Best Exterior Wood Filler for Decks | Crack Repair

Discovering the perfect exterior wood filler for decks is no easy task. After putting 11 different products to the test, I found a standout that exceeded all expectations. RTG Wood Repair Epoxy Putty emerged as the undeniable winner.

Exterior wood fillers are diverse, and various products excel in specific situations.

So, as you read on, I’ll delve into the nuances of each ‘best for’ case, ensuring you find the perfect match for your deck restoration needs.

Don’t miss out on transforming your deck with the ideal wood filler. Keep reading to discover the most suitable option for your outdoor wood repair project.

Our Top Picks

Best Exterior Wood Filler for Decks

1. Best Overall Exterior Wood Filler – RTG Wood Repair Epoxy Putty
2. Best Bang for the Buck – J-B Weld 8258 KwikWood
3. Best Wood Filler for Outdoor Use – Bondo All-Purpose Putty
4. Best Stainable Wood Filler – Elmer’s E892
5. Best Exterior Epoxy Wood Filler – Abatron Wood Epoxy 2 kit
6. Best Wood Putty for Decks – Minwax 13617000
7. Best Wood Filler for Pressure Treated Deck – Pc Products- 163337
8. Best Wood Fillers for Big Jobs – Gorks GoodFilla
9. Waterproof Wood Filler for Outside Deck – Famo Latex
10. Best for Small Jobs – Elmer’s E855 Carpenter Wood Filler
11. Best Exterior Wood Filler – DAP Inc 16Oz Latex Plastic Wood Filler

Best Wood Filler for Deck Cracks Review

When finding the best wood fillers for exterior decks, we considered all the critical factors, from type to durability. We also read real customer testimonials to ensure these deck wood repair products are highly popular.

1. Best Overall Exterior Wood Filler – RTG Wood Repair Epoxy Putty

The RTG Wood Repair Epoxy Putty is the best overall filler for decks. It has a remarkable combination of qualities that make it an exceptional product.

Having tested this epoxy putty, I can confidently say it’s a game-changer for anyone dealing with damaged wood.

The 1:1 mix ratio makes it easy to use, and I found it perfect for interior and exterior projects. Unlike competitors, it doesn’t sag, shrink, or crack. This ensures a smooth and durable finish.

While it may be pricier than some alternatives, RTG’s Wood Repair Epoxy Putty is worth every penny. You’re investing in unparalleled durability and waterproof performance.

It’s the best value for your money and a must-have for any woodworking enthusiast or professional.

The cured material is not only 100% waterproof but also as reliable as real wood when it comes to holding nails, screws, and other fasteners. It offers quality and longevity.

What We Liked Most

Easy 1:1 mix ratio for user-friendliness.
Ideal for both interior and exterior applications.
Resists sagging, shrinking, and cracking, ensuring a durable repair.
Waterproof once cured, providing long-lasting results.
Excellent at holding nails, screws, and fasteners.

What Could Be Improved

The price may be higher, but it reflects the product’s quality
Precise mixing is key for optimal results.

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2. Best Bang for the Buck – J-B Weld 8258 KwikWood

Ranked as our second choice, the J-B Weld 8258 KwikWood is a wallet-friendly superstar in the epoxy putty for wood exterior decks.

It caters to those who want to do the job without emptying their pockets.

From my experience, I can testify that this hand-mixable two-part epoxy putty stick simplifies the wood repair process. KwikWood stands out for several reasons, making it accessible even for beginners.

It’s custom-tailored for wood repairs, ensuring it’s a perfect match.

One of KwikWood’s strong suits is its affordability. Thanks to this cost-effective solution, you can embark on various wood-related projects without worrying about your budget.

Plus, it doesn’t skimp on results. J-B Weld KwikWood provides robust, long-lasting repairs, breathing new life into your woodwork.

While the RTG Wood Repair Epoxy Putty is versatile enough for indoor and outdoor applications, KwikWood takes specialization to the next level by focusing on wood repairs.

This specialization and its affordability make it a top choice for anyone looking to save money while achieving impressive wood repairs.

What We Liked Most

Affordable and budget-friendly.
Easy to use, especially for beginners.
Tailored for wood repairs, ensuring optimal results.
Offers reliable and strong repairs, making woodwork restoration a breeze.

