Can You Paint Over Flex Seal? (How-To)

Flex seal is a liquid coating used for just about any DIY project from spraying to sealing. But can you paint over flex seal? Here is the answer to that.

You can paint over flex seal but not every flex seal product can be painted over. You can apply paint over flex seal spray and flex glue but you can’t apply paint over surfaces covered with flex shot or flex seal liquid.

So, why can’t you paint over some flex seal products? Let’s dig in.

Is Flex Seal Paintable?

Flex seal is paintable. But you can’t apply paint over every flex seal product.

Flex seal refers to a range of sealants and coatings perfect for virtually any type of DIY task. The product is used for painting, sealing, repairing, and even gluing cracked or damaged materials together. Flex glue can even be used underwater.

But many DIYers worry if they can paint over material after covering it with flex seal. Yes, you can paint over flex seal but you can only paint over flex seal spray and flex glue. This is because these flex seal products are designed to be used for mainly repair tasks.

Flex glue for instance is a very powerful adhesive paste that is used to join cracked materials together including window sills, concrete, and wall fittings. Also, flex spray is commonly used to paint over and cover roofs and extensions.

Since these products are largely used for repairs, they aren’t usually left as the final coating on a material. Flex spray and flex glue are usually finished by being painted over. So, they are designed to absorb paint.

Flex tape, another flex product will need to be sealed with flex spray before painting over it. Flex seal liquid and flex shot on the other hand are commonly used to seal various materials. As such, they are not usually finished or painted over.

So, these products aren’t designed to absorb paint. Rather, they are designed to seal repaired and painted materials. So, you can’t paint over flex seal liquid.

But what happens if you do so? Let’s find out.

What Happens If You Paint Over Flex Seal Liquid?

If you paint over flex seal liquid directly, the paint will not stick. This is because flex seal liquid is made from silicone and paint will not stick to silicone.

If paint is applied over flex seal liquid, the paint will run and have no adhesion at all. It will take very little to wipe off paint applied on flex seal liquid regardless of the type of paint used.

Flex seal liquid is one of the strongest coatings in the flex seal family. The coating is reinforced with silicone which makes the product not only strong but heat, moisture, and weathering resistant. However, for all the benefits of flex seal liquid, the coating had one flaw. It can’t be painted over and the reason is simple.

To get a silicone product strong enough to seal virtually any material, flex seal liquid manufacturers had to sacrifice paint adhesion. Flex seal liquid being silicone-based is slick, glossy, and non-porous. The coating when applied produces a strong moisture-resistant film that doesn’t allow any liquid (oil or water) to pass through or have good gripping.

Since paint is usually in liquid form, it will not penetrate the flex seal liquid coating and it will not grip the glossy layer either. So the paint will just wipe off or turn greasy.

However, there is a hack to painting over flex seal liquid. This hack is a 3-step strategy that includes sanding, priming, and painting the flex seal liquid. With good sanding and a quality primer, you can paint over flex seal liquid.

Let’s check out the steps involved in painting over flex seal.

How To Paint Over Flex Seal?

To make this guide more helpful, let’s divide it into two sections.

1) The first section is a guide for painting over flex seal products that can be painted over like flex spray and flex glue.

2) The second section is a guide for painting over flex seal products you can’t paint over like flex seal liquid and flex shot.

Here is a quick rundown of how to paint over flex seal glue and flex seal spray.

Wipe The Flex Seal With Tack Cloth

This helps to remove dirt, debris, and oils on the flex seal. If the flex seal is filthy, wipe it with warm soapy water. Don’t worry about water damaging the flex seal because all flex seal products are water-resistant.

Sand The Flex Seal Lightly With Fine-Grit Sandpaper

This helps to buff or abrade the flex seal a bit so the paint can bite into the material. 220-grit sandpaper is ideal for this task. Coarse and medium-grit sandpaper can remove the flex seal and expose the material that was glued or repaired.

Remove Dust

After sanding, wipe or vacuum the sanded dust.

Apply Two Coats of Primer

Though you don’t have to prime flex glue or flex seal spray before painting over it, priming will help to improve paint adhesion. Use primer that fits the paint to be used. The best paint to use over flex seal is water-based acrylic paint.

Apply The Paint

Apply the paint based on the manufacturer’s instructions.

Seal The Paint

This step is optional. You can choose to seal the paint to improve its durability and moisture resistance.

Now let’s check out how to paint over flex seal liquid and flex shot.

How to Paint Over Flex Seal Liquid and Flex Shot?

Scrape off The Flex Seal

Use a paint scraper or sharp object to remove the flex seal manually.

