Need Help with Air Compressor and Line Sander

[CLM65]

I am of the opinion, from some of the rebuilds on here, that a straight line sander would be a very beneficial tool to help with fairing my boat.  So, I have decided that I would put some of my tax return to good use.  Unfortunately, that also means I will need to get a new compressor as well, since all I have right now is a little pancake compressor.  I do not have a lot of room in my garage, so I'm not really looking for a huge compressor.  The one I would like to get is a Northstar 20 gallon, 2 hp from Northern Tools.  However, it is only rated for 5.5 cfm at 90 psi.  Most of the line sanders I've seen online say they need from 8 - 10 cfm at 90 psi.  There is one though (a Viking model V100) that says it only requires an average of 4 cfm.  I can't find any review information on it, but based on price it should be a decent one   .  Does anyone have any experience with this sander?  Does 4 cfm seem realistic?  Would this size compressor simply not work for a line sander?  Any help/advice would be appreciated!

[wingtime]

Most air tools such as sanders will use about 10-12cfm @ 90 psi.  The only way your going to get that kind of CFM is with a 220 volt compressor.  Now if you were using an air drill you could get away with a smaller compressor since your not going to be continuously drilling holes.  But a sander such as a DA or an inline is usually used continuously so even large compressors have a  hard time keeping up with one that is run for long runs at a time. A larger tank will give you a buffer that will allow you to run the tool a little longer before the pump can no longer keep up.  Then you will have to wait for the compressor to fill the tank up before you run the tool again. A 20 gallon tank won't give you much reserve air.  I'd look for a 30 gallon belt driven oil type compressor.  The oil less compressors are insanely  loud.  You'll just have to take a break now and then as you sand. It's not worth the $$$ for a big compressor your not going to need once the boat is done.  And shop by looking at the CFM at 90 psi.  Peak amps and peak HP mean nothing and are just marketing gimmicks.  If you see a 5hp 120 volt compressor don't buy it... it is impossible to get 5 hp out of a 120 volt circuit!

[icemanbryan]

Yeah, air tools that are continence use require big volume.
220 V large capacity tank.
That really is the only way this works out.
If you try to go 110, it will most likely be blowing the breaker.
I have a small cabinet shop for my construction business.
We use a few air tools, only one or two guys working.
Sorry, I know it is not what you want to hear.

[seabob4]

80 gallon Campbell-Hausfield and call it a day...

[RickK]

I have a 30 gal tank compressor and actually built a portion of my shop around it.  I used an inline for a day here recently and the compressor ran non-stop. Most tools can quickly exceed the storage potential of a small tank. I just have top put up with this shortfall of my compressor - an inline sander is an awesome tool.
Harbor freight has some decent prices on 80 gal tanked compressors and I was seriously thinking of buying one but just don't have a place to put it.
If you do, I'd go with one of them.

[CLM65]

Thanks guys.  Deep down I knew that was the answer, but I was hoping someone would convince me that the smaller unit would work.  I guess I really need to examine my garage/shop and see what I can do to fit a bigger unit in there.  I've seen some 60 gallon compressors rated at ~12 cfm@90 psi that should do the trick.  Thanks again

[SaltH2OHokie]

Thanks guys.  Deep down I knew that was the answer, but I was hoping someone would convince me that the smaller unit would work.  I guess I really need to examine my garage/shop and see what I can do to fit a bigger unit in there.  I've seen some 60 gallon compressors rated at ~12 cfm@90 psi that should do the trick.  Thanks again

Keep an eye on craigslist.  I got an 80gal compressor, all of the wire out of the fella's garage, 50' of air line, the motor starter, the wiring from that, and even help loading it for $200.  Was a woman who's ex-husband had died, and had never bothered changing his will.  Based on the prices she had on most of the stuff in his garage, she was not heartbroken that he was gone...

