How To Waterproof Cardboard Boxes In A Right Way 

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You know quite well that they are very susceptible to water and humidity if you frequently deal with cardboard. So, making the cardboard boxes waterproof is essential. Otherwise, the product could be damaged because it’s vulnerable to water.

Now, if you don’t know how to waterproof cardboard, I am here today to tell you about this. I can assure you with my years of study and experience that this isn’t complicated or costly.

You’ll find a lot of ways to waterproof cardboard boxes so that you can focus on your work without any additional stress. I will explore all possible ways to waterproof your cardboard boxes in this detailed guide. So, without further delay, let’s begin.

Why Should You Make Cardboard Boxes Waterproof? 

You know already that cardboard boxes are easily prone to water and moisture. Therefore, you should make them properly waterproof to keep your elements safe. You’ll get lots of benefits from waterproofing the cardboard boxes. Let’s see some of the essential benefits of waterproofing them.

  • You can reuse those boxes multiple times.
  • Waterproofing will make those boxes free from moisture, you can use them stress-free.
  • In a waterproof cardboard box, your products or elements will be always safe and in good condition.
  • Another important benefit that you are going to get by sealing cardboard is your box will be more robust and durable.
  • Whether it is dust or snow, an excellent waterproof coating for cardboard will make it always safe from the harsh environment.
  • If you want to preserve anything in your cardboard box for a long time, yes, you can do it, but make it waterproof first.
  • Many people use cardboard boxes for the craft. In this case, keeping them free from water and moisture is extremely important.

Cardboard Boxe

How To Waterproof  Cardboard Properly?

I can show you several ways to make the cardboard boxes waterproof. But, first of all, you need to keep in mind that the basic procedure is similar in almost every case.

You’ll have to apply an extra layer of waterproof coating to the cardboard box. But, you must make sure that every edge and corner of the box should be covered by it.

You want to make those boxes free from water or moisture, right? Honestly speaking, you can do it easily. But, you should be careful when applying any coating to the box.

Every single spot of the box should be covered. Even a small uncovered spot can alter the entire calculation and destroy the box if it comes to water contact.

A waterproof coating for cardboard could be your ultimate solution. In this case, find the best waterproof paint for cardboard. However, you can think about other possible solutions as well. Using taps in the right way can make a cardboard box perfectly waterproof.

Even shrink wrapping or using aluminum foil can also make your day in this case. However, you should know how to use them properly.

You can also think about waterproofing paper spray for sealing cardboard boxes. However, in this case, you should choose the best waterproofing spray for cardboard.

If you are considering some permanent solution, go for durable paints. Enamels, acrylics, or epoxy resin may add a waterproof layer to the cardboard box surface.

How To Add Waterproof Layer

Using a waterproof coating is a common practice to make cupboard boxes waterproof. A polyurethane coating, bright acrylic spray paint, or even a lacquer spray sealer spray can be used as a robust coating for making cardboard boxes waterproof.

However, you should keep in mind that proper precautionary measured should be taken before applying this coating. These coatings are highly flame retardant; during the application, you should maintain adequate ventilation.

As per the steps below, you can apply a waterproof coating to the cardboard boxes.

  • First of all, put on your safety gadgets. It is highly necessary to take care of your personal safety before applying a waterproof coating.
  • Then you need to prepare the whole area by laying a plastic sheet on the surface.
  • Now, gently place your cardboard boxes on the plastic sheet. It will be a wise decision to cover everything else in that place.
  • Prepare your coating correctly for application. Shaking the can will ensure that pigments are appropriately mixed in the can. It is necessary to get the maximum benefit from it.
  • Now, it is time to apply the coating to the box. Add a thin layer by using the coat parallel to the surface of the cardboard box.

But, you should remember that, to get the maximum result, you need to hold the can at least 12 inches away from the cardboard. You should continue spraying until you covered every space of the box.

  • Now, you should let it dry properly. It is essential as you want to spray the next layer after it is dried.
  • You need to make sure that you have covered every space of the box. Don’t leave a space uncoated, not even any corner or edge.

