7014 vs 7018 on the farm

[ryanjones2150]

7014 vs 7018 on the farm

Blowing stuff up? Now this post is on the right track...

[Bentrod]

Desiccant does work.

At work they repackage our rolls of 100 wire for welding HSLA-100 steel plate into plastic bags with two packages of the stuff and store it in buildings, but not in heated ovens or anything. Considering what that plate is used for, and where on the ships, it's storage would not be allowed if it was not overly studied by the government.

[cwgrizz]

Welding wire is one thing... 7018 LoHy rod "may" be something else. Desiccant does work for removing moisture from lots of things ie gun cabinets, electronic storage, etc. Still not so sure about LoHy that "also" absorbs moisture.

[mongobird]

It kind of goes back to the concept of what material shows what affinity to water, and presents a localized partial pressure gradient to attract more water than other materials in the localized atmosphere.

I am sure there are tables showing what desiccants have what affinity to water. If the characteristics of the 7018 rod are known one can then predict the effectiveness of a desiccant in keeping 7018 dry.

My bet is that it is a much lower partial pressure than is needed to keep wire from corroding.

Going back to the concept of using LN2 or even Ar as the prevailing local atmosphere...at least it does not come with moisture...just that it may suck it up faster than we would wish. So one thing is to look at how water vapor is absorbed into an atmosphere of N2 or Ar, or He or some other gas.

(I remain perplexed at the purple brake fluid...)

[old jupiter]

Me, too!! And it wasn't just a slight change of hue, but so dramatic a violet color as to instantly catch the eye. If it wasn't the argon, then WHAT? As I said, this was brake fluid from a newly-opened sealed plastic quart container. It has been a long while, but I believe the pressure-bleeder, which I had disassembled and detail-cleaned, would have been dry other than whatever moisture was in the air; I doubt that, for instance, there would have been any significant residue from any solvent I might have used in the cleaning. A head-scratcher for sure. Maybe for the heck of it I should try again and see if the effect is reproduced . . . but meanwhile I have a supply of cool-looking fluid for brake jobs, LOL.

As to whether the silica gel or the 7018 coating draws moisture more effectively, I just figure that whatever the dessicant picks up is that much less for the rod to pick up . . .

[chewinggum]

Dot 5 brake fluid is purple for identification.
CG

[mongobird]

Dot 5 brake fluid is purple for identification.
CG

You are right, blue/purple. We are all looking pretty dumb on that one.

[mcostello]

Just as it was getting interesting....................

[ryanjones2150]

7014 vs 7018 on the farm

Dang, I was gonna run out and have a little science project going on. What a bummer.

[old jupiter]

No, I never have used DOT 5 for anything. This was either 3 or 4, I think Pyroil brand DOT 4 from Schuck's (now O'Reilly's). And it was not any odd color when I poured it into the bleeder; as I say, this was such an intense color, I'm quite sure I'd have seen that right off (as if somehow the packing plant had mistakenly filled my DOT 4 bottle with DOT 5 fluid). The mystery continues. (I'm guessing I must have somehow introduced some impurity, I just don't see how the argon could have done it . . . ). I haven't thought about this weird incident in a long time, but now that you guys seem interested, I guess I better do a little test if one of you doesn't beat me to it. If time of exposure is a factor, I can't guide you because I don't recall how long it was between the back-filling of the bleeder with argon after the first brake-job and the next brake-job, when I saw the color change..

[mongobird]

We are off topic, and it is fun. I buy the DOT-5 theory. Perhaps that is what you dredged out of the system you were bleeding.

In my somewhat large family, I have a reputation as the chemical guru, and love esoteric trivia, but it is a real stretch to see how the Ar introduction to brake fluid would cause a color shift consistent with DOT-5 standard coloring. However, if this group insists I beg my PhD chemist brothers for their opinions, but we run a serious risk of this thread going south extremely quickly, or of me getting laughed out of the next Thanksgiving dinner.

[old jupiter]

I buy the DOT-5 theory. Perhaps that is what you dredged out of the system you were bleeding. . . .

Nope. Why would I save old brake fluid, bled out of the car, when I had a brand new quart container of it? Old fluid might be okay for the initial cleaning of brake parts you're rebuilding, but I sure wouldn't put it back into my carefully-cleaned out pressure-bleeder. And anyway, I've must never have bled DOT 5 fluid out of any vehicle, because I have never seen purple fluid; some dark, nasty-looking stuff in a car that hadn't seen fresh fluid in way too long, but never purple fluid.

As I said, like you I can hardly believe that it was the argon that did this to what was supposed to be new DOT 4 fluid, but I have no good explanation. Anyway, don't talk to your family about this until AFTER Thanksgiving dinner, LOL.

[mongobird]

So a late night interloper, dressed in black, stole your bleeder, and used it on his Batmobile, and topped off the bleeder with DOT-5, unbeknownst to you. Makes sense.

You might turn blue/purple if you keep breathing the Ar.

[ryanjones2150]

7014 vs 7018 on the farm

If you breathe a lot of argon, you will absolutely turn blue.

[mcostello]

Smurf Gas !