Air compressor/Spray gun Question

I just bought the stew mac touch up spray gun. It requires 1.5 cfm at 90 psi. I bought a DeWalt 4.5 gal, 1.8 HP portable compressor to run the gun.

http://www.dewalt.com/us/products/tool_detail.asp?productID=15538

The DeWalt can generate 5.4 cfm at 90 psi

My question is this compressor going to be big enough to run the gun? I am only going to do single guitars (hobbyist) occassionally. I'm going to strictly use water-based lacquers. For another $40 I can get a bigger DeWalt compressor that has a 13 gallon tank, but it will obviously be much larger and I'd rather not spend the extra cash. But I'm worried about not having enough air to finish guitars without problems.

So my questions are: 1. is the compressor I have enough for my needs? and if it is, would it be worth me getting the bigger compressor anyway even though I lack the space and would rather not spend the money?

Thanks for any opinions/help you can provide

I've never shot paint with such a small tank, but I bet you could pull it off.
If you find it's running constantly, you might need to stop a little more often.

Doesn't sound like 1.5 cfm is a real number on how much that spray gun needs, unless it's just an overgrown airbrush. Detail guns like the gravity-fed Porter Cable PSH2 require more than a single hot dog or pancake compressor can put out (I cooked a Porter Cable pancake compressor even though it theoretically would have had enough CFM output at 35 psi), and if you ever want another gun you're limited by your compressor. So buy the biggest compressor you can afford and you won't have to worry about burning it out. The best guns are high transfer efficiency (HTE) or high volume low pressure (HVLP) conversion guns and they require lots and lots of air.

Oh, and for water based coatings I hope you've discovered Emtech EM6000 from Target. More info at targetcoatings.com (they even have a woodfinishing forum). The company president, Jeff Weiss, is also into guitars and we're all (well, I have been) bugging him for a nice butterscotch blonde recipe.

I looked at a Dewalt compressor like that and it should work fine for what you want to do.
I ended buying a small dual tank Hitachi compressor at Lowes.
I use it almost every day to spray seats etc... I refinish leather interiors and do vinyl repairs in addition to auto upholstery.
I use a detail gun, it also works with my quart gun when I spray contact cement to do headliners etc...
Yeah it runs a lot but it has plenty of pressure , I do drain it every day due to the humidity here.
I got the small one to save space in my work van and it's portable so I can take it out and use it also. Also working out mobile, I have to run it off of a long extension cord, and the small compressors work better off extention cords, the bigger ones seem to draw too much current and flip breakers ( I use a heavy extention)
I've had it over a year now and it still runs fine.