[chase1994]

I keep hearing to use .023 welding mire, but I found the millermatic 140 and it uses .024 welding wire. So before I buy it, is .024 good for older cars and trucks? thanks

[boatbob2]

Hi,i have used .024 a lot on body work,use gas with it,because it does NOT have flux inside.

[Crosley]

Seems like I read some where that reverse the polarity helps with thin metal on the older cars ?

do not quote me on that .

[oldred]

Originally Posted by Crosley

Seems like I read some where that reverse the polarity helps with thin metal on the older cars ?

do not quote me on that .

You had better run that stuff on reverse polarity no matter how heavy the metal, it will run like crap on straight! Straight polarity is used for gas-less flux core wire however but if the welder is set up straight for flux core it MUST be switched to reverse (electrode positive, work negative) before attempting to weld with solid wire.

[ericnova72]

Also, there is no difference between .024" and .023" wire, it is only ONE thousandths of an inch difference in size and can be used interchangebly in either size machines

[OneMoreTime]

Originally Posted by ericnova72

Also, there is no difference between .024" and .023" wire, it is only ONE thousandths of an inch difference in size and can be used interchangebly in either size machines

Excuse me that One thousand does make a difference in the feed of the wire...I have the Miller 140 and the .024 wire feeds better///As far as the welding part the .024 wire works just fine..

Sam

[cranky1]

Whatever size you use, make sure the wire and the hose liner is clean. Dirty wire will clog up a liner pretty fast and then it own't matter if .001 makes a difference or not. If your wire shows the slightest bit of rust, spool off the top layer/layers until you can run the wire through your hand or glove and it stays clean.

[oldred]

Originally Posted by cranky1

Whatever size you use, make sure the wire and the hose liner is clean. Dirty wire will clog up a liner pretty fast and then it own't matter if .001 makes a difference or not. If your wire shows the slightest bit of rust, spool off the top layer/layers until you can run the wire through your hand or glove and it stays clean.

And to add to that, grinding operations go hand-in-hand with welding but BE CAREFUL where the grinding sparks are going! A great deal of the feed problems with wire feed welders can be traced to grinding dust stuck to the wire, those grinding sparks are tiny specks of red hot/molten metal that will literally weld themselves to the wire making it very difficult to feed. Since most wires spools are exposed and the welder is very likely to be in close proximity to the grinding operation it is very common to see a shower of grinding sparks falling onto the wire spool, when this happens the wire quickly becomes junk! Not only that but once this crap gets into the liner by way of contaminated wire the liner too becomes junk and the only option is replacement. Grinders are a VERY common cause of welder feed problems but some some reason it rarely gets mentioned but it is a very real problem. The trick is to keep your wire (better yet the entire welder) covered when grinding and at any time it is going to be out of use for a while, a welder sitting in a corner collecting dust is a PITA in the making.

[cranky1]

Oh yeah! Dust is a concern and so is grinding dust. My machine is a MillerMatic 200 and I got it used in 86 and had to do a little work on it recently and when I opened it up, I was amazed it was even running lol. The fan alone will pull in lots of dust too so they need to be cleaned from time to time.

[jmfalco]

I have a Dan Mig 141 with gas that I am learning how to use. I see no provision to change the polarity on the outside of the box. Is it done internally?

Jack

[oldred]

Originally Posted by jmfalco

I have a Dan Mig 141 with gas that I am learning how to use. I see no provision to change the polarity on the outside of the box. Is it done internally?

Jack

It is just a matter of switching leads actually so that what is now the work lead becomes the ground lead and vice-versa so look at the machine and decide how this is best done in your case. If your machine came set up as a MIG from the factory then it is already set up as reverse polarity. However if it was not a MIG (gas-less flux core welders are not MIGs, all MIGs use gas-(M)etal (I)nert (G)as) and was converted to use gas then it may not have been switched, which it must do. Just look at your machine and decide how it is easiest done, there may be several ways to accomplish this.

[chase1994]

thanks so .024 will be o.k. When I get some money I will buy the millermatic 140. Unless there is a cheaper miller that is even better, if you know of one please tell me.

[jmfalco]

Old Red, Thanks for the reply. I bought the welder used so don't know how it was set up. In welding sheet metal how would the welds differ between - polarity and straight polarity?

Jack.

[oldred]

Originally Posted by jmfalco

Old Red, Thanks for the reply. I bought the welder used so don't know how it was set up. In welding sheet metal how would the welds differ between - polarity and straight polarity?

Jack.

If the welder is set up for straight polarity (wire negative, ground positive) then you will get a lot of spatter, excessive burn-back and poor penetration with solid mild steel wire. The difference between the right and wrong polarity setting when using solid wire and C25 gas will be a lot more noticeable than trying to run the wrong polarity with flux core wire, most flux core wires anyway.

[chase1994]

I will mostly use the solid wire in it. I might every now and then use the flux-core but I got a flux-core only welder now and I hardly ever use it. So I will mostly be using the solid wire with gas. BTW what is the best gas mixture for welding on car and truck bodys? thanks