Quick, easy and safe RV refrigerator defrosting

Dometic User Manual Caution: “Do not use: A knife or an ice pick, or other sharp tools to remove frost from the freezer shelves. It can create a leak in the ammonia system.  A hot air blower. Permanent damage could result from warping the metal or plastic parts.”  We use neither sharp tools nor a hot air blower and yet easily and routinely defrost our Dometic RM2551 RV refrigerator (5 cu. ft.) in less than 30 minutes.

Frost and ice buildup on the cooling fins reduces the cooling efficiency of the refrigerator.  As seen below, our refrigerator is overdue for defrosting!

DSC_0004 Time to defrost RV refrig

I usually defrost our refrigerator about every two months depending on outside temperature and humidity conditions.  I like to start a trip with the cooling fins clear of most of the frost to make sure the refrigerator maintains safe temperatures for food (40° F or less).  We use our RV refrigerator full time (it acts as a supplemental refrigerator when at home) and it always has food in it, so it is important to be able to do the defrosting quickly, to prevent food spoilage and to shorten the recovery time to get adequately cold again.

DSC_0002 Gathering defrosting tools Once I determine that the refrigerator needs defrosting, I choose a warm day and gather five tools: a cooler, electric fan, large Tupperware lid, extra long chopstick, and a washcloth.

One of the benefits of our 23′ Airstream Safari trailer is that the large lobster sink/counter is directly across from the refrigerator, which provides a handy location for the fan to direct warm air directly into the freezer/refrigerator compartments.

I then turn off the refrigerator, fully open the door and place most food items in the nearby cooler. (I leave most condiments and other food items in the door in place.)

DSC_0006 Removing food

DSC_0004 Wireless sensor & thermistor

As you may have noticed,  our refrigerator’s white thermistor probe wire is not in its OEM plastic holder on the far right fin where it normally is moved up and down to regulate the temperature (See Adjusting the Thermistor to Improve Cooling*).  Refrigerator thermistors are NTC (Negative Temperature Coefficient) thermistors* and resistance decreases as the temperature increases.  The higher the position on the fin, the warmer the thermistor will be and the refrigerator will run longer and become colder.  But our probe wire is short and does not allow it to be moved high enough on the fin to obtain the proper refrigerator coldness.  So I found that by removing it from its holder and moving it away and down from the fins, I can adjust and maintain the proper refrigerator coldness (which for us is usually 36-37 ° F and monitored by our AcuRite Wireless Digital Thermometer).

I use a condiment bottle to prop open the freezer door (Thai sweet chili sauce* works well) and place the frozen items in the cooler.

DSC_0013 Freezer door propped open

A closer look at the tools is seen above: an inverted Tupperware lid to collect melting ice chunks, an extra long chopstick* (17.7″ bamboo chopstick for hot pot and wok cooking) to gently loosen ice chunks, and a white washcloth to wipe clean and dry the refrigerator.  (Note: we have greatly reduced our use of paper towels by purchasing a 24-pack of white reusable washcloths from Costco and also available at Amazon.com.)

DSC_0008 Ice cube trays in freezerTip: This set of 4 flexible silicone ice cube trays from Target works wonderfully for us.  It makes ice cubes quickly and takes up less space than traditional ice cube trays.  It helps keep other food items cool in the cooler when defrosting and it helps decrease the refrigerator’s recovery time after defrosting.

Packages of fish balls, jiao zi (dumplings),* and pesto are seen on the left.)

The fan is then turned on and defrosting will take about 20 minutes!

DSC_0016 Defrosting begins

DSC_0018 Water exits via new drain tubeAs ice begins to melt, water drips down and is collected in the condensation drain pan and flows through its bottom hole into the Dometic white drain pipe with cup, which connects with the drainage tubing on the backside of the refrigerator.

Our OEM drainage tubing had become brittle and we replaced it with Shields Rubber Series 162 Polyester Reinforced Clear PVC Tubing, 1/2″ ID (inside diameter).  I chose this tubing over the clear vinyl tubing because it is reinforced, can tolerate hot water (or being in a hot space such as near the boiler tube), is more flexible and is slightly less expensive than their clear vinyl tubing.

The chopstick is then used to gently nudge the melting ice sections forward and off the fins and collected in the Tupperware lid and deposited by nearby plants.

