Painting or staining in all areas of DIY can be a tricky proposition and in many cases not such a straight forward task. We often get asked about painting different materials and what types of paint to use for preparation and finishing. In this article, we will go over these concerns and hopefully put you on the right track to creating a successful paint job.
To get the best out of any type of painting project, preparation is the key to a great finish. Too many times people paint over different surfaces with inadequate preparation. While any new paint on any surface looks great once it is freshly done, the fact is, without proper preparation the paint may not stick and in a very short time, the coating will fail.
Not a great scenario when you’ve spent hours applying the paint, only to have to redo it yourself, or worse, having to pay someone to do it right.
What Types of Paint And Stains for DIY
There are only three types of paint or stain that the DIYer is likely to use. These are;
- Water-based paints – are often referred to as Acrylic or Latex paint.
- Oil-based paints
- Water-based finishes and Stains
- Oil-based stains and wood finishes
Water-Based Paints
Water-based acrylic paints (sometimes referred to as latex) are the most common types of paint used fin the Industry, domestic housing, and DIY finishes. Acrylic paints are water-soluble meaning they can be cleaned up in water.
Acrylic paints are fast drying so are ideal for any project that required several coats, whereas the job can be completed in one day if required. Typical drying time for Acrylic paint is between 2 and 4 hours, depending on weather conditions.
Acrylic paints are available for all-purpose primers, interior and exterior wall finish in matt, semigloss and full gloss grades. Also, Acrylic paint can be used on interior and exterior doors and trim by using water-based enamels. Flat and low sheen finishes are best for painting walls, both interior, and exterior. This type of low sheen will not show any imperfections as would when using a high gloss finish.
Where To Use Water-Based Paints
Water-based Acrylics are suitable for most paint applications. Using the correct undercoat you can paint interior, exterior, timber, galvanized iron, steel, plywood and much more. A good quality water-based exterior house paint is pretty well guaranteed for 10 – 15 years.
Interior paints for walls, doors, and trim are also best done with water-based paint. The only thing to watch is that for doors and trim you should be using a water-based enamel.
Oil-Based Paints
Oil Based paints have been around since the early 15th century and are renown for its hardwearing properties. These types of paint are much slower drying than water-based paints with drying times typically around 8 hours and re-coat times of 16 hours or more depending on the type of paint. The film thickness of oils-based paints will have a bearing on the drying times whereas thinner coats will dry quicker.
More suited in the painting of steel structures such as bridges, structural work, industrial machinery, Cars, and motorcycle painting. Also, the painting of timber that is exposed to harsh outdoor conditions. Ideal for DIY work where hard wearing is required, and for protection where corrosion is likely.
As Oil-based paint drys slowly the gloss finish will be more pronounced than water paint. The paint, being an enamel, is also more resistant to scratching and marking as opposed to water-based types of paint.
Decking Finishes.
Sealing a deck also requires proper preparation techniques. Always prepare using a cleaner such as oxalic acid first to help remove any tannins in the wood. The type of finish you use will have the preparation method written on the can. For a good life of the deck, I suggest you follow the instructions to the letter.
Oil-based or water-based for deck finishes.
Some people will use nothing but oil-based finishes on a deck, whether thy last longer depends on the weather and exposure to the elements. Undercover a deck finish will last many times longer than those that are exposed to sun, rain or snow. I have used both in all conditions and both are as good as each other.
I do feel that oil-based products may have the edge in extreme weather exposure. However, all deck finishes require regular maintenance and re-oiling. For exposed areas this should be done every six months, undercover decks at least once a year. So looking at it in the way that you need to maintain a deck regardless of the finish, it makes sense to use water-based finishes as the are quick to use and quick to dry.
Oil-Based Stains.
Typically, for DIY purposes, these types of stain are used on timber decks and woodworking projects. Thinning and clean up requires the use of mineral turpentine or thinners specific to the type of product being used. Oil-based stains are more likely to retain their color longer as opposed to water-based finishes.
Water-Based Stains And Finishes
Also becoming more common in the use of timber decking finishes as opposed to the traditional oil-based finishes. Water-based decking oil is easy to apply and will generally last well. Most manufacturers will give a form of guarantee, but regular maintenance is the key to long-lasting finishes.
