Aluminium and Ferric Chloride

They don't sell as well in the rain, sleet, and snow, eh? My glare guards don't sell as well in the winter, either.

A hobby anticipating commercial sales, then. I developed the glare guard for an attorney client of mine who wanted to use her laptop at the park when she was watching over her little girl. (Yes, I gave her a raised eyebrow over that one, too.) I've sold over 100 of them so far, and they continue to be tank tough. Fun, but not as profitable as I'd imagined, and they're a chore to make properly. I went through the same challenges finding the right adhesive as you are having with the etching. Most adhesives lay on in lumps, and that telegraphs right through the ripstop nylon cover. And would you look at the

-price- they're getting now for 3m Super 77 spray adhesive!

Grok that.

Sorry, sir. You're in the wrong country for that. I believe they serve tax grabs at/to you up there, not cuts. But we'll not have any tax cuts while The Chosen One is in office, I'm sure. (No matter what he might or might not say.)

-- You can't wait for inspiration. You have to go after it with a club. --Jack London

On Sun, 05 Dec 2010 06:13:13 -0800, Larry Jaques wrote: [...]

My favorite subject, glues. Today I counted that I may use up to five different glues on a single dial.

You're a real stickler, are you?

Finding the proper adhesive turns the product from amateur to pro in seconds, doesn't it? What a difference they can make.

-- You can't wait for inspiration. You have to go after it with a club. --Jack London

Or it could just be an unholy sticky mess...Seriously, the best fun with glues is re-wiring fencing swords.

Yes, an unholy, sticky, BUMPY mess which later untacks and blisters up. Not good.

Reminds me of an old play by Uncle Will. "Epee or not to epee. That is the question."

-- You can't wait for inspiration. You have to go after it with a club. --Jack London

Yes, but as the bubble leaves, in the center it is refilled with a more depleted solution, than the solution at the edge jk

snipped-for-privacy@gmail.com wrote in news: snipped-for-privacy@4ax.com:

I tried 'em all. I do all my re-wires with hot melt now. You need the right flavor, but it sticks well, is flexible, but easy to remove when the wire breaks.

Doug White

To make things even more confusing:

I tried a different electro-etching method today. I made myself a hand-held electrode (cathode) and applied it through a coffee filter folded several times and soaked with electrolyte and through a stencil made of acetate sheet to the work-piece (anode). The electrolyte was salt with some vinegar.

Results:

1) The current declined rather quickly and within 30 seconds was less than 10 mA. 2) There was a green and orange discoloration at the site of the stencil on the filter paper indicating formation of iron hydroxides. I was able to prevent this with the vinegar acidification previously. 2) There was a visible etch of undetermined depth both on mild steel and on stainless. The etch had well defined edges. However, when I tried it on brass just to see what happens there was a "halo" around the pattern. 3) Examining the etch with 10x magnification it was clear that a similar phenomenon to that described previously was present, i.e. deeper etch around the periphery of the etched area in a form of a well defined "trench".

I found the last bit puzzling. Yes, there is gas produced during this process (hydrogen - I had previously ruled out any significant production of chlorine with these electrodes) but this gas should be produced on the *cathode*, not on the anode (the work piece). The way the electrolyte is applied here should provide an additional barrier to the gas penetrating near the anode. So I wonder: Is it really the gas bubbles that are causing this phenomenon?

I assume that the current drop off seen with this set-up is due to the electrolyte depletion at the site of the etching. The appearance of the hydroxides would support it. I did not see such current decline when I used a salt bath (with or without vinegar) where there is presumably free recirculation of the electrolyte.

I am also puzzled why one gets the halo on brass and not on iron. I tried the experiment with a copper electroplating solution obtained commercially (I believe it contains copper sulphate and sulphuric acid but in what proportions I do not know). The halo was still present.

I am not sure that I am any wiser now than when I started.

Michael Koblic, Campbell River, BC

I find that different blades need different glues. I tend to use CA.

See what happens with reverse polarity.

Cheers! Rich

Limited refreshment of electrolyte under the pad, perhaps?

Do you get a green/orange scum collecting on top of the solution in all cases? Perhaps the paper is trapping what otherwise would be washed away by the "scrubbing bubbles" of electrolysis.

Difference in conduction rates causing a highly-charged, stratified layer above the plate, perhaps?

So electrolysis has its own sort of HAZ area. Question: Could it be that a more open surface is "scrubbed" more by bubbles, leaving more oxides at the edge? Is it a "dirt in the corners" kind of thing?

Hmm, are the bubbles a secondary-process or merely a byproduct of the electrolysis? (I have no college-level chem or science class exp.)

SWAG: It's probably some interaction between fluid flow and conduction rate for certain materials, electrolytes, and electrodes.

But you're having fun, so who cares? Note the results and use those specific processes you like where you like. As with many other things, there's some magic in patinas and etching.

-- Invest in America: Buy a CONgresscritter today!

Black deposit in the middle of the stencil pattern and the anode (previously cathode) starts getting eating away. Current pattern about the same.

[...]

With pure salt solution, yes. The green scum starts appearing almost immediately and later it progresses to orange. The whole bowl looks disgusting - like curry gone bad.

When I add vinegar to the salt hardly any precipitate forms.

My rudimentary chemistry tells me that the former case is formation of insoluble hydroxides (ferrous=green, ferric=orange). In the latter case ferrous acetate is formed which is soluble. However, soaked in the paper there is no circulation of the electrolyte so the acidification is swamped. Or I just did not put enough vinegar in...

[...]

Fun is one thing, wasting time is another. I was hoping to have a settled process to build on. Never mind, I have got a couple of further experiments lined up.

OTOH my wife is relieved that I no longer boil asphaltum in the garage. I do not think she particularly cares for the smell and it scared her on arrival with the shopping.

Michael Koblic, Campbell River, BC

Six of one...

Well, you-know-who said "Results! Why, man, I have gotten a lot of results. I know several thousand things that won't work.", so don't fret about it. (Has the light bulb come on yet as to who said that? ;)

She doesn't appreciate the "tarred and feathered" scents, eh? ROTFL!

-- Invest in America: Buy a CONgresscritter today!

[...]

Jara (da) Cimrman

One can see that a smell of boiling asphalt coming out of your house without an immediately obvious explanation might be of some concern.

Thomas Edison, inventor of the working light bulb after thousands of tries with damnear every element and alloy known to man at the time.

Yabbut, only once. Then again, she has an inquisitive and creative husband, so she should know better. After all, this isn't the first time you've pulled this cra^H^H^H^H^H^H^H^H^H^H^H^H^H^H^Hexperimented, is it?

-- That is what learning is. You suddenly understand something you've understood all your life, but in a new way. -- Doris Lessing

(...)

Er. Slight misspelling of "Joseph Wilson Swan" there, Larry.

--Winston

Edison finally got them to last worth a hoot, hence my term "working" light bulb. Thousands of trials later, he found tungsten. Thank you, Misters Swan and Edison.

Uncle Tom sure screwed the pooch on the AC/DC battle, though. Thank you, Misters Tesla and Westinghouse.

-- That is what learning is. You suddenly understand something you've understood all your life, but in a new way. -- Doris Lessing

Clever people, these Swedes! But look where it got us: They caused Global Warming!

BTW I did not know that Tesla and Westinghouse were AC/DC. I guess I did not ask and they did not tell...