The object of barrier coating is to build up an epoxy coating that provides an effective moisture barrier and a smooth base for final finishing.
- Prepare the surface for bonding.
- Mix only as much resin/hardener as you can apply during the open time of the mixture. Pour the mixture into a roller pan as soon as it is mixed thoroughly.
- Load the roller with a moderate amount of the epoxy mixture. Roll the excess out on the ramp part of the roller pan to get a uniform coating on the roller.
- Roll lightly and randomly over an area approximately 600 x 600mm to transfer the epoxy evenly over the area.
- As the roller dries out, increase pressure enough to spread the epoxy into a thin even film. Increase the coverage area if necessary to spread the film more thinly and evenly. The thinner the film, the easier it is to keep it even and avoid runs or sags in each coat.
- Finish the area with long, light, even strokes to reduce roller marks. Overlap the previously coated area to blend both areas together.
- Coat as many of these small working areas as you can with each batch. If a batch begins to thicken before it can be applied, discard it and mix a fresh, smaller batch.
- Tip off the coating by dragging a foam roller brush lightly over the fresh epoxy in long, even, overlapping strokes after each batch is applied. Use enough pressure to smooth the stipple, but not enough to remove any of the coating . Alternate the direction in which each coat is tipped off, 1st coat vertical, 2nd coat horizontal, 3rd coat vertical, etc. An 800 Roller Cover can be cut into segments to make a tipping brush.
Apply second and subsequent coats of epoxy following the same procedures. Recoat when the previous coat is still tacky (about as tacky as masking tape). To avoid sanding between coats, apply all of the coats when previous coats have cured to this tacky stage. After the final coat has cured overnight, wash and sand it to prepare for the final finish.