Air Compressor - need advice on a new one

[HondaFarmer]

Ok, Ive got it narrowed down to either a Kobalt or a Husky (Lowes and Home Depot.) They each make a 60 gallon 3.7hp and an 80 gallon 5hp. I think the CFM ratings on either of these is sufficient since I am the only one using the compressor. Obviously the 80 gallon compressor is considerably more but the 80 gallon husky also has a 3 cylinder compressor which is something I have not seen in this price range ($500-$900). So I have a couple of questions.

1. is the 60 gallon more than enough for what I will be doing which is basically completely tearing down small cars to be parted out. and...

2. would the 80 gallon last longer due to having the bigger motor and the 3 cylinder compressor? and...

3. what exactly is the benefit of the 3 cylinder compressor vs a 2 cylinder setup like most other compressors have

I only use my compressor about 5-10 hours a week. I may double that at the most but I have a day job so for now 5-10 is max.

Thanks in advance!

 

[redmondjp]

Are you using any continuous-use air tools to do this work? If yes, definitely get the larger one. Or if you have any plans on doing so later (sandblasting, sanding, grinding, painting, etc).

If just intermittent use of impact tools, the smaller one will be fine. I have an equivalent 60 gallon that I have been using for 25 years. It will not keep up with a die grinder and will start spitting out water after 15-20 minutes with it running continuously at around 80psi. Not a pretty sight.

The benefit of the 3-cylinder unit is that it pumps more air. If you are using high-cfm tools or a sandblasting cabinet, that will be beneficial.

After your wallet recovers, you will never regret getting the larger compressor.

 

[ddawg16]

What ever you do, do NOT get one of those oil-less ones....

Mine is and old Farmers Brothers from the 60's...2-stage 240Vac motor. Quiet and fast. Paid $125....bought it from BlueDog.....(the OG's here will know who I'm talking about)

Personally, I'd be checking CL first.

 

[ovrrdrive]

You should definitely buy the biggest one you can afford. Buy once, buy what you need.

That said, I have the Husky 60gal from HD and it works well for me. The biggest air user I have is my plasma cutter and the compressor puts out about twice what it needs. I added intake silencers tomine and it helps take a little of the noise away but it really isn't a terribly noisy unit anyway. I can't even hear mine running if I'm in the house.

I've been working on ways to get the water out in my spare time. I just build a small copper manifold (aftercooler) on the wall and I'm in the planning stages to build an intercooler for it too. I'll still probably add a refrigerated cooler to it soon though as I'm building a plasma CNC table and want the best quality cut I can get from it but the inter and after coolers can't hurt either way.

 

[HondaFarmer]

The benefit of the 3-cylinder unit is that it pumps more air. If you are using high-cfm tools or a sandblasting cabinet, that will be beneficial.

so are you saying that the third cylinder helps create a higher available cfm? I have a harbor freight blast cabinet and occasionally use die grinders - hope to use both of these more at a later date so it sounds like the bigger unit is probably best

 

[exranger06]

The most important thing to look at is the SCFM output of the compressor. You need to know how much CFM your tools consume and buy a compressor that puts out at least that much.

 

[theoldwizard1]

Are you using any continuous-use air tools to do this work? If yes, definitely get the larger one. Or if you have any plans on doing so later (sandblasting, sanding, grinding, painting, etc).

This is the question you have to answer ! For heavy duty grinding, most people use an electric grinder. Parting out cars will likely require Oxy-Acetylene and/or a plasma cutter.

The 2 cylinder, 60 gallon is sufficient.

 

[HondaFarmer]

one more question - most compressors I've looked at have 2 different CFM ratings - one for 90psi and one for maybe 40 psi - that's a but confusing since the compressor tank pressure tends to stay between 100psi and 120psi so what do the 2 different ratings actually mean? Also if a compressor has a max rating of 155psi like the units im considering what does that mean? I think the cutoff pressure is still around 120-130psi

 

[eddiemeddiem]

As for the 60 gallon ones... If I remember right, I think the Kobalt has a longer warranty. Also, it has a NPT air/filter inlet vs a bolt on one for the Husky. The NPT makes it easier to add a Solberg filter/silencer.


