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How to Care For RV Slide Out Seals So They Last

How to Care For RV Slide Out Seals So They Last

Knowing how to care for RV slide-out seals is critical if you want to keep them in good condition so they’ll last rather than requiring periodic replacement.

Slide-out rubber seals prevent water leaks into your living space. And having to replace them is a nuisance. So if you want to be able to extend and retract the slides on your travel trailer or motorhome without leaks developing, you’ll want to protect them. That requires regular maintenance of the seals on the tops and sides of the slides.

In this post, we’ll share our slide-out maintenance tips and the method of seal maintenance that’s kept ours in great condition for 18 years. That’s right — we still have all of the original seals that came on our 4-slide 2005 RV — and they’re still like new.

What Are RV Slide-Out Seals?

RV slide-out rooms have both inner and outer seals. (We sometimes refer to them as gaskets, but “seals” is the more accurate word.) Slide-out seals keep the rooms sealed against the elements, whether extended or retracted. So, RV slide-out seals keep water from leaking into your living space and allow your slides to extend and retract properly.

You should have a rubber bulb seal along the sides and the top of the slide-out. If you’ve got slide toppers, we have a little trick to get underneath them to maintain the top seals, which we’ll share a bit later in the post.

Do RV Slide-Out Seals All Break Down Over Time?

Definitely not! If properly cared for, your RV slide-out seals should last for many years… or even for the entire life of the RV.

We’ve lived and traveled full-time for over 20 years — the past 18 in our 2005 Newmar Mountain Aire. We stand by our method of maintaining RV slide-out seals because, after all that time, all of ours are still in like-new condition.

An original slide-out seal on the RVgeeks' 18-year-old motorhome

This is one of the slide-out seals on our 18-year-old Newmar diesel pusher. Despite its large amount of full-time use and exposure, it still looks and works as it did when brand new.

Despite the amount of use and exposure our slide-out seals have gotten over the past 18 years, they continue to function just as they did when they were brand new. Our experience shows that using our tip once or twice a year can keep RV slide-out seals working properly, and unlikely to require replacement any time soon.

How to Care For RV Slide-Out Seals

Although there are commercial products and rubber seal conditioners available for lubricating slideout seals, we don’t use them. When we picked up our new motorhome from Newmar, they recommended that we simply rub them with baby/talcum powder once a year, and nothing else would be required.

This has worked for us over the 18+ years we’ve owned our RV and avoids the cost of commercial products. It works so well because the powder prevents the rubber seals from sticking to the RV. That “sticking” sound you hear as a slide begins to move pulls on the rubber, slowly damaging the seals over time, eventually requiring replacement.

A major benefit of talcum powder is that it doesn’t attract dust and dirt like many liquid products. We’ll show you the steps to using our method in just a moment.

Important Note: Since we started using this method, a link has been established between talc and ovarian cancer. Please be aware of this, research it for yourself, and proceed accordingly. If you have concerns about using talc on your slide-out seals, we’d suggest wearing a mask while using it… or not using it at all. Also, if the manufacturer of your RV recommends some other method of maintaining your slide-out seals, then by all means, follow their guidelines.

Additional Note: If you don’t have an old container of talcum-based baby powder hanging around, as we do (we only use it for coating our seals once or twice a year) you should know that baby powders are now made with cornstarch and not talc.

Don’t use a cornstarch-based powder on your slide-out seals. Cornstarch is unlikely to work well for this purpose, and may also clump and attract moisture. In fact, many of the recommended replacements for talc have that same problem.

If you choose to use some other powder, you need one that’s fine enough not to scratch the paintwork on the slide-out and won’t dissolve in water and just get washed away. So, if you decide to follow our method, be sure to use a talc-based powder, not corn starch.

If you don’t have a baby powder that contains talc, try Tire Talc. It’s still talcum powder and will work just as well on your slideout seals.

Sale
Rema Tip Top No. 63 Tire Talc 16 oz Shaker Can for Inner Tube Installation
  • Single 16 ounce shaker can of REMA TIP TOP's No. 63 Tire Talc for inner tube installation
  • REMA TIP TOP's No. 63 Tire Talc is specially formulated for trouble free inner tube installation.

No matter what method you use to condition your slide-out seals, make sure they’re clean and free of debris before treating them. To do this, clean exterior seals gently, (the inner seals don’t get very dirty), using a mild soap and water solution. Ours get cleaned each time we wash our rig with the slides out.

Regular automotive car wash soap such as our favorite, Meguiar’s Gold Class, should work well. You could also use a mild dish soap like Dawn.

For the talcum powder method, once your exterior seal is clean, take the following steps, beginning with the interior slide-out seal:

  1. From inside your RV with the slide fully retracted, take an old sock or a rag and lightly sprinkle a small amount of talcum powder on it.
  2. Reach behind the edges of the slide, and slide the rag and powder all along the inner top and side rubber seals, coating them lightly with powder.
  3. Extend your slide-out(s), and head outside to the exterior of your rig.
  4. Sprinkle some more powder onto your rag or sock, and apply the powder all along the seals. Use a ladder to reach all the way to the top. Add more powder as needed, but don’t over-coat the seals.
  5. If you don’t have slide toppers, you can access the top seal from the roof, or from your ladder. If you do have slide toppers, see our video below for a tip on how to reach under them to coat the upper seal (the part under the topper).

