Cool clean water

Our camping season is just beginning and we are about to return to the desert.  I mentioned in my last article specifics of getting our Safari ready to roll and blithely mentioned that we topped off the fresh water tank.  Rich caught this and quickly reminded me of the importance of sanitizing the water system periodically with a bleach and water solution as recommended by Airstream.  I had wanted to do this last spring but I postponed it when I found that the fresh water petcock drain would not budge with normal hand pressure.

We have no need to winterize the trailer in San Diego and have never completely drained the fresh water tank before, but now I was motivated to do so.  I posed this issue on the Airforums and got a helpful reply suggesting that Dow Corning 316 Silicone Release Spray may help and alerting me to the importance of not turning the petcock too far open or closed (so that a finger won’t fit behind it).  My next challenge was to find this product, which is now called Molykote 316. I was able to order it from our local San Diego distributor for Kaman Industrial Technologies (It also can be ordered here.)

Two cans arrived via UPS and I was eager to use it but found no “How to use” directions included or on the label.  I finally found the product information along with “How to use” instructions.  So now I went out to the Safari.


I sprayed a light film of Molykote 316 on the petcock and let it be overnight.  (Directions say to allow approximately three minutes drying time.)  The next morning I still found the spigot difficult to turn by hand so I used pliers with plastic tubing over the teeth to turn the spigot.  This worked and I sprayed the petcock again and was able to move it now by hand (but due to my big hand and some arthritis, I found I still relied on the pliers).

dsc_0144-molykote-316.jpg Molykote 316 Silicone Release Spray is made by Dow Corning and is a release agent for many food and industrial applications.

The product information says that it helps prevent seizing and jam-ups of conveyor guide rails and reduces sticking of pulleys and valves.

It also says that this product complies with FDA21 CFR 175.300 and FDA 21 CFR 178.3570 regulations for incidental food contact.

This product has a H-1 designation meaning that the lubricated part may have incidental food contact not to exceed 10 parts per million.

Handling precautions indicate that this product contains a flammable solvent, so do not spray in a confined space where the possibility of spark ignition exists.

So now that I was confident that the petcock could open and close, I proceeded with the sanitizing of the Safari’s water systems.

I followed my Airstream Owners Manual for the Safari and computed the required amount of bleach to add to a water solution for my size tank (multiply “gallons of tank capacity” by 0.13 to get ounces needed).  For my 30-gallon tank I used 4 ounces of household bleach.  The solution was added and I topped off the tank, and opened all faucets (hot and cold), including the outside shower hose, allowing the water to run until the distinct odor of chlorine is detected (not so easy with my nose).  I then let this sit overnight (the manual says that this standard solution needs to have four hours of contact time to disinfect completely).

The next morning I opened the petcock and the water streamed out (and took two hours to completely drain).  I refilled the tank (with the white fresh water hose with a new TastePure RV Water Filter attached).  Again, I opened all of the faucets and purged the plumbing of all sanitizing solution.


I once again opened the petcock and drained the fresh water tank and, after another two hours, I closed the petcock and filled the tank for the final time and flushed the faucets once more.  (I then drained the gray tank.)


We did not want to water our plants with bleach-water so we allowed it to drain down the driveway.

But in this age of needing to conserve our precious water…

There must be a better way…

Perhaps an alternative technique or active agent…

Such as Purogene Fresh Water Treatment.

Or the use of the Drinking Water Freshener?

The second draining of the fresh water tank may not have been entirely needed.

But for now at least the fresh water system has been sanitized and the petcock works…

So we’re ready to hit the trail…

and enjoy cool clear water.