Now that you know how to make cardboard waterproof, you will want to get the best waterproof cardboard. However, you will find it challenging to get the best coating for you, given that all those cheap products are available out there.

Now, you’ll find different instructions in a different coating. So, you should follow the instructions carefully to get the best result. I’m going to give you a clear understanding of how these coatings work in this guide.

There are lots of waterproof coating that you’ll find. But, today I am going to show you some best ways to make your cardboard boxes waterproof.

Let’s find it out in detail.

#1: Using PVA Adhesive Coating

PVA adhesive coating could be a great option for you To ensure a perfect water-resistant surface on your cardboard box.

With this excellent adhesive, your cardboard boxes can withstand several cycles of soaking and drying because they are grade 2 water-resistant.

Let’s see how to apply this coating properly.

The first step is likewise the same as before. Using sheets on the floor, prepare the workspace and place those boxes on the wall.


  • Make a mixture of water and adhesive as per the product guideline. Add a layer to the cardboard surface.


  • Let the first layer of coating dry. Then apply the second layer of coating mixture after a few hours. Make sure that you have covered every space of the cardboard box. Now, let the box dry properly.


  • Now, in this step, prepare a more concentrated mixture and apply the third layer of coating to the box.


  • You should repeat the whole process once again. I believe, this time you’ll be able to see a shiny surface of the cardboard box.

I just want to say here that your cardboard box would be able to become water-resistant if you execute the instructions properly.


#2: Using Fiberglass Resin Coating

Here is one of my favorite types of coating for cardboard. You’ll note that several coats of fiberglass resin are compatible with other coating solutions.

The exciting part of fiberglass resin is you can use it to almost everything for adding a water-resistant layer on the surface. Let’s look at the product’s implementation process.

The whole application process will start by preparing the workspace with a plastic sheet or newspaper. For a safety issue, you can cover everything else in the workspace.


  • The next thing you should do is putting a silicone mat on the surface. I will tell you the reason why you should do it.


This type of resin becomes extremely hard after application. The adhesive can not adhere to the silicone mat in this situation.


  • I would like to recommend you put on your safety gadgets before going to the next step.


  • You should make a mixture of polyester resin with a catalyst. In most cases, you need to mix at least 12 drops of catalyst for getting a better result. This product sets in about 15 minutes.


  • Apply the mixture to the cardboard box carefully using a brush. You need to make sure that you have applied enough resin mixture to cover the entire cardboard box.


  • Now, dry the box for at least 24 hours. After that time, you are allowed to apply the second batch of resin mixture to the box. Don’t forget to dry it for another 24 hours before you touch the cardboard box.


#3: Using Alum Mixture

Did you know that a homemade Alum mixture is so useful to waterproof cardboard boxes? Let me show you how to seal cardboard boxes by using the alum mixture.

  • The necessary preparation of the workspace is the same for every type of product. Just make a proper surface for the whole process with some newspapers or plastic sheets.


  • Get a little pot of little water and make it a bit warm by heating it. It is essential for the alum solution preparation process.

You have to pour 8 ounces of alum, 3 ounces of grated Castile soap, and also take 4 ounces of natural glue. Now, you have to stir this solution to make it properly even.


  • In this entire process, you should not let the water boil, and within 3 to the 4-minute stirring process should be completed.


  • Take the solution in another container. Now from this container using a brush, apply the solution to the cardboard box. After the entire application process, you’ll see a thin layer that will make it waterproof.

#4: Using Paraffin Wax

Although it is not the best solution, you can still paraffin wax for waterproofing cardboard boxes. If you can’t manage waterproof cardboard spray or solutions, in that case, it could be your alternative.

So, can you waterproof cardboard? Let’s figure out how it works.

  • Prepare the workspace carefully.


  • Take a double boiler pot, and you need to pour a few inches of water on the bottom pan.


  • Now, it’s time to pour about 8 ounces of paraffin wax on the top hot.


  • You need to set the pot on low heat and stir it continuously until it melts clearly.


  • Now, you are all set to go. Take a brush, and with that, add a thin layer of wax to the surface of the cardboard box.