Roughen-up The Flex Seal

Roughen up the seal by sanding it with medium-grit sandpaper. 150-grit is perfect.

Even The Grain With Fine-Grit Sandpaper

After sanding with medium-grit sandpaper, use fine-grit sandpaper to smoothen the flex seal.

Remove Dust

After sanding, vacuum or wipe off the dust.

Apply Two Coats of Primer

Use an oil-based primer for oil-based paint and a water-based primer for water-based paints.

Apply The Paint

Apply the paint based on the manufacturer’s instructions.

Seal The Paint

This step is optional. You can choose to seal the paint to improve its durability and moisture resistance.

Tip: Always check the flex seal product you purchased to know if it can be painted over.

Now, let’s go deeper into why you can’t paint over some flex seal products.

Why Can’t You Paint Over Some Flex Seal Products?

You can’t paint over flex seal liquid and flex seal shot because these products have thick layers that repel paint coatings. Flex seal liquid and flex shot are made from silicone to make the coating super strong and waterproof. Paint will just not stick to these flex seal products.

Flex shot is a strong silicone-based paste that is used to fill, repair, and caulk any damage from hairline cracks to large holes. The product bonds to material instantly but it can’t be painted over. This is because paint will not stick to the silicone-based product. If paint is applied over flex shot, the paint will be wiped off easily.

Also, you can’t paint over flex seal liquid. Painting over flex seal liquid will make the paint coating greasy or sticky. The paint coating will not dry and will remain tacky for days. Eventually, the entire coating will fall off or become gluey or semi-solid. This is because flex seal liquid just like flex shot has silicone compounds that make the coating waterproof.

Since the coating is waterproof and not just water-resistant, it doesn’t allow any moisture (liquid or solid) to penetrate. Since paint is either oil or water-based, the paint coating will not penetrate the flex seal liquid and will not adhere to the material.

Also, flex seal liquid and flex shot are glossy when dry. The glossy texture prevents paint from biting or gripping to have a good bond. So the paint coating just sits on the flex seal layer and will be wiped off when exposed to minimal contact.

Another thing to know is if you can change the color of flex seal.

Can I Change The Color of Flex Seal?

You can change the color of flex seal but not by painting over it. To change the color of flex seal, you have to use flex seal color spray. The flex seal color spray is an aerosol spray that seals virtually any material with a colored paste. The spray comes in 12 colors so you have a broad range of choices.

As explained earlier, not every flex seal product can be painted over. You can change the color of flex seal spray and flex glue by painting over it with water-based acrylic paint. But you can’t paint over flex seal liquid and flex shot. So the question is: how do you change the color of a sealant that can’t be painted over?

The answer is by using flex seal color spray. Flex seal manufacturers know that some of their products don’t have good paint adhesion. So they designed a product that allows you to change the color of flex seal.

To change the color of flex seal, spray the flex seal coating with the required color of flex seal color spray. The color spray comes in 12 colors so you have a good color range to pick from.

Flex seal color spray is an aerosol paint in a can that doesn’t just add color but also seals cracks and holes. So in addition to getting a good sealant, you also get a colorful finish on the repaired material. However, you should only use flex seal color spray to repair medium-sized cracks.

For large holes and cracks, use flex glue or flex seal liquid. Then use flex seal color spray to change the color of the flex seal once it dries.

Can You Stain Flex Seal?

You can’t stain flex seal products. This is because stains unlike paints need to sink into the material to adhere properly. Since the flex seal coating is strong and moisture (oil and water) resistant, the stain will not penetrate or sink into the flex seal coating and thus, will not stick.

There is a big difference between stains and paints. Paints usually adhere to the top layer or coating of material and don’t need to sink into the material.

The paint coating when applied just needs a well-primed or textured top layer to adhere to. This is why paints can be used on both porous and non-porous materials.

Stains on the other hand are more common with porous materials like wooden floors and furniture. This is because stain unlike paint needs to soak into the grain or fiber of the material to adhere. This is why stains are usually chip-resistant. While coatings peel and chip off, stains will stay on since it is well soaked in the material. So how does this translate to flex seal coatings?

Well, since stain needs to soak into a material to adhere, it can’t be used over flex seal. This is because the stain coating will not penetrate or soak into the hard texture of flex seal. Since the stain can’t penetrate, it can’t adhere and if it can’t adhere, then flex seal can’t be stained.

Final Words

Overall, you can paint over flex seal but always ensure to check the container of the flex seal product you purchased to know if you can paint over it or not.

Remember, not every flex seal product can be painted over. Also, remember to sand and prime before painting and to change flex seal color, use the flex seal color spray.

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