The Best Way To Remove Plastic
What ever works for you. I guess.
I do not like to sand plastic, unless I need to absolutely smooth out the surface for paint. I find it is too dusty when you have to remove a lot of material and shape a piece. And when I try to sand one spot I wind up sanding all the area around the spot too, and this distorts the surface. Filing works good if you have a file to fit the space you need to shape, and if it is sharp enough not to tear the plastic. I usually file stuff to align it and make it fit square.
What I find to be a better way is to carve off the offending bits of plastic. I have a pocket knife that I have sharpened razor sharp and this works good because the blade has more guts to it than an Exacto knife. My pocket knife has a long pointed blade and a shorter rounded blade. I find the knife will do the same thing as sand paper or a file if it is used as a scraper to scrape the old distorted glued area down to near perfect. And I carve off chunks and even shape windows out, much like whittling.
But I have another weapon in my kit. It is a set of micro chisels. I keep these razor sharp too. They are real good for getting in areas I can't access any other way. My small gouge is about 1/16" wide and is good for cutting out bolt washers that I cast. My big gouge is about 3/16" accross and is good for cutting holes to start windows. I also have a skewed end chisel that is about 1/4" and it is a honey to carve in fine details. I use the square flat chisels to cut glue out of edges on bits I stuck together and clean off the glue to the smooth surface. And the V gouge is excellent for adding details like wood grains and chips out of the end of boards. I also use the V gouge to clean up some glue joints.
The blades leave the plastic smoother than sanding or filing and the plastic carves like hard cheeze. I also like how the chips are easier to clean up than the dust created by sanding. More control than a Dremel, although I have one of those too, and it has its special place. I have a few old dentist bits that are really small and they are a honey for some jobs. But I try to use the knife or the chisel set first.
Of course you need to know how to get that razor sharp edge. A dull knife will cut you sooner than a sharp one (ever hear that? It's true!) Get yourself some fine wet/dry sand paper. Get one sheet of 200 grit, one sheet of 320 grit, one sheet of 400 grit, one sheet of 600 grit and if you can find it, a piece of 1500 grit. I cut the sheets in half as soon as I get them. It makes them easier to store and use.
You also need some stroping wax, commonly called jewlers rouge. This will give you the absolute razors edge you want. Although you can replace it with the 1500 grit if you can't find any.
Get yourself a piece of 1"x2" pine about 6" or 8" long. Sand one flat side with 80 grit untill it is as smooth and as flat as you can make it. This wiill stand in for your sharpening stone. It elevates the action of sharpening off the table and gives your fingers holding the knife some place to go. Cut a piece of the 200 grit to cover the wood block. Use the 200 if your blade is in bad shape with nicks missing and needs alot of material removed to form an edge. Christ! this is taking too long!
Basically it goes like this:
200 grit to clean up the blade and shape a basic rough edge. Hold the blade up to a light, if you can see a reflection of light off the edge of the blade as you twist the edge towards your eye, you've more work to do.
320 grit is if the blade was already sharp and you just want to put a new edge on it.
400 grit is to refine the edge and start to polish the edge. Can also be used to touch up a blade that has just lost it's edge.
600 grit is to further polish the edge
Stroping wax is aplied to a piece of card stock like coloring it with a crayon. Get a nice thick layer of wax and then strope the blade, like a barber sharpening his razor. It is not the leather belt that puts an edge on the barbers razor, but the stroping wax he puts on the belt. Draw the blade back and forth over the wax, turning it carfully to drag the blade in each direction. If you have built up a little feathered bit of blade hanging off the edge of your knife during previous operations, then the stoping process is how you remove that. (that little flappy bit of steel is a good sign, so dont worry. It means that you have worked the edge down to it's finest tolerance.) Once you are satisfied with the stroping, wipe off the left over wax with a rag and look how she shines. Don't do the traditional thing, and drag your finger across the blade to see how sharp it is. You will likely cut yourself. It will be so sharp you won't feel the edge, it will feel and appear smooth. Do the right thing and try and cut some wood (always move the blade away from yourself untill your more experianced, of course) That knife is sharp now and will hold an edge (depending on how good the steel is) untill you mistreat it. And then you will be back at your sharpening stand.
The 1500 grit can be substituted for the stroping wax and produces a fine sharp blade as well. I like to use the wet/dry black sand paper as it is much cheaper than a wet or oil stone, and stores in a small space at my bench and is ready to go when needed. I also sharpen the kitchen knives too. I haven't bought a new Exacto blade in years, I just keep sharpening the old one. ( and it come out sharper than a new one too) I don't recomend using fluid while sharpening. When the paper gets too dull to take any steel off in a pass, you will feel the blade skate over the paper. Time for a new piece.
I had a hard time sharpening my micro chisels so I glued the sand papers to popsicle sticks and put the chisel in a vise and used the makeshift sanding boards with both hands to file on a new edge.
Keep your tools sharp.
Don't cut youtself!
:cry:
:curse:
ops:
TrainClown :thumb:
