I recently purchased a 1978 SG Custom all original but a little bit neglected. I had to replace the jack socket as it was proken, it also has a tone knob missing. I ordered a replacement but the numbers are nice and white but the others on the guitar are yellowed probably to years of smoke and sun. I don't want to replace all the parts but how can I get the new part to match the others better? Soak in Coffee or Tea? Any better ideas welcome. Thanks.
Those won't soak into the plastic - what you are seeing is the effect of years of exposure to UV and the chemicals in the air. You may be able to tone down the white a bit with a coloured Sharpie. It will rub off in time, but it's easily topped up.
Unfortunately I have got a Rottweiler Biddlin LOL. They're speed knobs btw so I suppose I could discolour the clear plastic?
If it's just 1 knob, buy an old one on ebay. If not, you try an aged one, like from 59parts. If you want to do it by yourself, try to spray with an amber nitro laquer.
Since some plastics are more susceptible to staining than others, here's something you may want to consider...hair dye. You can pick up some of the beard and mustache dye for just a few dollars. I'd try a light or medium brown. Anyway, mix it up and apply it to the knob and let it sit for about half a minute, then rinse it off to see if it looks like it is staining the plastic. If it does work and you need to go darker, the knob will need to be completely dry before a new application. You'll need to have the knob off the guitar to do this because when you rinse it you'll want to do it under running water. Like I said, different plastics stain differently, so it may not work. On the other hand, it may be worth a try. But, proceed at your own risk! You'll want to proceed gradually because if the knobs do accept staining you don't want to overdo it. The longer the dye remains on the knob, the darker it will get. Also, you may want to do just the bottom of the knob first to make sure the color is right.
Remember folks, always have a fully trained and licensed cosmetologist die your knobs... Oh that sounds dirty. But I like the idea.
I once had a cosmetologist who would polish knobs too... (rimshot) here's a source that claims they sell "aged' knobs http://www.ebay.com/itm/like/301628892751?lpid=82&chn=ps and if you want to DIY, here's a page full of leads to follow... http://www.google.com/search?client=safari&rls=en&q=Aged+guitar+knobs+for+Gibson&ie=UTF-8&oe=UTF-8
The last guitar I had aged knobs on was my 57 ES-225. The things literally disintegrated, all four, within weeks of each other, in 1979. I had just gone to work as a tech for a shop and bought four brand new Gibson knobs with my employee discount. They were still looking pretty new when I sold her in 2009. If I was looking for real old knobs, though, I'd check out the "As-is Parts or repair" guitar section of Ebay. ;>)/