Copper foil from ebay - Page 1
Forum section: electronics / projects

author: prasimix
author_rank: Unknown
timestamp: November 04, 2018, 12:44:28 pm
content: I'm wondering if any of you have an experience with thin copper foil as one marketedhere.What is the difference between "single" and "bidirectional" model/type?Is it possible to solder e.g. a wire to such type of foil? If not, does something else exists that is solderable?

author: langwadt
author_rank: Super Contributor
timestamp: November 04, 2018, 01:27:23 pm
content: yes you can solder to copper foil, I'm guessing bidirectional means conductive adhesive

author: prasimix
author_rank: Unknown
timestamp: November 04, 2018, 01:30:58 pm
content: Thanks. The price difference between single and bidirectional is minor. Therefore I can give a try to bidirectional but still would like to know what does it exactly mean.

author: chemelec
author_rank: Contributor
timestamp: November 04, 2018, 02:52:15 pm
content: Possibly means Sticky on One or Both sides?

author: prasimix
author_rank: Unknown
timestamp: November 04, 2018, 02:53:02 pm
content: Yes, that's possible

author: mikerj
author_rank: Super Contributor
timestamp: November 04, 2018, 05:45:44 pm
content: Is it pure copper, or copper covered aluminium which seems to be a Chinese specialty?

author: cdev
author_rank: Super Contributor
timestamp: November 04, 2018, 06:04:50 pm
content: If you have a roll of copper tape, how can you tell? I have noticed occasional strange phenomena with my (adhesive on one side) copper tape's conductivity which made me wonder hearing that.Quote from: mikerj on November 04, 2018, 05:45:44 pm

author: SeanB
author_rank: Super Contributor
timestamp: November 04, 2018, 08:06:27 pm
content: Odd things with copper tape are often due to the thin top film used to reduce corrosion. If overlapping the tapes best is to solder the seam every so often to get good electric contact between them, either just a solder spot or use some wire soldered both sides.To test if it is copper, CCA or plated steel use first a magnet, which will attract the steel. Then apply heat from a cigarette lighter, the copper will glow red and not droop, and the red surface will be noticeably softer when cold, and a lot easier to bend. CCA will melt and droop. Have not yet met copper plated nickel sheet, though it must exist, as an intermediate process to doing a full chrome or gold finish for things that are formed in a press from sheet or strip. Probably the cost of the base nickel is close to the cost of copper, so not a thing to fake.

author: cdev
author_rank: Super Contributor
timestamp: November 04, 2018, 08:26:51 pm
content: Thats been my experience, that it sometimes needed to be soldered. Contact wasn't enough. Sometimes it is and sometimes it isn't.

author: Bud
author_rank: Super Contributor
timestamp: November 04, 2018, 09:08:23 pm
content: Being sold as "Guitar pick up foil", thay may mean the sound can "travel in the tape" only in one direction or for the "bidirectional" flavour of it in both directions. Audiophools certainly know that.

author: prasimix
author_rank: Unknown
timestamp: November 04, 2018, 09:33:57 pm
content: Quote from: Bud on November 04, 2018, 09:08:23 pmHuh, this is a good one.

author: Mechatrommer
author_rank: Super Contributor
timestamp: November 04, 2018, 11:47:58 pm
content: then you tell me how it can improve anything by taping it on the guitar's body? will it sound better than curt cobain's guitar?and it can protect from slug and snail as well, maybe due to some type of earth resonance?...https://www.ebay.com.my/itm/Guitar-Pickup-Copper-Foil-50mm-x20m-Shielding-Screening-Tape-Conductive-Adhesive/362431461195?hash=item546299374b:g:1kYAAOSwl75ZuIbI:rk:12:pf:0joke aside. i think i will be interested at getting one of this (not for audiophoolery) but i believe there is clear lamination on top of the copper to avoid oxidation. i dont want it i want naked copper that we can directly solder on. if anybody know an easy way to strip that off with some chemical that will be interesting. one application is gluing it to a specified dialectric material (ceramic ptfe anybody?) so we can make our own RF grade pcb or such, RF pcb on the market is audiophoolery grade of price.

author: coppercone2
author_rank: Super Contributor
timestamp: November 04, 2018, 11:58:37 pm
content: how to tell: sand paper should do it. Just rub on it with sand paper till you get through to the paper side, it should at least tell you if its plated. As for if its electrical copper? No clue, resistance measurement maybe.

