Rebooting the 'micarta' production line

[Tripodmvr]

https://www.bing.com/images/search?q=micarta&qpvt=micarta&form=IGRE&first=1

[DaavG]

Thanks Oafpatroll, very interesting! Where do you source your raw material from as a matter of interest? I assume offcuts?

[oafpatroll]

Thanks Oafpatroll, very interesting! Where do you source your raw material from as a matter of interest? I assume offcuts?

My pleasure, hope it's useful to someone. Apart from the black denim sample which was made from virgin fabric bought for the purpose from Chamdor in North Riding the rest were from stuff I had at home. The cotton canvas one was from a criminally manky pair of work pants. I have new khaki and OD-ish canvas/duck, also from Chamdor,  for this weekends production.   

[oafpatroll]

A cross post of random tips that I put on GS for anyone who may like to try it.

* If you want perfectly parallel sides faces you need a seriously rigid form with hard stop spacers or the ability to accurately measure the thickness of the clamped layup all round. When I did this before to make plates for a friend who built drones way back when I used two 16mm mild steel plates with 6mm spacers and through bolts. The press in the pic was a quick lashup of 16mm formica chickboard with 20mm of pine on top and it flexed enough to make the first 200mm long block >1mm high in the middle.

* Baking paper (not wax paper) is excellent as a mold release. A few sharp taps with a mallet and it jumps apart clean enough that you can reuse it. Wax paper has to be laboriously peeled off.

* You need more resin than you probably think. Depending on the thickness and weave density of the fabric you use that amount will vary. You need enough to thoroughly saturate every layer of fabric but if you're using polyester resin and you catalyse it enough it may go off before you're done layering so it's best to mix smaller batches as you go. This obviously doesn't apply if you're using a slow cure epoxy.

* A credit card works great for squegeeing the resin through and then out of the fabric. It doesn't need to be dripping but it must be saturated and anything beyond that is just squeezed out when you clamp.

* A small painters tray is ideal for applying the resin. You dip the fabric in the reservoir and then pull it through under the credit card on the slope. Makes it really quick and you get good saturation and minimum waste. When the resin has completely cured it comes off the tray in one or two big pieces.

* Disposable nitrile gloves are a win.

* The more accurately you can cut your fabric to match the dimensions of the mold (if you are using one) the more of the block will be uniform and usable

* Loose threads must be cleared from the faces as you layup as they show through really badly when you expose them when shaping.