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Thread: Need to buy compressor today

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    Need to buy compressor today

    How much CFM is need to blow all lines including main drain?

    Im looking at these compressors. Hopefully one will be strong enough so I dont have to spend $400 on a mighty vac.


    http://www.craftsman.com/shc/s/p_10155_ ... +Air+Tools


    http://www.harborfreight.com/cpi/ctaf/d ... mber=95499

    http://www.harborfreight.com/cpi/ctaf/d ... mber=95386
    Kidney shaped ~ 10000 gallon Ig Plaster pool with pool cage. 120sf Cartridge filter. Pentair WhisperFlo WFDS-26, 230 Volt, 7.8/3.0 Amp, 1-1/2 Horsepower 2 speed pump, Solar panels on the roof. Heliotrope HelioMatic 4000D solar controller.

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    Mod Squad JohnT's Avatar
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    Re: Need to buy compressor today

    CFM will only affect how quickly the line fills with air. Virtually any AC compressor will clear the lines. I'd steer clear of any Harbor Freight power equipment.
    TFP Moderator
    20K Gallon 20X36 Vinyl Inground
    Hayward S244T Sand Filter with 1HP Whisperflo Pump. Liquidator C-201 and Solar Heat

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    Re: Need to buy compressor today

    Do you think that Craftsman is powerful enough to do it? It doesnt even list the HP of that one. My Shop Vac wasnt strong enough so I just want to make sure I get something that can definatly blow out the skimmer and main drain from the pump. Im just worried about the HP because somebody once said a 2 HP compressor is at least needed.

    Also, can these blow air for the length of time need to get the water out of the lines or do they have to "recharge" every so many minutes?
    Kidney shaped ~ 10000 gallon Ig Plaster pool with pool cage. 120sf Cartridge filter. Pentair WhisperFlo WFDS-26, 230 Volt, 7.8/3.0 Amp, 1-1/2 Horsepower 2 speed pump, Solar panels on the roof. Heliotrope HelioMatic 4000D solar controller.

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    Mod Squad JohnT's Avatar
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    Re: Need to buy compressor today

    Quote Originally Posted by mrshowtime3
    Do you think that Craftsman is powerful enough to do it? It doesnt even list the HP of that one. My Shop Vac wasnt strong enough so I just want to make sure I get something that can definatly blow out the skimmer and main drain from the pump. Im just worried about the HP because somebody once said a 2 HP compressor is at least needed.

    Also, can these blow air for the length of time need to get the water out of the lines or do they have to "recharge" every so many minutes?
    The compressor will continue to pump air as the pressure builds in the line. A shop vac or blower is much better at clearing the skimmer or returns, as it moves a much larger volume of air. i usually have a geyser coming out of my skimmer for several minutes as the residual water is carried through the pipe by the moving air. I've found that I need to blow the skimmer out from the skimmer end first, then finish by blowing from the pump end with the shop vac.

    Blowing out the main drain line is tricky. As soon as you remove the air, it will fill back up to the water level in the pool. The only way to prevent this is to have a method of sealing the line when the air shuts off. I use a union with a short piece of capped pipe with a Schrader Valve (tire valve stem) mounted in the cap. I pressurize the line and let it bubble a while. You can also rig some way to pressurize the line past the valve so you can close the valve to seal it after you blow out the line.

    You could potentially blow out the main drain with a bicycle pump, so I believe that unit will work.
    TFP Moderator
    20K Gallon 20X36 Vinyl Inground
    Hayward S244T Sand Filter with 1HP Whisperflo Pump. Liquidator C-201 and Solar Heat

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    Re: Need to buy compressor today

    The 6.5 HP shop vac didnt touch the main drain at all. It could blow everything else but that. Not even the slightest hint of a bubble came out of the main drain.
    Kidney shaped ~ 10000 gallon Ig Plaster pool with pool cage. 120sf Cartridge filter. Pentair WhisperFlo WFDS-26, 230 Volt, 7.8/3.0 Amp, 1-1/2 Horsepower 2 speed pump, Solar panels on the roof. Heliotrope HelioMatic 4000D solar controller.

