ot- air compressors

did the archive thing…

what would you do- 1) play money is tight, but dont want to skimp 2) want/need a compressor to start spraying 3) not looking to run airhog tools like sanders/grinders 4) would like to run nailers and obviously spray boards (full board and small work) 5) would like it to last a while and be quiet enough to not get complaints from the neighbors or the wife (painting done in a basement) 6) i dont do more than 8-10 boards per year, but i like quality

so what are youre thoughts?

is resinhead’s 20gal/5hp rule required in my case?

better to go with a better motor and less tank (contractor grade portable) or larger tank worse motor (home depot special)?

are oil-lubes that much quieter and longer lasting (and do i need that)

how frequently would an 11gal tank empty on a full board spray?

any help is much appreciated.

thank you.

Sorry John O I don’t have an answerr for you. In fact I want to add to your question rather than start a very similar thread.

I would like to get a recommendation for a dual purpose pump- vacuum (for bagging) and compressor for airbrushing.

Anybody got an idea?

You don’t need a dual-purpose pump. You can pull vac with a venturi valve hooked up to a regular compressor. Wiring & plumbing diagrams on the Joe Woodworker site…

Hi, I’ve been using a Campbell-huasfield(sp?) 20gallon 4.3 HP (i think) for both. Its an oil bath type compressor, so I put a water/oil separator inline when I use the airbrush. I think you would want to do that for any compressor. They all pull in moister from the air and condense it in the tank. I still have pretty limited experience with air brushing, but it seems to work well. I bought mine to run tools, so as far as size requirements etc. I’m not sure. I got a deal from Home Depot. I was returned for repairs, and hasn’t given me a bit of trouble in 8-9 years.

Its been working well with this unit to generate a vacuum. I set mine up with 4 reserve tanks.

http://www.joewoodworker.com/veneering/v2-about.htm

The largest bag I’ve used so far is 84”x 30” with no problem. I fact I have to shut it off part way to make sure everything is aligned and pull bag film out of the cracks between parts because it draws out the air so fast. Best part is that it does not leave my compressor running full time. It has a sensor that cycles the vacuum generator on and off as it needs to ±4 in. HG.

Hope that helps. If some one has more experience please correct me if I have some of this wrong.

Hafte

aloha,

sorry this may not be what you want to hear.

If money was not a factor, go with something with the highest CFM’s. There’s no other factor when purchasing a great compressor.

High CFMs and large tank! is the way to go

Most compressor will have some degree of noise, make a sound box with eps sheets that surrounds your compressor with a hole for air. You can use ac filters over the hole for more filtering.

Now, since play money is a factor. Check out your local auto recyclers, sometimes you may find a large tank for cheap. Ebay will sell lots of motors/parts to make your own custom compressor, for real cheap. Propane tanks are real cheap and come in lots of sizes. You be surprized how many propane tanks are being dumped daily, just check out your local dump site…you maybe able to get one free.

enjoy and have fun

Hi John,

Based on what I’m using -

Lets see- for nailers, one or two, or maybe some use of a 1/2" drive impact wrench, light air sanding, filling the tires, spray painting with a touch-up gun or adapted down to an airbrush, general stuff, I’d recommend one of the 1 1/2 -2 hp, not awfully big oil-type compressors. The contractor-type portables, in other words.

A few things-

Air nailers don’t use much air, really, unless you’re nailing off lots of plywood fast with a good sized framing gun. Finish nailers, you’ll never outrun the compressor.

An impact wrench 1/2" drive ( and take it from me, the 3/8" drive impact wrenches are useless little things) will use a lot of air if you’re the Wood Brothers or some other pit crew, otherwise no.

Small air sanders, like the typical 6" random orbit or disc sanders will outrun a small-ish compressor pretty quick, but if you don’t mind a moment now and then waiting for it to catch up, no problem.

Spray painting: you’ll want to get an aftermarket or add-on water and oil filter for your air with any spray painting in any event, so oil or oilless isn’t an issue there. Get a good regulator, and they are cheap, and you will be able to get the pressure down to what an airbrush wants, no problem.

If, on the other hand, painting becomes a serious item for you, then a stand-alone HVLP setup will be on your list eventually. It is on mine, but not too soon. I hate painting.

