Shielding (foam)

[Devon8822]

So I heard that foam behind the pickups was a good way to shield, I am wondering what kind of foam? I heard that mousepad cut up works, but i think thats a bit thin... Would basic household sponge, cut to fit behind the pickup work well? It will fit perfectly and fill the open spots well, I am just wondering if that material will work well to shield? thanks

[SnowGTR]

So I heard that foam behind the pickups was a good way to shield, I am wondering what kind of foam? I heard that mousepad cut up works, but i think thats a bit thin... Would basic household sponge, cut to fit behind the pickup work well? It will fit perfectly and fill the open spots well, I am just wondering if that material will work well to shield? thanks

Shield from what???

If it’s nonconductive it’s useless. A household sponge will absorb moisture and that’s about it and I don’t think that would be a good thing to do.

[GregP]

Foam or rubber are used behind P-90s to act as a spacer for height adjustment. Haven't heard of it being used as shielding, because it won't do nuffin'. If it helps keep the pickup firmly in place it might reduce... I don't know... maybe some microphonics from the mounting screws? Seems like a stretch and I'm not sure I buy that, but it'd be my best guess. Definitely not shielding, though.

[Devon8822]

Ok, so I better not waste my time with that, what can I use? What around the house will help? tinfoil?

[JohnRossitter]

You can get sheilding paint from StewMac.

You can get sheilding tape.

You can get a power conditioner for your rig.

[fookgub]

Ok, so I better not waste my time with that, what can I use? What around the house will help? tinfoil?

You can use aluminum foil and apply it with spray adhesive (like 3M super 77). That works well for flat surfaces like pickguards, but it's a huge pain in the butt to do control cavities and other stuff with curves. Also, aluminum is very difficult to solder to. Copper tape is a better solution, but conductive paint is less work. You can buy both the tape and the paint from stewmac. Personally, I would use aluminum foil on the pickguard (if there is one) and conductive paint for everything else.

[GregP]

I agree with fookgub-- I tried doint shielding on a budget with tin foil, and it wasn't worth it except for the pickguard. Ordered some copper tape from Stewmac and it's done the job perfectly. I haven't used the paint and I imagine it would be even easier though potentially less effective (depending on the density of the conductive material, etc). I think the tape is the way I'm going to continue doing it.

[killemall8]

how much difference does it really make guys? ive never shielded any of my guitars, and i really couldnt tell the difference.

[John Abbett]

how much difference does it really make guys? ive never shielded any of my guitars, and i really couldnt tell the difference.

It does make a difference. I have a strat clone, with an annoying buzz. I shielded it everywhere, buzz is gone. I was picking up some noise from somewhere, and the shielding got rid of it.

Check out this website for shielding info.

http://www.guitarnuts.com/wiring/shielding/shield3.php

If you don't have any noise already, I wouldn't bother, but to get rid of hum and buzz after you've checked all of your wiring, this will help.

-John

[GregP]

I would say that it can potentially make a huge difference. Unfortunately my concrete-and-steel basement apartment is near power AND communications junctions and is really just so insanely noisy that it's more an academic exercise than anything as long as I continue to live here.

Greg

[Devon8822]

Ok, well my problem is with squeels, mybe the sponges will fix squeels, just not hum? is that wrong?

[JohnRossitter]

I don't think that it has anything to do with electromagnetics at all.

I use them to dampen the pickup socket and make the pickups seat better, but as for sonic and or electric purposes, I can't see it would make one bit of difference.

Perhaps you could find a lead sponge

[fookgub]

Ok, well my problem is with squeels, mybe the sponges will fix squeels, just not hum? is that wrong?

Squeals usually have to do with microphonic pickups. No amount of shielding will help if your pickups are microphonic. I doubt foam will do anything either, but it won't cost you much (if anything), so it may be worth a try. Unfortunately, the only good solution is to buy better pickups. I suppose you could try to pot your current pickups, but I don't know anything about that.

[GregP]

Yeah, shielding won't do anything for squeal. Potting as per fookgub's suggestion is actually rather easy to do. The foam might help a miniscule amount but I wouldn't count on it. In any event, you don't need any special foam so just give'er a given'er.

[Devon8822]

Could it be the wiring causing screeching feedback (at high gain)? is that a possibility?

[JohnRossitter]

That sounds more likely.

Is this for a guitar you are building or one that already exists?

If you are having this problem with an already built guitar, you may want to call the maker to ask them about it.