OT: Compressed air - what do I need?

Hello!

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My house and garage project has come into a phase where I think I need (or I want) an air compressor with lots of big, heavy and noisy tools. I have been looking about the compressors they sell in the local auto part suppliers here. The sizes and prices vary between 100 euros to 600 euros and from compact to approx Beetle size apparatus that I would not like to try to stuff into the garage.

You might have experience about different tools and compressor power/max pressure/air flow values. What is needed for a normal DIY Beetle and daily driver repairs? At least air pressure meter gun (for inflating tyres), air wrench (for annual tyre exchances) are needed. Do I absolutely want something else that will make my life easier? What are the real requirements for the compressor for these applications? How about painting? How about sand blasting?

I have been away from here for a while, mainly because of the house construction project me and my wife have had going on. Now that I have a garage, maybe I will start the engine rebuild project I have had the parts for at least 3 years now...

Reply to
Olli Lammi
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It's all about flow rate at some specific pressure. Here in the US compressors are rated in CFM (cubic feet per minute) at some pressure (usually 90 psi). After you decide what tools you need, look at their specs and buy a compressor that has a flow rating that matches the tool you have chosen. You will probably want to buy something a little bigger in case you decide to get some other tool that needs more. I know my tools like company and I am always buying more!

Ken

Reply to
Pete

Yes look at the specs on the pump but also look at the tank size and of course QUALITY!!! If you are considering sand/media blasting then you probably want the biggest you can put in your garage or out side shed without draining your finances.

Impacts like good CFM but also high pressure. There are single stage pumps and two-stage pumps where the two-stage can take the pressure higher usually.

Not sure what they have over there but I believe you are already setup for

220Volts.........YOU are lucky! lol

JMHO

Reply to
dave AKA vwdoc1

dave AKA vwdoc1 wrote: >

I have 230V 1-phase and 400V 3-phase outlets in the garage.

Reply to
Olli Lammi

Dear Olli,

You've been 'crux'd', as in 'This is the crux of the matter!

Maximum compressed air requirement is for 'sand-blasting,' quotes because sand is rarely used any more. Nowadays they use some other kind of 'media' such as finely crushed slag. Or garnet. That's for removing rust & corrosion from steel. If you plan to do that (ie, remove rust from steel) you'll want to remove it OUTSIDE of your shop... and think about a fixture or jig that allows you to flip a VW pan upside down. Hell of a chore (and one where you MIGHT decide to use sand. Why? Because sand is the least expensive of the various medias. This is for the fabled 'Body-off resto,' of which I've done a few (and built the jig)...and found that a 5hp, 90psi & 100cfm was INSUFFICIENT. Indeed, the specs may have been juggled a bit. But the compressor purchased to fulfill those needs fit in the space provided

-- a square about 30" on a side -- and has operated trouble-free since the day it was purchased. It is a permanent part of the garage, installed in a lockable room at the rear of the structure. With the door closed and the inlet filters in place, it runs very quietly. (Is that possible? Indeed it is. The trick is to to build a 'muffler' of sorts -- a box-like affair consisting of a light frame & chicken wire. The 'muffler sits down OVER the 220vac 5hp motor and two cylinder compressor, which are installed atop the storage tank, which is about 60" in height to which the motor and compressor are installed via vibration dampers. When media-blasting, either indoors or out, the motor runs continuously. (Running 'indoors' means using a blasting cabinet -- a real time-saver when restoring old parts... or even new ones, in some cases. (I'd like to mention here that a VW crankcase is NEVER blasted with media of any type. NEVER. No exceptions.) But when trying to achieve maximum heat-transfer, the non-machined surfaces of VW HEADS may be blasted with relatively coarse media, mostly on the fins. (Such blasting INCREASES the surface-area of the heads; the greater the surface-area, the greater the heat transfer.

The garage was plumbed with iron pipe to conduct the compressed air to half a dozen outlets, plus one outlet on the outside of the building Each of the outlets is provided with a water-trap and pressure regulator. Only one of the interior outlets is plumbed to provide maximum output. That is, a 3/4" diameter iron pipe. It is also nearest the compressor. Farthest from the compressor is an outlet just beside the double doors of the garage. This is used to provide air for servicing tires, pressurizing radiators (yeah, I know...) and general errand-type work.

As a GENERAL RULE, you buy the largest generator you can afford. That is because a large air compressor can do the work of any small compressors...but the load isn't always equal.

Reply to
Bob Hoover

Hi Olli!

You need to step up to the biggest, baddest models only if you need them for: Painting, sanding, or sandblasting. For just about everything else, a mid-range compressor will do.

You can add more tanks later on if you want to have the air volume last longer, but it will also take longer to fill up. I had my extra tanks attached with a valve in between the main tank and the helper tanks, so the helpers would only get filled when I knew I would need them.

BTW, I'm moving into a house with a 2 car garage this month, excited!! Finally!

Jan

Reply to
Jan

Aawwk!

Dear Olli,

I hit SEND when I meant to hit SAVE.

Too many pills.

-Bob Hoover

Reply to
Bob Hoover

Man, I had a very strong de-ja-vu reading this message. I had to check the google groups if I had asked this before. Something 'snapped' when I read Jan's answer. Did not find anything similar in the history though. Maybe I am losing it ;)

New projects starting with the garage?

Reply to
Olli Lammi

Had to go for the dictionary for this one...

