Wood care : Use a two-component varnish to protect wood against infiltration
The parts of wood exposed to sea water and weather must be given special attention. They must be properly treated to avoid the risk of infiltration.
Among the treatment products available on the market, the marine varnish Bi-component is the most effective, it offers many advantages. First, it has excellent resistance to moisture. It also has a long service life and can refine any defects on the wood surface. In addition, it offers excellent water resistance and fits perfectly with the wood.
Parts and tools needed:
- Bi-component varnish (base + hardener).
- Abrasive paper (60, 120, 240)
- Chemical mask (or dust mask).
- Brush. (choosing quality brushes is essential)
- Measuring glass and spatula to prepare the varnish.
The first step is to prepare the surface of the wood. Using the sander, sand the wood with 60 grit paper and then with 120 grit paper until a well polished surface is obtained.
The preparation of the varnish must be done according to the manufacturer’s instructions. Be sure to follow the recommended dosage and safety precautions when preparing the mixture.
For optimal wood protection, preferably apply 5 coats of varnish to the surface prepared.
The first coat must be diluted with acetone (30%) to promote the absorption of the resin.
The amount of acetone mixed with the resin should be gradually reduced for the second coat and the 3rd coat (15% dilution).
For the 4th and 5th If you want to apply a layer, it is more practical to use pure resin (without dilution).
It is important to sand the resin after each application with 240 grit sandpaper and to remove dust from the sanded surface with an acetone soaked cloth to ensure good adhesion for the next coat. The operation should be carried out preferably at a temperature between 10 and 25 °C.
Then maintain the varnish regularly!
Besides its aesthetic aspect, varnish is an effective way to protect the wood of your boat against scratches, moisture, and UV rays. You should also know that marine varnishes contain special oils with excellent hydrophobic characteristics such as linseed oil or tung oil. Marine coatings also contain polyurethane resins that offer better protection against UV radiation.
At the slightest deterioration or color change, action must be taken to limit the damage. If the existing varnish shows little damage and adheres well to the wood, then treatment will be relatively easier.
Start by degreasing the varnish surface with a degreaser or denatured alcohol. Then sand with a sander and 280 grit paper. Dust the treated surface well and apply a first diluted coat to help the varnish absorb into the wood. You can apply several coats depending on the level of shine and protection desired. The idea is to “bring the repaired area up to the same level as the rest of the varnish around it.
If the varnish is completely degraded, remove the entire varnished surface with a scraper or a sharp scraper, taking care not to damage the wood with the angles of the tool.
Personally in this kind of case, I use a heat gun to remove all the successive layers of varnish.
You should also know that the preparation of the wood surface is the most important step in the varnish treatment process. In fact, insufficient preparation will limit the fixation of the varnish on the wood and will lead to peeling and cracking in the long run and you will have to start all over again.
Preparation is not the most fun part, but it is extremely important to the final success.
Thoroughly sand or scrape the wood surface and clean well to remove all residues of the old varnish.
Then apply several successive coats of varnish until you reach the desired thickness. Avoid varnishing wood in cold or wet weather as this may affect the quality of the drying and gloss. Also avoid applying varnish on wood exposed to direct sunlight.
Wood maintenance : What you should know
In general, wood maintenance is not difficult, but it requires a lot of patience and commitment. Pay special attention to the preparation of the wood surface and make sure to observe all safety measures regarding the use of chemicals (epoxy resin, varnish…etc.).
Finally, if you lack the necessary skills, don’t try to work on luxurious or very old wood pieces, leave that to the experts! However, you can practice on less important pieces of wood.
If some of you are interested, I will do an article where I will detail step by step the realization of a varnishing project.