Polyester resin casting finish.

The term of polyester is quite well-known in the finishing world. Polyester coating is used in the finishing industry as to coat the products that require 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 pouring it on the product surface. 

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

table with resin finish

Polyester resin is sold in 3 pack material, 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 mixed 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 to the resin mixed.  Keep the agitation to let the material in the perfectly mixed. Then pour the liquid resin mix to the surface needed. The resin mixed will dry and give a strong ant thick film layer. Polyester resin finish is thick and viscous mixed, pouring is the only way to layer it to the subject. To coat the object, then we need to make wall around to contain the liquid resin. The liquid resin will flow trough 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 application 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 start sanding the resin; for thick resin layer, we need about a day to make it dry completely. The sanding is also need to done gradually, started with coarse sandpaper and followed with the fine sandpaper. Sanding process is started the with the #180 or #150 grade sandpaper to correct and eliminate the defect to make even surface. After we got the even surface then we can continue the sanding with the #320 or #400 grade sandpaper.  Finally we end up the 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 requirement used. It is most used  to coat the object the need the thick high gloss finish, for top panel or flooring that need 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 will give the muddy looked finish. We can add some pigment to the mix and give the paint finish.  Some other ingredients such as sand, cement, paper, etc also can be added in the mixture to make some special effects finish. 

high gloss resin finish