" " wisno wood furniture finishing: Lacquer thinner

Wednesday, September 28, 2011

Lacquer thinner

Lacquer thinner is the thinner that is special designed to thin the lacquer. Lacquer is finishing a material that is dry and forming hard film layer by evaporation his thinner. According to this definition the lacquer are: nitrocellulose coating, acrylic clear coat, butyrate clear coat, vinyl material and the other 1 component coating materials. While the other coating that is dry film by chemical reactions such as: Polyurethane, Acid curing, Precatalyzed and Polyester are not included in the lacquer category.
The main function of the lacquer thinner is to reduce the viscosity of the lacquer so that it can be applied easier. The original lacquer is a viscous material that can not be applied by spray gun. Spray gun as the main equipment for lacquer application only works well to the materials with low viscosity (about 14 second with Nk # 2 viscosity cup). The application by brush also can not give good layer when the viscosity of the material is too thick.
Instead of reducing the viscosity the lacquer thinner also work to give some specific characters at the mixture. The lacquer thinner is also used to make better flow and adjust the drying time of the lacquer.
Lacquer thinner does not leave at the film resulted; it will evaporate in the drying process. Lacquer thinner is just a “vehicle” that deliver the lacquer to his destination without form the film layer. Although it just a vehicle, but the lacquer thinner play important role in the finishing process. Many finishing problems occur because are caused by inappropriate thinner, on the other hand, there are many adjustment can be made in the lacquer application by select and modify the lacquer thinner.

How lacquer thinner is made.

Lacquer thinner is made by a mixture of several solvents. The composition of the lacquer thinner could be varied from one supplier to another.  The composition of lacquer thinner is highly dependent to the type and ingredient of lacquer that will reduced. Since the composition of the lacquer is different from one manufacturer the other, then the composition of the lacquer thinner is also varied form one manufacturer to the others.
Basically the lacquer thinner is made of three kind of material, the solvent, latent solvent and diluent.

  • Solvent
Solvent is a main material in the thinner. Solvent solve the lacquer and reduce the viscosity. The material for solvent depends on the material in the lacquer mix. The examples of solvent for the nitrocellulose lacquer are: buthyl acetate, acetone, methyl ethyl ketone, methyl amyl ketone.
  • Latent solvent
Latent solvent is a solvent work to increase the solubility when it is mixed with a solvent. Examples of latent solvent for the lacquer thinner are: isopropyl alcohol and isobuthyl butanol.
  • Diluent.
The diluent is the filler for the thinner. It can not dissolve the lacquer but he solves and mixes each other with the solvent. This material is added to the lacquer thinner to reduce the price of lacquer thinner.
  • Additive materials
Into the lacquer thinner is often added some additive materials to build some specific properties of the lacquer thinner. The additive is added to adjust the properties to the lacquer mixed. For example:  to make better flow, to adjust the drying time and some other specific reason. A special additive is needed to improve the resistance of the mix at the electrostatic lacquer.

Tips on using lacquer thinner

  • Use lacquer thinner according to the lacquer materials used.
The mixture of lacquer thinner is specific depending on ingredients in the lacquer mixture. Meanwhile the material inside the lacquer is different from one brand to the other. Every supplier has his thinner according to its lacquer.  It is recommended to use the lacquer thinner from the same supplier with the lacquer. The thinner should be the best suit since it is already made according the lacquer
  • Do some test and experiment before use the thinner in the large scale.
Some time we have to modify the lacquer thinners or make our own composition of lacquer thinner for various reasons. The prices and quality are the reason why we need to adjust the lacquer thinner. The lacquer thinner from the same lacquer supplier should be the best suit material, but the environmental conditions and the application method force us to modify the lacquer thinner.
When we decide to change the lacquer thinner we must do some test first before use it in the large volume application. Mix some material with the thinner and see the results. View the physical properties and looked of mixtures such as: the clarity, solubility, and viscosity of the mixture. Then we still need to test it by applied the mixture on some piece of wood panel. See the result such as the drying time, the flow, the appearance, etc. After we are confident that the mix is ​​working well, then we can start to use the material on a larger scale.

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