Can You Epoxy Over Stained Wood?


There’s nothing quite as pleasurable in life as a well-finished piece of wood which has been beautifully stained, so we understand why you might be concerned as to whether you can now apply epoxy over that surface without ruining it? We’ve got good news for you – you can and what’s more, we’ll show you how too. 

Can you epoxy over stained wood? Short answer? Yes. Longer but more useful answer? Yes, but you need to ensure that the resin is properly compatible with the stained surface – if you don’t test then you risk ruining your work and removing epoxy resin from a large area is no fun at all. 

So, let’s take a look at how epoxy resin works and what you need to know when choosing an epoxy resin and then we’ll see how you can use epoxy resin to seal a wooden surface and what you should do when that surface has been stained. 

Epoxy Resin The Basics: No Degree Required

Epoxy resin for woodwork comes in two parts: a hardening agent and the epoxy resin. When you mix these two parts together, they create a thermosetting (this means it gives off heat) plastic which is highly resistant to chemicals, water, and scratches.

When you work with epoxy the most important thing to pay attention to is the way you prepare the surface, an inadequately prepared surface will not allow a quality bond to form between the epoxy and the wood.

The reaction to form the final product begins when the two parts are mixed but to fully complete (a process known as “curing”) it can take up to 48 hours. The curing speed depends on the product you use, the wood you use and some environmental factors

Choosing Epoxy Resin For Working With Wood

Choosing the right resin for the right job is a touch complicated but in general, you can say:

  1. You use a resin with a low level of viscosity when you want to coat a surface
  2. You use a resin with a high level of viscosity when you make molds or fill holes
  3. You need to think about whether you will use the resin indoors or outdoors

With Or Without UV Protection?

If the look of your resin is important then you will need to consider buying a UV resistant epoxy resin as, otherwise, UV will cause a yellowing of the epoxy resin. 

If you’re going to try and epoxy over stained surfaces in most cases, you will need a UV-resistant epoxy resin

The Big Advantage Of Epoxy Resin When Compared To Polyester Resin

You may also see polyester resins in the hardware store and the big difference (when working with wood) is that epoxy resin doesn’t shrink very much during the curing process. Therefore, you won’t need to apply as many coats, and you will get a higher quality finish. 

The Limit Of Epoxy Resin Thickness

One thing you should be aware of is that there is a limit to the amount of epoxy resin that can be used effectively. A layer that is deeper than 2 centimeters or where the total mass of epoxy used is greater than 20 lbs. is not going to set properly. This is because the epoxy reaction is going to generate so much heat that it dries out the epoxy too quickly and it will leave ugly marks on the surface. 

Epoxy Resin And Scratching 

While, theoretically, epoxy resin is going to be scratch resistant, we’ve found that cheap products often aren’t very scratch resistant. If this is an important quality of your epoxy finish – it’s worth investing a bit more money in the epoxy resin that you buy. This is likely to be true when epoxying over a stained surface. 

How To Seal A Wooden Surface With Epoxy Resin: A 10-Step Process

OK, so, let’s get to the meat of things. If you want to put all that knowledge about epoxy into practice, you’re going to end up sealing a wooden surface and that means you need an easy process to follow. We’ve got you covered here:

  1. Get the surface clean and dry. Your epoxy won’t bond properly with the wood unless it’s completely clean and dry. You also need the surface to be a little rough so that the bond will form effectively. If you have any contaminants on the surface such as oil or grease – they need to be removed before you do the epoxy work. 
  2. Get the substrate dry. The substrate is the layer of wood beneath the surface and you can dry this easily by running a heat gun over the surface of your wood (though please don’t burn the surface, take your time and go easy with this). If you need to remove any oils, now is a good time to do it with some acetone. Then roughen the surface slightly with some sandpaper.
  3. Get rid of any dust you’ve just created. Sanding, by its very nature, creates a bit of wood dust, you don’t want that in the way of the resin’s adhesion and that means you need to clean it up – you can wipe the surface first with a lint-free and slightly solvent dampened cloth after you’ve brought a vacuum to bear on the dust. Once you’ve wiped the surface down, try not to touch it again – your fingerprints will add oils that can spoil the bond.
  4. If you need to keep the resin on the surface and ensure it doesn’t spill – add a barrier around it. We’d recommend some simply adhesive tape though check it’s strong enough to withstand the pressure of liquid epoxy before you do. Once you’ve put your barrier in place, make sure that the surface is flat so you can pour the resin into the barrier.
  5. Then work out how much epoxy you need. There should be guidelines on your bottle to help you work out how much you need but, in our experience, – it’s always best to add a little more (say 10%) than to end up with too little at the end of the job. It’s really stressful trying to mix more epoxy before the stuff you already have has hardened. 
  6. Now mix your epoxy resin with its hardener in the manufacturer’s specified ratio (which is often but not always 1:1). Try not to get any bubbles in the epoxy as this will cause it to appear cloudy when it’s finished. Stir slowly and with purpose. If you intend to add color to the epoxy, now’s the time to add the coloring agent.
  7. Pour the mix into the center of the surface using an outgoing spiral pattern to evenly distribute the resin. You may need to do this a few times to get effective coverage of the surface. Leave it for about 5 minutes before you level the epoxy resin.
  8. Work while the epoxy is liquid. You only have so much time before your epoxy becomes too hard to work with – make sure you keep an eye on the time (check the manufacturer’s label) and ensure you’ve leveled your epoxy resin before it’s hit this hard stage.
  9. You can use a heat gun to remove any bubbles. If there are any bubbles apparent in your resin mixture gently go over them with a heat gun – DO NOT keep the heat gun in one place for too long. Move it around and if necessary, rest for a minute or two before going back. Resin that gets too hot will stay soft forever and if you keep the gun in one place for too long, you might burn the surface. 
  10. To add a second coat – wait for a few hours and then add the second coat. Don’t let the first coat fully cure if you want the second coat to completely bond to the first. 

Can You Epoxy Over Stained Wood?

Yes, it’s perfectly possible to apply epoxy resin over a stained piece of wood

How To Apply Epoxy Resin To Stained Wood

You follow our ten-step process to add epoxy resin to stained wood but before you do so, you should take a small piece and test the epoxy on it. You want to ensure there are no peculiar reactions between the stain and the epoxy – it’s unlikely, given the properties of epoxy, but it’s not impossible. 

If you do find that they’re not very compatible – you can always go and find a different epoxy resin to work with

Conclusion

Can you epoxy over stained wood? Yes, you can. Though it pays just to run a test to ensure that you’re not making a mistake with your choice of epoxy as it can be quite back-breaking to try and put things right after the fact. 

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