Year five is finally here and I will be showing you the results of my testing of five of the most popular wood filler and epoxy products on the market today. This will be the final year since after five years the chunk of cypress wood I used has suffered so much rot that the wood fillers are all that’s left! These wood fillers and epoxies have been exposed to the harsh Florida weather to help you find the best wood fillers on the shelf today this test has been a very telling study of how they each perform.
In this last year you should have a good sense of what products you can use effectively and which you should stay away from. The five products I tested here are Abatron WoodEpox, MH Ready Patch, JB Weld KwikWood, Minwax Wood Filler, Minwax High Performance Wood Filler. I chose these 5 because they represent a wide variety of formulations. WoodEpox is a structural wood epoxy for both large and small patches, Ready Patch a spackle for wood uses, KwikWood a simple two-part fast cure patching epoxy for small areas, Minwax Wood Filler is your standard multi purpose water based wood filler, and the Minwax High Performance Wood Filler is a styrene/resin filler similar to Bondo.
The Test Conditions
To make this test as scientific as possible, I’ve outlined the rules and conditions below.
I drilled out a 1/2″ deep hole with rough edges to try to simulate a chipped or gouged board and filled the hole above the surface with filler, after which, the patches were sanded level. Here are the conditions:
- The wood fillers and epoxies were all mixed and applied according to the manufacturer’s specifications.
- The wood use was a piece of 1 1/2″ thick rough sawn cypress.
- The sample was laid horizontally outside.
- The wood and fillers/epoxies received no pre-treatment, primer or paint other than WoodEpox which was used as per the manufacturer’s instructions with LiquidWood prior to application.
All the fillers and epoxies were applied and left to cure/dry until they were ready to sand smooth. I ranked the fillers in my previous post regarding ease of application, ease of sanding, and drying time.
The sample board was left outside uncovered laying horizontally. I will qualify this by saying that all of these manufacturer’s recommend that their products be primed and painted even though I have left all of them without any primer or paint.
This test will clearly show different results than if I had painted the repairs, but I decided that seeing how a product would stand up to unprotected exposure and on a horizontal surface would show results more quickly and accurately as to which product has the greatest staying power.
Product Info: 2-part epoxy filler
Test Results: After the first couple years the WoodEpox settled in and really hasn’t changed much at all. The same hairline cracks exist with no structural issues. It is still solidly attached and will not budge from the hole. A strong performer in my book especially since this can work for both structural reconstruction of pieces and easy wood filling like this.
Product Info: Spackling Compound
Test Results: It hung on till the end, but just by the skin of its chinny-chin-chin. The first year it suffered the most serious shrinkage of all the fillers and that was even in the first month. This year the cracking and separation around the edges got so severe that when I check the stability of the patch I could easily pry it out with a finger nail. Maybe I’d use this for a nail hole for gouges or anything larger this is clearly not a good choice.
Product Info: 2-part epoxy filler
Test Results: Still a solid patch that won’t budge under my extremely scientific “finger-nail prybar” the KwikWood has proved a solid performer over these last five years. I was especially impressed with the lack of mildew or algae growth on the patch. A great easy to use patch that will definitely stand the test of time. The only downfall is that it comes in small quantities so making larger patches is not feasible.
Minwax Wood Filler
Product Info: Water-based wood filler
Test Results: This was the total surprise and dark horse. I never thought this would last more than a couple years, but it has stayed strong just like the expensive epoxies. Of course, this is not a structural filler and I wouldn’t dream of rebuilding structural members or using it where holding power for screws or other fasteners is critical, but for filling small to medium size holes affordably this is now my go to product.
Minwax High Performance Wood Filler
Product Info: 2-part styrene/resin filler
Test Results: This Bondo style wood filler performed admirably and passed the finger nail test even with some real effort behind it. It did develop some of the most significant perimeter cracks of all the filler besides the Ready Patch which leads me to believe that over the long haul it will have a shorter lifespan due to water getting behind the patch, but for 5 years it is still solidly intact. It would likely not look as attractive under paint due to the cracking, but so far so good.
