803 Glue Brushes are handy, disposable ½” x 6″ glue application brushes with a hollow metal handle. These brushes, which are also referred to as “acid brushes” are extremely useful in a wide variety of small epoxy bonding and coating applications. Their hollow metal design dissipates some of the heat generated by epoxy’s exothermic cure reaction.
803-12, 12 Glue Brushes
803-12, 144 Glue Brushes
Video: A demonstration of bonding with WEST SYSTEM Epoxy and 803 Glue Brushes
Two-Step Epoxy Bonding
- Wet-out epoxy bonding surfaces-Apply a neat epoxy resin/hardener mixture (without fillers) to the surfaces to be joined. Wet out small or tight areas with a disposable brush such as the 803 Glue Brush. Wet out larger areas with a foam roller or by spreading the resin/hardener mixture evenly over the surface with a plastic spreader. You may proceed with step two immediately or any time before the wet-out epoxy coat reaches the final cure stage.
- Apply thickened epoxy to one bonding surface. Modify the epoxy resin/hardener mixture by stirring in the appropriate filler until it becomes thick enough to bridge any gaps between the mating surfaces and to prevent “resin-starved” joints. Apply enough of the mixture to one of the surfaces, so that a small amount of epoxy will squeeze out when the surfaces are joined together with a force equivalent to a firm hand grip (Figure 10). Thickened epoxy can be applied immediately over the wet-out surface or any time before the wet-out reaches its final cure. For most small epoxy bonding operations, add the filler to the resin/hardener mixture remaining in the batch that was used for the wet-out. Mix enough epoxy resin/hardener for both steps. Add the filler quickly after the surface is wet out and allow for a shorter working life of the epoxy mixture.
- Clamp components. Attach clamps as necessary to hold the components in place. Use just enough clamping pressure to squeeze a small amount of the epoxy mixture from the joint, indicating that the epoxy is making good contact with both mating surfaces (Figure 11). Avoid using too much clamping pressure, which can squeeze all of the epoxy mixture out of the joint.
- Remove or shape excess epoxy that squeezes out of the joint as soon as the joint is secured with clamps. A wooden mixing stick with one end sanded to a chisel edge is an ideal tool for removing the excess epoxy.
Using 803 Glue Brushes for strip planking
We applied mixed WEST SYSTEM 105 Resin/207 Special Clear Hardener thickened with 403 Microfibers to the cove with an acid brush. While there are more aggressive ways of getting the glue onto the plank, the acid brush puts just the right amount of glue in the right place. The cure speed of the 105/207 was ideal as it allowed sufficient working time to position clamps yet was fast enough to glue up two sets a day.—From “Strip Planking SPARKS” by Ted Moores, Epoxyworks #32