Looking for a compressor recommendation

Discussion in 'Shop Talk - BladeSmith Questions and Answers' started by Stang Bladeworks, Jan 2, 2020.

  1. Stang Bladeworks

    Stang Bladeworks

    661
    Feb 19, 2018
    Hi,

    I am wondering if someone can reccomend a good size and style of compressor for blasting. I have a small blast cabinet from canadian tire, it would be identical to the harbor freight one. About 2'x3'x2'. I have outgrown my small dewalt compressor. It does the job but the capacity is SMALL. I can only blast for a couple seconds. I want to upgrade to something that will allow me to continuously blast for a reasonable amount of time. As I run low on pressure the blasting isnt very even. Im not looking for a specific model or anything just some guidlines. Quiet would be nice too, my dewalt is the loudest compressor I have ever heard. Its almost hard to believe something so small can make so much noise. I have been doing alot of blasting as of late (titanium mostly)so I think its time to upgrade. Thanks.
     
  2. tim37a

    tim37a

    956
    May 18, 2010
    I have the HF blast cabinet with a 5 HP compressor. Five HP is about the smallest compressor that will work and even that one will require you to stop and build up the pressure fairly frequently.
     
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  3. ten-six

    ten-six

    139
    Mar 11, 2017
    I'm not an engineer, I'm just a guy in a shop that likes to build stuff. And I'd add that I'm pretty frugal in my shop...like "drilling out the inside of hose fitting a little larger and deburring them for better air performance" frugal.

    For your average shop compressor, i.e. not a three phase, refrigerated liquid cooled rotary compressor, the basic differences between them are maximum pressures, volume of storage, and longevity/quality of parts. Change these variables and get better, or at least different, performance. They're all rated pretty much the same at a given pressure within the same current/voltage specs or "class" because you can only do a finite amount of work with a given amount of energy. Anyone that states contrary to this is a liar, period. It's a law of nature. The differences in how much air the can deliver come from things like friction. It all comes down to how they tweak little things like bearings, tubing sizes, etc. If you boil it down it's all about avoiding heat which is lost energy.

    If you want to run a blaster non stop you're looking at a 240V, two stage compressor at a minimum. These are pricy. You already know that. You wouldn't be asking this question if it was an option for you to drop major money on a big ol' compressor and forget about it.

    The easiest thing to change is volume of storage. You can do it yourself with a T fitting, a few pieces of hose, a tank, and a valve. Add a T to your air delivery line, plumb in a larger tank that you can keep pressurized and turn on and off at will, and you can blast longer. When you're done blasting simply turn off the excess storage tank and bypass it. This is asking a lot from a small compressor but it can be done. It's exactly what I do with my HF cabinet and $120 blue light special, no name compressor. Sure, it'll take forever to fill up but you can get more done in one shot.

    Another thing a lot of guys simply don't think about is the size of fittings and hose. A larger hose means less hydraulic friction which means more air faster. This makes a big improvement too.

    I know I didn't really answer your question but I guess in my own way I did. Make a bigger tank, use bigger hose, prevent hydraulic friction in fittings. Get more out of what you've got. Save the money for abrasives. Just my two cents....
     
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  4. 12345678910

    12345678910

    Jul 13, 2009
    If you have money, gt a KAESER rotary compressor with an air dryer.

    Probably not though.

    I've written this out a few times, go search for it.

    HP means nothing, they are all crooks.
    Size of the tank means nothing, tanks are cheap compared to pump and motor capacity.

    SCFM of the tool, plus more - maybe double it.

    Modify the HF blaster with aftermarket ceramic nozzles - search that too - lots of info on the web on those.
     
    Last edited: Jan 2, 2020
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  5. razor-edge-knives

    razor-edge-knives Moderator Moderator Knifemaker / Craftsman / Service Provider

    Apr 3, 2011
    I use an Eaton 7.5hp 80 gal compressor and it keeps up no problem at all with my 2x4" (chamber size) grizzly cabinet (which is pretty big).

    I would keep an eye out for something slightly used but great condition on Craigslist or something .
     
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  6. Stang Bladeworks

    Stang Bladeworks

    661
    Feb 19, 2018
    Thanks for the replies everyone. Much appreciated. Looks like I have some research to do.
     
  7. Drew Riley

    Drew Riley Riley Knife and Tool Knifemaker / Craftsman / Service Provider

    Oct 17, 2007
    The shortest answer will always be "the bigger the better", but I wouldn't go less than a 60 gallon compressor. The average 11 to 13 CFM 60 gallon compressor from your local big box store will do the job for your average hobbyist/homeowner, and should run you about $500. It'll still wanna run fairly consistently if you're doing a lot of blasting, but it will give you decent enough volume that you won't want to take a hammer to your blast cabinet.

    If you're blasting fairly regularly, you'll probably want to upgrade to something with a bit more capacity though.
     
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  8. 12345678910

    12345678910

    Jul 13, 2009
    Look at the HF air dryer

    Apparently they do work.
     
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  9. Stacy E. Apelt - Bladesmith

    Stacy E. Apelt - Bladesmith ilmarinen - MODERATOR Moderator Knifemaker / Craftsman / Service Provider

    Aug 20, 2004
    I posted this a day ago, but for some reason it got hung up????

    There was a guy up in New England who had a whole row of 240 cu.ft. oxygen tanks that were past test date. He made a manifold of tees and pipe like ten-six described and had them all fed from a HF 5HP compressor without a tank (they are really low price). He said it delivered all the air he could use at 100PSI. I am considering the same setup in the new shop, as I have a bunch of old tanks that are fine for 100PSI, but are past test date for 3000PSI.
     
  10. Stang Bladeworks

    Stang Bladeworks

    661
    Feb 19, 2018
    Thanks everyone for your feedback. Last night i picked up a 240V 60 gallon 3.7hp compressor. I wired it up and tested it today. The difference is night and day. Blasting times are reduced significantly. I have not had to stop blasting yet for it to keep up.
    20200104_133524.jpg
     
  11. Stang Bladeworks

    Stang Bladeworks

    661
    Feb 19, 2018
    First project with the new compressor. Huge time saver.
    20200104_184945.jpg 20200104_185014.jpg
     
  12. 12345678910

    12345678910

    Jul 13, 2009

    100 pound or larger propane tanks are more plentiful and cheap

    Mount them upside down so you can drain them.
     

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