Rotted Wood Repair with Abatron Epoxy

By Scott Sidler • May 26, 2014

Rotted wood repair
Image Credit: Scott Sidler

You live in an old house? Good! Then you have rotted wood and know the frustration and worries it can cause. When a tree is still alive, water is its best friend, but after we turn that tree into lumber, water is the last thing it needs.

There are lots of products on the market today to patch wood. I listed some of my absolute favorites in this post here:

The 7 Best Products to Patch Wood

But if you are in need of a serious rotted wood repair, then you need a serious product and a structural epoxy is the just what the old house doctor ordered.

Unlike wood filler, structural epoxies don’t just cover up cosmetic issues in wood. They can replace whole sections structural wood elements. So, rather than having to remove some damaged piece of the house, you can simply fill in the damaged portion and move on.

My favorite structural epoxy is Abatron LiquidWood & WoodEpox. This system uses a combination of wood consolidant (LiquidWood) used to strengthen and rejuvenate weak, rotted wood and a filler (WoodEpox) used to fill in missing sections of wood.

Here’s how to work with it:

 

Step #1 Remove the Damaged Wood

rotten wood repair
Step #1 Remove the damaged wood Image Credit: Scott Sidler

The first thing you need to do is assess the extent of the damage. You’ll need to dig out the severely damaged wood. I prefer to remove any wood that is mushy or weak enough to dig out with a screwdriver.  LiquidWood can be used on extremely weak wood to strengthen it and bring it back to life so not all of the rotted wood needs to come out, but anything that is falling out on its own should be removed. Vacuum out the remaining debris and dust so you have a clean area to work with.

If the wood is still wet, it will need to dry out before you begin your repair. Cover it in plastic if you anticipate rain and make sure the sprinklers aren’t the cause of the rot while you’re at it.

Step #2 Prep & Protect

These are some serious compounds you are about to use and once they are in place it is very difficult to remove them (that’s the whole point isn’t it!) Anyway, you’ll want to mask off the work area with plastic and painter’s tape to prevent spills and drips.

Be sure to wear eye protection and nitrile or plastic gloves while handling any of these products. This stuff isn’t like shea butter for your hands. If it gets on your hands, think Chevy Chase in Christmas Vacation with the tree sap episode. Don’t touch without protection.

Have a container of acetone on hand which is the recommended cleaner and solvent for these products.

 

Step #3 Apply LiquidWood

liquidwood application
Step #3 Apply LiquidWood liberally
Image Credit: Scott Sidler

Once everything is dry, it’s time to mix up your epoxy consolidant. LiquidWood is a two part mixture. Part A (resin) and Part B (hardener). These two should be mixed together in a disposable container like a dixie cup or similar in equal parts. (<—Very important!) Mix them thoroughly, or you will have lackluster results.

Let them sit aside for a few minutes to setup. After about 5 minutes, apply the mixture liberally with a disposable chip brush. Once mixed, LiquidWood and WoodEpox both have a working life of about 20-40 minutes depending on weather conditions (shorter working life on hot days, longer on cold days). Don’t get too busy and forget about your mixture!

Depending on the condition of the wood it may need more or less of the consolidant. Apply until the surface is soaked and let it soak in for about 10 minutes before moving to the next step.

 

Step #4 Apply WoodEpox

woodepox application
Step #4 Apply WoodEpox
Image Credit: Scott Sidler

WoodEpox comes in two parts (a hardener and a filler) just like the LiquidWood. You’ll need equal parts of both and then blend them together until you have a uniform color. One is white and the other a tan color. If you see any streaks of color in your mixture, you need to keep mixing.

Once everything is well blended, it’s time to start pressing it into place. Press the mixture firmly into place to fill the missing areas. Press it deeply into the gap to make sure you fill any air holes and have a solid repair. The other important thing to remember is to leave enough epoxy proud of the surface so that when it is ready to sand, you have a smooth, well-blended repair. If you use too little, you won’t have a level surface to sand down to.

 

Step #5 Sand, Prime & Paint

The epoxy will begin hardening immediately and depending on the size of your repair, it will be ready to sand in anywhere from a few hours to a day. Warmer temperatures and bigger repairs cure faster, whereas small repairs in cool weather may take a full day. Below 50°F it may not harden at all so save it for a warmer day.

