Noob Questions about Shielding Paint and Masking

[Tlon]

Hi Folks,

I've been reading this thread, and on the advice of what is in there and one of the techs from ACME Guitarworks, I ordered the MG Chemicals Super Shield Nickel Conductive Coating. This will be the first guitar I've attempted to shield. It's a Fender vintage reissue stratocaster.

I'm wondering what the best masking techniques are for a nitro finish. Do you use a special tape? I've read various things from the 3M blue is fine if you de-stick it a bit by tacking it against cloth to buying the 3M orange delicate to the Green Frog stuff to Auto Detailing tape. Any advice would be greatly appreciated.

Is it best to paint the cavities with the guitar lying flat or do you hang it vertically?

Should I seal the input jack cover cavity as well as the pickup cavities? What about the back tremolo spring cavity?

Any other tips or techniques would be greatly appreciated.

Thanks!

[David King]

Tlon,
Just mask it carefully with the Green 3M tape or an equivalent lacquer resistant tape. I overlap the edges of the cavities by a 1/16th inch so that no spray is visible around the pickups. I also cover the whole top of the guitar with paper, wrapping around the edges so that no over-spray can get on the lacquer finish as it will melt in and be very hard to remove without causing damage and heartache. Wear a respirator, preferably one for organic compounds including xylene. Spray outdoors over an area covered with newsprint and away from houses, cars etc. Shake the can for 30 seconds after the ball starts rattling around. I wear a glove and hold the instrument by the neck so I can adjust the angle. Take light, quick passes all around each side of each cavity and then return for a light second coat. (Aka a "dry coat" in finishing parlance.) You don't want a wet surface or the particles will fall out of suspension and migrate into the corners where they will not do you any good.
Keep shaking the can every 5 or 10 seconds and when you are satisfied with the results (no wood showing under the paint) you hold the can upside down and spray for 2-3 seconds until only propellant comes out. This is very important if you ever want to use that can again. I usually pull the sprayer nozzle out of the can and dip it in acetone just to be sure it's clean. I also squirt a few drops of acetone down the sprayer tube at the top of the can, replace the nozzle and put the cap back on. I've never lost a can since starting that regimen and I get about 2 years worth of guitars out of a can.

[Tlon]

Thanks, David!!!

[Tlon]

Just wanted to follow up. I did the shielding on Tuesday. I used the 3M tape made for lacquer. It has a very high hold but it also comes off very clean and left perfect lines. The shielding took all of 30-40 minutes for three coats (5 minute dry time in between) and final drying. It took me about 60 minutes to tape up. I covered the entire guitar in newspaper as well. Painting was very smooth. The stuff dries quickly and evenly. No running. It covers very well. It looks very professional. I ended up not shielding the jack cavity, but the guitar is silent. Absolutely silent. It's amazing. The paint still smells a bit on the guitar after two days, but that should dissipate soon. I couldn't be happier.

Thanks for all the advice.

[Chuck H]

Try leaving the guitar out of the case for awhile (and if it's already been in the case, leave the case open too). That way you won't permeate your case with the smell and keep your guitar stinky for longer than it has to be.

Chuck

[Tlon]

Thanks, Chuck. I've had it hanging on the wall since. It still smells, but I think it's going away. The silence is worth the small odor. :-)

[David Schwab]

The silence is worth the small odor. :-)

Don't expect the shielding to get rid of the hum from the single coil pickups.

[Chuck H]

Right. Single coil hum is induced from outside sources. Unless you can effectively shield the pickups from this outside EMF, or track down and eliminate this outside EMF at it's source the hum will continue. I have fully shielded single coil covers with only a mild improvement in hum reduction (this is also reported to alter the tone of the pickup???). It's a fact of life I've learned to live with. If you have a profound hum from an outside source then I guess you'll need to either move your practice space, change to noisless pickups or find the hum source and try to reduce it.

JM2C

Chuck

[Tlon]

I have Fender SCNs in it, so it doesn't have the 60 cycle hum either. It's very quiet and the smell is gone.

Thanks again!

Right. Single coil hum is induced from outside sources. Unless you can effectively shield the pickups from this outside EMF, or track down and eliminate this outside EMF at it's source the hum will continue. I have fully shielded single coil covers with only a mild improvement in hum reduction (this is also reported to alter the tone of the pickup???). It's a fact of life I've learned to live with. If you have a profound hum from an outside source then I guess you'll need to either move your practice space, change to noisless pickups or find the hum source and try to reduce it.

JM2C

Chuck