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View Full Version : Urgent advice needed: Hobart 180 porous welds



ATL ZJ
10-07-2009, 01:39 AM
Recently my Hobart 180 has been acting up again. I'm getting intermittent porous welds like the material is dirty or I have poor gas flow. I don't think it's either of the above, because I've spent over 5 hours troubleshooting. So far I've checked the o-rings on the lead, removed the cover and checked the gas flow solenoid, tested the regulator, checked and tightened my ground clamp, cleaned any possible corrosion off cable lugs with scotchbrite, test welded on dozens of different pieces of clean steel at different heat and speed settings, and spent about an hour searching on Hobart's Weld Talk forum.

The machine itself is about 4-5 years old and has been used a lot, but is in good shape overall. This spring, I added a brand new HTP gun assembly, and I have a tweco ground clamp installed.

OK here's the question ;) - normally I weld with 2 or 3 short extension cords that are about 10 feet each connected to each other. The oldest one is a very rigid cord that has the only male plug that's compatible with my dryer outlet. Tonight I swapped the oldest one out that for a newer SJOOW cord that is more flexible and it seemed to fix my porosity problem. Is it even possible that a (damaged) extension cord could cause bad welds? The plasma cutter I've been running off the same extension cords seems to run fine even when the welder isn't.

I have some stuff I'd like to weld on Thursday (weather man says it'll be sunny that evening) so if you have any ideas, I am all ears, otherwise I may try to pick up a longer length of SJOOW and try that.

FortCollinsZJ
10-07-2009, 01:57 AM
I have a hard time thinking that poor quality electrical would have any effect on poroosity, I have welded with a surge protector and other tools sucking power at the same time, just makes for less heat I've seen.

Porosity typically is from poor gas quality, too little shielding gas, gas trapped in the weld pool, or impurities in the material.

Have you ruled out that the gas could be faulty? Maybe a bad mix or something.

ATL ZJ
10-07-2009, 10:48 AM
I have a hard time thinking that poor quality electrical would have any effect on poroosity, I have welded with a surge protector and other tools sucking power at the same time, just makes for less heat I've seen.

Porosity typically is from poor gas quality, too little shielding gas, gas trapped in the weld pool, or impurities in the material.

Have you ruled out that the gas could be faulty? Maybe a bad mix or something.

How often does c25 get mixed wrong? I'd hate to waste a half bottle of gas just because it might be bad.

What if my ancient extension cord had a broken hot lead, essentially making it 110v when the cord was laid in a position where the broken ends were not touching and unable to conduct? The strands in it are solid rather than braided wire so that's why I even suspect this. What would happen in that hypothetical? Would the welder even run?

Does anyone have any recommendations on leak testing products? I know there are some dyes/sprays you can use to detect inert gas leaks?

rstrucks
10-07-2009, 11:05 AM
I'm guessing that you do your welding outside too? You didn't just have a little bit of wind blowing did you? I know when I weld in my garage with the door open and it's windy, it will affect the gas shield.

What psi is your gas regulator set at?

ATL ZJ
10-07-2009, 11:21 AM
I'm guessing that you do your welding outside too? You didn't just have a little bit of wind blowing did you? I know when I weld in my garage with the door open and it's windy, it will affect the gas shield.

What psi is your gas regulator set at?

I do a good bit of welding outside, but I have also run a lot of beads in the back of the garage where there is almost no air movement.

I've had the regulator set as low as 10 and as high as 30 CFH

Ken L
10-07-2009, 11:33 AM
Are you still using the same brand of wire? I switched wire brands once with spectacularly shitty results. I use the Miller/Hobart labeled wire exclusively now.

ATL ZJ
10-07-2009, 11:39 AM
Are you still using the same brand of wire? I switched wire brands once with spectacularly shitty results. I use the Miller/Hobart labeled wire exclusively now.

I'm running blue demon .030 wire that came from mcmaster. When I unwrapped it out of the plastic and welded with it for the first time, it had an amazingly nice weld quality. That was a couple months ago. So I think it's decent wire, especially since I've never received a product from mcmaster that wasn't high quality.

BUT we've had a lot of rain here recently and it's been very humid. My welder lives in a garage that stays humid most of the time, so I'm wondering if the wire might have rusted a little. Think it's worth swapping a brand new spool of wire on? Should I be wrapping my welder up to keep humidity and moisture out?

ATL ZJ
10-07-2009, 01:16 PM
I'll add that the polarity is correct and the gas diffuser and nozzle are clean.

I'm thinking about copying an idea I found... Sliding the wire through a soft earplug to clean it as it comes off the spool. But I might grab a new spool of wire too and see if either makes a difference.

Any more ideas?

zj95maxx
10-07-2009, 01:56 PM
I have found for best welds on the hobart 180, is to set the gas flow at at right above 20, but below 25.