When it has hardened, sand the surface smooth and apply a coat of primer, then paint your preferred color. That’s it!

Abatron makes a really fantastic product and we keep gallons of the stuff in our shop to repair rotted windows and doors, siding, porch columns, really anything you can imagine. And the great thing about it is that the repairs are permanent. Abatron won’t fall out or fail like Bondo or even water putty. It creates a permanent bond with the wood. When your old house finally gives up the ghost the last piece standing will likely be your Abatron repair.

Here’s an idea of how serious a repair you can complete with LiquidWood & WoodEpox

rotted wood repair
Before
rotted wood repair
After

 

 

 

 

 

 

 

 

 

 

 

Abatron is expensive, but in this case you truly do get what you pay for. If you’re not sure it’s right for you but still want to try some, I’d recommend getting the Abatron 24 oz. Wood Restoration Kit. It has small quantities of all four components and won’t break the bank.

If you have large areas to repair, then it is definitely cost effective to buy the larger 2 gallon WoodEpox & 2 gallon LiquidWood packages.

As always, if you buy through any of my Amazon affiliate links, you’ll get a great price and give The Craftsman Blog a small commission at no extra cost to you.

Happy patching and don’t be afraid of making that rotted wood repair. Let me know how it goes!

 

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153 thoughts on “Rotted Wood Repair with Abatron Epoxy”

  1. How long curing would you recommend before I can start using nails or screws to attach additional wood to replace a very old window sill? I’ve read the directions on WoodEpox and it states it will take 1-3 wks for max curing. If this is the case, would I benefit from using a heat gun to cure it faster? If so how long? Trying to prepare our 1867 windows. Thanks

  2. I am trying to fix splits on the siding of an old house. Hard to find matching siding so better to repair. Splits are difficult to fix because the wood moves relative to each other due to sun and rain. What is the best solution?

  3. What is your suggestion for a termite-eaten beam under my home. It is no longer being damaged because we treated the entire building however, it is one of the major beams with only a 1 1/2 foot crawlspace so as you can tell, practically impossible without removing the floor. I’m hoping that we can just fill the remaining wood with your product.

  4. I prefer Abatron to every other wood filler or rotten wood hardening product I have used. Today I used a disposable Monoject 412 syringe to inject the Liquid Wood into ice pick holes to get deeper into the wood. I think it will produce a stronger repair as the wood was badly damaged. Time will tell. That is my tip for the day and happy patching!

  5. I’m restoring several vintage wood pillars and their other parts (bases, tarus, and capital) and Albatron products were recommended to me by a very well respected, local supplier. I was told to be sure to thoroughly mix the 2 equal parts to the LiquidWood mixture and allow it to set approx 10 minutes. I did both (mix and wait) but the pieces that I coated with the LiquidWood are still very tacky after 4 months. They have been stored inside so temperatures are what we keep our home. Still tacky. Too tacky to do the next step it seems. Is there a way to resolve this?

    1. Kate, I have it run across that and would receive men’s calling Abatron to speak with one of their product specialists. They provide great customer service and if it was a faulty batch or user error they can usually help you sort out the issue.

  6. Hello,
    I was researching a product to repair dry rot on a structural wood member and the engineer mentioned Restor-It since he was familiar with that product. I mentioned Abatron Epoxy, but he was not familar with it. …My question is, how does Abatron Epoxy compare with Restor-It, in regards to holding up to improving or maintaining the structural support characteristics of a structural wood column.

    1. Abatron is a structural epoxy and exceeds the strength of the wood it usually replaces. Check with the manufacturer about specifics but it should do everything you need for structural support.

  7. Do you have a you tube video? I’ve tried to patch with other products but they all fail. I’m no expert either. If I can do it, this product may save me from having to replace the damaged areas of my deck and some $$

  8. I have a big hole to fill in an ant eaten piece of wood. Besides being chewed up and missing, the wood is in pretty good shape… Would I be safe to assume that I would use much less LiquidWood than The WoodEpox? In terms of ordering the product.

