DC conversion for AC stick welder

Dozerash

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Upstate, NY
Welder
Hobart 210, Primeweld 520, Miller Thunderbolt, Wards 230
Has anyone done the conversion on an old AC stick welder to DC? My brother in law just did one with a 300 amp bridge rectifier. Cost him about $20. I would like to do my Miller Thunderbolt and be able to change it back to AC. Anyone else do this conversion?
 

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kayco53

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Shnook
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systematics
Didn't know that could be done. Let us know if it works! I have a miller ac like in the pics given to me. Cabin machine. DC would be nice.
 

California

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Sonoma County
Has anyone done the conversion on an old AC stick welder to DC? My brother in law just did one with a 300 amp bridge rectifier. Cost him about $20. I would like to do my Miller Thunderbolt and be able to change it back to AC. Anyone else do this conversion?
Don here did his Lincoln AC-225 and posted photos. Just a rectifier, an aluminum plate for a heat sink, and a fan.


lincoln_225_conversion_3-jpg.428
 
Last edited:

Dozerash

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19
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Location
Upstate, NY
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Hobart 210, Primeweld 520, Miller Thunderbolt, Wards 230
I have the parts to build this just haven’t got around to it yet. I hear it works well.
 

kjonxx

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Has anyone done the conversion on an old AC stick welder to DC? My brother in law just did one with a 300 amp bridge rectifier. Cost him about $20. I would like to do my Miller Thunderbolt and be able to change it back to AC. Anyone else do this conversion?
I did this to my ac welder almost identical to your pic and its easy and reversible.
 

Old Irish

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The River Sticks
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Lincoln SW200,PowerMig 180, A/C225 with rectifier, 2 Chinese plasma, stick, tig- 1-Chinese stick w/hot start&arc force and 1 Chinese 205A mig
I did the conversion on a L225, I didn't use a capacitor and was VERY disappointed with the performance. A capacitor would probably much improve it but not worth the cost since YesWelder sells a good welding inverter dc welder for a little over a hundred bucks. I had the 160 amp stick machine and it worked great, my son in law wanted to learn to weld so I gave it to him and my grandson's. I have the 205 mig/stick machine and I like it as well, mostly I use it for scratch tig. I have a Lincoln SW 200 a/c-d/c but the YesWelder is more convenient.
It was a fun project with poor results.
 

efred

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Edmore, MI
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Millermatic 250
I would like to do the opposite: convert a multi-process welder (MIG, TIG, Stick) into a AC/DC welder so I can weld aluminum tubing.

Does anyone know how to do it, and what it would cost?
 

Old Irish

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The River Sticks
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Lincoln SW200,PowerMig 180, A/C225 with rectifier, 2 Chinese plasma, stick, tig- 1-Chinese stick w/hot start&arc force and 1 Chinese 205A mig

bert47

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I would like to do the opposite: convert a multi-process welder (MIG, TIG, Stick) into a AC/DC welder so I can weld aluminum tubing.

Does anyone know how to do it, and what it would cost?
Im not sure about your question. If you still have the MillerMatic 250, add a gas bottle and a spool gun and go weld aluminum.
 

kpsp50

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Az
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HTP and Miller
Check out primeweld welders for $500 you'll get a ac/dc mig stick with spool gun for aluminum 3 year warranty. Happy welding
 

aircommuter

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Coulterville
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Lincoln, Esab, Linde
Lots of good used a/c, d/c machines out there with power factor correction and other factory designed filters that are very smooth. I still have my Lincoln TIG/Stick A/C, D/C 300 amp 1982 I bought new.
 

Don_

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Kern county mountains
Welder
Hobart 187, Primeweld AC-DC TIG Stick, Powermax45, Lincoln 225
The capacitor is needed in making the conversion work, otherwise you will just stick the rod. The capacitor gives the little extra to start the arch, the same reason there are start capacitors on large motors such as HVAC units.

I bought the Yes spool gun on Amazon for around $50 bucks and it worked surprisingly well. I managed to fab a gas tank for a tractor build and a few other items. Remember, you need straight Argon on aluminum.

I used it up until I purchased a Primeweld Weld Tig/Stick as mentioned by Kpsp50. It is just a beast. I torture tested the unit burning 40lbs of 1/8" & 5/32" on 1/2" - 3/4" plate on the 4' tilt bucket for my excavator.
I highly recommend their products.

Until then the DC conversion will work and give you incentive to upgrade your machine.
It's part of the process of getting to where you have the equipment that you need to do what you want to accomplish.

Just my 2 cents.

Don
🤠
.
 

Lowensenf

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16To12Twelve?
Welder
Old Lincoln Stick
Has anyone done the conversion on an old AC stick welder to DC? My brother in law just did one with a 300 amp bridge rectifier. Cost him about $20. I would like to do my Miller Thunderbolt and be able to change it back to AC. Anyone else do this conversion?
Where did he geet teh rectifier? What are the specs? Link?
 

Don_

Active member
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Location
Kern county mountains
Welder
Hobart 187, Primeweld AC-DC TIG Stick, Powermax45, Lincoln 225
Sorry guys I made three posts with three links to the Amazon items but they were deleted for some reason.
If you go to Amazon and do a search for the rectifiers and capacitors "for AC to DC welder conversion" they will take you to the items.

Also, I saw this today and thought it might be of interest to some of you.

Using a car alternator for a DC welder.

Don

.
 
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