Lyeden Jars

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Why not just cut the tops off the bottles to make jars? Spray-on conductive paint is available for coating plastic, I think it contains nickel particles. You might be able to adapt an aerosol can to spray inside the bottles.

Leon

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You offered a reference which states that the classic Leyden jar used a liquid inner "plate" with a connecting wire dangling into it.

Do you have a weight limit or some other requirement which makes you need to use a conducting film rather than just filling the wine bottles with water, and maybe some salt in the water for good measure?

But, if you really need to use a coating, then Google up "Aquadag". It's a black conductive coating which can be painted on glass. IIRC the outsides of some CRT envelopes used to be covered with the stuff. It felt like it might of had a lot of carbon powder in it. You could probably pour it in and out of your wine bottles to get what you want.

Good Luck,

Jeff

When you get right down to where the rubber meets the road, a Leyden Jar is a primitive, but quite effective, medium-high value capacitor.

Too easy: Make yourself a saturated salt solution (Water, plus as much plain old table salt as can be disolved in it) and fill the bottle to the desired level. Saltwater is a good conductor - at least as good as, sometimes better than, any foil you might apply. Now wrap your bottle in tinfoil, as smoothly as possible. Push a metal stud of some sort (Brass would probably be best, longevity-wise, but just about anything will do in the short term) long enough to make contact with the salt water inside the bottle through a rubber stopper, and put the stopper in the bottle. If you're looking to parallel them, pack a few of them together in a box of some sort lined with tinfoil, and "bus-bar" the stopper terminals together. The end of the bus bar is one terminal, the tinfoil on the bottom of the box is your other terminal.

Pretty standard design for low-dollar tesla coils, which need *BIG* caps.

Note: It's *MUCH* easier to tune bottles that don't taper - Tapered bottles can get screwy when trying to tune them to a specific value (which is done by raising/lowering the level of slatwater inside them. The taper really messes with accuracy)

Well, I want the look of the wine bottles with the long necks. If it was easy, anyone could do it.... :-)

--Kamus

You must not have noticed the "shoestring budget" statement - Aquadag is expensive with a capital !EXPENSIVE! in anything short of traincar-load lots. Last time I looked (several years ago, admittedly) 60+ bucks for a half-pint jar was the going rate. When I asked what was in it to make it so expensive, the response was "We don't want to mess around with hobby-level buyers, so we try to discourage them by pricing it high in small quantities. For industrial users buying multi-hundred-gallon lots, it's quite cheap."

I thought about that, but I couldn't find any more about the "liquid". I thought about salt water too... It would be kind of cool. Of course, figure these things will be charged up to maybe 100KV so the thought of salt water doesn't give me a warm and fuzzy.... But at worst it will knock me on my butt....

Cool, thanks.

--Kamus

Don Bruder wrote in news:NkItc.13692$ snipped-for-privacy@typhoon.sonic.net:

It's the cheapest commercial product I know of -- 2 pounds for under $40:

the other paints are metallic colloids, and the same $40 will only get you a few ounces of paint.

Look up info on silver plating mirrors, more specifically "Breshams solution " and correct my spelling as I know that is not spelled correctly.

Bill K7NOM

Actually, I found it for $40/2#; not quite cheap but certainly in line with other conductive paints I've found.

I'm not really too hot to trot on the $900/ 1/2 oz. price for gold paint....

--Kamus

Most conductive paints will not be at all cheap.

Given your desire for cheapness, I'd suggest that you just use foil and "ship in a bottle" tooling (grab some coathangers and start bending). Shove a slug of foil in, and then squish it out onto the walls with long tools from the neck.

Interesting timing. Two nights ago I was reading an old book on vacuum tube design. There was a great description of how the aquadag coating was applied. The CRT already had the phosphor applied so it was held upright and the aquadag was syphoned in and out so as not to contact to phosphor. There was also hot air and suction applied so that the water in the aquadag would not condense on the phosphor.

They mentioned that the aquadag formula was graphite, ball milled for 48 hours mixed 1:2 with water.

(Snip)

Powdered toner from your laser printer mixed with glue to form your own brand of conductive paste?

Here is a lifetime supply of conductive ink precursor for U$0.99

--Winston

Can you show me that toner is conductive?

Since the toner is applied electrostatically, I'd assume that it's an insulator.

About six months ago I made a couple of Leyden jars using the latex based conductive paint, Cupro-Cote from Less EMF. I picked it because I was making the jars from acrylic tubing. Anyway, the paint worked perfectly. It seems to me it would be easy to coat the inside of a wine bottle with conductive paint by simply pouring in a sufficient amount and tilting the bottle while rotating it to coat as needed. You could accelerate drying by rigging up a low pressure(aquarium air pump) air supply through a small plastic tube to establish a continuous supply of dry air to the bottle interior. You can also coat the exterior of the bottles to make the other plate: the paint I used is surprisingly tough.

Randy

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could you use a balloon inside the jar to tighten up the foil?

Put some gravel or scrap carbide tooling in a bottle and spin it in your lathe for a long while.

Mix up linseed oil and bronzing powder (aluminum powder) pour it in. Spin in lathe for an even coat. Pour out excess. Cure some. Pour in bronzing powder and coat more.

On the outside you could probably do the same or switch to the spray-on zinc-epoxy mix (99% Pure Zinc, or so says the spray can) from Eastwood.

What about doing a copper plating with a strong copper sulfate solution? How does that chemistry work?

Sees to me powdered nickel can be diffusion bonded into glass. You might be able to rough up the glass, add nickel powder and put in a ceramic kiln to get a nice bond.

What about spray transfer systems used for aluminizing steel? Fill up the bottle with stainless swarf, heat it up, add a charge and blast it. Do it on a turntable for even coating.

.

Yes, and after I finished posting I remembered that some CRTs are damn good Leyden jars too!

I nearly lost my after school job as a TV repair guy in the 50s 'cause I dropped a good sized B&W CRT which zapped me when I picked it up to take it to the truck. (Glass all over the place....)

I'd forgotten to discharge it after I disconnected the anode lead before taking it out of a customer's TV console cabinet.

IIRC sometimes that charge in the CRTs would "come back" enough to bite you even though you'd shorted it out once. (Dielectric absorption?)

Jeff

Would cold galvanizing paint work? I assume that to impart the corrosion inhibiting properties (actually more like a scrificial anode) it would need to be conductive.

-- Joe

-- Joseph M. Krzeszewski Mechanical Engineering and stuff snipped-for-privacy@wpi.edu Jack of All Trades, Master of None... Yet