While putting polyurethane over another surface or paint, you should think about it. Because polyurethane doesn’t adhere to any surface. But if the polyurethane adheres to a surface, it makes the surface smooth and durable. Moreover, polyurethane is one of the most effective coatings.
So, you might be confused about whether you can put polyurethane over mineral oil or not. You have to know about the properties and requirements of mineral oil before applying polyurethane. Moreover, knowing about the consequences of using polyurethane over mineral oil is essential. So, let’s see details about it.
Can I put polyurethane over mineral oil?
You should not put polyurethane over mineral oil. Because polyurethane will not sit over mineral oil properly. Mineral oil is a non-drying oil. This oil doesn’t dry or cure completely. So, the polyurethane will not adhere to the oil surface and will chip off from the surface.
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However, polyurethane can be of different types. Different polyurethanes have different properties. You have to know their properties in detail before applying them to an oil surface. So, let’s see whether you can put this polyurethane over mineral oil or not.
Minwax polyurethane:
Minwax polyurethane is not suitable to put on mineral oil. Because mineral oil is a non-drying oil. If you put Minwax polyurethane on mineral oil, the polyurethane will not adhere to the surface.
You might think that Minwax polyurethane will sit over the surface if you keep it for a long time. But the coating will not be effective no matter how much time you keep the coating. Mineral oil doesn’t dry and cure. So, Minwax polyurethane will not be compatible with the oil surface.
Water-based polyurethane:
Water-based polyurethane will also not stick to the mineral oil surface. Generally, water-based polyurethane can stick to the oil surface if the surface is completely dried and cured. So, water-based polyurethane can be used on oil-based paints sometimes. This can be possible when the oil-based paint is completely dried and cured.
But water-based polyurethane will not work in this way. Because mineral oil is not like oil-based paints. This oil will not dry and cure. So, water-based polyurethane will not stick to the mineral oil surface.
Oil-based polyurethane:
Polyurethane will not stick to mineral oil whether the polyurethane is oil or water-based. Because the first requirement of the polyurethane to adhere to a surface is dryness. If the underlying surface is not dried or cured, polyurethane will not adhere to the surface.
Mineral oil is such oil that doesn’t dry or cures. So, oil-based polyurethane will also not stick to the mineral oil surface.
3 reasons why you cannot put polyurethane over mineral oil
Now that you know you can’t put polyurethane over mineral oil, you might want to know the reasons. Let’s see why you can’t apply polyurethane over mineral oil.
Non-drying oil:
Mineral oil is a non-drying oil. It will not dry or cure. So, the surface of mineral oil will never be suitable to use polyurethane on it. Because polyurethane requires a dried and cured surface. Otherwise, this coating will not stick to the surface.
Polyurethane might stick to oil-based paints because these paints dry and cure. But when it comes to mineral oil, polyurethane is not suitable. No matter how long you allow the curing time, mineral oil will not dry well. That’s why you can’t put polyurethane over mineral oil.
Non-compatible:
Polyurethane and mineral oil are not compatible with each other. You might know that two different materials should be compatible to coat one over another. But being a non-drying oil, mineral oil is not a good surface for polyurethane.
So, polyurethane will not be compatible and will not sit over the mineral oil. These two materials lack compatibility.
Non-durable:
Polyurethane over mineral oil will not be durable since polyurethane doesn’t sit over the oil properly. If you still apply the coating over the mineral oil, the polyurethane will chip off quickly.
The main reason for this lacking of durability is the mineral oil. This oil doesn’t dry. So, polyurethane will remain non-durable on the mineral oil surface.
What finish can I put over mineral oil?
Now that you know you can’t put polyurethane over mineral oil, you might be confused about the suitable one. It becomes tough to coat over mineral oil. But you can do it with other finishes. So, let’s see what finish you can put over mineral oil.
Dewaxed shellac:
Dewaxed shellac can be applied over mineral oil. You might know that mineral oil never dies. That’s why most coatings are not suitable to apply to mineral oil. But when you put dewaxed shellac over mineral oil, it will stick to the surface.
Generally, dewaxed shellac is a very sticky material. It sticks to almost every surface. Even it can stick to the mineral oil surface. So, you can coat dewaxed shellac over mineral oil. But as a finish, dewaxed shellac will not be the best. You can use it as a primer and then apply polyurethane.
Waterlox Original Tung oil:
You can also use Waterlox original tung oil to give a finishing over mineral oil. Most of the finishes will not stick to the mineral oil surface. So, you can use this oil. This tung oil will provide protection to the mineral oil surface. Moreover, it will make the surface water-resistant.
Oil-based stain:
You can use an oil-based stain over mineral oil. Generally, mineral oil doesn’t allow other finishes to stick to it. For example, a water-based stain or finish will not adhere to a mineral oil surface. But if you can use an oil-based stain, it will stay on the mineral oil surface.
Can you finish wood with mineral oil?
Yes, you can finish wood with mineral oil. Generally, people often use mineral oil to finish wood. Most commonly, people use mineral oil as a finish for butcher block countertops and kitchen accessories. Moreover, it can also be used on wooden baby toys, cutting boards, etc.
However, a mineral oil finish is famous for using the wood material. Because mineral oil has some advantages for use on wood. This oil makes wood surface protected and water-resistant. Moreover, this oil is stable and doesn’t get spoiled at high temperatures.
Besides, mineral oil provides a clear finish and makes the wood materials’ appearance attractive. Mineral oil also resists wood from staining. For all these advantages, mineral oil is used to finish wood.
But if you want to add another coating over the mineral oil, you can’t apply. You have to sand off the mineral oil first; then, you can apply another coating to it. But most times, mineral oil is used as a final coating to provide a shiny appearance.
How do you seal mineral oil?
You might have already known that you can’t put any random coating over mineral oil. So, you have to use an appropriate way of sealing mineral oil. Let’s see how you can seal mineral oil.
Cleaning the surface:
First, you have to clean the surface from dust and dirt. You should also ensure that the surface doesn’t contain grease and residue. An unclean surface will not soak the mineral oil and other coatings.
Applying mineral oil:
Then you can apply mineral oil to the surface. You have to wipe off the excess after the surface soaks up the mineral oil.
Applying primer:
Then you have to apply a primer. You can use unwaxed shellac on the mineral oil surface. It will help the coating to stick to the mineral oil surface.
Applying polyurethane:
Finally, you can apply polyurethane over the primer or dewaxed shellac. It will stick to the shellac surface and also seal the mineral oil surface.
Final Thoughts
You can’t put polyurethane coating over mineral oil surfaces. Because mineral oil doesn’t dry and cure. So, on the mineral oil surface, polyurethane will not stick. You have to use a primer before applying polyurethane. Otherwise, you have to use a different finish to coat over mineral oil.