Weird RUST problem with my SG 90-Double

[trapdoorspider]

I have a 1990 SG 90-Double, and it has developed a very strange — and persistent — problem with RUST on the strings and screws — but only directly around the pickguard.

 

Take a look at the photo and you'll see what I mean.

 

When I first got the guitar, I figured the previous owner had sweated a lot, or maybe there was moisture in the case. So I replaced the strings and screws and polished the frets. There was NO indication of moisture inside the pickup cavities, or anywhere else for that matter. I even put the guitar in a different case. Everything looked fine.

 

A month later, I pulled it out, and it looked like this again! The rust had come back as bad as before.

 

But then I noticed something strange. Even the STRINGS had developed a coat of rust — but only in about a 5-inch area directly over the pickguard. (Take my word for it; I forgot to photograph them.) And look at the picture: Notice that the last three frets are tarnished (the ones closest to the pickguard). The others are fine.

 

Then notice that the humbucking polepieces and some of the pickup-ring screws — the ones closest to the pickguard — are the only ones rusted; the others are fine.

 

I think it's the pickguard itself. So I was wondering if the 22-year-old plastic pickguard is beginning to deteriorate and "outgas" — release some kind of fumes that are causing these parts to rust. Has anybody heard of such a thing?

 

You don't see SG-90s for sale too often, but one came up a few months ago on eBay, and it too had this same pattern of rust. It MUST be a problem with this guitar. I have 20 other SGs, all different models, and they don't rust like this.

 

I can't think of any other explanation. I guess the next step is to try to find a replacement pickguard.

 

Thoughts and suggestions?

[Searcy]

You can also replace the pick guard screws with stainless steel.

[trapdoorspider]

Clean the guitar well with guitar polish and wipe off the guitar before playing it. Wash your hands before playing it and after your finished wipe the guitar down again.

 

I have done this for 30 years not one issue with rust any where since I started doing this every time.

 

Thank you, but I don't think we've nailed the problem. I have 30 Gibsons and treat them like babies. I do wipe them down, and keep them in their cases. NONE of the others has a persistent rust problem like this one. And as I said, I've noticed other SG 90-Doubles for sale, which have this same pattern of rust around the pickguard. And why would the strings rust only in a small area above the pickguard, and nowhere else on the guitar? If it was moisture/oil from my hands, the strings would rust along the fretboard (where my fingers actually touch them), not farther down where they are touched only by a pick.

[trapdoorspider]

You can also replace the pick guard screws with stainless steel.

 

Yes, but that wouldn't prevent the rust from forming on the strings or the pickups, or tarnish from forming on the frets. Some folks on the everything.sg forum agree that it's a problem with the plastic used in the "pearloid" pickguards, but so far I haven't found a source for a replacement.

[Searcy]

I'm going to guess that the plastic is "gassing" off and rustong the metal parts. A lot of plastics do this. Ever seen an old Gretsch with binding root?

 

I would replace the pick guard by making a pattern out of the old one then cutting out a new one on the router table.

[none2low]

Same problem here... Tried everything I can think of including leaving the case open. Still results in the same rust issue. I'm also 99.9% sure it's a problem with the pickguard material out gassing. If you happen to find a source for replacement guards be sure to post it here. I've checked around myself and not found anything, nor have I found a source for suitable pearloid material to make a replacement. These guards have an interesting and unusual color/pattern to them that I've not seen on anything else.

[pfox14]

I'm going to guess that the plastic is "gassing" off and rustong the metal parts. A lot of plastics do this. Ever seen an old Gretsch with binding root?

 

I agree. The only way to know for sure that the pickguard is the problem is by replacing it and seeing what happens. If the rust problem goes away, then you know for sure that the pickguard is deteriorating and "off-gassing".

[DestructorsKillMusic1982]

You know, I tried out a used SG-90 at a Guitar Center a few months ago that had the same rust/corrosion issue (a white SG-90 just like yours.) I figured at the time it had just been played heavily and not cleaned well, but now I'm not sure, maybe this happened alot with that model for the reasons others have stated.

[merkaba22]

I've owned several over the past years and found that nearly all the mounting screws on the top of the body had a bit of rust on them -- in no instance did the rust expand into the white pearloid pickquard or past the pickup rings to the screws and slugs of the original pickup(s). I have swapped hardware on a couple of them and left one, being in near mint condition, with little modification -- it has a tiny bit of rust.

 

All the nuts (where the neck meets the head) were fine and perhaps totally normal for a guitar of its age, some of the volume and tone pot mounting hardware, especially for the push-push switch, was tarnished but not rusted ...

[trapdoorspider]

I definitely confirmed that the pearloid pickguard was "outgassing" and causing the rust problem, by simply removing the pickguard. I replaced the rusty screws and strings, and used steelwool to remove the rust from the polepieces and frets — and after 3 months now, I've had no rust anywhere with the pickguard off. I even put the pickguard screws back in the holes in the body — no rust.

 

Meanwhile, however, to test my theory, I put the old pickguard in a bag with some strings and screws, and within two weeks, they were covered with rust!

 

I even taped a 10-inch length of guitar string across the old pickguard, with half the string pressing on the pickguard and half of it hanging off. The part pressing against the pickguard was solid rust.

 

Other Double 90 owners on the everythingsg.com website have reported the same problem, but only with the white pickguards on this model, not the black pearl ones. There's obviously something wrong with the plastic used in those pickguards.

 

At any rate, a place called Pickguard Heaven (part of Chandler Music) sells replacement pickguards for this model, as well as the SG-Z, in your choice of white pearl or black pearl, so I've ordered a new one. In black.