I have actually a buddy that impulse bought a harbor Freight 90A flux-core cable feed welder. I have to admit come looking at them too, especially when they go on sale for under $90. They’re probably not a bad deal because that the sometimes weekend welding project, to add the 110V portability is nice. Yet as my dad constantly told me together a kid “you gain what you pay for”. Bottom line is the welds look at terrible. Penetration is poor and there is a most spatter. Problem with the share welder is it’s AC output, not DC. Existing flows ago & soon from the pond to the wire which reasons the flux-core wire to spatter even much more than DC flux-core wire welding. All other HF wire feed welders room DC if the tells friend anything. Ns did a small web research, watched a few YouTube videos and also found the it’s fairly easy to convert these systems from AC to DC. The two pieces that hardware essential are a full-wave rectifier and an electrolytic filter capacitor.The rectifier take away the sine wave AC and flips the an adverse wave to the optimistic side so the calculation looks choose “hills” running from 0V to top voltage and ago down, then back up again. The capacitor smooths out the “hills” to a relatively straight line or DC output. The videos ns watched recommended a minimum 47,000 uF electrolytic capacitor v 30V minimum rating (welder outputs 28V). I found a number of eBay sources for the rectifier rated in ~ 1000V and 100A because that $10. Uncovered a Siemens electrolytic lid rated in ~ 40V and also 47,000 uF for $25 delivered. One more important ingredient is a shunt resistor across the 2 leads that the capacitor. The resistor drains the capacitor after welding, otherwise the cable is quiet grounded and your ground clamp is tho hot! Some guys on your conversion discharged the capacitor by poignant the wire to the soil clamp; mean a pretty spark. The capacitor I discovered had a shunt resistor currently there, drains the cap in around 3 seconds.The switch is quite simple; reduced the calculation leads from the welder’s transformer and jump them to the AC next of the rectifier. The transformer calculation leads each have a tiny lead that runs to the welder’s circuit board, for this reason the splicing takes place downstream from that point. The rectifier has actually two calculation leads; + positive and – negative. Those leads operation to the proper terminals ~ above the capacitor. Because that flux-core wire, the welder ground clamp must be DC positive. So, the welder’s soil clamp lead is tied to the capacitor’s + confident lead. The weld pistol is tied come the capacitor’s – an unfavorable lead.One point I didn’t treatment for ~ above the on-line conversions is just how they placed the rectifier and also capacitor. Every one of the examples had the rectifier mounted on the next of the case. They mounted the capacitor by drilling a pair of feet in the case and tie strapped in down. Ns guess that’s probably just how Harbor Freight would carry out it . . .I chose to mountain the rectifier on the earlier of the case, just looks cleaner come me. Additionally made a sheet steel bracket to mount the capacitor next to the transformer. The cooling fan had to be relocated down to make room because that the rectifier. New fan holes to be made in the case, in retrospect i should have removed the ago panel and also punched lock on my Roper Whitney #218 press, however went the much faster route the drilling the holes. Then spent 15 minutes cleaning increase burrs . . . You have the right to see native the instance welds that the DC conversion renders a people of distinction on the top quality of the welds. Ns ran a bead making use of flux-core cable from my Hobart Handler 190, the HF share AC and also HF after the DC conversion. Much, much lessened spatter and much better penetration. The welder sounds better too, simply a sizzle while welding rather of numerous spattering.So what did i learn? due to the fact that everything in my shop will end up being my boy someday, ns went out and also bought one more Hobart, now have actually a Handler 140 (110V) come compliment mine 190 (220V only).


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Sure, the Handler 140 110V welder is $500 contrasted to the bottom line around $150 for the HF 90A converted to DC. But I don’t desire my kid to inherit my shop and say, “Wow, dad bought a lot of cheap junk!” top top the other hand, money doesn’t prosper on tree so if you do have one of these HF 90A welders, take into consideration spending approximately $50 and make some much better welds.Bruce
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