Keeps up with everything I've thrown at it.  Worst problem I've had is trying to use it when its bitter cold sometimes ice will form on the pressure switch and it won't cut off (but you're in Florida, so the weather won't be a problem...the drivers on the other hand, seem to be some of the worst in the world, so good luck with that  :pirat: )

[saltfly]

A friend of mine had the same problem. He asked me what he could do. This is what I told him. Get a 5hp compressor with a 20gal tank. Then get a few independent 10 gal tanks he bought 4 from harbor freight. We put them in the rafters of his garage. Then hooked them in series. This gave him more then enough air storage and the tanks were light enough to put in his rafters and out of the way. I’ve found, that getting a 5hp or more if you have the room is always best. when it come to cfm output and being able to run any air tool. Also with the smaller tanks you can mount them on a shelve high on the wall. They don’t have to be on the floor. Just my opinion.

[gran398]

Craig, given that its most likely a one-time event.....could you rent what you need for a week or two?

[seabob4]

Craig, given that its most likely a one-time event.....could you rent what you need for a week or two?

Was thinking the same thing, Bro....

[CLM65]

Thanks guys.  Deep down I knew that was the answer, but I was hoping someone would convince me that the smaller unit would work.  I guess I really need to examine my garage/shop and see what I can do to fit a bigger unit in there.  I've seen some 60 gallon compressors rated at ~12 cfm@90 psi that should do the trick.  Thanks again

Keep an eye on craigslist.  I got an 80gal compressor, all of the wire out of the fella's garage, 50' of air line, the motor starter, the wiring from that, and even help loading it for $200.  Was a woman who's ex-husband had died, and had never bothered changing his will.  Based on the prices she had on most of the stuff in his garage, she was not heartbroken that he was gone...

Keeps up with everything I've thrown at it.  Worst problem I've had is trying to use it when its bitter cold sometimes ice will form on the pressure switch and it won't cut off (but you're in Florida, so the weather won't be a problem...the drivers on the other hand, seem to be some of the worst in the world, so good luck with that  :pirat: )

Damn, that sounds like a great deal!  I periodically look at craiglist, but haven't seen anything that doesn't look like total crap or costs as much as new...but I'll keep looking - great suggestion!

[CLM65]

A friend of mine had the same problem. He asked me what he could do. This is what I told him. Get a 5hp compressor with a 20gal tank. Then get a few independent 10 gal tanks he bought 4 from harbor freight. We put them in the rafters of his garage. Then hooked them in series. This gave him more then enough air storage and the tanks were light enough to put in his rafters and out of the way. I’ve found, that getting a 5hp or more if you have the room is always best. when it come to cfm output and being able to run any air tool. Also with the smaller tanks you can mount them on a shelve high on the wall. They don’t have to be on the floor. Just my opinion.

Now that is thinking!  I'll look into that.  I have found a few 3 to 3.5 hp, 60 gallon units that are not much more money than the Northstar unit I originally was looking at.  They provide about 12.5 cfm @ 90 psi - should be enough for what I intend to do.  But the idea of "hiding" the smaller tanks does sound appealing!

[CLM65]

Scotty & Bob,

That is a good suggestion and I actually called around to a few rental places last year when I started getting "big compressor envy" (I think it was for sandblasting the interior at the time).  A rental unit big enough to provide the air I need will cost about $145 - $180 per week, or $375 - $475 per month.  I do not yet know what all will require fairing - I know the transom will.  The transom cap will.  I'm sure I will need some on the sides where I'm patching holes.  Might need it on the bottom (haven't flipped the boat yet or stripped the bottom paint).  May need it on the deck.  I guess what I am trying to say is that I won't be able to fit/schedule all of the fairing work into a two week window.  And if I rent a unit for a month, it is quickly approaching the cost of buying a new compressor.

I figure worst case, I can buy a bigger compressor than I need in the long run, and then sell it for a couple hundred less than I bought it for, and still come out better than renting.  But hey, I like manly tools, so I will probably keep it anyway.

[seabob4]

Craig, unless you're a glutton for punishment, you'll want to spread that air-filing out over some time.  It's not something I'd want to do day in, day out for 2 weeks...

[CLM65]

Craig, unless you're a glutton for punishment, you'll want to spread that air-filing out over some time.  It's not something I'd want to do day in, day out for 2 weeks...

You're right Bob.  Plus I've never used one, so I imagine there is a learning curve.  I think it would be better to go at a slower pace and not worry about how much more time I have on the rental.