  • You need to dry it as always. Now, you can apply this wax to add another layer.


  • You should make it completely dry before you are ready to use it.

#5: Using Shellac Solution

Have you ever heard about lac bugs? Who knew we would find these bugs so helpful in the waterproofing of carboards? Shellac made from lac bugs has been commonly used for musical instruments as a lacquer.

Here comes the most exciting part. To make your cardboard boxes waterproof, you can directly dip the box in it or apply the solution by using a brush. It is so powerful that the procedure needs to be further clarified.

  • Prepare your workstation first. You already know what you have to do. Spread plastic sheets on the floor so that you can put the box on them during the application process.


  • The next step is to prepare the shellac solution. Here the mixing ratio of shellac and Borax should be 5:1, maintain this ratio carefully. Stir the mixture continuously to make an even solution.


  • After preparing the solution, you are all set to go. Apply the solution directly to the box by using a brush. You can even bathe the box in the solution. Either way, you will be able to make the box waterproof.

#6: Using Lacquer

Wouldn’t this be awesome to get an easy solution to make those cardboard boxes waterproof? Yes, of course. Let me introduce you with Lacquer, your most straightforward solution. You can follow these steps to apply to this product.

  • Prepare the workspace and try to choose a well-ventilated space as the workspace.


  • The application is simple. It’s a spray. So, you need to apply the spray on the surface of the cardboard box. After applying, you should let the box dry for a few hours.


  • After adequately drying, you can apply the second layer of spray. Make sure that the full box is covered. Then, dry the box carefully for a few more hours.


You might become confused about seeing the box wet during the application process.

Yet when it dry, the magic occurred. Across the top of the box, you can see a waterproof coating that makes it waterproof.


#7: Using Self-Laminating Sheets

I used this method sometimes. The Self-laminating sheet method is a popular DIY method for waterproofing cardboard boxes.

But, you need to ensure first that you have enough sheets in hand to cover the full box. These sheets can be used by the following ways.

  • Measure your box carefully to determine the right size that you need for your box.


  • Try to laminate one side at a time. It will ensure its proper application. You can use adhesives to get the maximum benefit.


  • Make sure that you have covered every side and space with the laminating sheets so that it can become completely waterproof.

#8: Using Rubberized Coating

I’m assuming that now you know there might be several ways to make your cardboard boxes waterproof.

The rubberized coating is another excellent way to make your day shine even brighter when it comes to the safety of your carton boxes.

Let’s see how easily you can apply it to the cardboard boxes.


  • First of all, I would like to mention that you should take extra safety care as the flames are toxic. For instance, you can choose a workplace with proper ventilation.


Also, make sure that your floor is fully prepared with plastic sheets or newspapers to place the cardboard box.


  • Now, you know what you have to do. Just take a paintbrush and apply the rubberized coating with it. Make sure that every space of the box is covered with the coat.


  • After applying the coat, you need to dry the box. But you should keep in mind that every coating comes with its application guideline.


So, always follow the guideline suggested in the product manual to get a better result.


Drawbacks of Waterproof Coating

I bet, now, you can’t deny all of those benefits you might get from the waterproof coating. But, honestly, everything has its drawbacks as well.


You may make your cardboard boxes waterproof by using it. But, in return, it will not be any more recyclable. You can’t print anything else on the surface of the coating.


Another thing you should be careful about is the coating is not a permanent solution always. Many coats deserve multiple applications for many times.


Besides, it will not be a wise decision to store food items in a waterproof coated cardboard box.

Cardboard Boxes

Final Words

In bad weather, a waterproof cardboard box will be your best companion to protect your valuable items. For a long time and safe use, I recommend you to make your cardboard boxes waterproof.

You need cardboard boxes for many reasons. Maybe you need to store those old books in the basement. Perhaps you need to preserve your valuable items.

Whatever the reason is, waterproofing your carboard boxes will save your items, and you’ll be stress-free for a long time. I believe this comprehensive guide has helped you to understand how to waterproof cardboard boxes in the right way.

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