Sent from my iPhone using Tapatalk

 

[creativecars]

one more question - most compressors I've looked at have 2 different CFM ratings - one for 90psi and one for maybe 40 psi - that's a but confusing since the compressor tank pressure tends to stay between 100psi and 120psi so what do the 2 different ratings actually mean? Also if a compressor has a max rating of 155psi like the units im considering what does that mean? I think the cutoff pressure is still around 120-130psi

These are just advertising numbers.
40 psi will do nothing but blow up a beach ball or some bicycle tires.
90 psi is the minimum most air tools will work at.
They like to use the numbers to confuse those who don't understand what they want.

As others have said you need CFM that is how much compressed air the compressor pump is making in Cubic Feet per Minute. The larger the number the more air, but ratings at 40psi are just for the ignorant to throw around.

Single stage (home owner type) compressors will use 90/40 numbers as they are not rated for much more than that with continuous use.

Two stage compressors are much more efficient in pumping air and will have working pressures around 150 or more... this is air pressure at the tank. (Not the same as the 155 max psi that it can only do once, then blows up)

If there is 90 psi at the tank it may be closer to 75 by the time it gets to the tool (called line drop), so most will bump the pressure up at the tank so you have the correct pressure when working with an air tool.

Hope this answers some of your questions.

 

[ovrrdrive]

so are you saying that the third cylinder helps create a higher available cfm? I have a harbor freight blast cabinet and occasionally use die grinders - hope to use both of these more at a later date so it sounds like the bigger unit is probably best

I think usually the 3 cylinder machines are big single stage units. The third cylinder is just to get more CFM out of it without going to 2 stage. CFM is the name of the game.

As for the 60 gallon ones... If I remember right, I think the Kobalt has a longer warranty. Also, it has a NPT air/filter inlet vs a bolt on one for the Husky. The NPT makes it easier to add a Solberg filter/silencer.

I fit a dual Solberg setup on my Husky with a little modification. I posted a howto thread here when I did it.

 

[HondaFarmer]

UPDATE: - ok, I decided on the 80 gallon, single stage, 4.7 HP Husky. I got my 10% military discount plus 12 months of 0% intereste so I'm pretty happy with that. I decided on the bigger one because I've always heard, "Buy Once, Cry Once." Those seem like wise words.

I had to get it home laying down on its side in the back of my Pilot so I thought I would share that. I drained all of the oil out at Home Depot and then let it sit upright in m shop for 24 hours before filling and starting it up. Wiring was a breeze. It takes about 7 minutes to fill up - Cut out pressure is 150 psi which was not in the manual anywhere but I thought it odd that the cut out pressure would be so close to the max PSI of 155.

I still have one question though - rubber isolation pads are highly recommended so does everyone else use these pads? Would just a rubber stall mat work? Right now I just have it on the pallet/skid that it came bolted to. Also I read somewhere that bolting it down solid to the floor with the pads is a bad idea. I read that it should be bolted down but not tightly - just enough to keep it from "walking." Any thoughts on this? Would love to hear what everyone else is doing.

 

[FTG-05]

UPDATE: [snip]

I still have one question though - rubber isolation pads are highly recommended so does everyone else use these pads? Would just a rubber stall mat work? Right now I just have it on the pallet/skid that it came bolted to. Also I read somewhere that bolting it down solid to the floor with the pads is a bad idea. I read that it should be bolted down but not tightly - just enough to keep it from "walking." Any thoughts on this? Would love to hear what everyone else is doing.

What does the manual say about mounting it?

I have my 80 gallon compressor on 3/4" rubber horse stall mat stuff. That should work for you in keeping the 'pressor from walking.

Good luck!

 

[Davefr]

You should also take a look at the HF 5 HP/60 gallon unit. I think it's superior to the HD/Lowes offerings.

Made by Bel Aire in the USA with an Italian pump. (not China!)

 

[creativecars]

Many people use hockey pucks under the feet to reduce vibration and keep it from walking.

The 150 cut off 155 max is how some of the consumer grade companies engineer the machines life expectancy. The numbers look almost like the big boys.

 

[boosteddsm92]

I still have one question though - rubber isolation pads are highly recommended so does everyone else use these pads? Would just a rubber stall mat work? Right now I just have it on the pallet/skid that it came bolted to. Also I read somewhere that bolting it down solid to the floor with the pads is a bad idea. I read that it should be bolted down but not tightly - just enough to keep it from "walking." Any thoughts on this? Would love to hear what everyone else is doing.

I've been using stall mat under mine for about 5 years now, hasn't moved one bit