Alkyd Varnish vs Arm-R-Seal

[Mike Conley]

I am curious as to what is the advantage of an Alkyd varnish such as McCloskey Heirloom varnish over General Finishes Arm-R-Seal?

Is there a difference in appearance? Is the Alkyd varnish clearer than the Arm-R-Seal?

What other differences?

[Steve Schoene]

The Arm-R-Seal is a polyurethane varnish, which means that polyurethane resin modifies some other resin, most likely alkyd. (Pure polyurethane finishes are two-part products.) The polyurethane adds abrasion resistance--a great thing for use on floors. It also is a little less clear, giving the plastic look when applied thickly. The appearance differences are subtle. You might notice the differences only at some angles.

Poly is also more prone to adhesion issues.

In my view, the most significant downside to polyurethane varnish results directly from the enhanced abrasion resistance. Poly is harder to rub out to an even sheen. (Rubbing out is a abrasive process.)