How to custom repaint a SYNTH

[Chummy]

As a complete noobie. Is it possible for me, to pick up an air brush, mask the writings and paint them (maybe) and the rest of my synth? My Yamaha KX5 is begging to be restored, although fully operational in a bad comsetic condition and I have no idea where to start, what would I need etc.. I saw some youtube vid but IDK if I need to use sand paper wash the Metal with water (yeah, it's mostly metal and some plastic) after I extract the panels of the exterior what color should I be using? brush? what to use for mask? drying time? etc.

 

any help would be appreciated.

[WRGKMC]

From the pics I goggled up it looks like there's a couple of different versions. Some are all black and look to be plastic and others are grey in color and look like there may be some aluminum panels.

 

Is it something like this?

 

 

These black ones look to be plastic.

 

 

 

I suppose you can repaint the metal using auto body spray paint. You can buy it in most auto parts stores. There are two basic types. Lacquer and acrylics. If you use acrylics you have to stick with them and use the matching clear coat. if you yse acrylic and try and use a lacquer clear coat or some other paint over it you're more the likely going to have issues. When it comes to painting you need to stick with the same base chemicals.

 

The 5 main types are:

 

Alcohol = Lacquer, Shellac. These can work on wood or metal so long as they are properly prepared and applies.

 

Poly = is an epoxy/plastic resin. They do make some polys that will stick to plastics but you have to seek those out. Some polys may melt plastic so be careful. The chemical combinations in all of these categories keep changing and manufactures keep coming up with unique formulas forcing you to use only their products in the painting process. you may have to use their base coat, their paint coat and their clear coat to get all three to stick together properly. I ran into issues first hand in many occasions using one manufacturers base coat and another paint. The two rejected each other and cracked and peeled.

 

Oil = These are usually Petroleum based paint. You do have oil based enamels commonly used on metal surfaces, But these take a really long time to dry. Varnish and Tung oils are also in this category too. both work well on woods but not on metals or plastics. They can be tinted but they are not paints and not used on metals.

 

Acrylic = Often water based lacquers or polys. I'd avoid these on instruments because hands sweat and the finish can break down from moisture, and they don't mix with other types of chemicals in many cases. if you're gong with lacquer, the Autrobody lacquer is what you want on metals.

 

Latex is for houses. Its not an instrument based paint, especially metal. It would just rub or peel off.

 

 

As far as actually doing the work, you'd obviously have to disassemble the unit and tape off all areas that are not to be painted. You need to clean all the dirt and grime off first using soap and water then followed by denatured alcohol or naphtha (lighter fluid).

 

This is the problem. Some plastics can melt with alcohol and naphtha so you need to test it first. I know I can use alcohol on many plastics and have no bad effects. other plastics may turn white, get fragile and crack or just melt. I cant advise you here, It would be something I'd have to see first hand and then give my best educated guess. hopefully the naphtha wont hurt anything. It should remove old polish, silicon, oils that prevent the paint from sticking.

 

You can likely use some super fine grit sand paper to roughen the surface then begin your spraying process.

Use Light coatings. Dust it on. You can do one heavy layer and get all kinds of runs and streaks. Do 20 dusting layers from farther away and you'll get better results in the end. lacquer dries fairly quick. you may be able to do a thin coat per hour till its thick enough then let it dry 24~48 hours. You can then wet sand and apply a clear lacquer coat or three to give it some nice gloss. After that its a buffing wheel and swirl remover followed by a good paste wax.

 

I should tell you its unlikely you'll get a pro looking job on your first try. I been refinishing guitars for 40 years and I hate it worse then anything else. Its expensive, its nasty sticky work and no matter how hard you try using a spray can its not going to be perfect. If you've never used a spray gun before, I say forget it. By the time you buy all the gear and chemicals and actually learned how to properly mix them, you could have just taken the thing to an auto body shop and gotten a pro job done. The cans are good enough, you'll just have to read up on it and if you do screw up, lacquer is forgiving. You can buff out flaws and add additional layers and they all melt in to become one thick layer. Scratches can be buffed out too so its the best finish for musicians in the long run.

 

Personally, I'd suggest some kind of contact paper to put on the thing. You'd only need to loosen panels and tuck the ends of the paper in and you have a gazzilion different types to choose from. I'd likely suggest staying away from geometric lines because they can be difficult to cut and align properly. Solids or metallic would surely be the easiest. I've seen drums resurfaces with contact papers and when done right thay can look killer. Just realize they can also be scuffed or torn so you do have to take care. They do make some thicker stuff too which is very good. Some actually needs to be glued on.

 

You could also use Tolex, the stuff they cost amps with, but I think the vinyl might do a better job. if it gets worn, you can just peel it off and put new stuff on.