Stainless steel or galvanized steel are materials that do not accept any paint, and if they do, after a short time the paint peels, cracks or peels.
Usually these pieces, when painted or in some color, because they put them in different “tubs” with acids and other products, to anodize the material and give it one or the other finish.
But if in your case you have a virgin and want to paint it, even if it is a heavy paint material, it is not impossible and we can achieve a great result, as we will see in this article with the steps and materials needed to see how to paint steel, stainless or galvanized step by step.
Stainless steel or galvanized paint materials
- Medium grain sandpaper which you can buy here. (Manual block or grinding discs P320 if using an electric or pneumatic grinder).
- A fine-grained sandpaper sponge that you can buy here.
- Polyurethane primer
- Polyurethane enamel.
- Polyurethane solvent.
- Brush, pore-free roller for hand painting or spray gun equipment and compressor for spray painting.
One or the other metal is usually painted with enamels, because these are products that have higher adhesion, thickness and resistance.
But inside the enamel there are some more suitable for one type of surface than others.
In this case, we will use polyurethane enamel to paint stainless or galvanized steel, which is one of the hardest and best anchored enamels that can exist.
We will also apply a primer before applying the enamel, and the primer will also be polyurethane.
You can buy these products wherever you want.
I work a lot with one of the Montó brands and I will just recommend it.
The Montón paint company has a polyurethane enamel in its catalog called Acripol, which is one of the best enamels I have ever tried. In addition, along with the two-component enamel, it also has its own primer called Impripol.
Both Acripol enamel and its Impripol primer are two-component.
That is, on the one hand we have paint, and on the other a hardener or catalyst that must be mixed with paint to dry and harden.
The mixture of these products, although everything is stated on the bottle, is 1/4.
This means that for every 4 parts of the paint we have to add 1 catalyst.
Imagine using 500 ml of polyurethane enamel to paint steel. In this case you need to add 125 ml of catalyst.
The same thing happens with primer. If you are going to use 500 ml of primer, it must contain 125 ml of catalyst.
While this may sound a bit confusing, don’t worry because if you’re going to buy paint, if, for example, you ask for a pound of polyurethane enamel, the clerk will give you exactly the right amount of catalyst.
So go to the store and just ask for Acripol and Impripol and they will give you accurate measurements.
Well, with that said, let’s take a look at the steps we’ll follow to properly paint steel.
How to paint stainless or galvanized steel step by step
Step One: Sand the surface
To grind it, we can do it with a medium grinding block or an electric or pneumatic grinder with P320 grinding wheels.
You have to “hurt” the surface. It’s a material that doesn’t drink very well, and if we don’t, it may not have the necessary adhesion.
So, without exaggeration, we need to grind the entire surface perfectly.
As we grind the sand, we will see the surface begin to be marked with final stripes. We have to leave the whole surface like this. Of course, just the surface, don’t go over the sanding so that all the streaks are then noticed when applying the paint.
The second step after grinding the steel is cleaning.
Step Two: Clean the surface
We blow or remove all dust from the sanding, and then clean the surface with a universal degreaser or any basic cleaner you have at home.
After grinding and cleaning the steel, we move on to the third step, which is applying the primer.
Step 3: Apply a primer
To apply the primer, we must first mix the paint, as I already mentioned.
So, open the paint bottle and the catalyst bottle and mix them in a 1/4 ratio.
Stir well to make the mixture homogeneous.
Add 5% polyurethane solvent to this mixture, which will make application easier. Although not required, it is highly recommended.
Once it is well removed, it is time to apply the primer.
It is applied as if it were a common color. Or a brush and roller without pores, which leaves no hairs or traces, or a gun and compressor equipment.
Apply the primer well over the entire surface, distributing all the primer well.
We don’t have to cover it from obligations. Simply spread all the primer well on the surface without leaving too much product anywhere.
If after applying the first coat of primer we see that it is not well covered, we give it a second. Of course, respecting the drying time between the hands.
Once the entire surface is properly covered with a primer, let it dry and succeed, we move on to the next step.
If you are going to apply two coats of primer, do not mix the entire primer with the catalyst, because when you go to apply the second coat, after waiting at least 6 hours for the first coat to dry, the primer will already become hard on the catalyst and will be useless.
So, imagine buying 500 ml of primer. My advice is to divide it into two parts: 250 ml + 250 ml.
In the first layer, use 250 ml and add the catalyst to the paint. If you have to give it a second coat after that, you still have another 250 ml that you have not catalyzed and are therefore in good condition.
This is very important. As soon as we mix the catalyst with the paint, we will have a few hours to apply the product because it hardens quickly and is unusable. And so it is with both the primer and the paint.
So do not mix any paint or primer with the catalyst. Just mix what you will use in that hand.
Step 4: Sand the primer
Now that we have a dry primer, we take a fine-grained sponge and gently run it all over the surface to remove any dirt that may have remained when applying the primer, then clean the surface again to remove any dust that may have come out of this smooth sanding.
The way the sandpaper passes must be very smooth, without causing damage. Simply remove impurities such as dust or dirt stains that may be found on the surface so that it is smooth to the touch.
That is, if you run your hand over the base surface and it feels smooth and smooth, no additional sanding is required.
Step 5: Apply polyurethane enamel
Now that we have the steel cracked and clean, we can only apply Acripol polyurethane. That is, the color in the selected color.
The method of applying the paint is exactly the same as what we did with the primer.
We give it layers until it perfectly covers the entire surface, respecting the drying time between layers.
Also, between hands and hands, we sand gently, as we did with the primer, so that there are no impurities and the surface is perfectly smooth and well painted.
And voila, we already have well-painted steel. If we do, we will have no problems in the future.
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