DSC_0023 Chop stick coaxes ice free

DSC_0026 Ice placed in tray:lid

Each section slides slowly and smoothly towards me and reminds me of Dave using a simple tool/key to selectively disengage electronic circuit modules in HAL’s Logic Memory Center.*

The washcloth is then used to remove excess water and wipe down the refrigerator’s insides and door seals, which completes the defrosting process in 30 minutes or less!

 

DSC_0029 Defrosting completed

Additional information: Airstream’s How to Operate Your Refrigerator* and Airstream Life’s (Nearly) Complete Guide To Airstream Maintenance.

*This is a link to a YouTube video.

 

Tire pressure monitoring system II

Special Trailer (ST) tires have a maximum speed rating of 65 mph,* and if exceeded or if the tires are under-inflated, the tire temperatures increase, causing a weakening of the tire structure, which can lead to a shortening of the life expectancy of the tire and/or a catastrophic accident.* We have learned the importance of continuously monitoring the tire pressures (and our speed) from preflight to our arrival and midway during our stay and during our return trip home.    To facilitate this, we have relied on a tire pressure monitoring system (TPMS) since 2008, first with Doran, and then with PressurePro since 2011 (See “TPMS-Update“)

DSC_0005 PressurePro monitor

Typically, two or three days before departure, I install the sensors on the tires and adjust the tire pressure to be as close as possible to the specified maximum 50 PSI cold for our ST 215/75R14 Goodyear Marathon tires for the expected temperature at the time of departure.  (Our tow vehicle’s truck tires also get the sensors and have a cold PSI of 60 for front and 75 for rear tires.)

DSC_0200 ST Tire, PSI spec- cold 50

I keep a running log of the pressures and temperatures for each trip, which is started at the beginning of our trailer trip prep week and detailed in my post “Airstream Safari trip notes.”

DSC_0123 Tire pressure logOn the left is the log for our December trip.  The sensors were installed on Thursday and I noticed that the street-side rear sensor pressure reading was lower than the other sensors, which may indicate a slow tire or sensor leak.  I added air to this tire on the following day.  Early Saturday morning, the outside air temperature was 40°, and I noticed that the rear curbside sensor was not transmitting a pressure reading until it warmed up to 50°.  We departed Sunday afternoon and when we arrived at our campsite, I discovered a 1″ washer head machine screw embedded in our rear curbside tire as I was covering it for the night.  The next day, our PressurePro monitor confirmed my fear that the screw had penetrated the inner tire.  I replaced this tire with the spare and documented this in my post, “A Marathon tire repair.”

DSC_0015 I" machine screw in tireWasher head machine screws, commonly used on automobiles and motorcycles, are often encountered on highways and back roads, and I suspect that the washer head, when run over, causes the opposite end to rise towards the tire and puncture it straight on.

We find the most screws and nails in campgrounds, often brought in with firewood by campers, as seen in my post, “Nailing it… A TPMS encore.”

This camping season, our PressurePro TPMS sensors became 5 years old and were showing their age.  As seen in the log above, one was not transmitting a pressure reading in the early morning cold and another was very slowly leaking air, confirmed by temporarily putting another sensor in its place.  I contacted PressurePro and they sent me 4 new sensors for my trailer at a discounted rate, along with a Sensor Seal/Installation Tool Kit, that I will use to upgrade the truck’s sensors.

DSC_0012 New PressurePro sensor

An obvious improvement in the new sensors is that each sensor has a unique green identification number displayed on its side, which decreases the chances of placing a sensor on the wrong location.  (Each sensor is programmed for each tire location and I place each sensor in a zip lock bag assigned for each tire location when not in use, thus prolonging the battery life.  See how to set up the PressurePro tire pressure monitoring system in the video, “Protect Your RV with a TPMS“*)

A less obvious, but more important improvement is that the new PressurePro sensors now have a new Sensor Seal, a two-piece valve system that uses a hard plastic depressor to more fully depress the valve and yet, provides a hard stop during installation, protecting the seal. (Older sensors were often over tightened, resulting in damage to the O-ring seal.)  Older sensors with the one-piece seal can be upgraded by using PressurePro’s Sensor Seal/Installation Tool Kit that contains 10 sensor seals and a seal installation tool.