What Could Be Improved

Limited versatility compared to the first product
It may not be as waterproof as the premium option, so it’s best suited for indoor projects.

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3. Best wood filler for deck boards– Bondo All-Purpose Putty

Bondo wood filler is a professional, versatile filler for repairing interior and exterior wood surfaces around the home.

This fast-curing two-part filler allows you to make high-quality, long-lasting repairs to metal, masonry, concrete, painted wood, plastic, drywall, and more.

This filler is temperature and hardener proportion sensitive – the warmer the air temperature, the harder and the faster the cure. Always mix and apply with a plastic spreader and wear disposable gloves.

While this deck wood filler is fairly thick, it can still flow a little until it sets, so you may need to form a “dam” to keep it from migrating for a few minutes.

When mixing it, follow directions and scoop the desired quantity out; don’t mix it in the can.

Don’t overdo the hardener; if your first batch still hardens too quickly, reduce the hardener used, per the instructions.

What We Liked Most

Dries quickly and is hard.
It’s waterproof
Wood filler for outdoors and indoors

What Could Be Improved

It’s not good on softwoods like plywood
The hardener with the putty is too small; you might need to buy an extra tube to match the putty in the can.

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4. Stainable wood filler for deck– Elmer’s E892

Elmer’s Carpenter’s is a stainable wood filler designed for interior and exterior surfaces. It contains wood fibers with little or low VOCs, which is good for the environment.

These are some of the best wood fillers for filling holes and gouges in the wood. Typical uses are filling dents and holes in furniture, baseboards, molding, and kitchen cabinets.

This wood filler takes time to dry but can be sanded by hand or with a high-speed sanding tool once dry. It sturdily holds nails and screws and resists cracking and shrinking over time.

Note that this wood filler is non-structural, so it shouldn’t be subject to critical stress.

What We Liked Most

Contains fibers for superior sanding, staining, and painting
Firmly holds screws and nails
It is solvent-free
Best for interior and exterior use
Has an unlimited shelf life

What Could Be Improved

Takes a while to dry, so thicker repairs take time and can be a bit messy.
Comes half full.

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5. Best wood epoxy for deck repair – Abatron Wood Epoxy 2 kit

Abatron epoxy wood filler is available in a two-part epoxy paste, a 32 oz epoxy filler container, and the other a 32 oz hardener. This particular brand of epoxy fillers has a fast-drying time, and it’s easy to work with.

When mixing wood epoxy for deck repair, wear disposable gloves. This exterior epoxy wood filler turns pale beige when everything is mixed in together, doesn’t drip, and cures in about 60 minutes.

The Abatron outdoor wood filler epoxy works well to fill large voids, and it’s easy to shape to fill a crack effectively. It’s expensive compared to other wood fillers, but its ability to work well stands out, making it the best wood repair epoxy.

What We Liked Most

Contains no VOC’s or Noxious OdorsLong-lasting repairs
Bonds permanently to wood and other surfaces.
Perfect for rotted wood
Temperature-resistant
It can be cleaned easily with acetone

What Could Be Improved

Takes a longer time to cure or dry
It’s not good on softwoods like plywood

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6. Best Wood Putty for Decks– Minwax 13617000

Minwax Wood Putty is a non-hardening pre-mixed putty that repairs small holes and covers other minor imperfections in painted, stained, and finished wood.

It qualified to our list of the best wood fillers because it’s a user-friendly product that’s perfect for DIYers who don’t have the patience for lengthy procedures.

You don’t have to sand this outdoor wood putty once it dries, as it will naturally blend right into your rotted wood.

What We Liked Most

Has No VOCs and contains zero toxic ingredients.
The deck wood crack filler doesn’t split, no matter the weather conditions.
Reconstitutes when you add water.
Doesn’t require sanding.

What Could Be Improved

It’s only suitable for small repairs
It has a slow drying

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7. Best wood filler for pressure treated deck – PC Products- 163337

PC-Woody is a Two-part epoxy paste used to fill holes and gaps in damaged or decaying wood decks.

This wood filler for pressure-treated lumber has an easy-to-mix ratio. Mix equal parts of the resin and the hardener in a plastic or metal container, then apply them to your project.

