what is min compressor CFM for blasting???

[nosnerd]

i went compressor shopping two weekends ago with my father...but havent pulled the gun yet...i just drew a blank when i got there...brain fart......


so i held out....dad says to buy ONCE.




( i did purchase an 8inch bench grinder though lol-so not to come back home empty handed in front of the wife-we made this an all day deal me and dad lol)


alan

 

[Charles (in GA)]

What kind of blasting? Blast cabinet? or open sand blasting?

Blast cabinet will use all a real 5 hp 18 cfm two stage will put out, and then some. I have a 7.5 hp two stage, 24 cfm and it works real hard when I'm doing something large and don't stop too often.

Charles

 

[alan camby]

I agree with Charles. Make sure the motor pulls at least 21amps at 220. If the compressor shows 6.5 peak hp or 5 peak Hp, this is a sign that the compressor is probably only 3-4hp. Moral is, Check the motor amps.

I would make a 2 stage a priority.
Single stages are great at filling the tank but if you are running non stop for only 10 min the single stage is going to make a lot of heat and wet air.

Make sure the compressor is 100% duty cycle if you want to blast more then nuts and bolt.

 

[nosnerd]

thats what i wanted to know....the amps on motor...soda blasting outside once in while...and a blast cabinet...so how many CFM should i be looking at?at least 30??

the IR guys were at the Syracuse nats ,but the crowd in the tent was constant,,,so i passed...which i shouldnt of...


thanks guys


http://www.princessauto.com/pal/pro...age-Stationary-Air-Compressor---Special-Order

 

[alan camby]

You will need around 10hp to get 30cfm.
True 5hp will put you in the 17-21cfm at 90psi range.
My IR is 18cfm. I would look for something other then IR.
Quincy, Champion, sure others will chime in.

Blasters are made for all CFM ranges. The bigger the better when it comes to blasting.
If you see yourself doing a lot of blasting in your future, don't be one of those guys that say your budget is 700-$1000 for the setup. because, buying new, this won't happen.

Buy the largest comp. you can. Add ons like Baldor motor, magnetic starter, aftercooler, and all cast Iron pump, ect ect, all add a lot of life and reliability. Like I said before, go 2 stage.

 

[nosnerd]

ok..what is your opinion on this??

http://www.princessauto.com/pal/pro...age-Stationary-Air-Compressor---Special-Order

i can get it for less$$..i consider it my yardstick for now....

 

[Bob C]

ok..what is your opinion on this??

http://www.princessauto.com/pal/pro...age-Stationary-Air-Compressor---Special-Order

i can get it for less$$..i consider it my yardstick for now....

I recognize that pump. It is a copy of a saylor-beall 10 hp pump. It has steel disc valves, tapered roller bearings, Centrifugal unloader. If sized to run at 800 R's it will deliver 35.8 CFM at 125 PSI. Do not be afraid of buying this style pump. I normally sell this unit on a 120 gallon with 10HP 3 phase motor with magnetic starter ready for use for $2795 delivered for free in my area.

 

[darkk]

If it is for occasional sandblasting at home with a small unit, just buy the best you can afford and call it a day. Blast a little, let the compressor catch up and start over. I have an older IR compressor, 5hp 2 stage 19cfm @ 90lbs that's 35+ yr old and it works really well, it runs a frequently but it keeps up. If you are using it for commercial, then you need to really step up your equipment.

 

[EOC_Jason]

There are a few factors to consider:

1. Space - Do you have enough space (or want to use up) for a 120 gallon horizontal? Or do you want to be space conscience and go for a vertical? Horizontal units have wider availability in larger sizes.

2. Cost - What is your price range? There is always what we *want*, but what do we *need* that is within our budget?

3. Power - I'm guessing you are limited to single phase? If so then 10 HP is going to be the upper limit.

4. Usage - Will this get used daily, or just on the weekends and special projects? Why spend a boatload of money if it won't be used often?

5. Duty cycle - Different compressors are rated for different duty cycles. Also some models you can get unloader valves so the pump/motor will run continuously. When it reaches pressure it opens a valve so the pump isn't really working to build pressure, it's just passing air through the system (and helps cool the pump), when it drops to a certain point the valve closes and it builds pressure like normal.


Realistically, I would go for a good quality 2-Stage, 7.5HP, 80 Gallon, Vertical. 120 gallon tanks are nice, but they do **** up a lot of floor space (unless you get a 120 gallon vertical).

Since you are in Canada I don't know what brands are available or competitive.

 

[ms fowler]

You can always size your blast nozzle to the compressor. I did a LOT of sand blasting when I restored a '64 Falcon Sprint Convert using a Craftsman 4HP. Lots and lots of rust needed to be cleaned off. I started with a TIP suction blaster, and quickly went to a small pressure blaster. Wore out the 4 HP motor, and the compressor in the process. Neither was as fast as the blasters that the pipeline Contractors use to clean gas pipe before welding or coating.
Just match your blaster ( and your expectations) to the air supply you have.

I really liked sand blasting; I described it as " unpainting". It was fun to watch paint and rust turn into clean gray metal. ( And, on humid days ( Baltimore area) back to tan before I could get it painted. )
Blasting really cleans the metal, and clean metal really likes to return to its original (iron oxide) state.

 

[MoonRise]

Define your needs vs wants (cost, size, power needed, etc).

And remember the mantra - Good, cheap, fast. Pick any two.

Then pretty much just go get the 'biggest' air compressor (motor, pump, and tank) you can fit and afford.

Cause almost no one ever says 'Gee, I should have gotten the smaller air compressor'. (short of someone waaaay overbuying for their needs and electrical power available, like buying a 15 HP continuous screw compressor to fill a bicycle tire and all they have is a 120V wall outlet for power).

Also don't forget some sort of air-drying 'system', cause all the air that gets compressed brings with it all the moisture that was in the air in the first place. And moisture in the air stream is a bit$h for a media blaster or fine spray painting.

And no, just putting a 'filter' in the air piping is almost never enough. The typical air filter just traps droplets or solids (aka not vapors). So you need a way to cool the air down and then run an air dryer (or dryers) of some sort (refrigerated or dessicant or some combination).

The CFM needed depend on the blast gun/tip being used. Smaller tip opening and lower air pressure means slower working and a smaller needed CFM. Bigger tip opening and higher pressure means faster working but more CFM needed.