Never had a problem with porous welds except when something isn't as clean as it should be.

Here is something you can use as an alternative to the "ear plug" idea, this lubes it as well.
http://store.cyberweld.com/weaidlulupa.html

rccolacc
10-07-2009, 02:05 PM
I would bet that it's some rust or something on the wire. FWIW I also only use lincoln brand wire and I try to keep the welder inside the shop as much as possible. I've had trouble with porousity when I use other brand wire.
I don't think your cord has anything to do with your problem. If the welder was only getting 110 I think it would just quit all together. If it wasn't getting enough amperage from the cord I think you'd notice penetration issues or the welder hitting its duty cycle more often.
Try the earplug idea or get new wire. I bet it fixes your problem.
-RC

zj95maxx
10-07-2009, 02:07 PM
Here is someething I found on teh enternetZ machinesz

Porosity in welding is a result of dissolved gases or gases released during the welding process, being trapped in the metal when there is insufficient time to escape prior to solidification. If in the shape of rounded holes, the gas is called spherical porosity or just porosity. However, if elongated the terminology is wormholes or piping. Causes of porosity are;

excessively long or short arc length
welding current too high
insufficient or moist shielding gas
travel speed too fast
base metal covered with oil, grease, moisture etc.
wet, unclean or damaged electrodes.

Also

How is your welding nozzle? The one where you can pull on and off, not the contact tips. When mine was melted down a bit, it would make bad welds. To solve the problem without buying a new nozzle, I would slide it up as far as I could go without removing it. This directed the gas flow better than the melted tip that was letting gas out easier because of the more wide open area.
Obviously now I have a new nozzle.

ATL ZJ
10-07-2009, 02:48 PM
I swapped on a brand new contact tip and my nozzle is very clean. I remove any slag that builds up in my nozzle often, and the nozzle itself is less than 6 months old because I got a new one with my HTP gun assembly.

zjeepin
10-07-2009, 03:33 PM
use a piece of scotchbrite pad with a clip on it to clean the wire before it goes into the rollers.. cheap and effective. if there is any rust on your wire it would be obvious but its copper coated so corrosion there isn't very likely.

it may be a good idea to put some damp-rid inside the welder, just set a can of it inside where the wire spool is. try to eliminate some of the humidity, it is effin humid in the A-town...

are you sure you havent let something fall on your new lead possibly pinching or damaging the outer liner?

I have gotten bad bottles of gas in the past, it does happen, they sometimes get mislabled too. are you running 100% co2 or unimix?

make sure your diffuzer in the gun is clean, spatter can get down inside the little holes and cause gas flow problems. its the part that the contact tip screws into..

I don't think that supply amperage is a problem but i'd still take a volt meter to the extension cable in question and check for continuity and resistance on each wire.. I can't tell you what the resistance should be other than it should be the same for each wire.. also plug the cable in and test it with the volt meter and make sure you are getting the correct voltage and amperage.. but like i said i don't think the power supply is your problem..

im not sure if you've tried it or not but you may just try taking your liner out of the lead and putting it back in, maybe a piece of trash is blocking gas flow intermittently?

make sure it isn't twisted either, that can cause it to kink like a water hose

edit: inert gas leak testing solution=soap and water mixture

ATL ZJ
10-07-2009, 03:45 PM
Awesome ideas trey.

The scotchbrite pad is a great idea, I'll try that and maybe the earplug also. I have noticed a light brown dust forming on the drive rollers occasionally, so the wire may be oxidizing somehow.

the diffuser is very clean. I checked it yesterday and fished a piece of wire into each of the 4 holes to make sure they were spotless.

I've been very careful with the new lead but I'll try pulling the liner out to check for blockage.

The gas is c25 (argon/co2 mix) and there is about 1400 psi in the bottle now. I have gotten some awesome welds out of this same bottle.

One last thing, when I set the welder to purge to test gas flow, there is a large puff of shielding gas out the end of the gun. If I hold the trigger down after that, the gas flow gets very weak and silent. Should the flow be more constant than that? It almost like the solenoid is opening and closing right back.

zjeepin
10-07-2009, 03:52 PM
you might even put some graphite lube on the scotchbrite, i don't think that would hurt anything but i think they have a lube they sell at the welding shop just for lubricating the liner..

try blowing the liner and solenoid out with compressed air, the welder has got a few years of age on it and has been used outside alot, and it has had a lot of wire run through it.. (my miles of wire welding theory) there could be some corrosion developing in the solenoid itself.. can you take it apart and spray WD or something through it?

i can see there being an initial puff of gas but pressure should stabilize pretty quickly.. i wonder if there is a way to test the output pressure at the gun.. it still makes me think of a piece of trash acting like a baffle somewhere in the system.. like the baffle opens up when flow stops, then when gas starts to flow again it blocks it..

