I recently went to a junkyard and pulled an airbox to gut. My dilemma is that I don't have a dremel and I don't want to spend the money to get one only for that...is there any other tool I can use to gut the airbox?

 

A knife? Lol idk

 

Here's a cheap one. Throw it out after you're done
Rotary Tool Kit - 80 Piece Set

 

Dremels are really useful. I bought one and use it a lot

 

I'd advise getting a Dremel and a variety of bits (great place is WidgetSupply.com). I got one as a Christmas gift and struggled for uses for the first couple years, and then I began using it like crazy (heck, I was just in the garage using it on a project).

 

Even if you don't want to lay down $40+ for an actual dremel, you can get a $10-15 knock off from a close out store/Harbor Freight/ebay.

The quality isn't as good, but it will last a few years and you will certainly get your moneys worth. I bought a cheap one to mod a heavy gauge steel computer case, worked just fine.

Even those with an Dremel will often buy cheaper tools and accessories for it as the branded stuff is a bit overpriced.