800 Roller Covers are thin polyurethane foam covers and are the only roller covers recommended for applying epoxy. The thin foam allows you to control epoxy film thickness, avoid drips and runs, and get a smoother epoxy coating overall. The 7″ covers can be cut for smaller jobs, narrow strips and tight areas. By cutting these into segments you can make to make an ideal tipping brush.
VIDEO: Barrier Coating with WEST SYSTEM Epoxy
Epoxy Coating Basics with 800 Roller Covers
Complete all fairing and cloth application before beginning the final coating. Allow the temperature of porous surfaces to stabilize before coating. Otherwise, as the material warms up, air within the porous material may expand and pass from the material (out-gassing) through the coating and leave bubbles in the cured coating.
- Prepare the surface for epoxy bonding.
- Mix only as much epoxy 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 epoxy lightly and randomly over an area approximately 2 ft x 2 ft 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 epoxy-coated area to blend both areas together.
- Coat as many of these small working areas as you can with each batch of epoxy. If a batch begins to thicken before it can be applied, discard it and mix a fresh, smaller batch.
- Tip-off the epoxy 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 epoxy coating. Alternate the direction in which each epoxy coat is tipped off, 1st coat vertical, 2nd coat horizontal, 3rd coat vertical, etc. A WEST SYSTEM 800 Roller Cover can be cut into segments to make a tipping brush.
Disposable, thin urethane foam rollers, such as WEST SYSTEM 800 Roller Covers, allow you greater control over film thickness, are less likely to cause the epoxy to exotherm and leave less stipple than thicker roller covers. Cut the covers into narrower widths to reach difficult areas or for long narrow surfaces like stringers.
Epoxy coating on vertical surfaces
The only recommended way to coat vertical surfaces with epoxy is the roll and tip method. Roll the epoxy on with a foam roller, then “tip” by dragging another roller across the surface to smooth the epoxy layer. These roller covers provide excellent control over film thickness, are less likely to cause the epoxy to exotherm and leave less stipple than thicker roller covers. Cut the covers into narrower widths to reach difficult areas or for long narrow surfaces like stringers.