Auxiliary air tank advice

[wef]

I just got a Makita MAC2400 2.5 hp, 4.2 cfm @ 90 psi compressor. Unsurprisingly, it has a hard time running an impact wrench. It has a 4 gallon twin tank. What are the drawbacks of using a 12 gallon tank designed for air horns (working pressure 150 psi) to be plumbed into the 4 gallon tanks?
http://www.amazon.com/gp/product/B001F15SPU/?tag=atomicindus08-20
A regular compressor tank cost considerably more and the air horn tank will be a good fit next to the compressor. Any suggestions?

 

[StaggeringGoat]

It will work, but for $135 you can get more than a 12 gallon tank. You can just about get a whole ~25 gallon tank/compressor from Harbor Freight. I have like six tanks hooked up to my system, for around 150 gallons of air.

 

[Motofixxer]

3/8 hose with 3/8 fittings and Milton type V high flow couplers or similar will do wonders.

I picked up a 25 gal like new Porter Cable air tank for $20 on CL. Works great for auxiliary or a portable tank.

 

[Iron-Iceberg]

Your compressor will have to run 4 time as long to fill it up. Be carefully not to burn it up.

 

[REPO]

I use an expired propane tank. It's the large style that would sit beside your house, shop, etc. it's 500 gallons, so it lasts for awhile.

 

[vartz04]

I got my 21 Gallon HF Compressor used for $50. It runs an impact fine. Look for a cheap larger compressor.

 

[Gary S]

Your compressor will have to run 4 time as long to fill it up. Be carefully not to burn it up.

Correct. The larger a tank you put on the compressor, the longer it runs without a break to fill the tank. If the compressor can handle continuous duty, it won't hurt it, but if it is designed only for short runs and then needs to cool down, it could be rough for it.

 

[corvairdad]

I have a question for you guys that have the second tank. Is it plumbed in line with the current system or T'd off to the side?

 

[madosta]

I have a question for you guys that have the second tank. Is it plumbed in line with the current system or T'd off to the side?

Does it matter? I think path of least resistance will hold true. Interesting question.

 

[LLundstedt]

I have a small 20 gallon aux tank in the garage attic. It has a 1/2" line with a valve teed in to the 30 gallon compressor in the garage. When i need a little more capacity i can open the valve.

 

[REPO]

I have a question for you guys that have the second tank. Is it plumbed in line with the current system or T'd off to the side?

Mine is T'd in with a valve to isolate it. If the air comp begins to get too hot from the continuous run time, I can shut the valve and isolate the big tank. Once the air comp has sufficiently cooled, I can open the valve to begin filling it again.