  9. Scott, I disagree with your Step 1 — to remove the rotted wood. I’m an architect, and use Liquid Wood frequently to repair historic wood windows and sills. The last thing I’d recommend is removing the rot. Leave it in place. Abatron is formulated to penetrate this stuff, and make it strong as new wood. To do this, one has to make sure the mix penetrates the rotted wood. This can be done by making tiny holes (less than 1/8 inch, and injecting the liquid with a glue syringe. After doing it, test with a tiny probe. If there’s still any softness, do it again. The rot becomes reconsolidated wood/epoxy and is very durable. Saving the original wood fiber this way makes an old window good again. Also, for filler, I dislike Wood Epox, as I find it hard to shape and work with. Instead I mix Liquid Wood with some sawdust, and use that as filler. I find this much easier to smooth out and sand than Wood Epox.

    1. I’ve tried it both ways and I agree that your way is workable too, but I have it more effective to remove the loose wood than to try and consolidate multiple times with loose wood fibers.

  10. Scott, while filling up patches in stages, when shd the liquidwood be applied on the epoxy- when wet or when set?

  11. Scott!! I need help!! I have a 150+ year old house. I just had a small portion of wall (concrete up to ground level, will be stone to sill) and the outside basement stairs replaced. The area above where the stone wall will be has rot damage, roughly about 5 inches wide at the widest by maybe 18 inches long by up to 4 inches deep. My contractor will be removing all the loose stuff, spraying it with 3-M wood hardener and then filling the void with mortar as he replaces the stone wall. (The damage is on the BOTTOM of the sill) I think he is planning on doing this tomorrow!! Is this ok or should I really have started researching much earlier??!! Would this product work for filling this void better than mortar?? And can it be applied to a workspace that is overhead??!!! I do hope that you might see this very shortly, if not like I said, my house is over 150 years old, there will still be plenty of sill repairs needed!!! Thanks!!! Dana.

    1. Edit, got out the tape measure when I got home. Damaged area is a little bit larger than I thought it was. Sill beam is about 11 1/2 x 7 1/2, I do not know what type of wood, probably a hard wood?? Damage for the most part is long ago bug damage/powder post beetles?? Damage at its largest is about 3 feet long, about 6 inches at its widest and about 3 inches at its deepest. Damage is also from about center of bottom of beam to outside edge. Right now I have my contractor on hold. IF this product will work best in guessing I may have to apply it in layers?? Thanks Scott!!
      Dana Bennett.

    2. Dana, hope I’m not too late, but mortar is not an acceptable materials for patching wood. WoodEpox is a structural epoxy and would likely work we’ll in this application.

      1. Great!! Thank you Scott!! It’s not too late!!! I can get Abatron Liquid Wood and Abatron Wood Epox locally and will be picking up the 2 gallon size of each kit. I do have several questions before I use this product though as I really can’t afford to waste any of it, so I need to understand how to use it properly!! Shall I ask them here or can you direct me somewhere if there is a better way or place to ask them?? Thanks again Scott!!
        Dana Bennett.

        1. An amateur speaking here but… use of the stuff is really no different from any other wood filler. Scrape out any badly rotted wood – unlike other wood consolidators you don’t need to scrape down to clean wood, but you can’t rely on this stuff penetrating more than 1/4-1/2 inch at the surface. Treat with the liquid primer. Put some of the putty at the bottom of the opening, stuff most of the opening with solid pieces of wood. You need to have enough putty to bond the wood filler pieces together into a structurally rigid unit, but there is no sense in wasting fairly expensive epoxy to fill a big hole. Once you have most of the hole filled in finish it off with a top layer of putty. Be sure to build an “overburden” that you can then plane/sand/shape down to the original surface. Not sure if it is required, but if you have a large volume to fill in I would do it in layers, otherwise contraction of the putty as it hardens may cause it to crack. You do need to way 24 hrs between applications of layers to make sure that each layer is fully cured.

          1. One more thing – given your description of the situation, 2 gals of the liquid consolidator sounds like a drastic overkill. Remember, this is a surface treatment, not a bulk filler, so it goes much farther.

