How to paint a steel boat
Painting a steel boat is not difficult. It is only important to follow the right steps. In this blog you will read all tips & tricks on how to paint a steel boat with Epifanes. You can also watch the instruction video’s on how to apply a one-component paint system or a two-component paint system.
Step 1: How do you determine the condition of a paint system?
The Epifanes website contains the button “let’s get to work”. In the second folder “building a perfect paint or varnish system step-by-step” you can see how to apply a full paint system from scratch. In practice, most paint jobs consist of maintenance coats only. For maintenance it is important to determine the condition of the existing paint system.
A full well applied Epifanes paint system can last for years or even more than a decade, but it is important that the system is applied correctly. There are roughly 3 conditions of an existing paint system.
The worst state is where there is a lot of rust and/or paint is flaking off. In this situation the paint system is too far damaged and should be removed completely. Difficult places to reach can be de-rusted with Epifanes Rust Remover. Apply a new paint system including primer and topcoat.
The best-case scenario is where only discolouration and/or loss of gloss is noticed. Degrease the surface with Epifanes Spraythinner for Paint and Varnish and sand with grit 220. Now you only have to apply maintenance coats. For longevity always apply 2 coats.
However, most boats have both situations at the same time. Remove all rust patches that are locally on the surface. Start priming these places with a thinned primer. Sand the whole surface afterwards and apply the final topcoats on the complete hull.
Step 2: What type of paint is on my boat?
It is important to know what type of paint has been applied on your steel boat. A two-component poly-urethane paint can only be applied if the existing paint system is two-component based. A one-component yacht paint, i.e. Epifanes Mono-urethane and Epifanes Yacht Enamel can be applied on all previously painted surfaces.
You can simply test what type of paint is on your boat. This is done by placing an Acetone saturated with Acetone lint free cloth on the surface for 10 minutes. If the paint starts to wrinkle, you are facing a one-component paint which can only be re-painted with a single pack paint. You have a two-component paint system when the finish remains intact. Now you can apply either a one- or a two-component paint.
Step 3: How do you choose between a one- or two-component paint system?
A one-component paint such as Epifanes Mono-urethane and Epifanes Yacht Enamel dries and cures through drying additives that react with air. This type of paint provides easy application and flows out beautifully under various conditions. The elasticity makes this type of paint suited for working structures. The maintenance with a single pack product is far easier than with a two-component paint.
A two-component Poly-urethane paint is chemically drying and curing. This paint is tougher and stronger than the one-component paint, but the application is more difficult and demands specific working conditions.
A two component paint system can only be applied when the boat is inside, the temperature is above 12°C and a relative air humidity is max. 70%. A one component paint system is a better option when you cannot get these working conditions.
Step 4: Materials needed
Determine the type of paint and colour. Calculate the required amount of paint using the Epifanes app. Note that the paint calculations are mentioned for one coat only!
On the bottom of each can you can find a 6-digit batch number. Try to use the same batch for painting a specific surface. If this is not possible, mix both batches together. This to avoid small potential colour differences.
Also ensure to have enough and the correct Epifanes thinners and cleaners at hand. Do not forget necessary tools for the job, i.e. brushes, rollers, masking tape, good quality abrasive paper, etc. and mind your personal safety (protective gloves and clothes, mouth cap, safety goggles). Saving money on material will increase the chance of failure.
Step 5: Surface preparation
A thorough surface preparation is time consuming. In case of bare steel, start degreasing with Epifanes Cleaning Solvent or Acetone
Continue by sanding the steel surface with grit 60. After sanding, degrease once more with Epifanes Cleaning Solvent.
Old paint layers can be degreased with Epifanes Spraythinner for P&V. This is the spraythinner for single pack paints. Do not use aggressive two-component thinners or acetone for cleaning old paint layers. They can affect the paint system. Change (paper) towels regularly. Sand the old coats thoroughly with grit 220-240.
Step 6: Application of the primer (Go directly to step 7 if you don’t need to apply a primer)
Epifanes has multiple primers available. The most common one-component primer is Epifanes Multi Marine Primer. This fast-drying universal primer provides excellent rust prevention inside and outside above the waterline.
Epifanes Epoxy Primer and the Epifanes Epoxy HB Coat are epoxy based primers. These two-component primers are very tough and give the best long-term protection.
For deep penetration into the steel surface, it is important to thin the first coat by 25%. Apply at least 3 primer coats for sufficient rust protection. After curing, it is important to sand each primer coat thoroughly with grit 180 before applying a topcoat. Sanding will create good intercoat adhesion between primer coats and topcoat. A lack of sanding will lead to bad adhesion and might even destroy final coats.
Step 7: Undercoat
An undercoat is not absolutely necessary in a new paint system. It is always better to apply either an additional primer coat or an additional topcoat.
However undercoats have the benefit of being easier to sand and give a smoother base than an epoxy based primer. You can also use an undercoat when changing the colour of the boat.
Step 8: Choosing the correct paint.
Earlier the difference between one and two component paints was covered. Underneath we describe the difference between some paints.
1. Epifanes Yacht Enamel
This traditional one-component yacht enamel is very suitable for painting above the waterline. This classic alkyd paint flows very well and can be applied by anyone. In addition, it is available in 45 traditional colours.
2. Epifanes Mono-Urethane Yacht Paint
This modern one-component high gloss yacht paint is very suitable for various surfaces above the waterline. Due to its urethane base, it is much harder and more durable than Epifanes Yacht Enamel. The paint can be used indoors and outdoors from 5 degrees Celsius. Mono-urethane yacht paint is available in 24 modern colours. Special mixes, i.e. RAL colours can also be obtained through your local Epifanes dealer. This paint is very suitable for every boat, but also suitable for use in and around the house.
3. Epifanes Satin Finish and Epifanes Flatblack
Standard Satin Finish is available in white. On request also available in all other colours. As the name suggests, this paint has a pleasant semigloss finish. This makes it very suitable for interior use, but it can also be used outside if the surface has first been previously painted with a high gloss paint.
Epifanes Enamel Flatblack is a very matte black paint. This can be used both inside and outside. This matte paint with 10% gloss is great for a modern look. In addition, it can also be used on stairs, railings or facades.
4. Epifanes Poly-Urethane Yacht Paint
This two-component paint is standard available in 24 modern shades. It is also possible to order special mixes , i.e. RAL colours, in both gloss and satin.
With the correct primer, this is the strongest topcoat, but also the more demanding paint for the processor. With this yachtpaint a protective mask should be worn during processing.
Step 6: Planning
Planning is essential for a good final result. Make a paint schedule that is doable under current working conditions. Drying times increase when it is colder. So always take this information into account when you make a schedule.
On bare steel, the first (25% thinned) primer coat should be applied as soon as possible to seal the steel against moisture coming in and to protect the surface for rust. If this is not done, you have to sand again to remove fly rust.
Step 7: Take care of a potential setback.
Even if all preparations have been made and the planning is more than adequate, bear in mind that something could go wrong. Do not be put off by this, but try to solve the problem immediately. This prevents you from doing unnecessary work. It would be even more annoying if the paint detaches from the substrate because you have not solved the problem. Then it will only take even more time.
Step 8: Enjoy painting!
Preparing and painting takes time and energy. Still, a painting job can make you feel relaxed. Especially when the job is done, the final result can make you feel good and proud. If you follow the above steps properly, you will definitely achieve a top result!