I remember finding a great deal on a live edge slab – maple wood – that was just perfect. I immediately purchased it and when I got home was excited to work with it. Upon making the first cut with my saw, I realized that there was noticeable moisture still in the wood. Immediately going through my mind was “can I still use this today?” Maybe you have a similar experience…
The big question is whether or not wet or damp wood can be used with epoxy? The short answer is no – although there are exceptions to this and types of epoxy that could do it, you don’t want to risk an entire project due to certain amounts of moisture in the wood. Ideally, you will purchase or check wood to make sure it is down to about 6-8% moisture content (MC) before making anything intended for indoor use.
Although this 6-8% is a standard among many furniture makers and kiln dryers – below we will examine exactly what this means and why we may or may not follow this rule.
Negative Consequences of Applying Epoxy to Wet Wood
Ruining the Epoxy Cure:
This is the most likely and the most common issue when applying your epoxy to wet wood. The chemical reactions that take place between the two parts of the epoxy are well-calculated. When moisture, wet wood, and who-knows-what is introduced into this, it can cause the epoxy to cure improperly.
The Wood Can Change Shape:
This is also a serious issue that can ruin the whole project. If you aren’t covering the piece in its entirety, wet wood is still highly likely to change. When it dries it will shrink, this is possible to crack and distort the epoxy. It could also warp, causing your entire piece to be no longer level. The wood changing is something that will happen as it dries unless it is kept in a controlled environment.
Is it Ever a Good Idea to Epoxy Wet Wood?
For a furniture piece, no. You don’t want to compromise the integrity of the piece just to have it done a few days or weeks earlier. If this is a boat, a pier, or another submerged (or frequently submerged) thing, then yes there are epoxies that are made for this specific purpose. For more on that, I would suggest looking up boating guides that talk about epoxy.
If it is not truly “wet” as much as lightly damp, check out the rest of the furniture in your house. There is potential in tropical climates, that you the wood is going to be under lots of humidity. In this case, if the wood is not going to be completely covered by the epoxy, allowing it to be the natural moisture amount may be a good idea to avoid having the wood expand when it is exposed to the normal air.
How do I Know That My Wood is Dry Enough to Apply Epoxy?
Likely in a home shop, you won’t have an exact or perfect way of measuring. However there are definitely tools that can help you out. First off, buy kiln-dried wood, and if storing, store it in a dry area (use a dehumidifier if necessary). Ideally, you would invest a small amount into a handheld MC reader like this one. Even though they are often 1-2% off, that is a whole lot better than trying to eyeball it and having your project go to waste later on.
How can I Dry Out My Wood at Home?
If you cut your own wood, have a log out back, or just have a damp piece of wood you want to work with, follow these steps.
- When cutting, make sure to do it as soon as you can to allow more air to reach the wood.
- Cut it thicker than needed. As mentioned above, wood shrinks as it dries, so make sure to leave a bit of leeway when cutting fresh wood.
- Add weight to it. The wood has potential to warp and change, stacking or interlaying on the wood can assist in maintaining the shape and integrity.
- If it is very wet, cover the ends of the wood. This is the most porous section and therefore looses and gains moisture fastest. This can lead to splits in the wood.
- Add heat. A small heater or a strong lightbulb in the drying room/area can help add heat slowly to keep the wood from drying out too fast.
- Check the moisture content regularly. You want to control the speed and stop adding heat as needed. Using the MC reader will help you know exactly where you’re at in the process.
There are many other small things, adding fans, dehumidifying, etc… but doing the above should be more than enough to dry a few slabs in your home. Make sure to allow it time, you don’t want to rush the process and end up with split wood.
Here are some related questions.
Can I Apply Epoxy to Wood With the Bark Still On?
You can apply epoxy to a slab of wood with the bark still on, but should be aware that it is prone to falling off. When doing this, make sure the bark that is there is still sturdy. If it is, apply the epoxy across the entire slab, coving the bark, as soon as it is dry, do it on the other side so that the entire piece of wood, bark and all, is covered completely by a casing of epoxy. This will ensure that the bark does not fall off as easily. Make sure to note that bark can absorb more epoxy than other areas of the wood, so double check and pour extra coats as needed.
Can I Apply Epoxy to Epoxy That is Still Wet?
Of course! I would suggest only applying after it has had a few hours to cure. A good test is to push on it with a fingernail or something small and similarly sharp. If it leaves a mark but does not have a “liquid” texture, more of a “putty” you are able to pour the next layer.