|01-31-2008 06:06 AM|
Not to over simplify or be a smart guy but to me it seems to be air in vs air out.
I agree that a larger tank is usually good UNLESS it's been a while since you've been out in the shop, and you need just a little air to do something qick and dirty........then you have to wait for the whole thing to fill before you can get up to working preasure.
Sooooooooo. I have a larger one and a smaller one.
I have had a Sears compressor I bought in 1976 with a 20 gal tank. I have shot many many cars, done all the sanding, and even some sand blasting with it.
Change the oil, change the filters, and it'll go forever!
Part of the reeason that worked was because I was careful to MATCH the air consumpsion of the air tools to the air PRODUCTION of the compressor.
Even with a large tank, if your air tools require X cfm and the compressor can only provide Y cfm..........then the compressor will always be struggling to keep up.
This mmakes them run MORE and that causes them to run Hotter....which creates more moisture, oil, and all that jazz.
So in short.......SIZE DOES MATTER but look at the CFM number of the pump, your air tools, and make sure you look at the rating at the different operating preasures.
It may keep up fine for you spray gun, but not run your cutoff wheel properly.
|01-30-2008 11:53 AM|
you already have a tank... perhaps you can get a compresser motor combo for $300 less
if your old 5hp wont do it chances are a new one wont either.
about the biggest you will find in single phase is 5Hp
most gas powered are bigger than 5hp
so operating cost is not the issue if you dont have sufficient capicity.
if you are clever with pressure regulators and pressure switches and have 100amps in your garage you could make two 5hps work together and never have the second in use unless the first cant handle it alone
as for reed valves
the compressor is a piston with check valves on either side
when you get to more cylinders the valves can be loaded and unloaded and spring loaded to act as pressure regulators (interstage cooling and pressure setting)
a reed check valve is light and requires little effort to open.
most small compressors probably use them... its and item to put in the features list
for those who need a 100Hp or so gas compressor...
someone sells a cam kit for a v8
half is the engine the other half is the compressor it includes the manifolds... the cam changes the compresser side to a two stroke with check valves (two lobes on the compressor cams)
the opening and closeing of the check valves is all in the cam timing.
the first time i saw these kits was with a 6 cyl chev 235 inline
there is a bladder thingy to open the throttle when the pressure falls
|01-29-2008 09:06 PM|
I've been looking at air compressors for the last couple of weeks myself. Mine is going on 20 years old and never has been big enough to do the job I would like it too.
Old Red is right about using a larger tank instead of upgrading the pump. I removed my motor and pump from a 30 gal. tank several years back and installed them on an 80 gallon tank and about all it did was make it work harder. It gave me a little more using time, but in the same respect I would have to stop and wait for it to fill up the tank.
I checked out Harbor Freight today because they have a 5hp/2 stage on sale for $799. They didn't have it in stock, but said I could get a "rain check" on it and they would order it with their next order and that way I wouldn't have to pay for shipping. I would like to hear from anyone that has bought one of these to see how they hold up to normal home shop use.
There is a place in Keller Tx. that is listing Ingersol Rand compressors on ebay with a TO30 pump and a 5 horse motor for about $1,100.00 and free shipping.
I'm bouncing the idea back and forth between price and quality. The Harbor freight compressor is priced right, but I don't want to buy something that I'll have to replace in a couple of years or less.
|01-29-2008 06:44 PM|
|01-28-2008 09:15 PM|
That must be a typo on the HP rating (in the link below) as I am sure that is the same motor as the 60 gallon tank unit, it would be really odd finding a full 6 HP on a compressor such as that one. I am not sure about where to find a two stage 30 gallon, not at a reasonable price anyway, but when I ran my shop we set up a bunch of them with tanks around that size. IR and a couple of other good outfits have high CFM gas powered two stage compressors with 30/40 gallon tanks but operating cost would sure be high with that gas engine.
|01-28-2008 06:24 PM|
oldred...............I don't see a 30 gal unit by Puma..............any recommendations for a 30 gal unit? Eaton has a couple but pretty pricey.....I'm looking for a decent two-stage unit for spraying and other stuff....
|01-20-2008 07:01 PM|
|01-20-2008 06:59 PM|
I got it from my brother in law (runs a CarQuest Auto parts)
|01-20-2008 05:05 PM|
|oldred||The two units I have looked at also have Baldor motors (made in USA) and the overall quality of the rest of the outfit looks pretty good, above average for a compressor in this price range. They also have another thing in common with the more expensive industrial compressors, they are HEAVY!|
|01-20-2008 04:59 PM|
Re: Compressor Tank Size
Aminga did you get the 6560 model? It's the next larger one that Puma makes.
I found info on it but who sells it?
Where did you get yours?
|01-20-2008 04:47 PM|
I just hooked up a 7.5 HP PUMA in my garage. No word on durability. But it's a baldor industrial Motor. Cast iron pump (3 cylinder) And it appears to put out what they say 25 CFM) because it will keep up with my sand blaster running with the biggest nozzle in place.
The only downside is that tank pressure gauge wasn't reading right. I just haven't called them to get a replacement.
|01-20-2008 03:56 PM|
|01-20-2008 01:38 PM|
The $699.00 price of that compressor is getting close to the price of a cheaper 2 stage. If you're going to spend that much money you might as well add a little and get the 2 stage. You'll be much happier in the long run.
|01-20-2008 11:10 AM|
First let me apologize for giving incorrect advice!
Secondly, let me say, oldred... wish I would have ran across a post like this before I purchased my compressor. I actually purchased it due to the CFM rating being enough to run my Sata spray guns. Thankfully I don't have enough room in my garage to paint a disassembled car all at once. Nor the amount of stands to hold all the parts ! So it works well for me, for painting a couple panels at a time then rolling in the chassis and shooting it.
I will definitely reconsider piping the two together now!
|01-19-2008 01:55 PM|
|oldred||Most of those single stage pumps use reed valves and there really is nothing uncommon about stainless for the material. 11.2 CFM@90PSI and 3.6 HP, at least they are being honest about the numbers which is a refreshing change! IMO the Puma would be the better choice because, IMO anyway, the V type pumps work better and run cooler which means better efficiency = higher CFM per HP. Puma also has built a fairly decent reputation for reliability and even though I have never used one the two that I know of look like they are well built and the owners speak quite highly of them.|
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