Editing Making Micarta scale material

Cloth is much simpler to get your hands on. Take a trip to your local sewing supplies center and purchase a few half meters of some colored, cotton cloth. But it is just as simple to grab an old pair of blue jeans or other colorful bits of cast off clothing.

The cloth used in the demonstration measures as '''0.25 mm''' thick for both the yellow and orange cloth, while the cream measures '''0.45 mm''' in thickness. The seven layers of cloth – 2 yellow, 2 orange & 3 cream – give a total measured thickness of '''2.2 mm''' when dry. Depending on the epoxy fill and the clamping pressure, the actual thickness of the finished Micarta may end up being slightly more or very slightly less.

Applying the epoxy will require a brush. Whatever brush you decide to use, it will end up as a one-time throw-away. This would suggest that a cheap brush would make the most sense. Some of you use those little metal-handled brushes meant for the application of glue or acids. Not finding a source for them in this area, an alternative was found in some inexpensive paint brushes which come in a kit of four of five together.

The brush in the picture has two faults. First of all, it is somewhat larger than desired for this purpose. That means it will suck up a greater portion of that valuable epoxy resin (waste). Second of all, cheap brushes often tend to be badly glued so that they shed hairs… right into the work. This is definitely not cool.

A simple solution to both of those problems is to tie off the brush with some string or carpet thread. This effectively shortens the brush, reducing the amount of resin it will suck up. Additionally, this stabilizes and holds the hair very tightly. We can add to the effect by putting a few drops of super glue onto the brush hairs above the tied-off portion.

Now there isn’t much mystery about the actual mechanics of making Micarta. At its simplest it is resin-impregnated material which is pressed together.  There are some fancy ways of doing this using hydraulic presses or vacuum bag outfits, but since most of us have more modest budgets, we will be applying pressure to the Micarta with simple wood clamps.  The writer has seen others who used two, flat pieces of wood for the purpose of pressing the Micarta. Our approach is slightly different in that while a piece of wood will serve as the top half of the press, the bottom half of the press will be a thick slab of stone. Since stone does not bend, it guarantees that at least one surface of the finished Micarta is properly flat. By the way, that is a slab of Belgian Blue Stone. The better grades are sometimes used for inexpensive hones, but around here in Belgium it mostly serves for door thresholds, floor tiles and window ledges. It is so common that people throw away used bits of it without a second thought.  

The stone is supported on two blocks of wood so that the wood clamps used to apply the pressure will have some clearance away from the table top. On top of the stone you can see a sheet of paper. This is a special sort of silicon treated baking paper which is intended for use in the kitchen (cookies, bread, etc.). It is heat resistant and nothing sticks to it at all, so it is the ideal stuff to keep our epoxy-drenched Micarta lay-up from sticking to the stone. On the top of the lay-up stack will come a second piece of this silicon-treated paper baking paper, this time to separate the lay-up from that top slab of wood on which the clamps are exerting their force. Standing on top of it all are parts A and B of the epoxy (resin and hardener). Most usually, epoxies are so formulated that one mixes equal portions of both components to obtain the working resin mix, but in this case the ratio is 2 parts resin to 1 part hardener. Again, read the instructions for your own epoxy very carefully.