Theories about coil-shielding

[green]

http://www.stewmac.com/shop/Electronics,_pickups/Supplies:_Shielding/Conductive_Shielding_Paint.html

Maybe another option. Doesn't give a resistance spec. In a search, one person on this site replied it worked for them. I was reading some of the threads on graphite shielding a while back. I tried sanding some used motor brushes. The pile of carbon dust measured open or very high resistance. Maybe it was to coarse. Been afraid to order the materials to make my own coating if could order coating that would work at a reasonable price. I did purchase a tube of graphite for locks to try. Has anyone used it and how large a coil would it shield?

[Jerry]

Here is another that I have been looking at but have not tried.



(Shielding Paint... Sorry about the typo. Saved it with a typo and now cant fix it here.)



Amazon has it but I am sure it would be available elsewhere.

http://www.amazon.com/dp/B00CFSJ8F8/ref=wl_it_dp_o_pC_nS_ttl?_encoding=UTF8&colid=19H6WOEFLE3HV&coliid=I3GS9K1ACP5B5Q

Jerry

[Silver Dollar]

Seems right as shielding is a pain! All this shielding stuff is so expensive! We need an el cheapo solution.
I did keep some toner from an old laser jet cart to test out, some have conductive carbon but some don't.

My coil costs $100 so far...

[green]

[Seems right as shielding is a pain! All this shielding stuff is so expensive! We need an el cheapo solution]

I'll agree with that. I'm spending enough on electronics trying to learn, but at least I'm having fun and am learning something. The paint cost is to high to find out which one works or works best.

[Aziz]

Expensive? No! No way!

How about sugar + water + graphite powder? Yes, suger! It's a cheap water solvent binder.
^sif

[maikl]

i'm just wondering if the lacquer is needed at all.

Maybe I should not be lacquer... but if you chose the best acrylic lacquer, the conductivity and elasticity...

[Paul99]

Maybe I should not be lacquer... but if you chose the best acrylic lacquer, the conductivity and elasticity...

If you are just looking for a protective coating to hold the graphite together, try women's pressure pack hairspray.

[Henrikras]

Many good ideas are coming.. - Ive just made one more test, more like after adjustment at my 7" Deus coil.
Graphite powder dusting at some wet paint graphite 33, and I'm happy with the results.
Made a video. http://www.youtube.com/watch?v=RtA1iVOBquA&sns=em
Henrik.

[sled]

what about using an airbrush? you could mix transparent varnish with some graphite powder.

[Henrikras]

Remember to your good ideas... We need to measure the resistance after a paint.. A lot of good ideas with varnish and other stuf, this wouldn't Be accurate. Thats why I stay with my Graphite 33 spray and to lower the cost, a mix with some powder, someway dusting at the wet paint.

[sled]

true, here are some more ideas I've found:

http://www.talkbass.com/forum/f38/diy-conductive-paint-cavity-shielding-589012/

http://smackaay.com/2009/01/13/making-a-conductive-adhesive/

Maybe Aziz's idea to make your own glue isn't that bad at all, there are many DIY glue recipes out there and hey it costs almost nothing

In a saucepan mix 1 cup of flour with 1/3 cup of sugar.
Add half of the water (3/4 cup) required and mix into a thick paste without clumps.
Pour in the rest of the water (3/4 cup) and combine till the paste is smooth.
Pour one teaspoon of vinegar and put on medium heat until the mixture starts to thicken.
Cool and transfer to jar or an airtight plastic container.


This glue needs more time to dry, but when dried, the bond is really strong.

[golfnut]

It would also mean more if we standardised a test.

A square sample with electrodes is the best/ most consistant way to judge results. This way you get an ohms/square value - industry standard

[mohandes]

hi
i have not knowledge about the magnetic , and my question is :
if i use tinned copper braid for coil shielding for PI detector like DP2 ,it is increase depth detection or no ?
regards

[baum7154]

I think the short answer is 'No'. Copper is a slow decaying metal that will mask short target responses from small gold targets, assuming you may be interested in those. Graphite is much better.

Dan

[mohandes]

ok
when i can find graphite spray in my city , please say me how can i use this ? i spray it on coil or ....
regards
and it is improve the depth ?