Air compressor Opinions Please
I’ve been using a 4 gal Emglo that I’ve had for over 15 years and it will only get to 100psi. I was thinking of going up in size to something stationary. It will be used mostly for air nailers and possibly pneumatic sanding(dust collection looks like an issue). I don’t think I will use it for spraying since I have very good HVLP units. I think I can also use it for vacuum chucking on the lathe? Anyway, looks like I need to spend at least $500, so any help would be greatly appreciated. Thanks
Regarding vacuum chucking on the lathe; much of my reading and research indicates that a vacuum pump is a better option for this task. An output of 100psi will operate most if not all normal workshop tools. My "big" 1/2 air impact has a 120psi maximum limit on air pressure. From my experience tank size, capacity is a major factor. I've had 5 gal and 20 gal tanks. I now have an 80 gal tank. A 60 gal tank would work well for me, I got a "good" deal on the 80 gal.
You had best do your homework on this one.
Tank size and pressure provide a buffer but if your pump can't keep up with the tool, they will not be a factor. It must supply a certain CFM at pressure.
A sander will typically require about 9cfm at 90PSI. You would want some excess capacity otherwise the compressor will run continuously while you are working. In this example you would want about 12 to 14 cfm at 90 psi (60 to 80 Gal tank). Also you want a pump rated for continuous duty. Most of the less expensive compressors are rated for intermittent duty. You are going to spend upwards of $1000 or more.
Check the specs of the air tools you intend to use and size the compressor accordingly. Sanding requires a lot of air.
I agree with 27B_6. Air motors require a lot of air. I have an industrial 2HP Campbell Hausfield compressor that my now retired partner bought new about 50 years ago. (Before HP rating inflation.) Still works great. It can handle air nailers, dust blowing, and some intermittent air impact wrench use, but can't keep up with air sanders or constant air drill use. I have each of those, but never use them. If you don't have to use air sanders, save yourself a lot of money and buy a good quality smaller compressor, and use electric sanders. Long ago, air sanders were far superior to what could be had with an electric cord; now there is no such gap. Also, an electric cord is a lot easier to manage over a work piece than an air hose.
I have just been through this exact dilemma for much the same reasons.
I also considered your options however my uses are:
1. Compressed air to clean parts.
2. Nail guns
3. Occasional spraying of furniture or domestic doors.
4. Resin casting.
When I thought about it, none of these needed high power and the ability to add an air sander was trivial since I use a power RAS and having the noise of the compressor was not an appealing alternative. I don't do power sanding with wet paper so having a water-safe sander is not necessary.
In the end I went for a cheap 2.5HP 40 Litre machine with a 'high-flow' rating of 180 CFM. Made of finest Chinesium throughout. That is more than enough for my spray guns and given how rarely they come out, it's really not worth paying more for a heavier duty option. Same brand as my previous option which lasted well despite abuse (Black Ridge - about as low as brands get)
Many, even most woodworkers love the extra tools and options, but it's worth pulling back a bit and thinking - money is much easier to spend than to earn after all.
One way of looking at it is 'opportunity cost' - if I spend $100 on a compressor, that leaves me $400 to spend on tools to use with it. If I spend $500 on a compressor then I have $0 to spend on tools to use with it (so the compressor is in this situation useless) - even better news is the apparent frugrality seems to go down well with spouses who then readily accept that the 16" jointer is clearly a workshop necessity because you were so thoughtful and did not overspend on the compressor. Apparently.
There is an echo in here, but I will repeat that you problem isn't PSI it's storage and CFM if you goal is to run pneumatic sanders. Air Nailers can easily run off you Emglo, that's what they were designed for.
My question for you is why pneumatic sanding? With so many great corded and cordless sander of all types what is the appeal of pneumatic sanders that you would invest in a larger compressor just for that?
I have a 5HP Ingersoll. The compressor became weak and eventually didn't hardly work at all.
Even at almost $600 it was cheaper to buy a replacement compressor pump.
Air sanders require huge CFM's. For continuous use, I would double whatever the specs call for. I use a dust extractor with mine and it works great.
That said, air sanders aren't necessary for ww'ing. You might consider that and buy a smaller, quieter compressor.