Need help with proper compressor / dryer setup for sandblasting

[OpFlash]

My goal is this: Setup garage compressed air system properly so that I can use my HF sandblast cabinet with out trouble. I attempted to use my current craftsman 33gal 5HP oilless it has a cfm of close to 6 at 90psi. Looking over instruction manual The cabinet needs somthing like 10cfm at 90 to properly run. I also had problems with moisture I however was running straight from my hose.....

I want to properly set up my garage to use compressed air not only for the blast cabinet but for other tools aswell.

Heres what I have so far...

Johnson Controls A-4412-2 Refrigerated Air Dryer.

http://cgproducts.johnsoncontrols.com/CAT_PDF/1921105.PDF

Please look at the specs and let me know what you think.
I also have an Ingersoll-Rand EDV-2000 Automatic Drain Valve.

I want to purchase a nice 60 Gallon compressor that can adequately power my blast cabinet and I hope after you look at the specs of my air dryer you may be able to suggest a compressor that would work well with my dryer unit. I still have to buy airfilter / regulator and coalescent filter and moisture trap. Any thoughts would be greatly appreciated

 

[spongerich]

I have a slightly smaller Craftsman that's rated about the same. Works fine for smaller stuff, but I do run out of air after 4-5 min and have to take a break to let it fill up again.

I don't have anything as exotic as a refrigerated dryer, just an old school centrifugal water trap and that works just fine for blasting.

If you're going to be doing larger parts or blasting all day, get the biggest compressor you can afford.

 

[OpFlash]

That is the problem that I encountered with my current compressor. Running it at 90 psi the tank kicked in and stayed on after only about two minutes it seemed of blasting. I do have some larger parts but over all I have alot of stuff lined up that I want to blast. Im also trying to factor in that I may want to try some painting and thats where the dryer cam in. I got it real cheap thankfully. Im in the market for a 60 gal compressor. I looked at my dryer and it said its rated at 12 SCFM at 80psi with a max inlet pressure of 125psi. Im new to dryers and still learning this stuff. Im not sure if the dryer is rated well enough for use with a larger compressor. Im thinking that it should be ok because many 60 gal tanks are showing cfm's in the 10's @90.
The other think is that today I noticed that the actual cabinet has a sticker stating that the requirements for the cabinet are 12-16CFM at 70-125psi. This is different that the instructions. Im really wondering what "real world" ratings i need to have inorder to properly use this thing.

 

[stonesfan68]

There are several things to consider:

1. The Johnson Controls dryer that you have is only rated for a maximum inlet temperature of 125 PSIG. You are going to need to regulate the compressor discharge air temperature out of most compressors to meet this requirement.

2. You will need to buy a coalescing filter to install prior to the dryer, or the dryer heat exchanger will quickly become clogged with oil and dirt.

3. Be sure that the new compressor that you purchase includes an after-cooler, or you will overload the dryer, especially with the summer upon us.

4. The blasting cabinet will use more air with a bigger nozzle and higher inlet pressure (that's why there is a flow range listed), so use the smallest nozzle at the lowest pressure in order to minimize the air requirements.

5. You might find that just using a moisture separator and coalescing filter will provide the air quality that you need for blasting. Don't buy the cheap Craftsman stuff, buy industrial components from Ingersoll-Rand, Hankison or Zeks.

 

[OpFlash]

Thanks for the imput. Question regarding the inlet temperature The link for the dryer shows this:

1. The rated condition is 20 psig (140 kPa) supply pressure, 100°F (38°C)saturated inlet air temperature, 100°F ambient temperature, and 80 psig inlet pressure.
just wondering how you determined that maximum inlet temperature is 125Psig? im a bit confused. Also what is the normal temps for air coming out of the compressor?

 

[OpFlash]

Also is it true that smaller nozzles while using less air will be less effective at removing rust / paint?