It is stronger than most wood, offering a permanent solution for deck cracks. The filler is also waterproof, making it a great way to fix things like decks and docks that need to be able to stand up against the elements.

Not only that, this wood filler for pressure-treated wood demonstrates the ability to withstand the effects of UV light.

The product works on all types of wood, including treated lumber and pressure-treated lumber (PTL), redwood, cedar, plywood, pine, spruce, fir, and other varieties. It also provides an excellent base for paints or stains to adhere to.

These epoxy paste products can be used indoors and outdoors on wood, fiberglass & metal.

This epoxy is made from real wood and has many of its qualities. The PC-Woody formulation is a good way to do large projects. It takes longer, so you have more time to modify some sections while working.

What We Liked Most

Both indoor and outdoor wood filler.
The high tack helps reduce drips and sags while hardening
It can be painted, stained, and machined after being fully cured
Has excellent resistance to all weather elements

What Could Be Improved

It takes time to set up before you can mold it
It doesn’t work well in small gaps
It doesn’t bond to wax paper, Teflon, Polyethylene, or other plastics.

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8. Best Wood Fillers for big jobs– Gorks GoodFilla Wood Filler

This is the most innovative, easy-to-use, water-based wood filler. It’s designed for professional woodworkers but also perfect for your everyday DIYer.

Whether you have furniture to repair, a floor to finish, a craft to complete, or an instrument to design, this is your product. Goodfilla water-based fillers are so easy to sand you’ll be amazed by how much time you save.

Besides saving time, you can save money with this good wood filler as it doesn’t shrink, sink, or crack. It also has excellent adhesion, making it the best wood filler for exterior use.  This product can be mixed with any pigment, tint, stain, or dye.

What We Liked Most

It’s a green product: Zero VOC, zero waste, and non-toxic.
It’s a water-based filler
It has an unlimited storage life
It can create custom colors
You can sand, paint or stain it

What Could Be Improved

It leaves a yellow tint
It has a slightly watery texture

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9. Best waterproof wood filler for outside deck – Famo Latex

This latex wood filler can handle voids of different sizes. Like other no-mix wood fillers, it can be applied straight from the tub with a putty knife, but it stands above the competition in its no-crack, no-shrink water-based formulation.

It is made of latex and real wood fiber. It cures in 15 minutes to a harder-than-wood surface that can be sanded, planed, and sawed.

The Famo Latex Wood Filler can also be stained or painted, and with multiple colors, you may find a shade that matches your project perfectly.

What We Liked More About This Wood Deck Filler

It fills cracks quickly
It is non-toxic with no solvent fumes
Good for interior and exterior use
 It can be cleaned with soap and water

What Could Be Improved

It has a slightly watery texture

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10. Best for small jobs– Elmer’s E855 Carpenter Wood Filler

From filling nail holes in molding strips to filling gouges in hardwood floors, Elmer’s Carpenters tubes make the wood repair quick and easy.

Due to its size, this formula is excellent when you are looking to fill cracks on the surface of your wooden furniture.

Its squeezable containers improve the ease of application and a convenient size. This wood filler is water-based and can be sanded and painted.

In addition to the above properties, the Elmer’s E855 Carpenter’s Wood Filler is crack-proof and shrink-proof, which provides a clean and smooth seal to your wooden surface.

Secret tip: put a drop of water in the lid every time you close it. It keeps 95% of the clogs away, which stops the tube from squeezing easily.

If you have to squeeze hard, it’s time to put a drop of water in the lid, close it up for 5 minutes, and then try again.

What We Liked More About This Product

It resists shrinking and cracking·     
Easy water clean-up
Its best for interior

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11. Best Exterior Wood filler– DAP Inc 16Oz Latex Plastic Wood Filler

You can use this dap exterior wood filler in rainy or humid areas because it dries quickly enough that you won’t have to worry about it washing out.

It’s crack and shrink resistant, and you can use it to anchor screws or nails to the side of your deck to hang your flowers or baskets.

You’ll get a smooth and hard finish once it dries completely, and the plastic tub will keep the wood filler soft and moldable until you need it.

The DAP Inc 16Oz Latex Plastic Wood Filler is fast-acting, so you must apply it quickly, too. Because of its resistance to harsh weather, it is the best exterior wood filler.