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    Re: Need to buy compressor today

    I am going to make a comment and pose a new related question.

    Comment: My PB used a shop vac when he closed my pool, so I have always used one as well and never had any issue. As for the main drain, PB told me that I was merely trying to get the main drain line 'down' not empty because it lies so much deeper than the skimmer lines, it does not freeze and is therefore better protected. I still anitfreeze the line, but I do not worry about emptying it.

    Question: Reading this makes me wonder if all that is true? Also, I seem to recall reading somewhere that the main drain will have a sort of 'backflow' preventer in it. If that is true, Is it possible to blow out the main drain line? Wouldn't that backflow preventer keep it from being blown out?

    Things that make you go hmmmmmmmmmmmmm.
    Matt
    20,000 gallon, sand filter, IG vinyl

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    Mod Squad JohnT's Avatar
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    Re: Need to buy compressor today

    Quote Originally Posted by beaumatt
    As for the main drain, PB told me that I was merely trying to get the main drain line 'down' not empty because it lies so much deeper than the skimmer lines, it does not freeze and is therefore better protected. I still anitfreeze the line, but I do not worry about emptying it.

    Question: Reading this makes me wonder if all that is true? Also, I seem to recall reading somewhere that the main drain will have a sort of 'backflow' preventer in it. If that is true, Is it possible to blow out the main drain line? Wouldn't that backflow preventer keep it from being blown out?

    Things that make you go hmmmmmmmmmmmmm.
    There is no backflow preventer. The weight of the water in the pool is what causes the drain to stay full. I think your method is fine.
    TFP Moderator
    20K Gallon 20X36 Vinyl Inground
    Hayward S244T Sand Filter with 1HP Whisperflo Pump. Liquidator C-201 and Solar Heat

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    Re: Need to buy compressor today

    I have asked tons of questions about this....learned a lot here, a lot from the pool store (I know, I know, but they are awesome), and from my neighbor. This is the model I have.

    http://www.craftsman.com/shc/s/p_10155_ ... +Air+Tools

    SCFM ratings that are high are used for moving mass quantities of air over a long path, such as blowing out a sprinkler system, without having to wait for the compressor pump to catch back up. This is why you see sprinkler companies with HUGE compressors on the back of their trucks. Paint guns also require a large SCFM.

    I have heard of guys using pancake compressors, and some with these utility compressors, as you have listed. They are pretty much used for airing up tires, and light work, such as a brad nailer. I guess it would all depend on how your lines are laid out.

    I use mine for a variety of things, so I don't have it just to blow out my pool lines. My main question was how many PSI should I be blowing through the lines without blowing them up? The main consensus was anywhere from 20-40 PSI. This is nothing for a larger compressor. Low volume air + larger tank= less pump running on the compressor.

    As for the Harbor Freight deals, you might be surprised. I love the joint, trust me. It's good for generics, and things that you might use once or twice. I will usually head to Sears for power equipment, but I have been known to buy refurbished power tools from HF from time to time, and still be using them years later. If this is going to be the main purpose for compressor ownership, I say entertain the idea, especially if they are having a sale. If you plan on equipping yourself with all sorts of tools and projects that require air, I'd go to Sears, IMHO. Might quit on you the first time you use it.

    I plan on using mine for closing this year, and I have no idea if it will work or not. I'm assuming it will, but I'm anticipating issues with blowing out my spa lines.....spa sits about 6 feet about pool level. That should be interesting, so we'll see what this compressor is made of.

    GK
    Kansas City, MO
    13500 gallon Foxx vinyl sport pool--inground (1988)
    Cristal-Flo sand filter
    Ray-Pak 406A digital
    1.5 HP single speed
    400 gallon Heldor inground spa, octagon

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