Possibly the most commonly asked question with epoxy is whether or not it will adhere to different surfaces. As a woodworker, staining the wood can give it a desired look very easily – but this is more difficult to do with epoxy resin.
Epoxy does adhere to stained wood, usually within 24 – 48 hours. If you are going to sand or plane down the project, however, you may end up removing some of the stain and needing to stain it again. Staining the wood after can be a better way to work with epoxy and stain if this is the case.
There is no hard and set rule when it comes to staining before or after (or at all) when working with epoxy. There are different scenarios that would make more sense, and less work, to stain at particular times throughout the project, however. Here is a guide to help you know what to do as well as some things to keep in mind for this process.
Flood Coat of Epoxy
A flood coat (also known as a top coat) of epoxy is when you pour a standard epoxy, usually ⅛” – ¼” over your project to give it a clear, glasslike finish. This is popular for bar tables, bar tops, coffee tables, and other projects like this. It leaves the wood looking great underneath while providing a very strong layer of protection.
When applying a flood coat of epoxy, you are able to apply the stain prior to the pour, as the stained wood will not need to be altered with sanding or planing after this process. Even if you are to sand, you will not likely reach the wood after the flood coat so your stain will remain intact.
River of Epoxy
If you are doing a more technical pour, like a river of epoxy between two pieces of wood, you will want to consider doing the staining differently than the flood coat. Often when doing a river pour, you will either sand or plane or both. In this case, the top of the wood will not retain the stain after the pour.
In the case of an epoxy river, I would suggest staining the edges of the wood (where the epoxy will adhere) if it is necessary. Otherwise, it is best to wait until after the pour to stain so that any sanding and planing does not ruin the stain work.
Are there Benefits to Staining Under Epoxy?
While there seems to be no negative side effects of staining under epoxy in most situations, there could actually be a benefit to doing this. Of course, the main reason to stain is to achieve the color wood you are looking for, however I noticed on a flood coat that there was also another benefit.
The stain on the end grain of the wood almost acted like a sealer. End grain often soaks up epoxy and leaves the piece needing a second coat, but when I used the stain it ended up helping the epoxy not soak into the wood as much.
This is probably not the case all the time, and will require more testing on my end. Some stains will definitely have a stronger sealing effect depending on the base of the stain.
Things to be Aware of When Epoxying Over Stained Wood
There are a couple things you will want to be aware of before making your first pour with epoxy on stain. These could change the way you approach staining and pouring, and could save you an issue of not getting the bond that you need.
Be Cautious with Oil-Based Stains
The jury still seems to be out on whether or not oil-based stains will allow epoxy to adhere to them. If you check Facebook groups you will hear they repel epoxy, however this study seems to show that some of them do allow epoxy to adhere.
In general, I would suggest just sticking to water-based stains. I am going to do some testing of my own with different oil-based stains to see if there is a common issue with them or if it depends more on the flood coat and cure time.
Check How Your Wood Will Look Wet
One thing not everyone considers before pouring is the fact that the epoxy darkens wood naturally. If you are staining to get a darker look to your wood, you should try to see how it will look without stain.
To do this, take a small amount of rubbing alcohol on a rag and wipe it into the wood. Alcohol dries fast so you won’t have to worry about the moisture content added to the wood. This will give you an idea of the look of your wood once the epoxy is coating it.
Staining wood can add an element to your project that gives it a beauty and a personality that you cannot always find in a piece of wood available to you. Staining over the wood with a water-based stain will allow the epoxy to fully adhere to the wood and seal it, without any risk. If you are going to stain the wood for a river table or a non-flood coat product, I would suggest staining after the pour so you aren’t sanding or planing away the stain and wasting valuable time and resources.