# Air Compressors; Oil or Oil-free?



## ElMostro (Apr 10, 2008)

Need help deciding.  Looking to buy a 26 Gal vertical air compressor...what are the advantages or disadvantages of the ones that use oil over the oil-free or oil-frree over the oil required ones?  Compressor will not be used to run air tools for long periods.  The main use would be for casting in pressure pots and brad and pin nailers.  Thanks for the assist.

Eugene


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## rherrell (Apr 10, 2008)

OIL, OIL, OIL!!!! Oiless are LOUD, LOUD, LOUD!!! I have a little pancake oiless and a 60 gal. vertical oil type and the 60 gal. is MUCH quiter. Also, get the BIGGEST you can afford, you won't regret it.


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## Monty (Apr 10, 2008)

> _Originally posted by rherrell_
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> OIL, OIL, OIL!!!! Oiless are LOUD, LOUD, LOUD!!! I have a little pancake oiless and a 60 gal. vertical oil type and the 60 gal. is MUCH quiter. Also, get the BIGGEST you can afford, you won't regret it.


WHAT??? I CAN'T HEAR YOU, MY OILLESS AIR COMPRESSOR IS SO LOUD[:0][:0]


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## wood-of-1kind (Apr 10, 2008)

> _Originally posted by ElMostro_
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> Compressor will not be used to run air tools for long periods.  The main use would be for casting in pressure pots and brad and pin nailers.  Eugene



Eugene, I use a small 1HP Sears compressor (oilless) since I have similar use as you(casting, brad nailer). I have limited space in my small shop. Why do you need the power of an 26 GAL compressor(large?) for your simple needs?


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## ElMostro (Apr 10, 2008)

> _Originally posted by wood-of-1kind_
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Peter, the main reason is I have 4 pressure pots going at the same time.  I normaly do a round of casts in the morning (between 0400 and 0600) before I go to work.  My Studio (Ok, its my garage [:I]) shares a wall with the master bedroom and my little pancake compressor only holds enough air for one pot...then either operation halts or I risk it and turn it on waking the misses and that means I am sleeping on the floor that night.  Having the 26 Gal compressor will allow me to get all four pots going before I leave to work and ready to be worked once I return in the evening.  Now if the oil ones are silenter (is that a word?) then that is even better.  Less noise is a good thing.

I know someone may ask "why not put several molds in one pot then pressurize?" Well, working with alumilite does have ONE DISADVANTAGE and that is it sets fast so if I tried to make several mixes by the time they go in the pot the first one is starting to set before I can apply the proper pressure.


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## IPD_Mrs (Apr 10, 2008)

Rick is right.  You have no idea how many times I wish I had an 80 gallon upright oil.  I have a 26 gallon oiless and hate the darn thing.  It will wake the dead and anyone on the otherside of town!

Mike


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## Glass Scratcher (Apr 10, 2008)

I have a 80 gallon 6.5hp at work.  I have a 4 gallon twin at the house, works fine but doesn't have the tank capacity or brute force of the big one.  I wish I had the big compressor at home as well.

The oiless don't have the work capacity, or lifespan of the oiled compressors.  That being said it also comes down to care and maintenance.  But Oiled compressors are typically better.


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## Russianwolf (Apr 10, 2008)

> _Originally posted by ElMostro_
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If that's your only reason, you could also get an air tank then use your pancake to fill it when you are "allowed" to make noise. It basically just add the capacity that you need. 

If/When I get another AC it will be a larger oiled type and live in the garage (my shop is in the basement), but then I also plan to use it for working on my trucks, something the pancake I have simply can't do.


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## ElMostro (Apr 10, 2008)

> _Originally posted by Russianwolf_
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Mike, I did look at that option but it would only give me enough air for one additional pot.


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## tipusnr (Apr 10, 2008)

I have a small oil compressor and the only problem I have with it is that I have the darnedest time seeing the oil level in the sight glass!  I have defective color vision and the slight tinting of the compressor oil is not enough for me to see easily.  Other than that I really like the idea of it containing oil as I don't use it regularly and I have seen the oil-less seize up after sitting too long.


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## DocStram (Apr 10, 2008)

Oil. Besides being quieter, my sources at Capmbell-Hausfield also tell me that they last longer.


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## Nolan (Apr 10, 2008)

Oil-less is for "clean air" like paint and body shops. That way you dont get oily blow-by in the air stream. While its not alot of oil it can cause issues. Oil ones you can just put seperators and filters on them if you need the clean air, and yes they do last longer. But the best compressors out there IMHO are the screws.