 

[stonesfan68]

Thanks for the imput. Question regarding the inlet temperature The link for the dryer shows this:

1. The rated condition is 20 psig (140 kPa) supply pressure, 100°F (38°C)saturated inlet air temperature, 100°F ambient temperature, and 80 psig inlet pressure.
just wondering how you determined that maximum inlet temperature is 125Psig? im a bit confused. Also what is the normal temps for air coming out of the compressor?

The data sheet listed the maximum inlet air pressure.

Also is it true that smaller nozzles while using less air will be less effective at removing rust / paint?

I don't know enough about blasting to be able to answer this one.

 

[OpFlash]

There are several things to consider:

1. The Johnson Controls dryer that you have is only rated for a maximum inlet temperature of 125 PSIG. You are going to need to regulate the compressor discharge air temperature out of most compressors to meet this requirement.


the confusion was in your first response you stated inlet temp of 125 but it is indeed pressure. So hopefully Ill be able to regulate the pressure and be able to use the dryer.

any idea of what temperature air comes out of the compressor at?

 

[OpFlash]

Has anyone actually checked to see or knows that temp air comes out of their compressor?

 

[vga]

The important number is the inlet air temp into the dryer from the tank / receiver. The air out or the compressor into the tank will be above 120 deg F just due to the fact that air is being compressed. The air temp will drop once its inside the tank receiver. Most dryers like to see an inlet temp 0f 90/ 100 deg F. You will need to have an auto drain on the tank as condensate will build up inside it and carryover in the air flow and overload the coalescing filters. These filters will also req auto drains to get rid of the collected water.

 

[OpFlash]

So basically is the johnson controls dryer that i posted about under rated for 90psi with a cfm around 10?

 

[dodge610]

Use a medium size nozzle and jet you should be fine for rust and paint. Stay away from the oilless compressor lets not get into how I learned that. Just get 80 gallon tank or bigger if you can find one at a reasonable price and you should be fine. I have the craftsman pro one with a 7 horse motor on it mine is 10 plus years old and have bead and sandblasted numerous times with it.

 

[stonesfan68]

the confusion was in your first response you stated inlet temp of 125 but it is indeed pressure. So hopefully Ill be able to regulate the pressure and be able to use the dryer.

any idea of what temperature air comes out of the compressor at?

Sorry about that.

The discharge air out of the compressor is 300F. Once the air enters the tank and expands it will cool down to 150-200F. That's why and air-cooled aftercooler or dryer rated for a high inlet temperature.

 

[OpFlash]

I was looking at some of the 80 gallon compressors but not exactly sure that i would be able to afford something that size. also space is somewhat of an issue. this is why ive been searching in the 60 gallon size. It appears that Im going to have to install the compressor more than likely in my basement ( no 220 in garage) where i can run the 220 easily and then pipe in to my basement workshop and then out to the garage. Seeing that 80 gallon compressors are nearly 600lbs. thats also gonna be kinda tough. Im kinda scratching my head here. It looks like i screwed myself with this dryer so im out 150 bucks on that. more than likely im looking in the used market for a 60 gal but i dont want to buy something that wont work either. Wont be blasting every day but i want it to work when im ready to use it.

 

[OpFlash]

Update... Ok so I finally got my money together and Im waiting for my new compressor purchase to arrive at sears.. I went with the WV5248069 It is a Craftsman 80 gal 2 stage compressor with max psi of 175 and close to 14 CFM at 100PSI. Ive also decided that I will install this unit in my garage and not in my basement. Im in the process now of purchasing my air regulators and moisture traps. Im currently looking into making my decision on air lines. Its black pipe vs. the Max Air kit that you can find from eastwood. Its a flexible tubing with aluminum core (it bends) it also has quick connect fittings. Im also looking into picking up a better blasting gun for the cabinet. I like the skat blast gun. Any other suggestions?

 

[OpFlash]

Yeah Ive decided that Ill avoid the refrigerated dryer for now. I can use it for my powdercoating setup that needs much less air volume to run. I do though need some advice or suggestions on a nice moisture filter / regulator.