This isn’t, after all, production work, where somebody is painting or grinding all day.

The main differences between oil and oilless are the oil types last longer and the gutsier ones are all oil lubed. And oilless compressors make such an annoying sound, after any length of time you’ll want to take a sledge to it.

I like the 2 HP and under size…and don’t be misled by claimed horsepower, you want something that draws around 15 amps at 120V. You don’t need to worry about popping breakers or blowing fuses with one of them, where around 5 HP you’re looking at 220V and a lot of juice, not something you can just plug into the wall socket.

I have a Hitachi…and I suggest you go with maybe a Porter Cable or Rol-Air. The Rol-Airs seem to be indestructible with decent care, the Porter Cables have the gauges and chucks mounted in a kind of instrument panel deal so they don’t get hit or busted off. My Hitachi, on the other hand, has non-standard ( 1/4" NPT is pretty much the standard size for air stuff on small gear like this) threaded gauges and such which are more to replace than replacing the whole regulator/gauges sub-assembly with more common-sized stuff. And the gauges are set where they can be banged and busted in normal, construction-type use.

Avoid DeWalt for two reasons. One; they are DeWalt and thus just Yellow and Decker, two; they owned Emglo, maybe still do, and the quality went all to hell. Stanley/Bostich compressors seem okay, their nail guns suck. Hitachi nail guns are the best, but their compressor isn’t, as I mentioned. I have had okay luck with a $100 Harbor Freight cheapo compressor until some moron ( the owner) decided to take apart the regulator/valve/ pressure switch assembly and couldn’t get it back together. They will sell you adequate regulators very cheap.

And, a word about hoses. The word is ‘rubber’.

Unless you live in constant 70°F+ temperatures, the PVC hoses will drive you nuts, they don’t like to bend when they are cold. The harder plastic ( ‘Coca Cola hoses’ they call them here) hoses the roofers love will kink, the flow is miserable for larger tools and they like to break - their sole virtues are they are light and they are very, very cheap. The reinforced plastic, sorta-flexy hoses that look a lot like the hose the rinse attachment on your sink has - kink city, you really want to keep them on some sort of reel, as otherwise you will have knots and tangles that will make you want to chop them into link-size pieces.

Go with the rubber, neoprene air hoses. They are okay in the cold, okay in the warm, the reddish ones are non-marking, they come in all sizes and lengths and thicknesses.

Air fittings- get brass, not steel. Brass doesn’t rust, it doesn’t wear out the other fitting, male or female, that you are connecting to, Harbor Freight has 'em cheap. I get them in half-dozens and stuff 'em in my air tool cabinet with some teflon tape. They do wear out after a while, just replace 'em. Hoses usually come without quick-connect fittings, and they are double-male threaded, so you will want a female threaded fittings for each end of your hose. Again, 1/4" NPT is standard, but there are 3/8" and 1/2" threaded hoses out there, and finding fitting for 'em cheap ain’t easy.

Anyhow- that’s my little air compressor rant. Hope that’s of use

doc…

I sure wish people would fill in their user profiles. Where are you located? The reason I ask is because I know someone who has a nice large compressor they aren’t using (in fact it is taking up space at MY house).

(I’m guessing by the reference to a basement that you aren’t in Southern California, but who knows…)

hi keith- yeah, im real sorry about not filling out more info. i dont really login that much because im much more of a lurker/beginner- not too much to add. but i have made a few posts and i guess its rude not to introduce myself. due to my profession and the fact that i am completely paranoid, im a little hesitant to post my last name.

i know you are in san diego, but i do appreciate the offer!

doc- not that im in any position to say, but i think you might consider renaming yourself dr. thread-ender. if i had the time, i would start counting how many threads on this site end with your ever-insightful posts. you are a treasure. to be honest, i was looking for your opinion- i knew if i included a tool in the subject you wouldnt be able to resist.

now, one last question for you- lets say im only going to use this compressor for some nail guns (roof/finish) and spraying boards. what size tank?

(chuckling ) …yeah, I’m afraid I do do that, now and then, and I’ll apologise now to those I bludgeon with information. It’s kind of a compulsion with me.

And you do indeed know the bait that draws this particular rat.