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## MesquiteMan (Apr 10, 2008)

I own 5 oil-less compressors.  I am a custom home builder and me and my employees do all the carpentry work on my homes including framing and trim.  I prefer oil-less because they are quite a bit less expensive and when something does go wrong, it is almost always the cylinder sleeve.  For about $25 and 15 minutes of work, I can replace the cylinder sleeve and have basically a new compressor.  I don't think you can do that with oil filled but am not sure.  Oil less is typically lighter weight and is one less thing I have to worry about my employees checking (oil level).  Being considerable less expensive, if one does get trashed for some reason, it does not hurt as bad!  

One of the 5 that I have is my 30 gallon shop compressor.  It is oil-less and is noisy but it is outside my shop so it does not bother me!


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## Aderhammer (Apr 10, 2008)

Like nolan said, you get oil in the air, wouldn't want oil in your blanks?  I've not dealt with casting and pressure pots and all, but can't you put a quick connect and have a valve so once you pressurize the tank you close the valve and pressurize the next pot?


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## Mudder (Apr 11, 2008)

> _Originally posted by MesquiteMan_
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> For about $25 and 15 minutes of work, I can replace the cylinder sleeve and have basically a new compressor.  I don't think you can do that with oil filled but am not sure.



I have an oil type compressor (I think it's a Campbell-Hausfeld) that I have had and used hard for close to 30 years. I changed the rings in it twice and it is still going strong. (About $15 and half hour last time I did it.)
It is very quiet and being twin cylinder it comes up to pressure very fast. I don't anticipate ever having to replace this one but if I do I'll definitely go with with an oil unit.

I have to agree about the air screw. A buddy of mine works at a place that has an air screw and they use a lot of CFM's but the screw, which is surprisingly small, never let them down. An air screw is very expensive IIRC, and really not made for the home market.


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## Nolan (Apr 11, 2008)

Mudder is correct the screws arent for the home user, They are the top of the line compressors for ultimate performance. I just wanted to point out that they exist.


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## intillzah (Apr 12, 2008)

I currently have an oil less compressor, talk about a loud little bugger.  I had a old (and I mean OLD) oil bath model that died (had a rusted tank) and that thing was a beast, but quiet.  It would just chug along all day long...

I would like to build another one as soon as the compressor part of the one I have dies.  I'm thinking about using an old  Ford air conditioning compressor and a small electric motor to drive it and a pressure limit switch.  This setup should last for a very, very long time...


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## ElMostro (Apr 12, 2008)

> _Originally posted by n4631x_
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> Oil-less is for "clean air" like paint and body shops. That way you dont get oily blow-by in the air stream. While its not alot of oil it can cause issues. Oil ones you can just put seperators and filters on them if you need the clean air, and yes they do last longer. But the best compressors out there IMHO are the screws.



Thanks all for your input.  Since its main purpose will be for pressure casting getting oil in the pot would be a problem (I think?).  So Nolan, you say that with filters I can get clean air.  I think I have seen the filters but how often must these be changed? I know the more often you use it the faster you will need to change filter but lets say is it every 10 or 50 hrs of operation?  Thanks all.


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## RussFairfield (Apr 12, 2008)

Everyone has to own one oil-less compressor in their life to appreciate its advantages over the oil lubricated compressor.

Among the many advantages of the oil-less compressor - 

Their initial cost is less than that of a comparable oil lubricated compressor. 

They require absolutely no maintenance, where the oil-lubricated requires a check of the oil level twice a year for most owners. 

There is no way that any oil can get into the airstream so you will not have to use an oil separator of finishes that are sensitive to oil.

After that, you will find that the oil-less compressor is the best possible advertisement for an oil-lubricated compressor. 

They are loud, much louder than an oil lubricated compressor; and the bigger they are the louder they are. Unless you have owned one of them, there is no way you will believe how loud one of them can be. Plan on wearing ear-muffs if you have to share a room with anything larger than a pancake or hot-dog sized oil-free compressor.

They wear out quickly. Depending on how much it is used, their life expentency is measured in months to a small number of years, while the oil lubricated compressor will last for decades with proper care. That 1000 hours that the saleman touts comes a lot faster than you would think. 

The repair kits are inexpensive. But, a word of advice if you chose to buy an oil-less compressor - Buy the repair kit when you buy the compressor because they will be discontinued and no longer available when you need it.


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## Nolan (Apr 13, 2008)

> _Originally posted by ElMostro_
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Russ nailed it and as far as filter/seperator for your oil/type compressor they are very simple and require almost zero matenance. I have auto moisture releases on all my vapor traps at the shop. Basically when they trap enough water vapor they purge automatically. I would say for your personal home type use get a vapor / oil separator from the company you buy the compressor from and follow the recomindations of the trap manufacture. Honestly for casting and such around the house there is no real need for traps unless you just want to be sure. Best thing you can do for your compressor is drain the water out of the tank on a regular basis.


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