Do I need to sand my bus before painting?

In this article, we will answer the following question: Do I need to sand my bus before painting? We will discuss the importance of the sanding step in the process of painting a bus. We will also discuss what to do if you decide not to sand your bus at all. 

Do I need to sand my bus before painting?

Yes, you need to sand your bus before painting. Contrary to what one might think, you should not skip the sanding step when renovating a Skoolie! Indeed, for the new paint to adhere to the support, the latter must be freed of its layer which will prevent adhesion. 

So we scratch the old paint so that the new can sticks better. Without this preparation your new paint may not stick and your efforts would therefore be useless. In short, for a lasting result, sanding the bus before painting is mandatory!

This being said, here are a few must-know tips for properly sanding a bus:

  1. Do not stand in a linear way: Once the preparation is done, all you have to do is get to the heart of the matter! Take some sandpaper and sand the wall which will receive a new paint. It should be known that one does not sand in a linear way but that it is necessary to carry out small circles so that the sanding is uniform. Do not apply too much pressure to avoid sanding some parts but rather rub steadily. 
  1. Don’t settle for just one sandpaper: To achieve optimal sanding, it is recommended to use several sandpapers. First, change your paper as soon as you feel that it hangs less so that you avoid unnecessary efforts. Then go for a medium grain paper and wipe the surface again. You can finally ensure the finishes with a fine grain paper. The association of papers of different grains will ensure a good result.
  1. Don’t forget to dust off: Once the surface is sanded, the job is not entirely finished! It is indeed necessary to dust the surface so that there are no more particles when you apply the new paint. So wipe the surface with a cloth to remove dust. Then all you have to do is paint!

The importance of sanding and cleaning a bus before painting

To facilitate the application of a new paint, we recommend that you sand your school bus walls or ceiling to make it smooth and dust off. This is a very important step because it will allow your support not to have imperfections (blisters, scales, …) and facilitate the installation of an undercoat which will serve as a base for the application of a new one. 

Once your Skoolie is sanded, you need to wash it to make it as clean as possible. Be careful, however, how to proceed because depending on the type of paint that was used to cover your wall, the steps will not be the same.

  • If your school bus has been covered with acrylic paint before, clean it with a sponge dampened with soap and a little water. Proceed in small circular motions while trying not to exert too much pressure on the support.
  • If your school bus has been covered with glycerol paint, clean the entire surface of your support with detergent (count around 1L of water for 50g of detergent). Use a sponge to scrub the entire surface of your wall.

Whatever type of paint you have previously applied, your goal here is to make it compatible with a new paint job and to get rid of any dust or dirt that may have settled on it. Once your support has been washed, all you have to do is let it dry and then apply the new paint.

Applying new paint of a school bus

Before applying the final paint, you can coat your substrate with primer paint. The paint to be used will differ depending on your support: wall or ceiling.

For optimal results and rapid drying, it is customary to paint its support in small layers with a roller and to have an application movement from top to bottom. Use a contouring brush to paint the corners of your mount.

At the very end of the work, when your paint is dry, you can remove the masking tape applied to the edges of windows and electrical outlets.

How do you paint a bus without sanding it?

While we made it clear that we recommend sanding the bus before painting it, you still may choose to skip this step. Before you start, however, make sure you have the right equipment.

Ideally, it is advisable to use sandpaper very lightly on the surface to facilitate the adhesion of the paint. It’s not about sanding, but about touching it. Remember to remove dust with methylated spirits if it is greasy.

Apply your paint to the surfaces to be painted. The roller is recommended to spread the paint well on flat surfaces. Use a paintbrush for more irregular angles and spaces. Stretch the paint well to obtain a smooth result, without blisters or runs.

Let it dry well. If a second coat is necessary, proceed in the same way.

Paint that allows you to paint a bus without sanding generally costs more per gallon than traditional paint. The average prices that are communicated to you may change more or less strongly depending on the brands, models, quantities and places where you buy them.

  • multi-surface paint costs between 25 and 50 dollars per gallon on average,
  • the resin, the most expensive solution, is sold at a minimum price of 100 dollars per gallon,
  • for paint for raw, varnished or painted aluminium, count at least 20 dollars per gallon; this solution remains the most economical,
  • Steel renovation paint will be billed from 30 to 40 dollars per gallon.

What paint should I use to paint a bus without sanding it?

If you want to paint or repaint steel without sanding it, you will need to opt for water-based paint. It is an emulsion or dispersion paint based on water and diluted in water, hence its name. It is ideal for painting unsanded materials. However, you will find that some substrates, especially those already painted or varnished, will need a little surface chipping. It’s not about sanding, it’s about light rubbing to improve grip.

There are several types of water-based paint:

  • Multi-surface paint: Resistant and washable, it clings very well to smooth surfaces, both horizontal and vertical, for a successful and harmonious result without effort.
  • Resin: Perfect for painting surfaces of all kinds without sanding, whether vertical or horizontal, the resin consists of a mixture of a coloured resin with a binder base. Very easily applied with a roller, however, you will need two to three coats for optimal coverage.
  • Paint for raw, varnished or painted steel: This type of paint hangs very well on all types of materials without prior sanding, including those already painted or varnished.  Its peculiarity, however, is that it is only suitable for vertical supports; horizontal surfaces cannot be painted with this type of paint.

Available in a satin or shiny version, it has the advantage of being easily washable (being in the aqueous phase) and of being sufficient on its own. Strong and resistant, it does not need to be followed by finishes. On the other hand, a bad application can lead to the formation of blisters or runs; as the result is not always there, professionals will generally advise you to opt for other paint formulas.

  • Metal renovation paint: Very resistant, this paint has the same characteristics as the paint for raw steel, varnished or painted, with few details. Only available in a satin version, it is easy to wash and can paint all types of metals, as well as splashbacks, tiles and earthenware.

The bottom line

Sanding is an important step that you must take into account to repair all the imperfections before painting a bus. For example, if it presents rust, get rid of it with the help of sandpaper, this step is really simple. Sanding and cleaning the damaged surface of rust is enough because then you will cover and refine this in the painting process.

You may have removed all the rust from the bus. But this one contains some dents. This should also be repaired before applying the paint. Ideally, work on all these repairs so that the paint better seals the results and obtain a bus like new.

Please feel free to get in contact if you have any questions or comments on the content!

FAQ on Do I need to sand my bus before painting?

Do I need to sand my bus before painting?

It is preferable to sand your bus before painting. Sanding and cleaning the damaged surface of rust is enough because then you will cover and refine this in the painting process.

How long does it take to paint a bus?

It can take up to five days to paint a bus. Considering you have to clean, sand, make some repairs, paint one or more coats and retouch it – take it easy and do it properly. 

Can I paint my bus yellow?

Although there is no law to prohibit you to paint your bus yellow, in most states, it is expected to paint your Skoolie a different colour. 

How much does it cost to get a bus painted?

Getting a school bus painted can cost anywhere from $1000 to $3000, depending on the type of paint you choose, the size of the bus, and whether you hire a professional or do it yourself. Here are a few options:

  1. Get the bus painted at a body shop: $2000
  2. Get the bus painted at RVs repair maintenance place: $1600
  3. DIY: $200 to $400 .

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