This has been a fun test for me to see these products perform in real life and in my climate. The result you get may be different from what I have found since no one’s climate is exactly the same, but the general results are very applicable I think. I encourage you to do some of your own testing in your area on anything you want to know the long term performance of.
Don’t blindly trust the manufacturers, do your own due diligence whether it’s paint, wood filler, wood species, glazing putty or whatever matters most to you. If you have some test results from your own projects feel free to share them in the comments below so we can all learn and DIY better!
If you have found this test helpful consider purchasing any of these wood fillers by clicking any of the links on their names through my Amazon affiliate links to help support the blog. It costs you nothing, Amazon just gives me a little commission for sending you their way.
Founder & Editor-in-Chief
I love old houses, working with my hands, and teaching others the excitment of doing it yourself! Everything is teachable if you only give it the chance.
12 thoughts on “Wood Filler & Epoxy Test (Year 5)”
Late to the party but this was a fine episode. Let me add that I’m making repairs to a courtyard fence that involves filling screw holes and subsequently redrilling to hang a gate. (My new “treated” fence post seems a bit soft to hold the screws in place, especially after a hard rain.) Wood epoxy seems to be the best product from all I’ve read and viewed. While “Bondo” might be great for indoor repairs, it doesn’t appear good for exterior work. Any thoughts or comments would be welcome.
I have long cracks up to 1/2 wide in heart pine floor joints in an upstairs hallway which gets walked on. I think it flexes such that my previous attempts at filling pop out. Any suggestions for that?
Amazing test and thanks for sharing. I have had a box of wood epox in the basement that was previously used and I believe it maybe 10 years old. I was desperate to get going on some small repairs and tried mixing a small amount up the night before to see if it would still harden as it said it has a shelf life of I believe one year. It hardened very well so I went ahead with it based on not wanting to throw an expensive product in the garbage. I used it and am now getting ready to prime and paint but I guess time will tell if it holds up over the years, if not then I will just go at it with fresh wood repair and is easy since it is ground level repair work on our porch.
Thanks again for great info!
I really like the abatron product the resin and the epox. I’ve had great results with both. Just wish it wasn’t so expensive.
Which would you prefer for an old deck railing with lots of long cracks?
Long thin cracks would probably be minwqx wood fillet unless they are structural.
Thank you so much for the 5 year update. This update came just at the right time. My house is 90 years old & I need to make some repairs. I always look forward to you newsletter & blog.
So glad the timing was right!
So as a restoration contractor and having this information site for the public and other contractors I’m wondering how come there is no mention of the use of fungicide to protect the wood you are
Restoring. Iv written you to provide you with information on our Cobra rods or CUb both
A combination of copper and borate that protects telephone poles and can protect your readers projects. Wood damage from rot or other wood destroying organisms top more than 6 BILLION dollars as noted by the National Pest Management Associations and this amount continues to grow due to the accelerated growth lumber we have to build with and due to the milling process woods sits outside to be rained on and where the rot spores are initiated into the lumber. This is the reason it us critical to treat so when you are restoring wood critical to treat as well.
Once wood has spores they are in there for good.
We additionally have a products to test for Rod spores as well and will indicate the presence of rot and moisture content of your wood
We have a superior 2 part epoxy system and with additional product to create texture to match existing finishes at http://www.wizzardrepairproducts.com
Iv sent you email in order that’s I can introduce you to myself and our superior products but have not heard from you
Thank you for your study. I am using the epoxy style PC Woody. Do not know over 5 years though…
Thanks for all.
PC Woody, Abitron, and JB Weld all do well in our the freezing and thawing and hot humid summers in North Dakota.
Hi. Thanks for reviewing these products; it is super helpful. I am a homeowner who mistakenly mounted a very heavy TV on the wall and now wants to move it lower to get a better viewing angle. The mount is affixed to the studs in my basement wall with 1/4 wide, 3in long lag bolts. When I move it, there will be two new holes in each stud about 6in below the current ones. Do I need to use wood fill to fill the old holes so that the structural integrity of the studs remains after I move the TV down? If so, which would you recommend? Thanks again!