ATL ZJ
10-07-2009, 04:04 PM
i wonder if there is a way to test the output pressure at the gun.. it still makes me think of a piece of trash acting like a baffle somewhere in the system.. like the baffle opens up when flow stops, then when gas starts to flow again it blocks it..

I can slide a plastic bag over the gun, put a rubber band around it, and see if it inflates. Wouldn't test pressure but should indicate if there is any flow, right?

zjeepin
10-07-2009, 04:13 PM
would definately indicate flow, and how tight it will fill the bag would at least be an indication of pressure..

you might even try putting the bag over the nozzle after the initial puff...

ATL ZJ
10-07-2009, 05:17 PM
Hopefully I don't need this, but I'm putting it here so I don't lose it.

the p/n for the solenoid is 218422 and superseded the old p/n of 128751 that was printed in the owner's manual. This is the only one I can find on the web. http://www.weldfabulous.com/ClearanceCloseouts/Miller-218422-KIT-GAS-p7088366.html

rccolacc
10-07-2009, 05:35 PM
What about the regulator? Could it possibly have some dust or something in it causing weird things regarding flow or pressure? If you take your tank on and off a lot maybe some dirt or something got in it? I'd suspect a faulty regulator before I would go buying a new solenoid on the welder.
-RC

paulkeith
10-07-2009, 07:55 PM
swap/scrub your wire. since i only get to go fab like once every 6 months i run into this problem a lot. garage back home is not climate controlled and SC probably qualifies as "humid". wire gets rusted up all the time, and the cheap crap deteriorates quicker.


I can slide a plastic bag over the gun, put a rubber band around it, and see if it inflates.


thaaat's what she said

ATL ZJ
10-07-2009, 11:05 PM
I bought some new lincoln wire today, which I'll try today, along with the other tricks above.

Thanks for all the help guys.

zjeepin
10-08-2009, 10:53 AM
results?

ATL ZJ
10-08-2009, 11:14 AM
by today, I meant tomorrow, as in today.

I was too busy getting robbed yesterday to play with the welder.

zjeepin
10-08-2009, 11:24 AM
I was too busy getting robbed yesterday to play with the welder.



care to elaborate?

ATL ZJ
10-08-2009, 11:27 AM
from shoutbox thread


So my house got burglarized today... stole my laptop, camera, and a very important hard drive... as well as my roommate's computers, pistol, and plasma tv... shit sucks.

zjeepin
10-08-2009, 11:49 AM
Tate said she'd give you a good deal on a security system..

sucks though, file a police report and everything?

ATL ZJ
10-08-2009, 12:00 PM
Tate said she'd give you a good deal on a security system..

sucks though, file a police report and everything?

Haha thanks.

Yeah the police came and actually seemed to care, tried to get fingerprints but no luck. Hopefully the homeowners will end up being generous because I don't have renter's insurance.

One more reason to fix the welder on the cheap right?

ZJ TINS
10-08-2009, 02:01 PM
Keep your wire in a plastic bag with desicant. Porosity is typcially from moisture not set up. Also use a stainless steel brush to clean the weld surface just before welding (unless you just cut or ground them).

zjeepin
10-08-2009, 02:22 PM
shit sucks man, good luck with recovering your losses. i hope your roomates gun isn't used in a crime or anything. he's probably smart enough to cover his ass with it being stolen anyway,. jackass thieves will probably just pawn it.

would have expected a breakin in spartanburg especially with our projects in plain sight in the back yard in cracktown but not in your hood..

ATL ZJ
10-12-2009, 10:15 AM
OK got the welder working. Here's what happened just in case anyone is interested or searching in the future.

I changed the wire first, since that was the easiest thing to check. Put on a spool of lincoln .030 superarc. Made absolutely no difference.

Then I tried the plastic bag trick, and used a rubber band to hold the bag around the end of the gun. The bag inflated, but it took 10-15 seconds. The fill rate was very slow after the initial puff and the regulator was set to 30 cfm. It was only a small sandwich bag, so that didn't seem right. So this confirmed it was definitely a gas flow problem.

Mixed up some water and shampoo (soap) and dripped a little on the connections where the lead connects to the machine just past the drive roller assembly. Got a few bubbles coming out where the liner threads into the gun. So I pulled out the gun and put some plumber's tape around the brass part of the lead, just inside of the inner o-ring. Blew the entire lead out with compressed air. Tested it, and nope, still welding with a lot of porosity. Same result on plastic bag test.

Took the cover of the machine off. Leak tested the clear hose that runs from the solenoid to the lead. No leaks. Removed and disassembled the solenoid, tested it while it was apart to confirm that it worked. It did. Blew the solenoid out with compressed air and reassembled. Test welded again. Still porous. OK what is going on.

