[DonRotolo]

If welding steel is like stitches, welding aluminum is like brain surgery. It is challenging, and you absolutely must have competent instruction.

You cannot weld indoors without full and complete vetilation. "open a window" will not cut it. The room also needs to be essentially fireproof - sheetrock is not fireproof.

If you ever weld steel with that welder, it is useless for aluminum. If you dedicate it to 100% aluminum, and use the right supplies, then MIG welding (really, GMAW*) will work well for aluminum.

100% argon is not much different in cost from any welding gas. You will find that it is not a great expense, even if you rent the tank (common) and the regulator (usually you buy one), the cost of the gas is comparable to a nice dinner for four.

So, your next steps:
1. Can you really keep it?
2. Get someone who is an expert aluminum welder (not a steel guy who has done some aluminum. Trust me here) and have them help you...
3....find a good aluminum welding wire, and...
4. A source of gas, and....
5..Invest in a set of "aluminum only" tools (your welder will explain)
6. And personal protective equipment (mask, gloves, apron, etc)
7. Then find a location approved by the fire marshal (in most states you require a fire dept. permit to do indoor welding)
8. and practice, practice, practice. Then go and practice more. After 100+ feet of welding bead, you'll be passable.

This is NOT a lot of money, but step 2 for advice and instruction is critical...

Don

*Gas Metal Arc Welding
**Disclaimer: I know a lot about aluminum welding, maybe too much, but my eye-hand coordination stinks.