Quiet Air Compressor for Wide Belt Sander, How many CFM do I need?

OK, my workshop construction, outside of needing more cabinets, is mostly done. Woohoo!!!! Only took a year.

I've gone to great lengths soundproofing it from the house (Double 5/8" drywall, Rockwool Mineral Wood Batt insulation, and Green Glue between layers of drywall). The elephant in the room, is the old Sears Craftsman (>30yo) air compressor that I mostly use for the Grizzly G0445 24" wide belt sander, spraying away dust, etc... I very rarely use air tools. The compressor is extremely loud. Easily loudest tool in the workshop. More than the 5HP cyclone.

The specs on the Grizzly only state the compressor has to provide 75psi. Nothing about CFM.

I know California Air Tools makes quiet compressors, but will their compressors provide enough CFM for the wide belt sander? If not, which other compressors that are relatively quiet that can meet the Wide-belt's requirements?

Can you put the compressor outside?

Yes, but really don't want to disturb the neighbors. I went to pretty great lengths to make my workshop which is in my home quiet to both neighbors, and SWMBO.

Reduce max pressure to 100 PSi. reduce motor pulley diameter by 1/4? Put a muffler on the intake. Some folks use a new motorcycle muffler. I used a old oil bath air cleaner.
Bill D

I bet a used two cylinder diesel engine, water cooled, would be the start of a quieter compressor. I understand they stop running below 400PSI or so. So a worn out one would be good enough pressure for a air pump. Of course you would have to remove the cam shaft and add valves into the head or even make a simple new head. I think the radiator and water pump do not need to be used. Yanmar is a common boat and compact tractor engine maker.

I have had a variety of compressors, they can have considerable differences in noise.

Stay away from some of the big box designs that have relatively high rotating speeds.

Commercial designs will have a common compressor head, then change pulleys to change speed to match to a motor size. This is what you want, but you want to run at relatively lower speeds.

I rebuilt an older compressor head (Ingersoll Rand 242) and put it on a relatively small tank (60gal) with a 5hp motor. Lots of air. The quietest I have had was something similar, but with a 3hp motor (true 3hp, 1750 compressor motor) which was the same pump head but just turned slower. The slower compressor speed meant it was quiet.

You can piece all this together off craigslist. For a widebelt I would guess you would not need more than a 3hp (a real 3 hp).

Alternatively if you dont need air for other equipment, I have a small Dewalt/emglo wheelbarrow type that runs at a lower speed and is a nice little unit. It can run on 110 (2hp) but I almost always run on 220.

My widebelt took more air than I expected, but I cannot tell you the CFM (my 3hp ran it. my 5hp runs it)

Three years back I purchased a California Air Tools 100020C and couldn't be happier. 6.4 CFM @ 40 PSI and 5.3 CFM @ 90 PSI. I can run a ROS for my wood lathe with it with no issues.

Knowing what the required CFM is is kinda critical for choosing an air source...you probably want to ask the tool manufacturer to clarify that since it seems to not be in your documentation. That's the only way you can answer the question about the specific compressor you mention and whether or not it will work for your needs. If the purpose of the air for the sander is merely for things like balancing cylinders or tensioning, it's probably not an "air user" and the key is just maintaining pressure in a closed system. My CNC has a requirement like that for the air cylinder that counterbalances the heavy spindle and reduces the load on the Z axis motor, for example. Almost "no" CFM is required for that task...I just need to maintain 45 PSI.

"Loud" support tools like compressors and dust collectors can have that sound mitigated substantially by isolation. The best solution is usually a sound-reduced enclosure...I have both of those things in a sound reduced closet and ambient noise from both doesn't interfere with normal speech or even listening to the radio in my shop.

What is the belt sander using the air for? At a glance it looks like just for pneumatic activation and controls. I'd guess it needs very little in the way of cfm. I assume if that were not the case they would have specified a cfm requirement.

FWIW I too and a happy California Air Tools 100020C owner. It is pretty quiet as air compressors go, not as loud as my DC or table saw, but still not really quiet though.

As others have said, look at the WB design. Pneumatic tracking needs much more cfm than electric eye tracking and pneumatic tensioning. If it turns out you need a larger compressor, look for one that runs at 600-700 rpm rather than the normal 1000+ for cheap aluminum head units. I can run my electric eye WB on a small Jun Aire dental compressor so that type of WB doesn't need much air. I've rehabbed old Quincy QR compressors and they are quiet and much better than anything new for cheap money. Dave

I just got off the phone with Grizzly. They don't know the answer from the specs. They are going to contact the factory. So still in the dark. It's my impression that it doesn't use much air. It's rare that my present compressor has to recharge its tank while using it, though there is a 30 gal tank on my compressor. I don't think it's an electric eye machine.

I have a 1975 Sanding Master that has air tracking. This style is like a leak in ones system. Looking forward to converting it to electric eye or better one day.

Mine takes more than I thought it would.

A quick google I see some posts suggesting 50 to 75psi and 7 CFM. This seems realistic from my experience. You would want to account for line losses.

5-7 cfm seems about right for pneumatic tracking. You can tell by looking in the machine or running it with the door open and the kill switch disabled. Dave

I believe it's stating it needs 75psi continuous. So if your compressor can't keep up its going to cost you a lot belts.. when you start looking into quiet compressors your looking at cost.

I have a Kobalt Quiet Tech air compressor and it uses the same design as my California Air Tools quiet compressor (which got stolen, dangit!)

Quiet doesn't have to be expensive unless you need a whole lot of CFM.

How often does your old one turn on? And what kind of power does it draw? If it's a 220V unit that kicks on every few minutes, you're using a ton of air. If it's a 120V unit that kicks on once an hour, you're not using much air at all.