OK. I make pretty careful patterns out of poster paper. Then it gets traced onto x-mat. If there are bends I dot lines on the mat so I know exactly where it goes on the work. X-mat* is mat with light roving sewn to it, it is very docile, unlike cloth, it doesn't mind being poked into corners eg. Compound corners a problems but yer likely to do it without getting bubbles. I cut it with scissors -- even wet with resin -- if I get a dart wrong. It is easy to pile on layers. *Biaxial matt comes in a few heavy weights, and also in 'tapes'. This is matt made for epoxy resins.
When you start, it is just stiff enuf to stand against the work upright. So you can test it first if you don't trust yer pattern. It likes to stay where you put it. Then you wet the work, with lots of resin, pat the mat in place, you can briefly reposition, move it around, unlike cloth. The surface stays dry for a short while while you try to find a position to lie in with the container of mix on your chest or perched on yer neck and where you figure the brush will end up at the end of your arm which is on the wrong side of you body. Wetting it out sticks it good to the work and you use the tip of the brush to work out a bubble or flatten a hair or poke it into a corner. A 2 or 2 1/2" china bristle brush fits the tight work best, have more control moving the liguid to the mat. Too much epoxy and it can run out... but it's so thirsty you'll never allow yourself the luxury of too much!
Preferably, you can wet out the matt on plastic film, peel it off, slap it on, press it tight...without dragging a wet brush to your work. You can also make your gloved handy-work look clean and also soak up resin by laying on thin 4 or 6 oz woven glass cloth. Biaxial matt doesn't like handling. You can extend working time on matt by poking and pushing with the chip brush... But you can gloved hand shape & sculpt by cheating with pieces of light weight glass fabric. (However, if you later are going to grind or scrape when set, stay with the matt. Cloth is for finishing.)
When hard, it leaves an extremely rough surface that you cannot easily sand to prep - so you must use no-blush 100% solids epoxy, if like I often do, leave it for a day or two. The matt is a perfect mechanical surface to add to, without prep grinding, IMCO
Clean up accidents and runs and the work area with paper rags and isopropyl alcohol*. I have favorite mixing containers so I wipe them out with alcohol too. Mix Part A and Part B in straight-sided pint containers using a wooden paint stirring stick constantly scrapping the side of the pot. I often decant into a larger pail, and stir some more. The brush won't drown if the juice isn't deep and won't run the handle as much. Don't draw the bristles outward across the edge - pat one side of the loaded brush on the inside of the pail and quickly go to the work befor the brush understands what you're doing and recovers... to drip on your hair.
*Hardware store Methyl alcohol is toxic. It's better to use 91% Isopropyl alcohol from the drug store.
When it's hard, I use Sandvic carbide scrapers, smallest makita angle grinder with those hard-flapper disks, cloth back grit for finger work. Anything shiney: scuff it. Better to work on it first day or two befor it turns hard and glassy.
Hey, you still with me, boy? Wake up, there!!
Reply With Quote