WEST System Notched Spreaders

These work great for achieving an evenly distributed layer of thickened epoxy. I used them to apply a thin bed of epoxy thickened with colloidal silica, over which I applied woven roving that had been wet out with unthickened epoxy. The surface was vertical/overhead, so this helped the roving stay in place, and it prevented air bubbles from forming behind the roving. However, I discovered that these spreaders are made of a plastic that dissolves in acetone, and to which epoxy seems to adhere quite well. Don't expect to chip off epoxy after it has cured. If you wish to reuse a spreader, remember to wipe off uncured epoxy with a rag or paper towel. White vinegar might also be an effective solvent for cleaning these, but I haven't tried it yet.

My application was laminating three layers of MDF sheet goods for a bench top. I wanted to distribute a thin even layer of Tite-Bond III as fast as possible over a large surface before it began to set up. The first pilot attempt failed because with an unrelieved sawtooth profile, 1. the glue does not spread well and 2. most importantly the layer of glue even once spread will be 1/2 the depth of the tooth. This was too much glue even for the shortest teeth. I solved this by cutting off the tops of the medium height teeth using a straight bit on the router table. The glue spread much more evenly organized into ridges that collapsed into a very even and thin layer when the sheets were pressed together.

It sounds funny to call a plastic spreader a professional tool. But it is. The pros use serrated or notched spreaders just like these. The use them for a reason. Better control and distribution of epoxy, putty, fillers, etc. Try the right tool and be surprised at the good results.