How to Age/Relic Plastic Guitar Hardware (Pickup Covers, Knobs)

What’s worse than brand new white plastic hardware on my Stratocaster? Brand new plastic hardware that’s supposed to look old, but doesn’t.

Yes, I know that relicing and aging guitars is not really everybody’s cup of tea, and some of you cringe at the thought of it, but for some reason, I’ve always liked it. Most of it is probably due to me always wanting an original vintage guitar and the looks that go with it, so doing some of the relicing myself has made me feel like I’m at least somewhere close to that.

Recently, I have bought some cheap pickup covers and knobs for a project that I’m working on and decided to try out a few techniques that to me seemed to make sense. Some, I think, worked pretty good, but some seem to be complete nonsense.

Going for That Yellow Tint

When I look at actual vintage Stratocasters, I see that plastic parts, including the pickguard, over time become almost yellow, and sometimes even get a bit of a green tint.

I’ve read a tiny bit about it and learned that this happens due to a flame retardant called bromine in these old ABS plastics. According to this article [How to Clean Old, Yellowed Plastic on Retro Computers and Game Systems] – when exposed to UV light, those bromine molecules can destabilize and leech through to the surface, causing the plastic to turn yellow.

So, the best we can hope for is to somehow stain the plastic, since as far as I can tell, this chemical process happens rarely on the plastic made in modern times.

And, I know it may be self-evident – but I’ve found that the best thing to do is to simply buy hardware that already yellow (it’s really, really cheap). Working on brand new, white plastic, is, to say the least, unpredictable.

While working on white pieces in the past, sometimes I was able to add some white tint by soaking it in coffee or strong tea, other times it just wouldn’t work at all. And basically, any yellow tint that I was able to add successfully, I was also able to clean off pretty easily – meaning, it wasn’t permanent.

So, with that out of the way, I’ll be focusing more on aging the plastic than on purely just making it yellow.

Step 1: Adding Wear

Even if you bought “aged” parts that are already yellow-ish, they are most likely smooth and shiny, which just makes them look awful and phony. We need to make them look worn and used.

Furthermore, adding wear and removing the shiny top layer from the plastic parts assures that some other methods (which we’ll talk about later on) will have a higher chance of succeeding.

So, how to add wear effectively, while making it look authentic? In my experience, with gravel.

Grab your plastic covers and knobs, and fill a plastic bag or a container with gravel. Load the plastic hardware inside, and shake until your hands start hurting.

I do this for around 5 minutes, and then take the hardware out. You can wash it with water at this point, or just clean it up with some paper towels.

Step 2: Adding the Yellow Tint

Obviously, my set is already yellow (and as I said, I suggest you buy one too), but let’s try a few methods which might add some more yellow tint to the plastic. Whatever works on my yellow set, should be even more effective on plain white plastic, since the difference, at least in theory, would be more noticeable.

Method 1: Tobacco Smoke

I’ve seen some success stories with guys putting their plastic parts in a container filled with tobacco smoke. In theory, I see how this could work, but in practice, this method is far from effective – at least in my experience.

I used up two cigarettes and left the plastic parts sitting in a sealed container for around three hours. The results are below, from which we can conclude that this method makes no impactful difference on the color of the plastic.

I think, for this to work, the plastic parts would need to sit in the smoke a lot longer than just a few hours. It was, however, a fun experiment and I thought it will at least make some impact, but let’s move onto the next method —

Method 2: Coffee

This is a weird one because sometimes I found that it works perfectly, and other times it doesn’t work at all. I’ve to the conclusion that the effectiveness depends on the type of plastic used by the manufacturer to make the parts. Since this is obviously out of your control, the method itself is unpredictable and unreliable.

But, let’s try and see if coffee makes any difference on my cheap, pre-tinted set of covers and knobs. I’ve made a pretty strong blend, and let the parts sit in it for approximately 24 hours.

Warning – make sure that you wait for the coffee to cool down almost completely before putting the parts in. If you put plastic in hot coffee, it will bend and deform (yes, I’ve done that in the past).

To my disappointment, coffee didn’t make any difference in my case. However, as I already said, sometimes it works, other times it doesn’t. So it doesn’t hurt to at least try it. Maybe you’ll be luckier than me.

Method 3: Water-based Pigments/Toners

I’ve been using this method to successfully tint wooden parts, such as the headstock and the neck, but I’ve also had some success with it on plastic.

The stuff that I use is basically just a water-soluble pigment (we just call them toners here), which people use as colorants for plain white wall paint. You can find them on Amazon here – Mixol Universal Tints, Black (01) 20ml. I only use yellow and light brown tints.

As far as my method – it’s pretty simple. Damp a piece of paper towel with the pigment, and smear it all over the plastic. After a few minutes, wipe down the pigment as roughly as you can with paper, removing anything that didn’t stick.

In my opinion, this method leaves pretty good results, and the plastic looks fairly authentic. I’ve found that it works best if you roughen up the plastic before doing this (that’s why we did the thing with gravel), and I prefer it over other methods – such as shoe polish.

The good thing (or bad – depending on how you look at it) is that this method is largely reversible. If you find that you added too much pigment, just wash it all down with water. However, I’ve found that the longer you leave it on there, the harder it becomes to wash, and at some point, you’re just stuck with it.

I leave the parts a bit too yellow at this point because, with the next step, we’ll wash down most of the unnatural-looking stuff. Some of you, however, may prefer things looking like on the above photo, so in that case, skip the next step.

Step 3: Let’s make them dirty again

After I’ve successfully added the yellow tint, I always put everything back in my bucket filled with gravel, but this time I add some water to the whole mess and make everything dirty and rough again. Also, after I’m done, I don’t wash the plastic parts, I just wipe them with paper towels.

My reasoning is that this makes things look more authentic. They’ll get dirty and worn over time, and I’d rather have “controlled” dirt than the stuff that I don’t know (or don’t want to know) the origin of.

Below is the final result.

Now, if we compare this brand new aged set to something that’s actually old, and from an original 1960s guitar, I think things look pretty close. It’s of course not completely perfect, but at least it doesn’t look completely fake and it’s somewhat believable.