What We Liked More About This Wood Filler

This wood repair product is 3X stronger than the wood itself
It’s an outdoor wood filler
It covers chips and gouges while anchoring screws and nails

What Could Be Improved

It is difficult to spread
It challenging to clean
It has an odor

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How do I Choose the Best Wood Filler for Decks?

It can take many factors to choose a new wooden filler. All of the wood filler may seem very similar in a way but it’s true. These basics will take you from the beginning.

Before diving into your deck repair project, it’s important to explore preventive measures as well. To learn how to prevent a crack in wood from worsening and maintain your deck’s integrity, we recommend reading our comprehensive guide on this topic.

1. Types of Deck Wood Fillers

Solvent based fillers or Epoxy-Based Wood Filler

These wood fillers contain higher amounts of VOC and, therefore, have more odor. The time it takes for the solvent-based wood filler to dry is about an hour, and you need some turpentine or acetone to clean them.

The thing about these wood epoxy fillers is that they are much more expensive. The reason for the higher price tag is because the solvent-based filler is more durable.

As per durability factors, solvent-based wood fillers are water-resistant, handle most weather conditions, and won’t rot quickly.

The best exterior wood filler epoxy is the Abatron Wood Epoxy 2 kit.

Water-Based Wood Fillers

This is made up of fiber or gypsum and cellulose. They smell less because they don’t have any VOCs (Volatile Organic Compounds).

Certain water-based outdoor wood fillers are considered more useful than their solvent-based counterparts, as they can be diluted with water.

This makes it easier to be used on projects that need a thin filler.  They are mostly in powder form, and the drying time of water-based filler is also convenient. Soapy water clean-up is all that is needed after that.

2. Packaging

Most of the best wood fillers for decks are available in different sizes and packaging. A good packaging use is to protect the wood fillers, and this protection is important because some outdoor wood fillers can turn hard if air gets in.

If your wood fillers have a container that can allow air in, you might have a tragic story like receiving oxidized wood filler. Most wood fillers come in stick form, tubes, or tubs.

The tubs come in two varieties; the one you can use straight away without any mixing, while others come in a two-part system and must be mixed before application.

You can apply these using a spreader or putty knife. These are also more cost-effective, as they come in larger amounts and can be used on bigger projects.

Ensure that you know the size of your projects so that you settle for the right capacity that will serve you right.

3. Amount

The amount of wood deck filler that you need is important to avoid unfinished jobs. Fillers come in many sizes; there’s 3.5oz., 7oz., 16oz., 32oz., and many more.

Depending on the size and depth of your hole, you may have to look for smaller sizes or bigger sizes to get the required amount needed to repair it.

4. Consistency

Wood fillers can have thick (putty-like) or thin (pancake batter-like) consistencies. Putty-like fillers are primarily used to fill voids, while thinner fillers for filling pores in open-grain woods.

It’s important to choose the right consistency for your project, as thicker fillers contain large particles that don’t readily fit into the pores of open-grain woods, and thinner fillers generally lack the body to fill voids adequately.

If you want to fill in nail holes, you’ll need a thicker consistency. Note that some thicker fillers can also be thinned with water to fill pores.

How to Apply Wood Filler to Decks?

Applying wood deck repair filler is a smooth process if you follow the right procedures. The tools needed are the normal and affordable tools that are handy and can be bought in roadside stores.

The list of tools needed in applying wood fillers to your deck are:

• Hard brush
• Sandpaper
• Deck cleaner/Deck stripper
• Putty knife
• Exterior wood crack filler

The process of applying wood deck repair filler is only completed once the filled pores are sanded using medium-grit sandpaper.

Here is how to fix splintered wood deck – step by step:

1. Clearing the wood

For the best results, start with clearing away the rotten wood. The stages of this process are highly similar to all handy work. Once the damage is apparent on the wood, the dented part must be cleansed with a hard brush. This is done to get rid of any splinters.

2. Scraping the wood surface

Next, you’ll have to clean your deck. If your wood surface is finished, use a deck cleaner. If not, a deck stripper is best. ‘Again, it’s vital to follow all the instructions provided with the purchased product.

Allow the deck stripper or cleaner to sit in the wood for a few minutes before moving on to the next application step. Once the stripper or cleaner has sat on the wood, use your hard brush to scrape the surface.

