Tacky Trailer Top Q. I have just purchased a 33-foot Shasta fifth-wheel trailer with a rubber roof. I am getting a lot of pine pitch on the roof. I used to use denatured alcohol to remove the pitch from my old trailer with a metal roof. I am afraid that maybe the denatured alcohol will soften the rubber roof. What is the best pine pitch remover to use on an EPDM roof. Richard Boivin Worcester, Mass. A. Try this. Realizing that some petroleum products may be harmful to EPDM rubber roofing if it becomes saturated, carefully moisten a clean, soft, cotton cloth with regular mineral spirits and lightly rub the pine sap from the roof. Do not pour the spirits directly onto the roof, but use a clean portion of the cloth each time. Eventually you should be able to remove all of the pine pitch. Though not always 100% necessary, apply an EPDM protectant to the affected area after removing the pine sap. And don’t park under that pine tree any more!

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Pilot Burnout Q. I have a 1994 Nomad 23 1/2 foot trailer. It has a Suburban water heater. The orifice on the LP pilot was plugged. I replaced the pilot unit, but now I can’t keep the pilot lit. I even made sure all of the air was out of the lines by lighting the stove at the other end of the trailer. Any suggestions? Steve Queckboerner Longview, Wash. A. Here are a few things to consider regarding your pilot-flame situation. First, has anyone checked the LP pressure lately? For RV appliances to run at their optimum, the system regulator should be set at 11.0 inches of water column. Use of a “U” tube manometer will yield the most accurate results. If the flame goes out as soon as you release the button, you may have a faulty thermocouple — provided the thermocouple is correctly positioned in the flame to begin with. Only the tip of the thermocouple, the hot junction, should actually be in the flame. Additionally, the other end should only be 1/8 turn tighter than finger tight into the control valve. Too tight of a connection here will compress the contact pad and cause insufficient voltage to reach the electromagnet. RV service shops can easily bench test the thermocouple. If the pressure is correct and the thermocouple is correctly positioned in the flame, the electromagnet in the gas control valve could be faulty, though this is not the most probable cause. Finally, verify that the correct size orifice was used in the pilot tube. Contact Suburban or your local repair center for the correct size for your model.

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Plastic Surgery Q. I have a 1978 Dodge Xplorer with a leaking gray-water holding tank. I have found several cracks where the hangers hold the tank to the body of the RV. What is the best method to repair the tank? Charles Howard Sr. Berryville, Ark. A. The only true and permanent method for repairing polyethylene holding tanks is by plastic welding. Plastic welding is also recommended for repairing ABS tanks, as well as any other type of thermoplastic, including PVC polypropylene and plexiglass. Plastic welding requires specialized equipment found only in well-outfitted service shops. Only a small percentage of RV service facilities offer such services, so it may take some time to find one. If no shop in your area offers such a service, have them contact me. I do have an instructional training video entitled, Plastic Welding Techniques, which details the intricacies of this type of repair. It should provide some help.

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Q. We’ve had a 1986 Bounder 34S for about two years. The only problem is with the fuel gauge. It worked once and has since stopped registering anything. Mike & Sandy Green Orangevale, Calif. A. The fuel gauge and sender in your coach are probably rated at 90-ohms. This means the gauge should read at or near empty when the resistance is low, somewhere around 0-5 ohms. When the resistance is high (90-100 ohms), the gauge should read full. Aside from having no voltag