        2. Boyan, described the process fairly well. Follow the instructions on this post for how to apply. For the LiquidWood you can drill holes in the remaining wood every 1″ or so and inject the LiquidWood into the wood to strengthen it which will allow it penetrate deeper and work better.
          Also, you can do the patch in one sitting and don’t have to do layers, but keep in mind that the bigger the portion of WoodEpox you use the faster it cures. So if you need more working time then you can do it in several different batches, but ALWAYS prime between batches with LiquidWood.

          1. Wonderful!! Thank you Scott and Boyan!! I hadn’t even thought of using smaller pieces of wood to help fill the void using less epoxy!! And I am glad to also know that I can apply it in layers!! I’m not the quickest at doing things so yes, more working time and smaller amounts to begin with will be best for me at this stage!! The one issue that I may have trouble with though is that the bad area is on the bottom face of the sill!! I do have the room to get to it easily but wondering how difficult it may be to get either the liquid wood to soak in rather than just run off or be able to have the epoxy stay where it is put?? As far as the Epoxy I have read others suggesting to place some screws in the area to be filled and that screws will help give the epoxy a little bit more to hang onto, sounds reasonable to me??!! Also read someone who likened the mixed/activated epoxy to like a play dough consistency and you can place and work it by hand?? Too bad I can’t post/share a picture of the void here!! Would it be ok to do that on your Facebook page under readers posts??
            Thanks once again!! Dana Bennett.

  12. Hi Scott, Thanks for all this great info. I have a pine sub floor in my kitchen that has some deep gouges and cracks in it. I would like to use this to repair the floor, then sand it flush and then prime and paint it. I will need to recut lines between some of the boards after using this product. Will I be able to recut the lines when it is dry? Thanks.

  13. We just bought a 1908 bungalow in Tampa. We have removed all the lath and plaster. We have quite a bit of termite damage. The piers, beams, and floor joists have all been repaired. However, many of the studs and top plates have too much termite damage to make me comfortable. I plan to install new studs along side to damaged ones. Can I use this to repair the top plates? Thank you, any advise would be appreciated.

    1. Barry, Abatron WoodEpox is a structural epoxy so if it used correctly then it can rebuild structural elements of any building. Just follow the manufacturer’s instructions to a “T” and you should be covered.

  14. I have a damaged oak church pew with a corner damaged on the aisle side. Oak. missing piece is 1″ wide, 6″ height, 1/4″ deep at the front and tapers to the back.
    Would one of the products you discuss repair and hold well to the original oak.
    The damage is not from a split off piece. It appears to be ground down from movement of a scaffold or ladder during painting.

  15. Very interesting site, I have a picket fence with a lot of hairline cracks and
    a few cracks about an 1/8″ wide, one horizontal 2×4 with about an 1″ square 1/2″ deep rot, and a 1/2″ x 1″ slot I made for an old latch, I would like to fill these before repainting, Which one of the products would you recommend. Thanks you…John

  16. We have 1980’s garage doors, made of a heavy wood-like product, but it’s not actually wood. Would this product bond to my doors? Could I get away with taping off areas and skim-coating with it to created raised/molded surfaces that resemble the wood panels of a carriage door?

  17. FYI, uncured LiquidWood cleans up pretty effortlessly with water – no acetone required. I would not use water around the treated area, but for tool cleanup as well as runoff along walls and beams this works perfectly. In fact, if you clean up your brushes with water you can reuse them – assuming that you let them dry out completely.

  18. I have an area where a roof meets a vertical wall on the exterior and where a window exists. The specific location doesn’t allow for flashing which would be the ideal solution, however we’ve discovered a leak and some rotted wood. Would the abatron product work well in this area, I intend to use it to repair the rotted area but also form an angled area to shed water away. So the question is, is the resulting epoxy resin water proof – ie you could form a small bowl out of it and it wouldn’t leak if you filled it with water? The area in question doesn’t need to be sanded or painted, its discretely located.

    Great site by the way, just came across it.

    1. I don’t know if the epoxy is completely water tight. Never tried the bowl trick but now it sounds fun! I’m wondering how you have a vertical wall against a roof that doesn’t allow flashing though. That’s the first rule of that type of construction. What is the layout?