Now, for ( lets say ) a couple of roofing guns, or sidewall guns ( like my favorite Hitachi VH500, since supplanted by the NV50AA - a very nice gun for wood roofs, clapboards and porch decking by the way) or , let us say, some of the better 15 degree finish guns like the Hitachi or the Porter Cable, a standard, contractor-type compressor is fine, like this one: http://www.toolbarn.com/product/rolair/D2002HPV5/

~ 4 gallon air tank. The thing is, they tend to cycle on at around 100PSI and shut off around 125 while nail guns typically operate at 90 PSI or less in softwood, so you have to be nailing awfully fast to outrun even a tank that size before the compressor comes on and catches up. Framing nailers are considerably more air hogs.

Now, a disclaimer. As I said, I hate painting. And I kinda like brushes. So to really get the deal on sprayers, I had to refer to another source. So…

For a small-ish HVLP gun, such as http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=43430 , you’re looking at

[]Required air pressure: 15-50 PSI []Air consumption: 9.5-14.8 CFM

HVLP touch up ( detail ) gun:

Operating air pressure: 43 PSI; Air consumption: 3.7 CFM;

Another is 2.6 CFM at 29 PSI - http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=46719

And for the rinky-dink conventional detail gun I have,

Air consumption: 3 CFM @ 50 PSI

Basicly, if you’re going with a detail gun ( and using any more for surfboard work would probably be awfully wasteful of paint and such) , you should be fine with a small compressor that can put out around 4 CFM at 100 PSI. Airbrush work, of course, the compressor might come on once an hour. The Binks airbrush compressor I have…if it puts out enough volume and pressure to inflate a kid’s balloon I’d be surprised.

That help any?

Best regards

doc…

geez i feel stupid. all you had to say was “once every hour”. here i was concerned that i’d be spraying with the motor cycling every minute or so. i just havent been around these things much i guess.

i appreciate all the effort. im not really much of a power tool guy so sometimes i can get cought up in the terminology without having a frame of reference in my head.

j

Naw, John, don’t feel stupid.

See, now you can look at the specs of a compressor or an air tool and tell what it’ll do and won’t do, what it needs and what it doesn’t. And then you can tell somebody else.

You’re now armed and dangerous…just like me. And that’s the purpose of all this blather I put out.

'Cos somebody taught me, and got me started on this twisted path. And the tuition payment for that is to pass it on.

I’m paying in installments…

doc…

Howzit doc, The compressor I have is a single cylinder belt driven with a 3/4 HP motor that pulls about 6 1/2 amps and it has plenty of power for any surfboard building applications, don’t think you really need 2 HP pulling 15 amps, especially with the price of electricity these days. The best part is I can order any replacement part from Granger in case it breaks down, paid $75 for it at a garage sale.Aloha,Kokua

Hello JohnO ,

Doc,Kokua,Hafte,Manoa,Benny1,and Kieth all have some very awesome information for you. I recommend reading through it more than once.

Here’s my story / input

CFM…Cubic feet per minute (not sure what scfm means)

I was taught that all Craftsman power tools are actually made by other large tool companies. So Why buy Craftsman???

Well , I bought a Craftsman air compressor back in 1993 and I can still buy parts for it from the local Sears service center.

I don’t claim Sears to be the best but I’ve rebuilt/repaired my air compressor more than once and I know who has the parts I need. Keeping the original parts manual is also a good Idea.

I have a 3 1/2 hp motor with a 25 gallon tank. Plenty of power for Surfboard stuff but very weak if you want to restore a classic car…

Filters / traps are a must. Drain the tank often.

My compressor is “permanently lubricated”. (yeah right) This is great for the weekender but for heavy / industrial use the oil type are best.

I have one gauge for tank pressure and one gauge for line pressure.

I’d be lost with out an air compressor!

Looking for something small and quiet? I painted my first couple of boards with a nitrogen cylinder. Perfect for painting as the nitrogen is oil and moisture free, small footprint and completely silent. One fill painted two boards and blew the shop down. Just a pain in the A@# when it runs out half way through the job.

