**BUFFER** Unboxing, setup and demo
**UPDATE** Initial, succinct information about paint, sanding, compound and buffing.
The following methods described can be applied to 2K polyurethane, acrylic or nitrocellulose paints and lacquers/clear coats. This description will concentrate on 2K automotive finishes.
Up until now I have always used a wet compounding system to bring a high gloss finish back to the paint after it has been flattened (sanded). As 2K paints and clear coats are designed to be used in an automotive application, the polishing compounds have also been designed to work best with these paints. There are a huge range of paint manufacturers as well as a huge range of polishing compound manufacturers and they are generally all liquid or paste compounds. The paint and compounding companies are constantly doing their research and development and the consensus is obviously that liquid is the way to go for the foreseeable future, certainly for the automotive industry.
After spraying and curing of the paint, it is normally flattened and polished. This means sanding it with fine sandpapers of varying grades, usually ending with P2000 grade but can be taken further with P3000, P5000 etc. The higher the number, the finer the grit and this means it is easier to compound polish afterwards. It’s normally done wet, using water as a lubricant which removes creation of dry dust when working, increases the working time of the paper and somehow leaves a much better sanded surface than if it were done dry.
Water is also used during the compounding process (at least it has been traditionally over the past few decades) to help keep friction heat from the buffing head down, making it less likely to burn through the paint. A hand held rotary and/or random orbit polishing machine is used to perform this task.
This doesn’t sound like what we want to be doing with our guitars though does it?
Now, it doesn’t mean that this paint cannot be buffed using a dry approach. For us as guitar builders, we don’t really want water to be introduced into the equation at the late stage of polishing, it brings the risk of it seeping into the wood which causes swelling and will ultimately lift, crack and peal the paint in those localities. Using dry buffing methods can also bring the paint up to a high gloss and the way to do that is by using a bench top buffing wheel (or on a purpose built stand). Also, dry compounds can be used that have the appearance of a block of soap, cheese or butter. The abrasive compounds are suspended in these blocks and are applied to the buffing wheel as it spins by holding the block against the wheel. The guitar body will then be brought carefully up to the buffing wheel and the compound will cut through the fine scratches left by the sanding process in the paint. As there are grades of sandpaper, there are also grades of compounds and polish so a more coarse compound is used initially before moving onto finer compounding grades. This gradually brings up a high gloss finish and appears to be flawless to the human eye. After applying a finishing glaze and perhaps a wax, this is enough to satisfy our desire for the “perfect finish”.
So the point is, in terms of polishing, this paint product can be buffed to a high gloss using a wet method and a dry method. My comparison between the two will come in the next post.
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