<note: long read but worth it if you want to know about the Garage Air Kit from Harbor Freight, item #66747>
I bought this kit from HF and just finished installing a single run along the shop ceiling to just over my lathe. Took me about 3 hours from start to finish (not including 2 trips to Lowes for extra fittings, screws, hose clamps, etc). Here are some of my thoughts in case it helps anyone:
- The kit is NOT complete (unless you adhere strictly to how the simplest installation is shown). I needed two more terminations (I used pipe nipples with brass caps), three different types of screws, hose clamps, teflon tape (the one for gas, it is yellow, not white), and coiled hoses with female connectors on the ends.
- I had lots of trouble with some of the threaded connections. One of the ball valves must have had defective threads because it would not go in. I ended up having to use a tap and die to fix it up (after I demolished the threads on both pieces trying to "make" it work). I think these parts are just not machined well so use caution when fitting them.
- There is just not enough teflon coating on any of the threads (and some don't have it at all). The white teflon tape is what I had on hand and used first. Once I tested the system (before installation, thank God), I found that most of them leaked. I switched to the yellow teflon tape (for gas, it is much thicker) and that did the trick.
- You MUST cut the ends of the tubing as straight and square as possible. Then push the tubing into the connector all the way, with as much force as you can, and then pull the collar out a bit to lock it in place, if it isn't already.
- Plan out your installation and before you screw anything down, test the system for leaks. The way I did this was to install all the connectors to the manifold and outlets, then use some short pieces of tube to link them together. I connected it all to my compressor and fired it up. Using a little soapy water, I brushed every connection to check for bubbles. Wherever I found a leak I tightened it up or changed the teflon tape until it was right.
- The joints where the tubing meets the quick couplers are the most sensitive. You cannot tighten these or otherwise fix them if they leak, you have to remove the tube, recut it, then insert it again and pray. Make sure you practice this a few times when testing to get it right because once you start cutting tubing to length you may not have enough to play with if it's wrong.
- I had no problems with slack in the line. I also was not very fussy about it being straight. I was going to use a chalk line across the ceiling but it was sooo hot and I was by myself so I just decided to eyeball it. Not perfect but perfectly acceptable!
- Once the installation was done I hooked up the compressor and one of the outlets was leaking loudly. I think it was the tube/coupling joint. I turned off the compressor, got the ladder under the outlet, and went up there to check. Looked good. Turned on the compressor, went back up the ladder with the soapy water and there was no leak. Go figure. I'm not touching it again!
All in all I think this was a good purchase. It was on sale for $79.99 (reg. price 99.99) and I used a 20% coupon at HF so it was even less. Even with all the extras I had to buy afterwards, it was much less than the RapidAir brand kit of the same contents. I still plan to tap into the line I ran with a T-connector and put the other outlet in the ceiling over my bench. Hopefully that will go well too, but it was just too hot today to do any more...
Hope this info is helpful!
