Looking for SCFM rating for a Mastercraft Model # 820218 air compressor

https://www.google.com/search?q=Mastercraft++820218+Air+Compressor+parts

..

Request the manual from Mastercraft.

Hard to give an exact number, however, as pressure and temp of air increases, the scfm drops as you see in your numbers. With low pressure such as 0 thru 25 the temp of the air is also low/nominal thus the scfm will be very close to the actual cfm listed for the compressor pump.

just get some ptfe tape from and plumbing shop and wrap the plug

Hi and welcome to FixYa, I am Kelly.

Air Tool consumptions are based on 15 seconds per minute (25%) of tool use.

Usage rates refer to the total time that air is flowing through the tool. If your applications result in more extensive usage, calculate air tool requirements as

follows.

(25%) 15 seconds = rated scfm x 1

(50%) 30 seconds = rated scfm x 2

(75%) 45 seconds = rated scfm x 3
(100%) 60 seconds = rated scfm x 4

Your impact wrench is rated a 8 CFM Cubic Feet Per Minute Usage

SCFM is Standard Cubic Feet per Minute (pre-compressed air volume)

I would be more concerned that the plumbing from the compressor tank could support the 8 CFM required by the 1/2" Impact. Remember the Air compressor will recover the pressure loss regardless of size. The only problem your going to have for "small jobs" is if you use too small of an air line to supply the impact wrench you are not going to get the full torque that it will produce to the drive head. In other words... a 1/4" supply line or 1/4 fittings anywhere in the system just isn't going to cut it even at 120 PSI. If you have the patience... a 5 gallon tank compressor that has the output volume required should be all that you need. I have been a mechanic over 4 decades and rarely have to use a 1/2 in impact for very long. Examples of 1/2" vs 3/8" useage. Wheel nuts, crankshaft pulley center bolt, some starters, steering, suspension and rear end parts. Other than that a 3/8" Impact works great.

One other thing you can do if you have an Air-Peen portable tank (with added fittings) is to add that in line with your output hose when your using the impact wrench so that you have longer use times.

I know this does not answer your what SCFM compressor is required question but it will resolve your needs. I just can't see telling someone that is a "small jobs" user to buy a larger compressor when really all they need is more volume for a brief period of time. The re-plumbed 1/2 inch output / in-line Air-Peen tank is a much cheaper and reasonable work around and you can disconnect that tank when your not using the impact wrench.
Lastly... if your inpact wrench has a SMALL male air fitting everything above will be a waste of time. You have to get that volume into the tool without restriction so that the rool will work properly for you.

Thanks for choosing FixYa.
Kelly

I would opt to reseal this compressor.

THE PSI RATING IS 70-100PSI. I WASN'T ABLE TO FIND THE SCFM AT THEIR WEBSITE. NO MANUALS AVAILABLE AS OF YET.

You can get the manual for model 41214 from my dropbox area:

http://dl.dropbox.com/u/54567653/husky_aircompressor_model_41214.pdf

BTW, if you find this manual helpful consider installing dropbox using this link (full disclosure -- I do get about 0.2 GB freespace from dropbox if you install using this link):
http://db.tt/vQycqXIW

Thanks,K

One of the factors used to designate compressor power is motor horsepower. However, this isn't the best indicator. You really need to know the amount of air the compressor can deliver at a specific pressure. The rate at which a compressor can deliver a volume of air is noted in cubic feet per minute (cfm). Because atmospheric pressure plays a role in how fast air moves into the cylinder, cfm will vary with atmospheric pressure. It also varies with the temperature and humidity of the air. To set an even playing field, makers calculate standard cubic feet per minute (scfm) as cfm at sea level with 68 degrees F air at 36% relative humidity. Scfm ratings are given at a specific pressure–3.0 scfm at 90 psi, for example. If you reduce pressure, scfm goes up, and vice versa. You also may run across a rating called displacement cfm. This figure is the product of cylinder displacement and motor rpm. In comparison with scfm, it provides an index of compressor pump efficiency. The cfm and psi ratings are important because they indicate the tools that a particular compressor can drive. When choosing a compressor, make sure it can supply the amount of air and the pressure that your tools need.

One of the factors used to designate compressor power is motor horsepower. However, this isn't the best indicator. You really need to know the amount of air the compressor can deliver at a specific pressure. The rate at which a compressor can deliver a volume of air is noted in cubic feet per minute (cfm). Because atmospheric pressure plays a role in how fast air moves into the cylinder, cfm will vary with atmospheric pressure. It also varies with the temperature and humidity of the air. To set an even playing field, makers calculate standard cubic feet per minute (scfm) as cfm at sea level with 68 degrees F air at 36% relative humidity. Scfm ratings are given at a specific pressure–3.0 scfm at 90 psi, for example. If you reduce pressure, scfm goes up, and vice versa. You also may run across a rating called displacement cfm. This figure is the product of cylinder displacement and motor rpm. In comparison with scfm, it provides an index of compressor pump efficiency. The cfm and psi ratings are important because they indicate the tools that a particular compressor can drive. When choosing a compressor, make sure it can supply the amount of air and the pressure that your tools need.