Some very good reasons for using Teflon pipe thread compound instead of tape. And the need for anti fatigue mats.

In the process of building my pnuematic plumbing system, I used teflon tape, which I have used extensively in the past with no failures, but somehow, this time around, somehow a persistent hissing noise, and fairly rapid pressure drop / frequent compressor cycling.

Well time to troubleshoot the problem...

Step #1. Mix up a batch of super duper hi tech leak detector solution. I.E. soapy water. I use Dawn Dishwashing soap, but take your pick. You want something to apply to where you think the leaks might be that will make bubbles.

Step #2. Prepare a super advanced hi tech leak detector solution pad. I.E. fold up a piece of paper towel, and soak in the solution.

Step #3. Apply the solution to the points where you think the leak may be...

The joint pictured above isn't leaking, if it was, there would be bubbles coming out. Sorry I didn't think to take pics before I sealed it...

Once you have found your leak, assuming it is like mine, at the joints, disassemble the joint, remove the pipe thread tape. I used a brass bristle brush to clean the threads, and insured NO tape had gotten into the tubing / airway. Then apply a thread compound to the male threads being careful to avoid compound in the airway, reassemble, apply pressure and retest. Repeat until all leaks are no longer, well, leaking...

I followed this process yesterday, and have held steady pressure since then.

I still have no clue what caused the drain valve on the filter to open up the way it did, but that has not recurred. Sadly Harbor Freight has no manual available online for the filter, however it appears that it tightens counter clockwise, and loosens clockwise, apparently it was just loose enough that the action of the air through the filter opened it up and dumped. I am being VERY careful to NOT keep my compressors powered up just in case though... 

I have all the hose joints from the big compressor, to its coupler and reducer tot he Tee, and the feed line for the reel, not to mention the coupler at the tee for the small compressor done. I may have to go back and simply do all of the joints eventually, but so far no real need...

With what I know now, if I were to start another air plumbing project, I would not consider, nor do I recommend anyone use teflon tape for pressure applications. 

My next addition to the shop is going to be anti fatigue mats. I find myself diagnosed with Plantar Fasciitis which is inflamation / damage to the big tendon that runs from the heel to the ball of the foot, and no small part of the cause is quality time on concrete. I wanted the bright red Craftsman anti fatigue mats, but at the cost, and lack of availability I am planning instead on going to Home Depot to get a few of the Traffic Master Anti Fatigue mats for a bit over 1/3 of the cost of the Craftsman mats, only difference is color, and the lack of the Craftsman logo. Big whoop. I will put one between the workbench and miter saw, one in front of the table saw, and one by the band saw / mortiser. 

I will need a smaller one to put in place by the router table / wing. I may just move the lathe mat back and forth when I use the router...