RF shielding paint? - Page 1
Forum section: electronics / rf-microwave

author: daqq
author_rank: Super Contributor
timestamp: November 25, 2019, 01:51:12 pm
content: Noticed this:http://www.mgchemicals.com/downloads/pdf/flyers/EMI_RFI_Water_Based_Conductive_Coatings_Flyer.pdfApparently you can just paint a wall with that stuff and get a reasonably good shielding. It's not perfect, but still... Pretty cool.

author: radiolistener
author_rank: Super Contributor
timestamp: November 25, 2019, 02:54:08 pm
content: But there is a problem, if you have any electronics in your home, their radiation cannot fly away from your room and will be reflected back

author: iMo
author_rank: Super Contributor
timestamp: November 25, 2019, 02:56:04 pm
content: I will paint my hat with it..

author: TheSteve
author_rank: Unknown
timestamp: November 25, 2019, 06:45:04 pm
content: Check the price before getting too excited

author: CalMachine
author_rank: Frequent Contributor
timestamp: November 25, 2019, 07:12:48 pm
content: I looked into this stuff when I was working for a Cal Lab in their standards lab. It was going to be used for shielding the entire standards lab, as they had no EMI shielding.You're looking at ~$300 / liter for the silver coated copper stuff, which is only their middle grade paint.

author: Mechatrommer
author_rank: Super Contributor
timestamp: November 25, 2019, 07:47:34 pm
content: digikey sells 150ml size... $55... i have one on my desk right now (but havent tried nor tested EMI-wise).. should be capable to paint very many small small things..https://www.digikey.com/product-detail/en/mg-chemicals/841WB-150ML/473-1421-ND/9658023the non-water based probably sticks much better, but it is heavily toxic class and wont export to 99% of countries including mine. thats why i guess digikey doesnt sell it.

author: TheMG
author_rank: Frequent Contributor
timestamp: November 26, 2019, 01:46:42 am
content: I'd imagine you could get similar or better results covering the walls in sheet metal (galvanized steel) as long as you ensure to have a good electrical bond between the sheets. Copper would be ideal but $$$$$$. There's a couple of small buildings I've gone into that have galvanized roofing, siding, and doors. RF shielding was never the intent, so the sheets are not really bonded to each other or anything and there's some gaps, nevertheless it's pretty much an RF dead zone in there when the door's closed, purely by coincidence. FM radio, cellphones... forget about it, no signal.The paint is, of course, a more practical and easier (perhaps even cheaper due to lower cost of labor required to install) option, and less permanent especially if you don't own the building.

author: TheUnnamedNewbie
author_rank: Super Contributor
timestamp: November 27, 2019, 02:58:40 pm
content: Quote from: TheMG on November 26, 2019, 01:46:42 amsure, perhaps less permanent than actual walls being made of conductor, but I have never seen people strip walls of paint around here, usually you just paint over (in which case the conductive paint is still inside)

author: rhb
author_rank: Super Contributor
timestamp: November 29, 2019, 09:45:09 pm
content: For reference I estimate it will cost about $800 US to shield all faces of a 16 x 12' x 8' room in my shop with 28 gauge galvanized steel sheet, All seams will be soldered, power filtered, etc with insulation and its own HVAC zone. I'm told that properly executed it will provide 100-120 dB of suppression. However, the devil is in the details.For small enclosures copper or aluminum foil tape with adequate overlap of the seams is quite affordable unless you have to do a lot of enclosures in which case painting is cheaper.Reg

author: coppercone2
author_rank: Super Contributor
timestamp: December 02, 2019, 07:06:42 am
content: is that going to stand up to building movement if its all soldered?its going to feel shitty if you don't put something over it like properly finished sheetrock. Then repairs would be a bastard.. maybe cedar

author: ChristofferB
author_rank: Frequent Contributor
timestamp: December 20, 2019, 10:30:37 am
content: I wonder how feasible it would be to make rf shielding paint yourself. Loading a cheap wall paint with copper powder and/or coarsely ground ferrite.Is the base paint directly conductive? Or is it just RF conductive via capacitive coupling between individual metal particles.--chris

author: Gyro
author_rank: Super Contributor
timestamp: December 20, 2019, 10:35:18 am
content: I can't speak specifically for the water based paint in the OP, but yes, shielding paints are conductive - the sheet resistance drops as the paint dries too.

author: coppercone2
author_rank: Super Contributor
timestamp: December 20, 2019, 10:55:09 am
content: the epoxy actually gets DC conductive as it cures. When I measured a pool of it, it was non conductive.