| TIP #1 The single biggest tip for Tig welding | | | | casting. A 200 degree preheat will work wonders and |
| aluminum castings is to use a helium/argon mix | | | | if you are using a small tig inverter like a Miller |
| instead of straight argon. That's a pretty strong | | | | Dynasty 200dx or a Lincoln Invertec v205t, you only |
| statement, but I stand behind it 100 percent. | | | | have about 200 amps to play with and you will need |
| A 50/50 argon/helium mix works great and so do | | | | every bit of it. A preheat will get you over the hump. |
| mixes that contain up to 80 percent helium. Helium | | | | It doesn't really matter how you get the part hot...A |
| adds more energy to the arc and makes more | | | | propane torch or old gas grill both work great. |
| difference on heavy aluminum than any other welding | | | | TIP #3 The third tip is to be careful not to use too |
| technique you can think of. | | | | much torch gas. Just to be clear, that's the gas |
| Did you know that a tig welding arc carries more | | | | coming out of the tig cup. |
| voltage with helium gas without even adding more | | | | Enough is enough and more is worse , not better. |
| current? It's a fact. | | | | Use just enough flow to shield the puddle and not |
| Have you ever lit up on a heavy aluminum casting | | | | much more. If the noise from the arc is rattling your |
| using straight argon gas and had to wait a really long | | | | brains out, you probably have too much gas flow. |
| time to even get a puddle? Not so when you add | | | | Think about it, why would you want to blow cool gas |
| helium. You get a puddle immediately and it's even a | | | | on something you are trying to heat? |
| cleaner puddle... an added bonus. | | | | When you use too much torch gas flow, It is |
| Welding textbooks recommend straight argon for | | | | working against the arc, not with it. |
| anything less than ¼ inch thick aluminum. But I | | | | Turn the torch gas down to 13-15 cfh and you can |
| am telling you that once you use an argon helium | | | | actually hear the difference. But remember that not |
| mix, I will wager you won't want to use straight | | | | all flowmeters are calibrated the same so if you get |
| argon again except for really thin aluminum sheet. | | | | a fuzzy puddle, you may need to adjust the torch |
| TIP #2 The second tip is to preheat the aluminum | | | | gas upward...but only enough to clean up the puddle. |