permanently and I will have all the power I will need.
I worked with electric vehicles for a while. The rule of thumb is never discharge a 12V lead acid battery below 10.4V.
Rindert
Ideally you have enough battery capacity that you never push your batteries beyond the manufactures recommendation.
Some types of battery might go a little deeper than others depending on the chemistry.
But the less deeply discharged the better for making your batteries last
For many years we got along pretty good by trying to keep the batteries always charged as possible.
Example of you know you are going to need a lot of DC.
And if you have a delco plant start it before you draw your batteries down.
If you do draw your batteries down charge them asap to reduce large crystal hard sulphate formations that are the killer of batteries.
Some people will want to avoid gasoline powered lighting plants.
I get is you want something that’s wood fueled.
By all means built that! But have a gasoline back up lighting plant too
On hold but not a still born project this will one day be an automatic battery charger.
See the automatic choke?
That’s my special doing, made from Kohler lawnmower parts ( XT-6 series engine )
Stick with a good Chinese Copy of a Honda and you never go wrong.
There will be parts and pieces of these around forever.
Cost of this build to day is about 60 bucks in scrap parts including an old Ford alternator not shown.
The alternator is an old FORD G1 with external regulator.
It can charge or it can also weld as long as you stick with small rods and light duty jobs.
You might even get creative and re power an old flux core with one
Out yard saling with the wife?
This little fellow is an APU off military vehicle from the 40s.
Its a Johnson chore horse generator rated at 300 watts.
But its electric start and frugal in gas.
if your batteries are low and you just need lights for an evening these little lighting plants are still out there to provide you with some AC late at night.
So, off on a ramble there, but you get the message don’t abuse your batteries by deep discharging.
Have a back up ready to provide supplemental power and lighting and your batteries will thank you for it.
You guys may have noticed always a paper bag from the liquor store seems to appear in my photos…
One might think I have a problem ha ha.
No I keep all paper bags and these are all filled with charcoal.
Adding great vid of a DC chorehorse ( mine is AC 120v for a radio )
Not a great welder, but you can stick things…
Did anyone ever make a proper video on how to do these mods such that i don’t kill myeslf?
I can do the labor to build this modded welder, but I don’t have intimate knowledge about electrical parts, etc or not know where to stick them.
Any suggestions on a DC welder from factory?
You shouldnt attempt these mods as a first project.
here are some basic tips if you insist:
your welder takes 120 or 240vac from the wall and drops it down to lets say 10v-25v at what ever the number on the side is (usually) in amps. Most list open circiut voltage but there will be a sag with actual weld. so lets first demonstrate some theory. volts = ohms * amps and power in watts=amps*volts…
allweldgeneric 90 … number is usually amps but wait what? do they make a breaker that big? lets say 15v actual weld v on average 15*90 = 1350 watts of power using algebra we can see that to get amps at 120v we can then divide the watts by wall side voltage… and 11.25a is the answer.
how much does it take to stop a heart? 0.01a to 0.02a is actually the most effective. heres the good news, your dry unbroken skin has a resistance of around 100k ohms.
volts = ohms * amps and visa vi algebra …
amps = volts / ohms
Normally 120v isnt going to kill you. but things like sweaty hands high humidity and capacitors, or some kinda fetish for sticking things up your… 120v CAN kill you do not treat it otherwise. 120v ac is also a RMS measure. Add a capacitor on the 120v side and around 170v is actually the shock you will be getting.
usually under 50v the shock risk is minimal. you can google around but I think all relevant agencies will deliver with in 15v of what i just said as advice. ALWAYS TREAT 120v wall power as deadly, once you get down to under 50v… shocking burning blinding fire etc still risks
and again the big Capacitor(s) found on the low v side of a welder, could blind or burn the hell out of you, possibly blow up if shorted out. Assume Any Capacitor on the wall plug side of things will stop your heart, as well as make you wish it had for the blind, burn, blowup reasons.
google proper way to discharge a capacitor. before you open the box.
otherwise there is a rule called one arm behind the back. this works better with another bit of kit called an isolation transformer but is decent as is. the theory is you minimize the chances of actually getting a shock across the heart.
google electronics types of passives and familiarize your self with what they look like.
understand the hazards i said above and reread. I cant hold your hand here. Its great if you have an interest. im not trying to be elitest here which is why i include the reasoning and some advice on how to acquire the knowledge you need. I do want to make sure you stay safe and tried to point you in the right dirrection down that path.
one last tip. 60/40 leaded electronics solder. Flux made for electronics soldering. wash your hands…dont go lead free especially learning and or trying to do a big first project. lead was used for so long because it was hard to beat the preformance of it for what it was used for. some argue it hasnt been done yet. its also pretty easy going on the soldering profile / doesnt need exact temps and times… just the right flux
Just try this. I think you’ll like it. Clean your soldering iron, solder, circuit board and all surfaces you want to solder with vinegar. THEN assemble everything. Do not use flux. Flux just makes a mess. Use white vinegar, the cheap kind you can buy by the gallon at the grocery store. Just as a sanity check, put a drop of vinegar on an old brown penny, wait for an hour. You will see a color change. The vinegar will have changed the copper oxide back into copper metal.
Rindert