A tire pressure monitoring system adds to our peace of mind while on our safaris, where we’d rather come face to face with a coyote than with tire trouble!  (See Author’s update below regarding high temperature alerts and other PressurePro improvements.)

DSC_0046 Coyote in my face

*This is a link to a YouTube video.

RV refrigerator drain tube failure

Our Airstream Safari trailer became 9 years old last December when I discovered that our Dometic refrigerator drainage tube was falling apart behind the lower, vented, outside panel door of the refrigerator compartment.  The OEM white, thin plastic drainage tubing becomes brittle and falls apart, some say as early as 3-years old,* undoubtedly accelerated by being near heat.

DSC002 Broken refrig drain tube

This was not an immediate problem because water only drains out of this tubing when defrosting the refrigerator or when condensation forms and drips from the cooling fins, and we live and camp in a relatively dry climate.  Typically, we can go 2-3 trips before needing to defrost the refrigerator.

(Defrosting for me goes quickly: I choose a warm afternoon and place a fan on the covered lobster sink directly across from the opened refrigerator door. I turn off the refrigerator, prop open the freezer door and, as the fan blows warm air into the refrigerator, I use chopsticks to gently nudge the melting ice sections off the fins and slide the chunks toward me and catch them in a Tupperware lid and deposit them on nearby plants.  Water that drips from the fins is collected in the condensation drain pan and flows through its bottom hole into the Dometic white drain pipe with cup, which connects with the drainage tubing on the backside of the refrigerator.)

After our third trip to the desert and coyotes this season,* it was time to replace this failed part, so I rustled up three feet of a more durable, vinyl plastic hose from our local West Marine store.

DSC126 PVC tubing from West Marine

Shields Rubber Series 162 Polyester Reinforced Clear PVC Tubing, 1/2″ ID (inside diameter).  I chose this tubing over the clear vinyl tubing because it is reinforced, can tolerate hot water (or being in a hot space such as near the boiler tube), more flexible and is slightly less expensive than their clear vinyl tubing.

DSC134 Shield's Rubber Series 162 PVC tubing

We saved the original Dometic drainage plug (seen above), which is valuable because it keeps critters out of the tubing and currently costs $11.99 to replace!

Some have found that the only way to gain access to where this OEM tubing connects to the Dometic drain pipe in the back of the refrigerator is to move, tilt or slide the refrigerator towards the trailer interior, which involves disconnecting the gas, AC and DC power, and foot screws!  In our case, I was able to reach this spot with my hand.  The old tubing was easy to remove because it disintegrated as I touched it!  I reviewed RV refrigerator condensation drain tube videos such as this one.*  The new tubing was attached to the protruding end of the Dometic white drain pipe seen below.  Larry held the pipe/cup from inside the trailer while I pushed the new tubing into place.

DSC142 Dometic drain pipe with cup

Cable (zip) ties were used to secure the tubing connection and to keep it away from the boiler tube seen below.

DSC150 Drain tube held by cable ties

Once the tubing reached the refrigerator compartment floor, it was brought to the opening of the space and secured by the OEM black vinyl coated loop hose clamp and Phillips head screw.

DSC153 Drain tube held by loop hose clamp

At this point, the tubing was trimmed and the Dometic drain plug was inserted.  Refrigerator water is now properly channeled and free to flow under the lower refrigerator access panel door and exit the trailer.  I am confident that this tubing will last for many years to come!

DSC158 Drain tube top to bottom

And future refrigerator defrosting with this upgraded pipeline* will almost be as much fun as surfing the tube!*

*This is a link to a YouTube video.

A Marathon tire repair

Cold and darkness were rapidly descending as I was completing our trailer unhitching for our holiday camping stay in the desert when I noticed a screw in the Marathon tire as I was placing the tire covers for a long winter’s nap.  My hopes that the screw did not fully penetrate the tire were dashed the next morning when our PressurePro tire pressure monitoring system showed 21 psi for this tire, which should have been 50.

DSC_0013 Screw embedded in tire crown

After breakfast, I carefully unscrewed it with pliers and was amazed at its length of 1 inch.  It turned out to be a Torx hex washer head self-tapping machine screw* commonly found on automobiles and motorcycles.  I marked the puncture site location with masking tape (and later the wheel & drum to make sure the wheel was replaced in the same position per the Airstream Owners Manual).