  19. I have dug out some rot that goes clear through a step and, to keep it from falling through, I need something to back up the epoxy filler while it is setting. In the picture it looks like you used a sponge for that purpose on the column base. It seems like a good idea because it will expand into the space. Is that true?

    1. You could use a sponge, some wadded up paper, a little spray foam might work too. Whatever you use it should leave enough space for a decent thickness of epoxy (maybe 1/2″ minimum depth).

  20. Hi Scott,
    I need to fix up my giant 1913 wooden door on my colonial revival row house in Brooklyn. It has a 4 foot crack down the center panel that goes all the way through the door. Also there are holes from a previous doorknocker or two.
    I’ve used ordinary Elmer’s wood putty a couple times just to keep the wind out but was a temporary fix and it keeps cracking. I’d also like to sand this door down and go with a more natural pale color. Is there a clear product that can fill in these voids and not be so noticeable? Thanks so much!

  21. Where can I buy this product Abaton wood Epoxy 2 part filler.? Canadian Tire,home depot Rona store ? I live in Richmond Vancouver , canada

      1. Likewise, I ordered from Amazon, their smallest kit at first to check it out, then the mid-sized kit, which I’m now using, and think it will be enough for current needs. Package insert had instructions and sticker for LogHomeMaintenanceAndSupply.com, (303)288-0066, which might be another option.

  22. I’ve started repairing some outside window sills on an old farmhouse, and under filled, now needing to add another level of the wood epox to come above level and then sand to smooth/more level. I tried just sticking another layer of the wood epox onto what I’d already applied, and it didn’t stick. I’m guessing I need to re-apply the Liquid wood as a sort of primer, but don’t find anything addressing that issue on your or Abatron’s page expensive as it is, I don’t want to screw this up again, as I wasted a bit of the wood epox. :-(. Can you please advise me? Thanks!

  23. I’m in the process of painting a wooden porch floor on a 100 year-old house. The boards are perfectly sound except for the ends. The last 3 to 4 inches are somewhat soft and cracked and missing some wood around the nails. Would you recommend Abatron LiquidWood and WoodEpox to fix this or another method?
    Thanks

  24. Help, I repaired and upstairs window sill with a Wood Epox kit. I mixed Am and B Liquid and painted the dug out hole of about 3 Inches and somehow it all ran down the side of my outside wall which is siding. It is a about 6 panels of siding with four brown streaks. I tried mineral spirits and a wire brush and had no results. It had already hardened by the time I realized what had happened. I can reach a hairdryer out the window but I have no idea what to do. So far so good in patching the rotten wood though.

  25. The trim beneath my front windows consists of two boards sistered together. In addition to using the Woodepox to hid the gap, I’d like to spread a thin layer on top. How thin can I safely go?

    1. Linda, stay away from skin coating wood because the moisture inside the wood will need to migrate out and will eventually push the epoxy filler off the surface. Fill voids and cracks yes, skim coat no.

  26. I used Bondo to repair wood on the threshold of a door and the fumes are horrible and have persisted. Does Abatron LiquidWood have the same toxic odor?

    1. The Abatron products have an almost unnoticeable odor. I’ve used Bondo in the past and you’re right that the odor is awful and the performance isn’t nearly as good as Abatron.

  27. I have an outdoor shed – the door front crossbraces and roof to ground corner wood pieces – 1x6s and 1x4s – have rotted in places. On the doors, where they join at angles in the corners, and the 2 sides of the shed front, about 2-3 ft up from the bottom. Should I just use the hardener and WoodEpox to remold that 2-3 ft part and paint? Or would it be better to just cut that wood out and have new wood there? On the doors, the inside corners are hard to get to, so I just want to use the liquid hardener then paint – not using the WoodEpox to fill in. Can that be done – just paint over the liquid hardener? Also, I recently primed with a latex primer on most of the shed except for the parts that need repair. Can/should I use a real good oil top coat? I painted it 15 yrs ago but don’t remember if I used oil or latex. It’s held up incredibly well – only failing where the rotted wood is. Will use the best outdoor/exterior paint I can get so it’ll last another 15 – 20 yrs. Looking at Sherwin-Williams and Benjamin Moore – any preference between the two, or some other recommendation? BTW, I know you can put oil over latex, but not latex over oil.

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