author: thermistor-guy
author_rank: Frequent Contributor
timestamp: November 05, 2018, 12:37:11 am
content: Quote from: Mechatrommer on November 04, 2018, 11:47:58 pmI bought some adhesive-backed tapes - kapton, copper, polyester - to experiment along the lines you mention. E.g. a low-impedance, flexible, cut-to-shape power bus with kapton/copper/kapton/copper/kapton layers.I also bought a silver (conductive) ink pen, to see how practical it is to make a small-ish circuit on layers of tape. Punch holes in the correct tape layers (different pattern for each layer), draw the traces on each layer, let dry, stick the layers together, add ink to connect the layers, let dry. Ink in the component pads, add components, let dry. Connect the pads to traces, let dry. Result: a low-cost multi-layer flexible PCB with good rf properties. As many layers as I want.It's only an idea at the moment, but I have uses for it if it works.

author: Mechatrommer
author_rank: Super Contributor
timestamp: November 05, 2018, 01:03:19 am
content: Quote from: thermistor-guy on November 05, 2018, 12:37:11 amno it wont work. i have silver conductive ink it too fragile to hold anything even a single strand of wire, it will peel off, have done that. it only usefull at connecting broken traces. or you may glue your component with something else before tacking it with the ink. it might work never done that.

author: cdev
author_rank: Super Contributor
timestamp: November 05, 2018, 01:56:14 am
content: Kapton makes a great insulator and it withstands high temperatures, the problem is that its so thin that whatever the impedance you would get using it is likely to be unsuitable for RF.My guess is that it likely has a fairly high dielectric constant.As far as printing circuits (in an additive way) There is a group at Georgia Tech that has done a lot of research on printing things like RFID antennas (To power sensors using RF in the air) with conductive ink, and a lot of their research is on the web.You know that does work okay as a substrate for RF circuits is foam core/foam (double sided sticky) tape. And its likely fairly low loss. But very solder unfriendly -Another widely available rigid material thats easy to work with is cardboard. Ive built a number of antennas using combinations of copper tape, cardboard and aluminum foil.

author: thermistor-guy
author_rank: Frequent Contributor
timestamp: November 05, 2018, 03:21:35 am
content: Quote from: cdev on November 05, 2018, 01:56:14 amHmm, I have a bunch of old business cards in good condition. Maybe I could punch them out to form a honeycomb pattern, and stack the cards inbetween tape layers (kapton or copper or ...)., to get the desired thickness/impedance, ideally forming a near-air dielectric.I can't help thinking there are some useful possibilities here, for low-cost prototyping. Some experimenting and testing required, obviously.

author: GigaJoe
author_rank: Frequent Contributor
timestamp: November 05, 2018, 03:51:13 am
content: bought have this tape. it copper, no coating, solderable, very thin, expensive. often sell as guitar shielding ..

author: Mechatrommer
author_rank: Super Contributor
timestamp: November 05, 2018, 04:15:49 am
content: Quote from: GigaJoe on November 05, 2018, 03:51:13 amthe link the OP provided is cheap tape in a roll version. there is another china version 30cm x 20 cm about less than $5 per sheet. and then there is another "dupont pyralux" type (you can find in ebay) that is real expensive. are you talking about the china cheap version in the OP? or the pyralux version? the china version seems too good to be that kind of shiny uncoated. wait... here is the pyralux...https://www.ebay.com.my/itm/Pyralux-Kapton-Flexible-Printed-Circuit-Board-Material-Various-Models-9-x-12/153153567548?hash=item23a8a9fb3c:m:mZd9yxPw_PT3JDsXBsOafTw:rk:4:pf:0

author: BurningTantalum
author_rank: Frequent Contributor
timestamp: November 05, 2018, 05:02:22 am
content: I have used the cheap Chinese version in 4mm (?) widths. It solders OK if one is quick about it, and the glue is very sticky. I surrounded the bottom of my house walls (70 metres) with two runs of it spaced about 6mm apart, connected to an HV generator. This was the only way to stop a biblical invasion of Portuguese millipedes. The tape has lasted for 3 years without peeling off.BT

author: Mechatrommer
author_rank: Super Contributor
timestamp: November 05, 2018, 06:45:09 am
content: i'm thinking of gluing it to some plate, apply etch resist ink and then etch it in FeCl, just as normal diy pcb making, is it doable?

author: glarsson
author_rank: Frequent Contributor
timestamp: November 05, 2018, 07:51:40 am
content: Quote from: Mechatrommer on November 04, 2018, 11:47:58 pmNo, not earth resonance. Snails and slugs just can't stand copper and will not travel across it. Must be bare copper; no plastic film to protect the copper.

