Polyurethane is a proper finishing formula for different types of wooden structures. It offers protection to the surfaces, keeping them safe from impacts and scratches. If you can apply polyurethane well, it will give your surface a beautiful glossy appearance. What if you have a surface with glossy paint, Can You Put Polyurethane Over High Gloss Paint?
Yes, you can apply a polyurethane finish to any paint or stain provided the painted surface is completely dry and applied correctly. The paints include different types of semigloss paints- latex, acrylic, and oil-based.
If you have a surface containing glossy paint and looking to give it a final finish, polyurethane should be up there with other finishes that you might consider for this project. Ensure that you apply two thin coats of polyurethane, giving enough drying time between the coats.
How to Apply Polyurethane Over Paint
Overall, you need to apply one or two layers of polyurethane to a painted surface if you are looking to give it extra protection and beauty. If yellowing of polyurethane worries you then consider using water-based polyurethanes.
NOTE: Overall, Oil-based polyurethane evens out to give a smoother finish compared to the water-based one. Water-based polyurethane, on the other hand, dries way faster than the oil-based one.
Feel free to apply polyurethane over any paint type. Even so, ensure that the painted surface is clean and prepared adequately. Below are the key steps that you need to observe even as you look to polyurethane over your painted surface:
If you are looking to polyurethane over a freshly painted surface, you need to allow the paint to cure first before applying the poly finish. Different paints have different curing times, so ensure that you check yours from the manufacturer’s label. On average, paints take about 7 days to cure.
Step One: Clean the Painted You Want to Apply Polyurethane
If the surface was painted a while back and not fresh, you should start by cleaning to remove grease or any form of imperfection using a strong detergent solution. One such is trisodium phosphate, mix 1/2 cup of this compound with one gallon of warm water and use a rag to scrub the surface. The cleaning action deglosses the finish and helps keep it clean. A clean surface ensures a proper adhesion between the surface and the formula.
Step Two: Scuffing the Cleaned Surface
Once you have cleaned the surface, let it dry then use 120-grit sandpaper to etch the surface. So why is that? The idea here is to flatten the sheen slightly without necessarily causing deep scratches that might end up showing once your polyurethane finish cures. You can use any method that works for you to scuff the surface. You can use your hands or even wood sander. In case you are working on a large area like a wooden floor, it would be best and easy if you are using a floor buffer and a 120-grit sanding screen. Wipe the sanding dust away with a damp rag or tack cloth.
Step Three: Choose Your Method of Application.
The best way to apply both oil- or water-based polyurethane is by the use of a brush or spray. Much as you can apply this formula using a roller, I’d advise that you avoid using it. Rollers will leave bubbles that cures with the polyurethane to give a less impressive look.
For the best result, avoid thinning the polyurethane before you spray. Usually, you will find the polyurethane thin enough for application by spraying. Adding thinner to the formula makes it run.
Step Four: Apply One Layer the Sand Lightly
After applying the first thin layer of polyurethane, allow it to dry as per the manufacturer’s recommendation then use 120-grit sandpaper to scuff it lightly. Scuffing helps with the removal of small dust particles. Additionally, it flattens any bubbles that might have formed in the finish.
Step Five: Applying the Second Coat.
Usually, two coats of polyurethane are enough to do the job. More than that might not be necessary whatsoever. After applying the second layer, allow it to dry as per the recommendation by the manufacturer. 24 hours is enough time, after which you can walk over your surface. Ensure that you are walking on the surface with clean bare feet.
Can I Put High Gloss Polyurethane Over Semi-gloss?
Yes, you can. However, if the gloss is less than a day old, I’d advise that you do a light sanding to etch the surface so that the subsequent coat adheres. In case the surface is shiny, and you don’t like it, you can use a 4 ought (0000) steel wool to rub it down. Rubbing down helps remove the shine without leaving scratches on the surface.
NOTE: Rubbing down is very different from sanding, and you should not confuse the two or consider sanding as an alternative. If you intend to apply another coat, allow the first one to dry, sand lightly, then apply the second coat.
How Do I Get a High Gloss Polyurethane Finish?
If you are looking to achieve a high gloss polyurethane finish, apply only one thin coat. Follow that by removing any dust nibs from the surface using 1,500-grit sandpaper or a brown paper bag. Conclude by a polishing pad. Use the pad to buff the finish to a high shine with automotive paste wax.
Watch the video below on how to apply polyurethane:
What Type of Paint Can You Appy Over a Polyurethane Treated Surface?
You can use any paint on a polyurethane treated surface provided the surface is pretreated and ready to accept the paint. Paints do not stick properly to a poorly prepared polyurethane surface.
Here are the different types of paints and polyurethane surfaces they best fit:
Acrylic Latex Paint
Acrylic latex paint is the perfect formula for primed external polyurethane treated structures that do not encounter great duress such as foot traffic.
Oil-based Enamel Paint
Oil-based enamels are the best if you are looking for polyurethane treated surfaces that will experience a lot of duress and increased traffic levels.
I’d understand when you want to give your high gloss painted surfaces a different finish when it reaches a point. It could be because you want to try something new or give your surface-enhanced protection and beauty. There are so many finished out there in the market that you can apply over your painted surface, what if you are thinking of using a poly finish?
Can You Put Polyurethane Over High Gloss Paint?
Yes, it is okay to apply polyurethane over all kinds of paints. It would be best if you undertook the procedural approaches highlighted earlier in this article to ensure that you get the best finish possible. Ensure you sand your surface slightly before application. Also, avoid rollers to minimize the chance of bubbling.
I hope you found this post helpful if you have a question or opinion regarding the topic, please drop it in the comment section below.