This post is a guide on painting marine primer on your boat. We have recently published several articles on boat painting. These are aimed to give you an overview of what’s involved in painting a boat and how we go about it. There is lots of information on the prep work, such as boat paint stripping and how to use marine filler. If you are attempting to paint your boat partially or completely by yourself, please read the previous articles before painting marine primer.
Painting Marine Primer – Before You Begin Painting
When we are painting marine primer, we make sure to get the prep work right. All of the old paint will be removed beforehand. We follow best practices and usually strip the whole boat back to steel. The new paint will only be as strong as the material we paint it on to. Painting over old paint coats is never a good idea. This might at first seem like it will help protect the boat from the weather and corrosion, but you will soon see the rust coming back. The paint will crack and peel within months and you will have to start all over again. Doing it the right way means your boat paint will last for up to 10 years. The Floating Boatyard team never cut corners when it comes to preparing the boat for painting.
Cleaning The Surface
Once all the prep work is complete, you need to clean the surface before painting marine primer. Cleaning the boat will allow the primer to properly stick. You should catch all of the old paint with a dust extractor and dust sheets during the prep work. Any residual paint dust can be brushed and hoovered up. Make sure none of it goes in the water. Paint is very toxic to aquatic life. It is also illegal to pollute the waterways with paint.
When all the boat is free of dirt and dust, it can be wiped down. We use disposable paper towels for this. We apply white spirit and wipe the entire boat clean. Special care is taken in corners and hard to reach areas. Most of the surplus white spirit left on the boat will evaporate and any residual traces will not affect the next stage of preparing the boat for painting marine primer.
Before painting marine primer, it helps to kill and seal of any residual corrosion. Fertan is often used for this and is an adequate rust converter. Some Boat Painters prefer using Vactan. This is self sealing and acts as a primer. At the Floating Boatyard, we prefer to use Owatrol. Seeping into the steel and any left over corrosion, Owatrol Oil is a perfect pre-coat before painting marine primer. It is also a very good as an additive for conditioning the paint. It further increases the anti corrosive properties of the primer. We always apply a need coat of Owatrol Oil before painting marine primer. This allows the oil to seep into all the nooks and crannies your boat.
This boat has been fully stripped of old paint and treated with Owatrol Oil. It is ready for painting with marine primer.
Painting Marine Primer – How To Apply It
Marine primer can be applied like any other paint. It is however important to think ahead. The boat painters at the Floating Boatyard always brush out any paint coats. Brushing out the paint is mostly done in direction of the rain water flow. Painting marine primer with a roller only, or not brushing out in the right direction will lead to problems later on. Brushing out in the correct way will encourage and rainwater to run off the boat. Brushing out the primer coat in the same direction will add to this effect and will make for an even and streak free finish in the following paint coats.
We also consider other factors such as the temperature and dew point. This will tell us if it is the right time to paint the primer and how much paint conditioner we want to use. The amount of paint conditioner used is a to a large extent a personal preference of the boat painter. Dew point are important to make sure to paint holds and lasts. We always check the manufacturer’s data sheets and never paint below the dew point.
One of our bilge painting projects after painting marine primer.
After The Painting
It is important to get the steps after painting the primer on your boat right. We allow the primer to dry for 16 hours and always apply at least two coats. It is important to check the manufacturer’s data sheet before work begins. These will detail the exact drying times needed. We also make sure that the marine primer coat stays dry before painting undercoat. Primer is not designed to repeal rain water and absorbs moisture. This is often not visible in the primer. Applying undercoat over damp will cause problems and the paint job will likely be ruined or not last as long as it could have. We always keep the primer dry and aim to carry on with the subsequent coats is soon as the last coat is dry.
If you have any questions about painting marine primer or would like to get in touch for a quote, please ring 07886 388 689, or email us.