Ok. Larger is better because I would want to prepare for the future need. Two cylinder one better because it can provide more constant air flow or more throughput. How about then the statement "oil-less" in the descriptions? Does this mean maintenance free, better, worse or something else?

Reply to
Olli Lammi

Nah, no money for anything. The first 'projects' will be a harmonic balancer for the 2000 Windstar we bought recently, and rear wheel bearing savers for the '70 Nova, plus maybe tighten up the pinion in the rear differential to get rid of some howling. Oh and fix a leaking coolant hose joint on the Jeep ('87 Cherokee) coolant reservoir.

Looking for side jobs to do at home.....

Jan

Reply to
Jan Andersson

OK it is not the "BIGGEST" or "LARGEST" but the one that produces more CFM while maintaining the PSI. You could get a "BIG" compressor (air tank) that is weak with the CFM and/or PSI. For media blasting you definitely need that strong CFM and PSI. I have to do media blasting in spurts giving time for my compressor/tank to refill or catch-up. I don't do this often so I did not need to spend hundreds of dollars more for a higher CFM producing air compressor, although a 2-stage higher producing PSI unit would make my air tools more powerful!

Brand names are good to have since their parts hopefully are good quality, but they are more expensive unless you can find a used one in good shape. ;-) Pumps that require oil will probably last decades with the proper upkeep and may be quieter than those "oil-less" ones. My Craftsman air pump (home rebuilt air compressor) is about 28 years old and lives in a cold garage in the wintertime, until the heat is turned on. ;-) BTW I am running it with synthetic oil too! JMHO

Reply to
dave AKA vwdoc1

What does a no-oil compressor really mean? For painters does it keep oil out of the line? Or do they all do that.

Reply to
John J

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Reply to
Joey Tribiani

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Thanks! It makes perfect sense. I was imagining a system to remove oil by forcing it through a coiled tube to throw it to the outside, then, then, then.... aw, my idea is half-assed. Never mind!

Reply to
John J

Olli, (and everyone else) Last year in March, I started setting up my garage for powder coating parts and pieces, thinking I might actually make a buck or two on the side.... No bucks per se, at this time, but still plugging along....

A friend of a friend, gave me a Harbor Freight Blasting Cabinet,... FREE. The price was right huh? Another gave me a HF powder coating gun he'd bought and never opened. The gun was given to me after I expressed an interest in the powder coating. He gave it to me probably

2 years earlier,... but last year in march, I came to realize some potential for some unknown reason.... or maybe because I could see the light dimming on my income source or whatever.... longer story than this one....

When i bought my house 6 years ago, a neighbor was having a garage sale, from which I bought a nice little 25 year old DeVilbiss horizontally mounted 30 gallen Compressor, that was WAY TOO much Air for my needs, but I really enjoyed the extra oomph. I did some mechanickin of sorts and used air nailers and such around the house doing repairs, and had a really great little compressor.... I thought.

I hooked up the little DeVilbiss to that sad little free blasting cabinet and found out what a bunch of wasted time this was going to be using such a little source..... Course it was just a 110v of questionable horsepower.... on 110 it was forever trying to keep up. I feared burning it to the ground, so I went to Northern Tools and stepped up to that 60 gallon upright 3 or 3.5 hp compressor and ran two 220 circuits in my garage (knew I'd be needing a second one for an oven). Hooked her up and found I'm getting better Blasting fulfillment, but It aint enough. I spent 600 US dollars plus some more,.... Now I'm wishing I'd saved a bit longer and went to Somewhere in the neighborhood of 4500 bucks would do I think.... LOL

I'm still using that Northern Tools (Ingersol Rand) compressor. I have worked to make the blasting as efficient as possible and think I have the best it can get with the given set-up. Long stories suck but the moral is...........

GET EVERYTHING YOU CAN AFFORD in a compressor. You'll certainly need it for the body working tools and die grinders..... It's all about the highest CFM you can get at the highest PSI (although blasting truly only needs 60 psi,.... no matter what the CFM is.)

If you want to learn how to use a blasting cabinet effectively with a cheesy Siphon feed gun,.... I can hook you up though.

For most of you, unless you plan on doing much media blasting, you won't need nearly as much as I do. But I highly recommend you get as much as you can afford,..... trust me,.... you're gonna wish you had all of it one day.

Those of you who have tons of money to spend, and want to make the rest of us jealous, Screw Drive compressors are actually almost affordable to the home shop. Like I said,.... 4500 bucks. It'll probably outlive it's owner..... Even if the owner is quite young, if you buy a decent one and maintain it well.

Reply to
MUADIB

Thanks! I have done some blasting of vehicle floors with my 5hp 220v homemade air compressor. It works hard keeping up and usually I have to slow down the blasting. I keep the media reservoir higher than the gun so that gravity helps feed the media to the gun. ;-) I also needed a water filter on the gun to stop media clotting AND USE safety equipment for your body like your lungs and eyes at the very least.

I agree...........buy an air compressor that has enough power, both pressure and cfm! Oh and make sure your connections have no leaks in them especially at the tool! I recommend you buy good quality quick connects like Milton since I have gone through too many HF connectors and even had a HF male connector snap off. Some say you need to purchase connectors with larger internal passageways so you don't create bottlenecks and restrict air flow. ;-)

JMHO

Reply to
dave AKA vwdoc1

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