Spray the product clean with a hosepipe and allow the wooden surface to dry before proceeding with the filler.

3. Mixing/Applying wood fillers for exterior

Now, get your putty knife out and scoop some filler out of the tub (if a tub wood filler is what you’re using). If your filler is in 2 parts, you’ll need to carefully measure and mix the two parts using the manufacturer’s recommended ratio.

Got a tube filler? Squeeze the necessary amount on a paper plate or empty ice-cream container and mix it with the correct wood hardener. Once you are done mixing, use the wood putty knife to apply the filler to your deck’s surface.

Press the filler down with the knife properly before you add 1/8 of the filler.  Resume the same process until the hole has been adequately filled and is in line with the rest of the wooden surfaces.

4. Drying Time

Drying time for wood fillers is of utmost importance. First, let the wood deck filler dry, have a look at the directions on the label for the drying time. If the filler shrinks while it cures, add more filler and let it cure a little longer.

Check within the time range to see if it’s cured completely, then use medium-grit sandpaper to sand the surface until it is even with the deck. If there’re more holes, follow the same process—paint and stain when you’re done sanding as needed.

Related: Best wood filler for large holes

What’s the Difference Between Putty and Filler?

Wood filler and putty are substances that can fix wooden objects, fix defects, and repair mistakes. The wood filler contains wood fibers or sawdust, which is suspended inside a binder. The putty is generally a plastic-like epoxy, polyurethane, or fiberglass.

The differences between Wood Filler and outdoor wood putty:

• Wood filler is usually water-based, whereas putty is most often oil-based.
• Wood filler can be sanded and is typically used for unfinished wood, whereas putty can’t be sanded and is ideal for finished wood.
• Wood fillers should only be used for woodworking items that will remain indoors, whereas putty can be used with projects for any environment

What is the best wood filler for decks?

The Pc Products- 163337 is our favorite wood filler for treated lumber. Its strong resistance against all-weather elements makes it the best exterior wood fillers and indoor wooden surfaces. The formula is made from wood to help it blend into your wood grain better. You can expect this filler to last for years.

Read also: What is the best caulk for painting trim?

What is the best way to repair rotted wood?

For rotten or damaged wood, you can use polyester filler. Apply a wood hardener and filler on the surface. For example, when repairing a rotten window frame: Remove the rotted pieces with a sharpened tool. Once finished, you can then add a coat of the hardener. Next, mix the polyester filler and insert it into the hole with a putty knife.

You can learn How To Repair Splintered Wood decks with our quick guide.

How to Fill Gaps on Wooden Decks?

When the decks become too broad, you will need to do some fixing to avoid any accidents. One of the measures you can use in filling gaps is to remove all boards and reinstall them. However, this process can be expensive and time-consuming.

Another option is to use wood filler or caulk. However, professionals believe that caulking, especially for the gaps on deck, doesn’t always turn out well.

The hardest part is making it look good, and the natural movement of the boards can eventually cause the materials to break loose and make the gaps even worse.

However, you can use fiber ropes to fill the gaps easily. Then even if the size of the gap changes, you can refill it with a new rope.

After you clean the deck, cut a sufficient amount of natural fiber rope to fit each gap’s length. Don’t use synthetic rope because wood stain and paint won’t adhere to the material. Make sure the rope is slightly wider than the gap so you’ll have a tight fit.

Next, pour stain or paint that matches your deck into a bucket, and put the rope in the bucket. Allow it for about an hour so that it reaches the desired color.

After the rope has dried, insert it into one end of the gap and use a flat-head screwdriver to push the rope into the gap until you reach the other end of the board. Use a utility knife to cut the rope’s end and repeat the same procedure to fill in any other gaps.

Deck Crack Filler FAQs

Outdoor Wood Filler for Decks Summary

Wood filler is a necessity in every household and workshop. Finding the best wood filler for decks for your wood repair is always a hassle, but that burden has been lifted off your shoulders with this review.

RTG Wood Repair Epoxy Putty is the top choice when fixing decks with wood filler. But remember, different deck jobs need different fillers.

This review should ease your worries about wood deck filler, doubts, or reservations for any of these products and also guide you to get the perfect wood filler for your job.