Leveling and Polishing Poured Epoxy

Epoxy can be tricky to work with, especially in combination with other finishes. Here's a good example for learning. March 9, 2008

Question
Due to apparently not having the precision level work surface, this "self-leveling" epoxy pour inlay required, well, some leveling to bring it flush to the frame. I had great difficulties bringing the abraded epoxy to its original poured level of gloss, even with a tight sand/wetsand index up to 1500, then compounding. Frustrated with working the epoxy, I chose to do several coats of Waterlox original over the epoxy. I brushed rather than sprayed to gain sufficient build, then sanded/wetsanded 400, 600, 800, 1000, 1500, then compounded. In this process I seem to have gone through at least a coat of the Waterlox and now have subtle but annoying halos throughout the finish (see picture close up).

Any ideas on either A: somehow diminishing the halos, or B: stripping the varnish and finding a more effective means of sanding epoxy to a gloss? For anyone researching/considering large self-leveling epoxy pours, I can't stress enough the importance of an absolute precision level working surface.


Click here for higher quality, full size image


Click here for higher quality, full size image


Click here for higher quality, full size image


Click here for higher quality, full size image

Forum Responses
(Finishing Forum)
From contributor M:
The Waterlox should come off with lacquer thinner. Pour the epoxy proud, then sand down level. Ending with 220 should be fine. Then pour a thinned coat of the epoxy to "reclarify" the inlays. If the epoxy blushes, wash with soapy water the next day. After 3 days or full cure, spray with satin spar varnish if you don't want the typical super gloss of the poured finishes.


From contributor L:

I do the same thing with my wood tops - pour on the epoxy as heavy as needed and wait till dried. I then sand flat with 150 or 180. Mohawk vinyl sealer goes over the epoxy to "pack in" the sanding marks. I then spray whatever sheen pre- or post-cat lacquer, making sure I get a good mechanical bond on each step. It is time consuming, but it works.

From contributor P:
The "halo" in the picture is a good example of witness lines. It comes from sanding through a coat of finish that hasn't melted into the previous coat. Cross-linking finishes like the oil-base varnish you used (Waterlox) don't melt into previous coats and each coat is an individual layer. When you rub out a finish that has individual layers, you have to avoid cutting through the top coat or you'll get witness lines.

When you want to rub a finish out to a gloss, the finish has to dry hard (aka, brittle) in order to accept the polishing. Waterlox is not a hard finish; it's durable, but relatively soft. There are oil-base varnishes that dry hard and can be rubbed out, but Waterlox Original isn't one of them.

To move forward, it's best to remove the Waterlox and use a harder varnish. It's never a good idea to apply a hard finish over a soft finish because of the likelihood it will crack. If it has started to cure (crosslink), you will likely need a paint and varnish remover to get it off. Once off, you can apply a different finish in its place that will rub out better.

Related Articles