Bick
Hey Guys - have you forgotten BonAmi (hasn't scratched yet Ads used to say) but to the original poster. Go to your local Walgreens or Rite Aid or ? and pick up a finger nail finishing board (can't remember the correct name). It's about 3/4" square in X section and 5 in long and has 7 different levels of abrasives on it - 2 on each of three sides and one side with just polisher or buffer ?
EMERY BOARD is what you're referring to. This has only two grits on each board. You have a coarse side for removing rough edges, and finer side for sanding out the coarse scratches. FLEXI-FILE is the one with four individual grits that are strictly for polishing. Each one removes scratches from the grit before it if you use it in the correct order.
Wolfman_63
I had a canopy that was scratched from being in a box without the plastic bagging. The surface was all messed up from rubbing against the other sprues and parts. I wet sanded the entire surface with 1500 grit sand paper which left the surface hazy. I they used a dremel tool with a cotton buffing pad and used Meguire's #10 plastic polish. It is designed to polish automotive headlight lenses. The stuff works amazing. The canopy came out crystal clear and was as glossy as a future dipped canopy. I now use it to polish all the canopies to give them a high gloss finish.
Note you will need to wash the canopy with dawn dish soap to make sure the polish has no residue on the frame area you want to paint. (around rivots/details) The paint will not stick on the polish residue.
Here is a link to the polish: http://www.meguiars.com/en/professional/products/m1008-clear-plastic-polish/
I used Meguiars for over twenty years, but now you can no longer get this in the creme bottle in my town - unless I special order it from a local supplier of Meguiars products. They only sell the detailing stuff at the automotive outlets, and the local paint jobbers charge an arm and a leg for a big bottle of it because the smaller bottles are ridicuoulsly priced! The only other option is to go online to get it. The only problem you'll have with it that it's oily, and it will need to be rubbed completely into the surface. This has no hard abrasives in it, but rather it breaks down the surface slowly as it rubs across the surface with soft, or MILD abrasives, and oil to remove scratches that can be seen by the naked eye.
The rest of the polishes are like Don (Stauffer) said - they do have some MILD abrasives in them, but these are only entry level polishes that are meant to remove scratches left from wet-sanding. As you go higher in the line of micro fine polishes the abrasives get smaller until they have none in the next polish = number 9. This is what many use to get that showcar shine without tell tale sanding, or buffing wheel marks left behind from a D.A. polisher. This has no abrasive action in it as it's meant strictly to break down the paint surface chemically to remove all the paint with micro scratches in it.
It's like this people: Wet-sanding is the process of removing uneveness, or imperfections in paint from being sprayed with a professional DeVilbiss HVLP gun, or knock-off copy of it made by another manufacturer. HVLP = High Volume - Low Pressure which was introduced by the DeVilbiss company in 1948 (if memory serves correctly). Any way, it was designed for the automotive industry so that paint could be properly applied to the surface of an automobile with more durability, and ease as opposed to the dying wands that the early manufacturers used to paint their cars with. In 1923 Plasti-kote introduced what we now know as nitrocellulose lacquer which is made from tree gum spirits and cellulose fiber. Before then there was no such thing and was not mentioned in any literature although many so-called antique experts will claim otherwise as "Japanese lacquer" was supposedly made from the same stuff although it came before Plati-kotes' product. What they truly mean is ENAMEL which has been around about as long as porcelain which is made from the same stuff basically - ceramic sludge, or Koalin clay but rather fired differently. Lacquer on the other hand is not!
Spraying leaves uneven ripples called "orange peel" which used to be rubbed by hand with a cotton cloth, and special abrasive polishes to get the smoother look of a new car. When freshly spayed lacquer is duller, and polishing it gives it the look of a new piece of furniture finished in varnish. Wet-sanding was introduced in the late fifties to make the surface smoother with less time polishing, and in the early to mid sixties D.A. polishers were designed to be used with the new polishes that Meguiars' introduced over twenty years before. Now everyone and their damned brother, and sister have copied Meguiars' polishing system!
How this works is that with each sucessive grit of wet-sanding paper you remove more, and more scratches, but also you're removing more, and more paint! The Meguiars' brand is made so that you can do minimal wet-sanding to produce the same effect with a high gloss finish. Each grade of polish has mild abrasives made usually from walnut shells, or some kind of synthetic oil, and plastic particles to abraid the surface to remove those sanding scratches while leaving a somewhat dull, but shiner surface. The finer grades of polish only use soft clay, and oil to polish with although all the Meguiars brand polishes have the same basic formulation. Each grade of polish does the same thing without sanding. However these will rub a thin layer of paint off with them as this is what they are designed to do the more you rub to get to the next step so that you can get the desired amount of gloss required to achieve that showroom look. Wax was developed to help protect the paint from road dirt that is kicked up when you drive, and bugs as well as things flying through the air picked up by the wind. The wax also keeps water away so that it doesn't sit on top of the paint, and eat its' way into the surface dulling it even further.
Plastic polish works on the same principal as abrasive polishes for metal do. These work with ultra fine micro abrasives to break down scratches, but the grade of polish you use as opposed to the grit size of the scratches will determine what you'll need to use to properly remove them. Harder grit for bigger scratches, and light grit for smaller scratches is obvious, but what most people don't know is that light scratches in plastic can usually be removed with a mild plastic polish, or even a mild, or mid grade paint polish. Try it on scrap first as Meguiars' doesn't like some soft plastics, as this will mar it if the polish is too abrasive! No. 1 scratch remover, No.2 scratch remover, No. 3 Scratch remover, No. 4 scratch remover, No. 5 Scratch remover, No. 6 Scratch remover, No. 7 showcar glaze polish, No. 8 sealer polish, No. 9 swirl remover polish, No. 10 PLASTIC polish, No. 29 yellow wax - these are the most popular ones other than the maroon coloured bottles with 1, 2, 3 on them. These are made for MILD paint restoration. You can also buy clay bar paint restorer for soft plastics if you have deep scratches that you want to get rid of without buying a whole line of paint restoration products.
Experiment with these as I don't know what plastics most of the manufacturers use today, and not all polystyrene is equal! Some plastic may gum up, and other plastic may dissolve if you use something with a high solvent content. Meguiars' is pretty tame, and contains no harsh solvents, but the oil in it clumps up if you don't use it all within a year - especially if you use only half a bottle the air inside will eventually dry it out. Remember to shake your bottle no matter what it is, or who made it unless it's soda! Meguiars' has a tendency to settle, so shaking it for about five to ten minutes is HIGHLY recommended. Use a soft terry cloth towel - use a new one so that you don't leave scratches from one that has been through the washer dozens of times and will be rough and leave as many scratches as you're trying to remove! A new micro fiber cloth works well too. Sorry this post is so long - I hope that this will help a lot more with a better explanation.
~ Cobra Chris