For a good visual, check out our video to see Peter treating our RV slide-out seals using talcum powder.

For those of you with slide toppers, our method for reaching the upper seal involves using the extension pole we use for washing our rig, as well as a ladder.

Mr. LongArm 3208 Pro-Pole Extension Pole 4-to-8 Foot
  • Fluted fiberglass handle for a comfortable grip in any climate
  • Medium duty pole with 1-1/16-Inch composite fiberglass handle

We simply extend the pole about halfway out, wrap a sock around the end of the pole and secure it using a rubber band, and then sprinkle the baby powder onto the sock. Then we use the pole to rub the baby powder onto the upper seals under our slide toppers.

Peter sprinkling talcum powder onto an old sock secured to the end of an extension pole

Here’s Peter sprinkling talcum powder onto an old sock secured to the end of an extension pole using a rubber band.

To see the process in video form, check out our demonstration showing how we reach all the way under our slide-out toppers:

Alternative Methods of Caring for Slide-Out Seals

If you choose to avoid products containing talc to maintain your RV slide-out seals, there are a couple of other methods that you can use. Again, we suggest going with your RV’s manufacturer’s guidelines. If they recommend using some form of rubber conditioner, avoid using aerosol-based products and use pump-spray products only.

That’s because although there are many silicone-based sprays on the market, the added propellants in the spray can be harmful. They can cause the rubber in your RV seals to eventually break down and crack.

The chemicals in the propellant can damage the polymers found in the rubber, leaving you with a weakened seal. One way to deal with this issue is only to use products that use a pump for delivery rather than an aerosol.

Here are a couple of options that use a pump spray for delivery so there are no propellants to damage your slide seals:

Star Brite

STAR BRITE Premium RV Rubber Seal Conditioner - 16 OZ (076116)
  • Engineered to preserve and protect rubber slide out seals
  • Helps prevent seals from sticking, keeping slide-outs from sticking

Aerospace 303

303 Automotive Protectant - Provides Superior UV Protection, Helps Prevent Fading and Cracking, Repels Dust, Lint, and Staining, Restores Lost Color and Luster, 16oz (30382CSR) Packaging May Vary
  • Ultimate Protection – Shields against UV ray damage to prevent fading and cracking, while also repelling dust, dirt, lint, and staining
  • Non-Greasy – Dries to a smooth, matte finish with no oily or greasy residue. Apply every 3 – 5 weeks for maximum UV protection

We hope this information is helpful to you in your quest to get your RV slide-out seals to last as long as ours!

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Morgan Fagerman

Saturday 1st of July 2023

Hi Geeks! I follow your content and I think you're doing a fantastic job for us full timers and RV owners! I'm a newbie so I have a lot to learn still, and I'm studying your content intently...:)

I read your article about maintaining the RV slide out rubber seals and using talcum powder is for sure an easy and simple solution. You say you apply it once per year or so, but when you have the slides pushed out, the outer rubber seals are exposed to the weather, and since talcum powder is water soluble a rain storm or wash would wash it off. How do you deal with that? I mean I have seen the pictures of your RV and the rubber seals, and you're obviously doing something right. But I don't understand not applying it to the outer seals after a wash or rain, and I don't get the lack of UV protection in the talcum powder either. There is none. And the seals still look this good after all these years?

Anyway, I look forward to your reply and I appreciate all you are doing, and maybe we'll run into you out there on the trails one day.

Best, Morgan

TheRVgeeks

Saturday 1st of July 2023

Hi Morgan! Thanks so much for the comment and the excellent question. I think the key to our success with talcum powder is that rubbing it on likely gets into the pores of the rubber, meaning it doesn't wash off when it rains. The best thing we can suggest about how often to re-apply more powder is to listen for that "sticking" sounds when extending or retracting the slides. That's the sound of "pulling" on the rubber and exactly what leads to it being slowly pulled apart. In most years, we only apply it once a year... when we do our Spring cleaning, and that seems to be often enough. (We never hear the sticking sound). As far as UV protection... as per Newmar's recommendation, we've never applied anything else, so either Newmar uses superior seals, or seals in general just aren't all that sensitive to the sun (in 18 years of full-timing in it, we've never had it garaged, so ours get LOTS of sun exposure)! If your manufacturer specifically recommends another way of caring for the seals, we always suggest defering to them. Hope this helps, and happy travels!

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PLEASE NOTE: We're handy RVers, not professional technicians. We're happy with the techniques and products we use, but be sure to confirm that all methods and materials you use are compatible with your equipment and abilities. Regardless of what we recommend, consult a professional if you're unsure about working on your RV. Any task you perform or product you purchase based on any information we provide is strictly at your own risk.

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