Polyester Resin Coating Finish

The term polyester is quite well-known in the finishing world. Polyester coating is used in the finishing industry as coating material to coat the products that require a thick film layer and maximum protection. (You can visit our previous article: polyester coating for wood finishing.) Now in this article we want to share about polyester resin casting finish. It is resin polyester that is applied by poured on the product surface. 

The uses of polyester resin in the wood finishing are not as many as the polyester coating, but it will give some special look that cannot be obtained with the polyester coating or other coating material. The polyester resin can build a thick film finish with a strong and durable coating. The polyester resin may have properties as the polyester coating or polyester paint with the ability to build thicker film or paint layers. The polyester resin actually is more used to make the special products with the casting process. He can form many objects, such as ornaments, carved forms, and even panels, with the molding process. In the furniture finishing, polyester resins can be used to coat the special surface that needs a thick film layer. With resin finish, we can make a finish layer mm (millimeter) or cm thick where the coatings cannot. The top panels, floors, or objects with uneven surfaces can be coated with resin to give the flat, thick, and strong film layer. 

table with resin finish

Polyester resin is sold in 3 pack materials: the resin, hardener, and cobalt. The three materials need to be mixed in the proper ratio in the application. Mixing the three components must be done carefully. Cobalt should not be mixed directly with hardener; the direct mixing of those materials could cause an explosion. Add the cobalt into the resin and then agitate slowly to make good mixing, then put the hardener little by little into the resin mixed. Keep the agitation to let the material in the perfectly mixed. Then pour the liquid resin mix onto the surface needed. The resin mixed will dry and give a strong and thick film layer. The polyester resin finish is thick and viscous mixed; pouring is the only way to layer it on the subject. To coat the object, then we need to make a wall around it to contain the liquid resin. The liquid resin will flow through and fold the surface as a resin pool. The resin will react and form a hard film that will stick and coat the surface.

Since the way its applied, then the resin won’t give you the perfect even and smooth finish layer. Some orange peel or defects often appear at the finished surface caused by the imperfect layering process. To produce an even and smooth surface, we need to sand and polish the dry resin finish. Make sure the polyester is dry completely before starting to sand the resin; for a thick resin layer, we need about a day to make it dry completely. The sanding is also needed to be done gradually, starting with coarse sandpaper and followed with fine sandpaper. The sanding process is started with the #180 or #150 grade sandpaper to correct and eliminate the defect to make an even surface. After we get the even surface, we can continue the sanding with the #320 or #400 grade sandpaper. Finally, we end up sanding with #1000 or #1200 wet sanding and polishing with compound to get the high gloss finish layer. 

In the furniture finishing, the polyester resin is used for some special requirements. It is most used to coat the object that needs the thick, high-gloss finish, for top panels or flooring that needs a strong film layer. The low gloss it quite rare used. For the transparent finish, it is used in the clear form. We may be able to add some matting agent to the mixture, but it will give the muddy-looking finish. We can add some pigment to the mix and give the paint color finish. Some other ingredients, such as sand, cement, paper, etc., will also be added in the mixture to make some special effects. 

high gloss resin finish