How to Make Waterproof Cardboard?

Cardboard does not do well if it gets wet, although it is strong & durable material. When the cardboard interacts with water, it can lose shape and becomes dysfunctional. However, there are some can-do ways to waterproof the cardboard that can help it last longer and stay strong.

Each method has its own perks, but this guide will explore each way in depth to make cardboard waterproof. More so, every method requires a different budget. So, you will not need to go anywhere because we will also cover the average cost per square feet you might need for using each method. Let’s get started by exploring the significance of waterproofing cardboard.

Why Making Cardboard Waterproof?

Cardboard is used most frequently in sustainable packaging, like for crafts, storage, or shipment. However, water can make it soft and weak, which may cause product damage, especially during transportation. By making waterproof cardboard boxes, you can protect your products while enhancing the durability of the box. Here’s why it’s important:

• Helps keep cardboard strong
• Prevents it from bending or falling apart
• Makes it last longer in damp places
• Protect the products inside despite the rain.

If you need cardboard to stay in good shape, waterproofing becomes a must!

Simple Ways of Waterproofing Cardboard

Method 1: Use a Waterproof Spray

A waterproof spray is an easy way to protect cardboard. These sprays create a layer on the cardboard that stops water from soaking in.

Steps of Using Waterproof Spray

1. Buy a waterproof spray – Many brands like Rust-Oleum NeverWet and Thompson’s WaterSeal are available in craft or home improvement stores.
2. Spray the cardboard – Spray evenly on the surface, holding the can 6-8 inches away.
3. Let it dry – Wait until it dries completely. This can take a few hours.

Repeat the process if you need extra protection. With each coat, the cardboard becomes more waterproof.

Pros and Cons of Applying Waterproof Spray on Cardboard

Pros:

• Easy to apply and quick to dry
• Provides a smooth, clear finish
• Works well on large cardboard surfaces

Cons:

• May need multiple coats for strong protection
• Not the most durable against heavy rain or soaking
• Can release fumes, so best to use outdoors

Average Cost per Square Foot: $0.15 – $0.30

Method 2: Use Wax to Coat the Cardboard

Wax coating is another great way to waterproof cardboard. This method adds a protective layer that keeps water out.

Steps for Wax Coating:

1. Get some wax – Candle wax or paraffin wax works best; Gulf Wax and Yaley’s Paraffin Wax can be purchased from craft stores or online.
2. Melt the wax – Carefully heat the wax in a pot until it melts.
3. Brush it on – Use a brush to apply melted wax onto the cardboard.
4. Let it cool – Allow the wax to dry and harden on the cardboard.

Wax keeps the cardboard dry and gives it a smooth feel. Be careful with hot wax!

Pros and Cons of Using Wax on CardBoard

Pros:

• Provides high durability and protection from moisture
• Gives the cardboard a shiny, smooth finish
• Ideal for small projects or craft items

Cons:

• Can be messy and requires careful handling of hot wax
• Takes longer to apply and dry than spray
• May not cover large surfaces easily

Average Cost per Square Foot: $0.10 – $0.25

Method 3: Use PVA Glue for Waterproofing

PVA glue can also make a good water resistant cardboard. When dry, PVA glue forms a solid barrier on the surface.

Steps to Apply PVA Glue:

Use a quality PVA glue – Leading brands like Elmer’s and Gorilla Glue are widely available.

1. Mix with water – Add water to the glue to make it easier to spread.
2. Apply the glue – Brush it evenly over the cardboard.
3. Let it dry – Wait until the glue dries completely.

For extra strength, add more layers of glue. This glue layer stops water from getting into the cardboard.

Pros and Cons of Using PVA Glue

Pros:

• Easy to find and inexpensive
• Provides decent water resistance
• Can be layered for stronger protection

Cons:

• Can make cardboard slightly stiff
• Not fully waterproof; works best for light exposure
• Requires drying time between coats

Average Cost per Square Foot: $0.05 – $0.15

Method 4: Laminate the Cardboard

Laminating means adding a plastic sheet over the cardboard. This plastic layer keeps the cardboard safe from water and makes it very durable.

How to Laminate Cardboard:

1. Use clear plastic – Buy laminated cardboard sheets or plastic wrap. Scotch Self-Sealing Laminating Sheets and Fellowes Thermal Laminating Sheets are popular options
2. Cover the cardboard – Place the plastic on top of the cardboard.
3. Seal the edges – Use strong tape around the edges to keep the plastic in place.

Laminating is great for cardboard projects that need extra protection.

Pros and Cons of Laminating Cardboard

Pros:

• Highly durable and fully waterproof
• Provides a smooth, glossy finish
• Excellent for long-term projects or heavy use

Cons:

• Costs more than other methods
• Adds thickness to the cardboard, which may not be suitable for all projects
• Not as eco-friendly due to plastic use

Average Cost in USD per Square Foot: $0.20 – $0.50

Comparing & Summarizing Different Waterproofing Methods

Each technique has its own best features, so try one which works best for you.

Technique	Difficulty Level	Durability	Cost
Waterproof Spray	Easy	Medium	$0.15 – $0.30
Wax Coating	Medium	High	$0.10 – $0.25
PVA Glue	Easy	Medium	$0.05 – $0.15
Lamination	Medium	Very High	$0.20 – $0.50

Tips to Make Waterproofing Work Best

Each waterproofing method works well in different situations. Here are some tips to make sure your waterproofing lasts:

• Apply more than one coat: Extra layers make the cardboard even stronger.
• Dry each layer fully: Give each coat time to dry before adding another.
• Use cardboard indoors: Waterproofed cardboard lasts longer if not left in heavy rain.

With these tips, your cardboard will stay in top shape!

Final Thoughts

Making cardboard waterproof is easy and helpful. It keeps cardboard strong, safe, and ready for any project. Each method, from spray to lamination, has benefits. Pick one that fits your project, and you’ll have waterproof cardboard in no time!

Now you know how to make water resistant cardboard. Whether you’re making crafts or building a model, waterproofing is a simple and effective step. Give it a try!