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Alkyd Coatings and Marine or Underwater Applications

Posted by Kevin Hughes | Oct 25, 2018 9:31:39 AM

 

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If you are thinking about using Alkyd coatings for your marine applications, it is best to do as much research as possible. It can be a bit confusing if you do not have the correct information. The reason you would potentially use this type of coating is to decrease the time that it takes for oil paints to dry. To accomplish this, drying modifiers were included to establish larger molecules. It still does not dry as fast as other types of coatings. However by drying slower, it helps the application make the surface as even and level as possible.

What is an Alkyd Coating?

Alkyd is the results of the combination of acid and alcohol, and is made from the distillation response connecting dibasic acids, polyols and fatty acids. Some of these fatty acids include coconut, linseed, safflower, soybean, sunflower and tall oils (which is made from a vegetable material oil). Since Alkyd is partly made from a renewable source, it means a more affordable cost for you.

Alkyd resins are created using three key processes, which are:

  • Fatty Acid (a one-step process)
  • Monoglyceride (a two-step process)
  • Acidolysis (a two-step process)

Of course, the success of job that you need Alkyd coating for will depend on the right mixture combination. You will have different mixture combinations for exterior, interior, underground and underwater jobs. Alkyd is made to go on over a suitable primer or undercoat to be able to protect the chosen surface. Some of the modifications of Alkyd resins for commercial purposes are phenolic, polyamide, silicone, urethane and vinylated.

Some of the drawbacks to this type of coating is that it is not impervious against acids or alkalis and it is not as environmentally friendly as other options, but the advantages can outweigh the disadvantages.

Some of the advantages of Alkyd coatings include:

  • Greater bonding
  • Resistant to moisture
  • Non-flammable
  • Prevents corrosion for up to five years
  • Can be used on areas that run at a high temperature
  • Flexibility
  • Cost of the coating is lower than many others

Some areas of marine application that alkyd coatings can be used on are:

  • Boat Hulls and decking
  • Bridges
  • Steel
  • Tanks
  • Wood

Choosing the Right Underwater Application

Even though we have discussed Alkyds in detail and established that they are good for moisture resistance in marine applications, that does not mean it is your best option for all underwater uses. Depending on the type of underwater need you have, such as boats; ships, pools, decking, bridges, buildings, oil platforms or piping - you will need to find the right type of coating that will work best. Many factors can be at play for each of these projects.

When it comes to total immersion, underwater epoxy coatings seem to be the better fit. An epoxy coating consists of one part epoxy resin and one part hardener. To determine the hardened portion of the coating, you will need to factor for the surface that you will be applying it to. For example, the hull of a boat. When you have two separate containers (two part epoxy), one being the resin and the other being the hardener, care will need to be taken to combine the two together just before application to get the strongest result.

With the use of epoxy coatings and resins you will be able to apply them in the water, which is not the case when you are applying alkyd coatings. This can be very useful when needing to repair your item that you are unable to take out of the water.

Polyurethane coatings are also another good choice due to its diverse range of coverage. It is a polymer that helps to protect the surface of whatever it is applied to, and is erosion resistant. Polyurethane is easy to work with, and it goes on over the surface without harming it. It is also not combustible. I most cases, there is no extra step needed during the curing process.

As you can see there are other options when it comes to marine applications. You will need to make sure to choose the right one for your needs. Many knowledgeable companies know just what your project needs and can get you going in the right direction, so do not hesitate to ask for help if needed.

Topics: Waterproofing

Written by Kevin Hughes

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