we have a sullair 10 hp rotary screw compressor that runs all of our pneumatic machines and two sanders. we can run a third sander for a little bit but the compressor really cannot keep up once the third sander is going. i'm anticipating more third sander usage and am looking to upgrade our compressor.

would it be better to sell our 10hp and replace it with a 15hp, or to keep our 10hp and add another 10hp?

10hp compressors seem to be more readily available on the used market. space, electrical requirements and usage, and maintenance are the arguments against having two 10's, but we'd have a built-in back-up compressor, plus (in my understanding) enough air to run four sanders (i think a 15hp only has enough cfm to power three sanders).

thoughts?

If it was me, I'd add the second compressor, if one goes down you can still operate, somewhat with one

Buy the 15 and keep the 10 as a backup. We have the same setup

thank you, bobs.

hen bob - sure, if money were not an object. i cannot seem to find a nice used 15hp machine. new ones, with dryer, etc. run $8-10k. i could likely get a used 10hp with dryer, etc. for half of that.

i just didn't know if there was something else i would me missing if i go with two 10hp's vs a single 15hp.

Have you thought about just adding storage tanks?

we already have an extra 80 gallon tank.

i'm not sure i fully understand the advantage. it takes longer for the compressor to fill up at start up, but what else? once the pressure drops, the pressure drops, regardless of how much capacity we have. if the compressor cannot keep up, then the pressure continues to drop. maybe not as quickly with larger capacity, but the compressor is not going to overcome the air usage draining the system.

Are you saying sanders like an orbital? If so have to looked into a really nice electric one like a Mirka or Festool. We used all air orbitals until we started buying the other ones. They work just as good and have vacuum hookups. Its nice having the vacuum this time of year when all of the doors are closed in the shop. A $600 sander is way cheaper than a new compressor. We have a 15hp Kaeser screw and it runs our SCM 5x12 CNC, edgebander, 52" wide belt, and several air orbitals and never has a problem. If I were you, I would add a second compressor if you need more air. That way if one goes down you can use the other one until they are both up and running. We keep and old piston compressor that can run if the screw happens to go down. Thank goodness that hasn't happened since we got it though.

We were in the same situation and I did as Ryan suggested and bought an electric sander. There are lots of advantages to them and they are WAY cheaper than a new compressor.
That said, the idea of another compressor to use as a backup if your other goes down is pretty appealing too.

There are a lot better ways to rate a compressor than just horsepower. Is your current compressor producing the rated cfm? Might be time for a rebuild.

Rich C. brings up a good point. Our 10hp has plenty of CFM to run the whole shop, If its getting tired might me time to be looking at rebuild/replacement any way.

We bought both ours new, some machines are not worth the risk when you rely on them daily

thanks for the replies.

electric sanders - i know the mirka is a little different, but the weight difference would be a big turnoff with my people actually doing the sanding. we run 6" sanders exclusively and i'm not sure if the mirka set up will turn this big of a pad. regular electric sanders simply weight too much to use all day long, all week long.

i'm not sure how i would test our compressor. it is rated at 37cfm @90psi. i'm pretty sure the sanders are rated at 15 cfm, so simply math tells me that we cannot run three sanders at a time. our compressor also supplied air for our wide belt, upcut saw, blow guns, and finish equipment.

our sullair was a very good deal. $700 for a compressor with 4500 hours. we had to install an attic fan to keep it from overheating (after replacing the thermostat and temperature probe didn't yield any results) but with the fan on, it runs like a top. we added a dryer and filter for $1300+ and, aside from looks, it performs like a new machine costing $5k+.

We run a 10 HP and a 7 1\2 HP. I've had the smaller one go down for repairs and still been able to run our shop at limited capacity, ie no Taylor clamp rack or something else big so the spray booth can keep going. I would go for the extra compressor and hook it into the system. Spares or duplicates are the best investment for getting Mr Murphy to not show up.

Ya. I feel your pain.

15hp VFD rotary screw in our stone shop and a 10hp rotary in the cabinet-corian shop

We bought 2 Mirka Derosband they are great, but we need a better solution too. 2 cncs A bander. Doweller and they really need their own conoressor. I have a hydrovane 10hp I’m thinking of putting in for them making their consumption not interrupted by sanders and grinders.

I’m almost afraid of s single compressor any more or cnc, bander, etc. we are looking for redundancy in all aspects of the shops.

The best thing to do is add a second compressor, it gives you a spare for when you have to do maintenance. then also add a big tank 80 gal not big enough. probably 400 gal. make sure you also add a refrigerated air drier. Sullair is the best choice. most small compressors are made in China. Sullairs are still made here. everyone should always have a big tank bigger is better. you can find them used all the time.

Not all of Sullair is made in the USA. From their website. Sullair was founded in Michigan City, Indiana in 1965 and has since expanded to serve customers in every corner of the globe. We have offices in Chicago and manufacturing facilities in the United States and China

Bigger air tanks are good but at the end of the day your compressor only pumps out what it can. Even a big air tank can easily be bled down with orbital sanders if the compressor is too small to keep up.

The bigger tank is not helpful as much as one would think.

Bigger manifold pipe diameter is in a complete loop. 3/4” will only get you by for so long. 2” has been recommended to us by Kaiser.

We are just going to add the 2nd compressor for the machines right now, until we can afford one new one with a VFD

I vote for a second compressor of similar size. Probably no need for anything more expensive than a good oil-lubed piston type, those are usually a good bit cheaper and plenty reliable. The only tricky part sometimes is modifying the low PSI trigger to a value you want, so that it only runs when the Sullair can't keep up.

everybody,

thanks for the replies.

with the piping - we have .75" flexible air lines right now. would we really see much benefit to upgrading to 1" (or bigger) lines? i don't think we lack any air at any of the tools - we just get in spots where we're using more air than the compressor can make up.

dryer and tank - in thinking about how to do this for the least amount of cash as possible - would we need another tank and/or dryer? i'm guessing no to the tank, since we already have a 80 gal storage tank. with the dryer, if i got a bigger dryer (rated for more cfm) and put each compressor right next to each other, i think we could plug both into the same dryer and we'd be okay. this isn't considering running a bigger dryer with less cfm than it is designed for when we're only running one compressor. assuming, and my next step is to talk to a local compressor company, this works, would it still work if the compressors were located on either side of the shop? i'm not sure i'd do this but i want to know if it is possible.

thanks again for your help.

Instead of buying another compressor of 10hp, Buy a 15hp compressor and keep the one with 10hp for the backup.

Fleck 5600sxt