Found a few breaks in your RV’s sealant? If yes, then it is time to get out your caulking gun.
Water damage is one of the top threats to RVs. There are a hundred different potential points of entry, and it only takes one to destroy hundreds to thousands of dollars of your mobile home. To prevent this catastrophe, you will want to reseal your RV roughly one to two times per year. This guide will focus on resealing the siding of an RV. The roof requires a different approach which you can read about in my guide on How to Reseal an RV Roof
Here are a few tools that you will need or want to have present.
- Mineral Spirits or Denatured Alcohol
You will need one of these cleaners to prepare the surface. Water is a poor substitute. Alcohol can be rough on the paint finish, so I’d recommend Mineral Spirits. Mineral spirits are less harsh, but they do have mild rubber damaging effects. It is petroleum based, so don’t pour it directly onto the RV. It will be okay to apply it to a terry cloth, and then use the terry cloth to wipe the areas targeted for resealing.
- Terry Cloths
You will want this for cleaning the targeted areas and for wiping away the excess caulk.
- Two Types of Sealant: Self-Leveling Lap Sealant and Non-Leveling
You will need two types of sealant for a complete RV resealing. There is one type for the siding and the other type for the roof. The Dicor brand is a very common recommendation.
- A self-leveling lap sealant will be used for the roof.
What is a lap sealant?
A lap sealant is a specially formulated sealant that works with RV roof materials. A sealant used for a brick and mortar home is created to bind to a different surface than an RV roof, so don’t go to your Home Depot and buy the wrong type of sealant. RV roofs are typically made of aluminum, fiberglass, rubber, and vinyl. These materials necessitate a different formula.
- A non-leveling sealant will be used in the siding. It doesn’t level itself out into a puddle and it stays where you put it which makes it perfect for those vertical seams.
- A Quality Caulking Gun
Don’t go for the cheap $2 caulking gun. Pay for the $15+ guns to make your resealing experience much less of a hassle with a drip-free and evenly pressured caulking gun.
- Disposable Gloves
They are not totally necessary, but it can be useful to have a set. Sensitive skin can sometimes be bothered by mineral spirits. Beyond that, your gloved fingers are useful for smoothing out the applied sealant from its beaded form into a concave shape that is better for ridding your RV of potential damage from water. Of course, you can do this without the gloves, but it’s just a bit messier.
- Plastic Edged Scrapers
Useful for removing most of the caulk. The plastic edge makes it safer for those painted surfaces while still being a competent tool.
- Pick and Hook Set
You can find some of these sets for under $10, and they are fantastic for the areas that give the scrapper trouble. They do have the ability to scratch up the paint, so use with care. If you do scratch the paint, it will still probably not be much of a problem since it will probably be covered in sealant.
- X-ACTO, Box Knife, Pocket Knife, Etc.
There are several options. The important part is to have a blade capable of cleanly cutting the caulking. The X-ACTO will probably serve you best because of its precision and ability to fit into spaces that a bulky knife will make difficult.
Check the Weather Forecast Before You Begin
Just to be on the safe side, you will want a couple of days of clear weather ahead of you. According to Decor (sealant company), their lap sealant takes 4 hours to become waterproof, but most recommend two days of curing before you want any rain to touch it. At two days, the sealant will be 80% cured, and by 30 days it will reach 100%.
Wash the RV
Caulking requires a strong bond, but that bond cannot be sufficiently achieved if dust, dirt, bird droppings, and insects are sitting between the surface and the sealant. Give your RV a wash before you get started. After your soap and water wash, extra care should be given to each individual section that you are about to reseal. In this second cleaning, use your chosen alcohol or mineral spirit cleaner.
How to Remove Old Sealant?
First, not all of the sealant will need to be removed. You can leave it if it isn’t flaking and it still has that smoothness to it. If it is flaking then you will want to do the following.
How to Remove Caulking-type Sealant
- Separate the bad caulking from the caulking that is in good shape. Cut two lines, one on each side that is roughly one to two inches beyond the bad portion of caulking.
- Remove the bad portion by hand, the pick and hook set and your plastic edged scraper.
- Use your alcohol or mineral spirit partially soaked terry cloth to wipe away the remnants.
How to Remove Tape Sealant
If you are trying to remove a tape sealant such as Eternabond then you will want to go get a hair dryer and some acetone-based solvent.
- Using the hair dryer on high heat, warm up the tape for a few minutes. When sufficiently heated, slowly pull up the tape. Repeat as needed.
- When it is mostly residue left, you can use the solvent, scraper, and terry cloth to remove what is left.
- At this point, you can use your mineral spirits to prepare for the application of new sealant.
Careful with Opening the Sealant
When you are prepping your sealant, do not cut a big piece off of the end of the nozzle. You will want the diameter of the tip to be as small as possible to prevent applying an excess of sealant. A lot of people initially follow the incorrect impulse of applying extra sealant. That is a big point of separation between a newbie and a professional. Less is typically best, at least initially. You will want to fill and cover the cracks without going beyond that.
The standard caulking gun has a hole in the handle of the gun that you can use to snip off the tip of the caulking tube’s nozzle. Try to put a slight angle on it; somewhere in the ballpark of 25 degrees.
How to Reseal Your RV Siding
Now that you have the supplies, the deteriorated caulking has been removed, and the surface has been cleaned; you can add the non-leveling sealant. This part is actually very simple.
Step 1: Assuming that the targeted area is clean and dry, apply a thin bead of caulking down the line that needs resealing. Only use enough caulking to seal the line. It does not need to exceed it. It doesn’t help to have excess caulking and it makes the job look unprofessional.
Step 2: I’d recommend that you have some disposable gloves on at this point. Some people have skin that is sensitive to mineral spirits. Dampen a terry cloth with the mineral spirits, and then touch one of your hopefully gloved fingers to the damp cloth.
Step 3: With your finger now lightly damp with mineral spirits, wipe it down the line of freshly applied sealant. This will squish and flatten the beaded sealant into the cracks, and make it less vulnerable to potential damage. Additionally, it will form the sealant into a concave shape that is more capable of repelling water.
When you wipe your finger along the line of sealant, your finger will pick up the excess. Every few inches there will be enough sealant on your finger that you should wipe that excess sealant onto the damp cloth. Keep repeating steps 1, 2, and 3 until complete. It’s really pretty simple once you have everything and know what you are doing.
I am a well traveled Marine Corps veteran that enjoys the outdoor and nomadic lifestyle that RV living provides. I am also a member of the National RV Inspectors Association (NRVIA.org). As the founder of Camperguide.org my goal is to provide you with well researched information so that you can enjoy the best of the RV lifestyle.