Hi Kokua,

Oh yeah, I agree - thing is that the compresor 'horsepower ’ is a whole lot different than real horsepower like your motor. Same sort of deal as router ‘horsepower’ - it bears no relation to the actual amperage. It’s a funny thing - my compressor with 2 claimed horsepower draws less amps than my (again, claimed) 1.5 HP table saw. And that’s a nice, efficient motor on that saw.

Though then we have the question - is a 12 amp/110 V motor running for 6 minutes during a given working hour a whole lot different than a 6 amp/110V motor running for 12 minutes during that same hour. Both are using up the same wattage, which is what they are charging you for.

This, by the way, is an argument in favor of the more motor/smaller tank compressors versus smaller motor/bigger tank type. Thing is, every time you fire up one of the latter, you have to get that big tank up to pressure. Even if all you want to do is fill up the neighbor kid’s basketball.

I also have, for instance, a big ol’ Emglo, 220V, lots of CFM, tank is in the 30 gallon range. But I rarely fire it up, unless I am gonna need a LOT of air, say like doing some sandblasting or air grinding. 'Cos I have that basic tank to fill.

While I was looking up a few things this morning, I looked through the Grizzly catalog - turns out they sell compressors under their own name now: http://www.grizzly.com/products/category.aspx?key=120000

While I haven’t used a compressor from Grizzly, I will say that I have had very good luck with their bigger shop tools over the years. They stand behind their stuff. Besides which, the small ( ~$160 US , 14 amp/110V) ones come with regulator, gauges and such and not all others do. I’d buy one if I was buying a small compressor today.

hope that’s of use

doc…

I used to work with a carpenter who ran his finish nailer off a scuba tank. One tank would last dang near all week and a refill was $2 at a shop near his house…

Outside the box.

hey guys- i really appreciate the responses and ideas. im thinking ill go with the twin tank grizzly doc recommended. i do like the scuba tank/propane tank ideas, but i think i would go into an uncontrolable frustration rage if they ran out mid-board. i do stupid things when frustrated (like use spray paint).

so in summary (for archive readers and to make sure im on the right path)

  1. know what you are going to use it for

  2. get as good/big a machine as you can afford

  3. ignore all numbers except amps and cubic feet/min (cfm)

  4. higher cfm = better motor and faster tank fills

  5. bigger tank = more time between motor cycles, but takes longer to fill

  6. for airhog tool use, follow the 20gal/5hp rule (not sure of the amps on that one- sorry doc)

  7. oil-lube is the way to go for durability and no sledge temptations due to irritating noises

  8. none of this will make a bad board good

(chuckling once again )

Ah, life is good. I have created another knowledgable tool freak.

John, you’re smack on on all counts. Especially the last.

A couple of clarifications;

As Manoa said, it’s all about CFMs, or SCFMs (Standard Cubic Feet per Minute )… the claimed horsepower is like a lot of other things ‘claimed’ - bag it. Look at what your tools use per minute, and then at how many minutes you are using them in a given period of time. Long periods of using a tool that will use a lot of air, lots of CFMs and a big tank. Short bits of use with not too thirsty tools, small tank and a small compressor.

Scuba tank - metz a metz 72 cubic feet at a reasonable pressure - well, it’s a small-ish tool and not a helluva lot of use. I have no idea how they rate those things for volume, certainly a 9" inside diameter by roughly 30" high tank is less than 72 cubic feet overall. Let’s see - pi times 4.5 squared, times 30 (where’s a calculator, dammit ) gives me roughly 1 cubic foot - gota stuff a lot of pressure into that to get to 72 cubic feet at normal pressure, like 72 atmospheres or around 1100 PSI. That’s a lot.

ah well, life is still good. And John, as for me, I throw things when I get frustrated, got a few things to fix cos of that.

doc…

Doc, a regular scuba fill on a full-size single tank is 2200 psi +…

Some of the newer composites go to 2500+.

Yep - that’s a heck of a lotta ft3 to tote around :slight_smile:

Howzit Benny, Back in 94’ in Mexico I met a guy who would get about 3000 psi in a scuba tank and use it for fillinf tires instead of using one of those pumps you connect to your ciggie lighter. Told me he could fill a lot of tire with 1 tank full. Seems to me the thing is getting a regulator that could handle 3000 psi. Aloha,Kokua