205 Torx hex washer head machine screw

As the tire went completely flat, I consulted The (nearly) Complete Guide to Airstream Maintenance, which has 12 pages devoted to tire care, repair and issues.  This guide reminded me that when accessing the spare tire,* just pull out the cotter pin and hold up the handle while removing the bolt, rather than doing it the hard way of removing the lower nut and bolt as seen below (which I have done before)!

DSC_0029 Accessing spare tire

The trailer’s stabilizing jacks were raised before placing the truck jack under the exposed section of the trailer’s frame between the wheels.

DSC_0027 Tire jack placement

Before raising the trailer, I made sure the opposite side trailer wheel chock was in place and I loosened the lug nuts with a cross-type 4-way lug wrench that enhances leverage.

DSC_0020 cross-type lug wrench

The trailer was then raised, the flat tire removed, and the spare put in place.  I hand tightened the lug nuts before lowering the trailer.  Once on the ground, the spare tire lug nuts were then tightened with a torque wrench.*  Our Airstream Owners Manual reminded me to tighten the lug nuts on the spare steel wheel to 95 foot-pounds, rather than 110 for our aluminum wheels, and to recheck the torque at 10, 25, and 50 miles (I rechecked ours at 25 and 65 miles on the way back).

DSC_0022 Torque wrench to tighten

Once back in San Diego, I took the flat tire back to where we bought our replacement Goodyear Marathon tires, San Diego Tire & Wheel Outlet.  Per the Tire Industry Association,* this tire was repairable because the puncture occurred in the tire crown (and not the shoulder or sidewall) and was not larger than 1/4-inch (6mm), ours was 4.8mm.  The tire was removed from the rim so that the inside could be thoroughly inspected and repaired.  The inside puncture site was prepped by buffing and applying vulcanizing cement and after it dried, a mushroom-shaped patch-plug was applied.

394 Mushroom patch-plug close-up

393 Plug part of mushroom patch:plug

The patch-plug keeps water from entering and rusting the steel belts.  The plug was trimmed and now the tire is set to go and we’re ready to roll into a new year of living riveted!*

DSC_0397 Tire repaired correctly

*This is a link to a YouTube video.

Resealing our Airstream plumbing vent

Last month,  I posted about our annual “Wash, wax and treat II” job and mentioned that I used a ladder to wash and wax the roof of our 2007 Airstream Safari trailer, while inspecting the roof seals for any signs of deterioration.  Five years ago, I resealed the Fan-Tastic Fan and bathroom air vent seals.  This time around, the plumbing vent pipe seal was cracking and in obvious need of repair.

DSC_0056 Cracked plumbing vent seal

This job needed to be done before the beginning of our fall-winter-spring camping season, so I consulted Rich Luhr’s The (nearly) Complete Guide to Airstream Maintenance, and read that Sikaflex 221 is a good general multi-purpose sealant, especially for roof work such as around vents.  I was reminded that the shelf-life of sealant is relatively short (12 months from the date of manufacture), and of course, my old tube of sealant had solidified.

Airstream Life's Maintenance Guide p

I ordered a new tube of Sikaflex-221 Multi-Purpose Polyurethane Sealant/Adhesive from Amazon and once it arrived, I checked its expiration date (12 May 2016) and gathered my tools: a caulk gun, plastic scraper, isopropyl alcohol (see note below) and…

DSC_0166 Resealing tools

a sturdy ladder (Little Giant*).

DSC_0157 Removing old sealantPlease note that this time inquiring readers should feel relieved that I am standing on the second step from the top and not the first, per the American Ladder Institute.*

Our plumbing vent is near the trailer’s edge, but if I needed to get up on the roof, I would review Colonial Airstream’s video and maintenance tips, “How to climb onto a roof of an Airstream Travel Trailer.”*

 

I used a plastic scraper (putty knife) to remove the old sealant that was softened with isopropyl alcohol.

(Note: alcohol can prevent the polyurethane in Sikaflex from properly curing, so care must be taken to remove any traces of alcohol by washing, rinsing and drying the prepared surface before applying Sikaflex.)

 

DSC_0170 Cracked sealant removed

The flange of the Ventline plumbing vent was intact (no cracks adjacent to screws) and new sealant was applied with the caulk gun* and smoothed by my finger.

DSC_0174 Sikaflex 221 Sealant

Now it’s time to get on the road again!*

*Note this is a link to a YouTube video.