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Up Topic Welding Industry / Technical Discussions / Manual hotwire TIG
- - By Plasma-Brain (**) Date 11-21-2007 22:53
Greetings once again all,
I have recently aquired an old 110v mig welder which im planing to use with my TIG welder to supply wire instead of feeding it by hand.
Ive heard of Hotwire GTAW as an automated process and im wondering how it would adapt to manual useage and weather or not running 2 arcs that close together will dammage my machines at all.
My original intent was to just leave the ground for the MIG off and use it to spit wire, but now im wondering how well it would work running it on its low setting (it olny has low and high).
It should be noted that im olny really woried about dammage to my TIG and that as long as the MIG spits wire im happy.

thanks again, Clif
Parent - - By DaveBoyer (*****) Date 11-22-2007 04:27
I think this aplication is covered in the "Farm Code" someplace, but I can't quote the paragraph. I wouldn't expect the machines to damage each other if You don't use HF. If You use HF there is a posibility that You might blow the rectifiers in the MIG unit. I think this is a posibility even if You don't hooh up the ground. This posibility would come from the HF trtaveling to the filler wire instead of to the work, might happen, might not. Twice in the last year I have seen the same OTC brand cold wire TIG unit on eBay. It looks like a cross between a spoolgun and a TIG torch. I guess the same arc blow problems that every multiple arc aplication has to deal with would troubble You as well. Do You have an aplication that actually NEEDS the resistance heating of the filler wire? If not, how will You know if You are getting any benifit for Your grief ?
Parent - - By Plasma-Brain (**) Date 11-23-2007 18:17 Edited 11-23-2007 18:22
you are quite correct that this whole idea belongs in the "other red book", without a doubt.
As for aplication, all im trying to do is to see what happens so youve helped me avert alot more grief than dealing with arc blow.
as long as I keep the TIG on DC, and I keep the MIG wire away and the ground off until the HF start turns off, I shouldent blow up the mig...
Ill probibly end up running it "cold" anyways but its good to know what id have to watch for if I wanted to do it "hot".

thanks for the response - Clif
Parent - - By DaveBoyer (*****) Date 11-24-2007 03:58
I don't know what sort of voltage & amperage controll is normally used with Hot Wire TIG, but keep in mind that Your MIG welder is DESIGNED TO BURN CLEAR when the wire stubs into the puddle. This probably is not what You want for the TIG aplication, but I am going to let You do Your own research. You could, and probably should use a capacitor to block the HF from going into the MIG welder, I am not the guy to tell You what value cap that will take.
Parent - - By Plasma-Brain (**) Date 11-24-2007 17:09 Edited 11-24-2007 17:16
Voltage and amprage control is kinda a moot point with the machine I have... all I got for heat is High and Low and 1-10 for wire feed, so I dont really have much room to play with interms of settings.
I get what you mean with how MIG is set up over Hotwire GTAW... Hot wire usese just enough current to get the wire "warm" before it hits the puddle... MIG might hit the puddle and blow it apart from the short circut...
So the hot wire idea will olny work if the MIG arc isnt too harsh...
Adding the capacitor to block HF is an intresting idea, how would you set that up regardless of cap size? Im trying to picture how that would work and im not getting it...
Would you have the cap touching the Mig electrode, or wired up somewhere else in the system?

thanks again - Clif
Parent - - By DaveBoyer (*****) Date 11-25-2007 05:17
You can add resistance to the circut to limit the power going to the wire. The element from an old cloths dryer will work for this, You might need more than 1 strand [put 2 in parallell] to cary the current. It will get hot, and be electricly energized, so treat it acordingly. Aditionally, You might want to feed the MIG gun with AC [move the feed cable to the TRANSFORMER side of the rectifier] to controll arc blow.
The bypass capacitor would be mounted asross the MIG welder output. There are caps for this purpose used to keep the HF from going back through the welder when using TIG atachments [HF boxes]. Lincoln Ranger 9 owner's manual mentions adding one, but doesn't give a part #. 
Parent - - By Plasma-Brain (**) Date 11-25-2007 17:43 Edited 11-25-2007 20:48
Along the lines of adding resistance, anything that will absorb the current and not melt is what id be looking for? I have an old electric stove element kicking around the garage somewhere which might fit that bill.
As for running the MIG with AC, I just ran down stairs and looked and for the record, its a Century "Quick-Fix" wire feed welder and the transformer isnt easy to get at...
Its good to know that bypass caps are out there, now ill have to go pester the local welding store.
Theyre gonna look at me like I have a fork stuck in my fore head again... (they get alot of odd requests from me).
Something else I thought of for combating arc blow, especily if I get my hands on one of those caps, running the Tig on AC.
If the caps can do it for a Ranger 9 then im hoping they could handle a Percision TIG 185.
either way,
Thanks for your help
Clif
Parent - - By DaveBoyer (*****) Date 11-26-2007 04:47
A stove element is all or nothing, the ni chrome wire is inside the tube. The cloths dryer or similar element is open, and You can use as much or as little by bolting the cables to it with a machine screw, nut and washers. The transformer and rectifier are seperate components, look for cooling fins or aluminum plates in the cooling air flow to find the rectifier.
As for the bypass cap, have the guy pull up the Ranger 9 PDF and lok at page 34. It may be part of K799 High-Freq Kit, I would expect it to be available as a replacement part, or for use with other brand Hi-Freq boxes. Look at Lincoln part #T 12246 and T 11577-52A. And You had better do something about that fork stuck in Your forhead.
Parent - By Plasma-Brain (**) Date 11-26-2007 14:16
Well ill start looking around for a junked dryer, and as soon as I get the chance ill make my way over to the welding store.
When I get the chance ill pop the cover off the mig and take a look, its been cold lately and that makes it hard to want to go down to the garage...

About the fork in the forehead... ive been trying to get rid of it but it seems like every time I ask a question it comes right back...
I dont know if im asking the right questions to the wrong people or the wrong questions to the right people. One of these days ill ask the right question to the right person, and until then I can olny hope that the people I ask (like all of you on the forum...) will continue to indulge my "mad scientist" like ideas. So thank you for taking time out of your day to respond to a kid asking silly questions.

Part of being a college student I guess...
thank you again for your time, Clif

(ps, At least the fork dosent hurt anymore :) )
Up Topic Welding Industry / Technical Discussions / Manual hotwire TIG

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