The best way to apply water-based decking oil is to use sheepskin or synthetic application pads. These make quick work of oiling a deck. Tip, if using oil-based finishes, instead of cleaning the applicator simply drop it into the can of leftover finish. You can then just wring it out when you next re-seal the deck. You can also apply water-based oil using a paint sprayer.
What Paint To Use On Concrete.
Painting concrete varies depending upon the type of surface. Painting block or rendered concrete walls is best done using Acrylic water-based exterior house paint. Most good quality exterior paints require no priming and can be painted directly to the surface.
For new concrete better results can be done by thinning the paint for the first coat. As concrete materials are porous, this allows good penetration into the concrete surface, Depending on the job two coats is necessary but three may be required.
Preparation, clean or treat any mold or dirt from the surface. Heavy mold may require chemical treatments. Finally, best to wash down using a water blaster.
Application – best applied using a wide, heavy Knapp roller or by using an airless paint sprayer. There are now specific rollers available just for concrete.
How To Paint a Garage floor.
Garage floors require different treatments than walls. First, you will need to determine if the floor already has had a treatment applied. Obviously, previous paint is visible, however, some garage floors are treated with a clear finish when the concrete was laid.
To test the floor for previous finishes, simply drip some water on to the surface. If the surface water ‘beads’ then you have a product previously applied, If the water soaks in straight away then you are good to go and can proceed in your preparation.
Proper Garage Floor preparation is a must
Should the surface have a previous product applied then the surface needs to be ground off. Yes, a right pain in the butt! But your paint may not stick to an unknown finish. I believe surface grinders can be hired from an industrial hire store.
Should the surface be previously painted the all you need to do is remove any flaking paint, and then treat any bare areas. Unless the paint had been applied to a surface that should have been ground off first! You may want to test any bare spots using the water test.
Once the surface is clean from any previous treatments, you first need to wash down the surface using a power washer. If any oils are present then use a detergent wash. Once clean and dry you must apply an acid wash to etch the concrete surface. Pressure wash off the etch, wait 24 hours for the surface is dry then apply two coats of garage floor paint using a concrete roller.
Test for moisture – Tape down a square of cling film to the concrete floor for 30 minutes, if when lifted the film has beads of moisture then you need to wait for a day longer for the concrete to dry.
Most garage floor paints are oil-based. You will also find the appropriate acid wash product to use written on the paint tins directions. Different manufacturers use their own brand of concrete etch.
What Types Of Paint to Use on Metal
Generally, metal finishes require some kind of primer first. For new steel, cold galvanizing paint is ideal followed by either enamel or acrylic topcoats. Always clean any contaminants like grease or oil, wire brush or sand back before painting.
Rusted steel needs to be taken back to sound metal by wire brushing or grinding. The rust should then be treated using a rust converter solution. Next, you will use a primer and two topcoats to finish with. Most good paint companies have there own specific set of primers ant topcoat systems for rusted steel.
Aluminum, brass, copper all require an etch primer first, this can be followed with a general-purpose primer and the two topcoats.
Which Paint To Use On MDF
MDF and particle board are easy to paint, just apply a general-purpose sealer/primer and any type of topcoat using water-based enamel or water-based acrylic interior wall paint. For a harder wearing surface use oil-based enamel for your top coatsMDF and particle board is not suitable for outdoor use so any interior topcoat is ok.
For painting kitchen cabinets see our article here.
What Types Of Paint To Use On;
- PVC – Water-based exterior house paint, no need for primer
- Kitchen and bathroom tiles – Tile paint is available in various colors, prime with tile paint primer
- Interior walls – Acrylic interior paint, low sheen, new wallboard, and plaster require a primer-sealer undercoat
- Exterior walls and timber – exterior acrylic house paint, most modern house paints are self-priming.
- Bare exterior trim – prime using an oil-based primer, topcoat with exterior acrylic.
- Galvanised metal,- prime with galvanized metal primer, topcoat with Acrylic house paint.
I am a blog content researcher and writer for habitatdiy.com