Precat vs Postcat Varnishes – A Guide

When it comes to protecting a wood project long term varnishes are an excellent solution. However when thinking about protecting your wood product you have to consider whether you rather use a pre or post cat varnish. Both have benefits and drawbacks to consider to ensure you achieve a quality finish that will properly protect your wood project for a long time to come.

Precatalyzed varnish (precat varnish)

Precat varnishes

A common misunderstanding is that a precat varnish has no catalyst in it. This is not the case as a precat varnish has actually had the catalyst added in during the manufacturing process. In general, a precat varnish is not as thick as post catalyst varnishes. However, they often do not provide as durable of a finish as a post cat varnish. This can be important especially if you want your cabinets to meet KCMA (Kitchen Cabinet Manufacturing Association ) standards. The positive to precat varnishes is that they are easier to spray and a bit more forgiving when being applied. By more forgiving I mean that they do not require mixing in of catalyst (though you can sometimes add additional catalyst to help speed up the time it takes to cure). They are easier to spray because they are typically not as thick as post catalyzed varnishes which makes them easier to spray.

Postcat (conversion) Varnishes

Post cat varnishes require mixing in the catalyst at time of application. Proper mixing of the catalyst is critical because if it is not done right the coating may fail to cure properly resulting in potential coating underperformance or even coating failure. The proper mixing of the catalyst is one of the major downsides because it requires more consideration from the person apply the conversion varnish. The other negative to postcat varnishes are they can be harder to spray. Postcat varnishes are typically higher in solid contents which makes them slightly harder to spray though we can help you in knowing how to spray them.

While they have a few negatives there are also positives to postcat varnishes .  One is they are more effective at resisting heat, acidity, and environmental conditions. This makes them one of the longest lasting finishes. Additionally, the higher solids content typically gives them a better coverage rate. The improved durability and better coverage rate can often contribute to a better overall cost (though they are often higher priced on a per gallon basis).

Summarzing the pros of postcat and precat varnishes

Precat Pros

• Easier to Spray
• Less learning needed

Precat Cons

• Not as durable

PostCat Pros

• Better durability
• Overall value can be better after considering improved durability and greater coverage rate

Postcat Cons

• Harder to Spray due to higher solids contents
• Require greater consideration due to mix requirement needs