February 2017: Post treatment: Water Repellent 

Welcome to another installment of Textile U! This month, we’re focusing on something that our customers often ask us:

Do I really need to reapply a water repellent every year? 

The answer is YES! Periodic reapplication of a water repellent (also known as Post treatment) is the most important step in keeping your boat cover in pristine shape. You’ve spent the time taking care of your boat and the money to have a custom cover/top/enclosure made for it; by not taking care of it, you risk having unnecessary wear to the fabric. That’s why it’s so important for preserving the look and quality of your investment for years to come. First, let’s take a look at WHY you need to reapply a water repellent. 

How and why do water repellents break down? 

Here at Marlen Textiles, every fabric we make has a water repellent on the surface. It’s strong and protective, but it needs a little maintenance now and then. Normal ultraviolet (UV) exposure, like you get from the sun, along with rain and snow all break down the “film” of water repellant and causes it to deteriorate. Along with general deterioration, the water repellent’s molecular chains and molecular weight also weaken. That means that the finish is not held as well by the fabric, and once that happens, rain can gradually wash it away. Everyone knows (hopefully) that periodic cleaning of your fabric is recommended. And thanks to detergents, even this periodic cleaning can break down the water repellent. 

How do I know if the fabric has lost its water repellency?

A simple test will help determine if and when your fabric needs a new application: Take some water and throw it on the fabric. If the water beads up, you’re good. If it doesn’t, then you need to reapply a water repellent. Keep in mind, too much of a good things is bad. If you have too much water repellent on the fabric (if you put too much on during the application or you apply more when it is not needed) cause a cloudy, milky appearance. So, be careful! 

OK, So I’ve lost water repellency. Will that effect the fabric’s water resistance? 

Actually, yes. While water repellent and water resistant are two different things, they are closely related. The more water repellent a fabric is, the less likely it will leak. Simply stated, The goal of water resistant and water repellent fabrics is, of course, to prevent water from entering your boat, vehicle, window or other items that use covers. Knowing these two terms is important to understanding how your fabric will perform in different situations and how you need to maintain it. 

Water resistant is the ability of the fabric to resist water permeating through the fabric, even at high pressures. 

But water repellent is the ability of the fabric to bead moisture on the surface and have it “roll off” the fabric rather than allow it to penetrate the yarn and “wet out” the fabric. 

If a fabric “wets out”, that means the water has soaked in to the fabric and now just the force of gravity pulling on the water will cause it to leak. This will happen if the force of the gravity is greater than the surface tension of the “wetted out” area of the fabric. Think about your blue jean when you take them out of the washing machine. They are usually damp and heavy. If you hang them on a line, it is likely the water will start to drip from the wet jeans. 

Let’s take a closer look into how you can keep your cover/top/enclosure lasting longer. 

How can you keep water repellent from deteriorating? 

First, make sure that you’re cleaning your fabric properly. We’ve shared useful cleaning tips before, but one of the most important things to remember is to use a mild soap or detergent that isn’t harsh on the surface. A true soap is your best bet, as it’s easier to rinse out than detergents are. Make sure to rinse the fabric thoroughly so that the soap doesn’t interfere with the water repellent. 

After line-drying the fabric or drying according to the manufacturer’s instructions, it’s time to reapply the water repellent. Make sure the fabric is absolutely dry, and then apply a treatment of Aqua-Tite Green (or a similar post treatment water repellent) as we note in our tips here. It’s important to do this yearly to prevent the water repellent from breaking down too much between treatments. 

Water repellent is vital to the strength and performance of the fibers in your fabric. Post treatment will keep the life of your cover lasting longer. With the proper treatments and care, you can ensure that your fabric does everything it needs to for many years to come. So make the post treatment a part of your yearly maintenance.