author: bloguetronica
author_rank: Frequent Contributor
timestamp: November 05, 2018, 02:08:03 pm
content: Quote from: Mechatrommer on November 04, 2018, 11:47:58 pmSnails don't like copper and copper salts that result from natural oxidation because it is toxic to them. There is also the hypothesis of them being "electrocuted" by copper, but I don't buy that. The chemical reaction seems more plausible.Kind regards, Samuel Lourenço

author: tggzzz
author_rank: Super Contributor
timestamp: November 05, 2018, 02:51:44 pm
content: Quote from: Mechatrommer on November 04, 2018, 11:47:58 pmNo. It doubles the natural Reiki homomorphic crystal frequency, thus interfering with the snail's vision. That encourages them to go elsewhere.

author: thermistor-guy
author_rank: Frequent Contributor
timestamp: November 06, 2018, 01:51:55 am
content: Quote from: bloguetronica on November 05, 2018, 02:08:03 pmMakes sense. Apparently, copper sulfate also kills algae. Copper compounds are used in some pool/spa cleaners:http://lochlor.com.au/company-profile

author: coppercone2
author_rank: Super Contributor
timestamp: November 06, 2018, 01:56:26 am
content: has anyone measured the purity of this cheap tape?i bet you the 3M shit is so expensive because its electrical grade copper thats oxygen free. I have doubts about my chinese tape.

author: BradC
author_rank: Super Contributor
timestamp: November 06, 2018, 02:02:10 am
content: Quote from: thermistor-guy on November 06, 2018, 01:51:55 amCopper is used in almost every anti-fouling coating applied to boats (of all shapes and sizes), although the EU is now starting to make mumbles about banning it.

author: KL27x
author_rank: Super Contributor
timestamp: November 06, 2018, 03:04:07 am
content: I have a roll of 3M copper tape. It is tinned to prevent oxidation, and the adhesive is intentionally conductive. It was probably 25 dollars, which could get expensive if you used it for shielding and large projects. Most what I use is very tiny bits on the odd hack.

author: bloguetronica
author_rank: Frequent Contributor
timestamp: November 07, 2018, 11:45:27 am
content: Quote from: thermistor-guy on November 06, 2018, 01:51:55 amYes, indeed. Copper has antimicrobial properties too and is quite effective. Even copper alloys are effective. There is an interesting wikipedia article about that:https://en.wikipedia.org/wiki/Antimicrobial_copper-alloy_touch_surfacesQuote from: BradC on November 06, 2018, 02:02:10 amEU bans everything. They also should ban themselves because they are one of the most toxic people on earth.Kind regards, Samuel Lourenço

author: Mechatrommer
author_rank: Super Contributor
timestamp: November 07, 2018, 12:45:25 pm
content: so copper consumption should make intestine much cleaner from negative microbial, no?

author: cdev
author_rank: Super Contributor
timestamp: November 09, 2018, 11:17:59 pm
content: Actually, the gut is the home to a great deal of beneficial bacteria, and recently a lot of science has been pointing to the kind of bacteria you have there as being really important for your health.You definitely don't want to kill this beneficial bacteria because if you did, you wouldn't be able to digest your food, food would just sit there and likely poison you.Probiotics like yogurt are made from milk, etc, by seeding the milk with some of this bacteria and warming it to approximately body temperature for a period of time until it turns gelatinous. That makes many nutrients more bioavailable.So, all this is a good reason to stay away from things that could kill them. Babies pick up their beneficial bacteria from their mother and their environment and a good helping of beneficial bacteria gives them a good start on having a healthy life.Antibiotics can kill off the bacteria and that can cause major problems for people. They may actually end up someday reseeding their guts with bacteria from somebody else.

author: Kasper
author_rank: Frequent Contributor
timestamp: November 10, 2018, 08:35:39 am
content: Might want to try brass strip.http://www.ksmetals.com/29.htmlLast time I used foil I covered the thing in it and still had RF leakage. Then I used a bit of brass strip from a hobby store and it worked well untill I soldered every edge, then it worked great.

author: not1xor1
author_rank: Frequent Contributor
timestamp: November 10, 2018, 09:02:26 am
content: Quote from: bloguetronica on November 07, 2018, 11:45:27 amNothing is more toxic than ignorance and while politicians are mostly quite ignorant about scientific matters, average people are even worse.Copper is highly toxic for the environment besides being a limited resource.Restrictions on copper and copper compounds usage do make sense.