Removed the regulator, blew it out with compressed air, reinstalled, and test welded. It welded with zero porosity like a brand new machine. I guess somehow the regulator got stuck and would only let the gas flow initially, then cut it off to just a very slow trickle. I think I'm going to try to start turning the regulator completely out when the machine is not in use, in hopes that it won't get stuck again.

zj95maxx
10-12-2009, 10:17 AM
Glad you got it figured out man. Sucks you had to go through all that to get it working though.

paulkeith
10-12-2009, 12:39 PM
so you were shutting the gas off at the cylinder?

I guess I've always turned the regulator all the way out after use, but not for any specific reason/instruction, just kind of did it.

Good to know, thanks for the tech follow-up.

ATL ZJ
10-12-2009, 12:46 PM
so you were shutting the gas off at the cylinder?

I guess I've always turned the regulator all the way out after use, but not for any specific reason/instruction, just kind of did it.

Good to know, thanks for the tech follow-up.

Yeah, gas flow was getting stopped up in the regulator somehow. I always close the main valve on the bottle, even if I'm only pausing for 15 minutes between welds. I'd never in a million years have thought it would have been necessary to relieve all the pressure at the regulator after every use. Seems like a regulator would be a set and forget item but apparently that isn't the case.

Pearce
10-12-2009, 09:02 PM
For what its worth Tim always told me to shut the tank valve and then drain the system after every use. I'm now in the habit of always doing that.

rccolacc
10-12-2009, 10:26 PM
The welders I used to work with would always open the tank valve a second to blow out any dust that was in the threads before they put on the regulator whenever they were switching tanks. Apparently it doesn't take much dust build-up to make the regulator act up. Obviously if you have a small tank or you're constantly taking the regulator on and off for transport or something, then the problem's worse.
Glad the fix was easy. Those are always the best kind.
-RC

chadjans
10-20-2009, 02:58 AM
I am just now finding this thread. Sorry to hear about the house rob.

There were a few things that were mentioned in this thread that should be considered before implamenting.

Stainless steel brushes are used for cleaning aluminum. Regular wire brushes are fine for steel and will last longer.

Welding wire comes prelubed from the factory. If you use one of the mentioned wire wipes (ear plugs) you are wiping off all the lube that is applied to get the wire to run better through the liner. Leave off the wiper and get in the habit of cleaning off your rollers and checking your liners and doing general R and R on your welder.:drinkers:

ATL ZJ
10-20-2009, 09:31 AM
I am just now finding this thread. Sorry to hear about the house rob.

There were a few things that were mentioned in this thread that should be considered before implamenting.

Stainless steel brushes are used for cleaning aluminum. Regular wire brushes are fine for steel and will last longer.

Welding wire comes prelubed from the factory. If you use one of the mentioned wire wipes (ear plugs) you are wiping off all the lube that is applied to get the wire to run better through the liner. Leave off the wiper and get in the habit of cleaning off your rollers and checking your liners and doing general R and R on your welder.:drinkers:

Good to know about the lube on the wire, chad. Is the purpose of the lube to allow the wire to slide through the liner easier, or does it have the potential to affect the quality of the weld as well? Sounds like those pre-drive roll lubing devices might be the best solution to clean the wire and keep it lubed. Although these days, I'm burning wire so fast it shouldn't be a problem.

chadjans
10-20-2009, 02:14 PM
Is the purpose of the lube to allow the wire to slide through the liner easier

or does it have the potential to affect the quality of the weld as well?

Sounds like those pre-drive roll lubing devices might be the best solution to clean the wire and keep it lubed.



Yes

No

Leave them off.

ATL ZJ
10-20-2009, 02:30 PM
I'd rather have my wire clean than lubed. I've never had a wire feed problem that proper drive roll tension didn't fix. So that formula may be fine for the southwest, but here in the southeast, we have to constantly fight oxidation, as paul mentioned...

But that's good to know about the purpose of the lube itself.

paulkeith
10-20-2009, 04:44 PM
I've had to replace the liner on my gun as well, after maybe 40-50lbs of wire. the guy at lincoln was like, "that's unusual"

maybe my lincoln is a pos...

but in any case, when i replaced it, i cut it open to scope it out, and it was filled with what looked like rust-dust. i figured it was from my oxidized wire. all my bare tube and metal rusts inside the garage anyway, so its a lost cause.

*.......cue dreams of an insulated 5000sqft shop with a/c......*

ATL ZJ
10-20-2009, 05:02 PM
*.......cue dreams of an insulated 5000sqft shop with a/c......*

If you'd ever be inclined to go in on a small warehouse space, I've found good spots for very reasonable rates, even itp. They're just out of the range I'd be willing to take on solo, but half of what they're asking would be very doable. I can guarantee that your rig or whatever else you want to work on will get finished if it's within 10 minutes of home. :D