By Tom Pawlak
Tip 1— Paintbrushes
are often used to apply epoxy to small or irregularly shaped surfaces, or to wet
out fiberglass cloth. Unfortunately, typical paintbrushes are too soft and
flexible for this task, especially in cool weather when the viscosity of the
epoxy is higher.
Stiffer bristles move the epoxy along better. We often modify new paintbrushes for epoxy application by cutting away 1/3 to 1/2 of the bristle length (below). Shortening
the bristles creates a brush "with an attitude" that moves the epoxy along
and spreads it uniformly, reducing drips and runs.
We go through many 1" wide china bristle brushes because they are readily
available, inexpensive, and we don't have to clean them when we're done.
However, they shed bristles badly. To overcome the frustration of "hair
loss" we use a trick that glues the base of the bristles together.
To make this process more efficient, we modify a dozen or more brushes at a time by
sticking the handles into a cardboard box (above). We mix a small batch of
epoxy, add acetone or lacquer thinner at about 10%—20% by volume and apply the
diluted epoxy to the base of the bristles with an 807 syringe. This saturates
the bristles and glues them together. The syringe can be inserted between the
bristles, allowing the epoxy to be injected into the center of the banded
bristles. The thinned epoxy wicks between the bristles better, and since this
isn't a load-bearing project, we don't need to worry about compromising the
strength of the epoxy by diluting it. After the epoxy has cured, we use the
brushes confidently in applications where we can't afford to have stray
bristles show up in our coatings.
Epoxyworks 16 / Fall 2000
Copyright © 2002, Gougeon Brothers, Inc. All rights reserved.
Last Modified on 10/28/02.
Reproduction in any form, in whole or in part, is expressly forbidden without the consent of the publisher. EPOXYWORKS, Gougeon Brothers, WEST SYSTEM, Episize, Scarffer and Microlight as used throughout this publication, are trademarks of Gougeon Brothers, Inc., Bay City, Michigan, USA.