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Aluminum foil (2021)

dernocua.github.io

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Re: Aluminum foil (2021)

#131

Post by kragen »

elil17 wrote: post #122
0-_-0 wrote: post #11

This made me wonder about a 3D printer alternative that builds things by folding a thin sheet of metal into arbitrary shapes instead of extruding filament.

Like this? https://www.youtube.com/watch?v=dCXu8Ju_fdY

That's SPIF ("single-point incremental forming"), which is mentioned in passing in my note:

> These can presumably be removed, permitting traditional SPIF processing of raw foil by sliding the point over the foil; a better alternative might be...

I don't think it's closely related to 0-_-0's "folding" idea.

Re: Aluminum foil (2021)

#132

Post by kragen »

shmeeed wrote: post #130
kragen wrote: post #87

Earlier quoted context omitted.

Aluminum is a major component of all soils, and soluble aluminum salts have been used in medicine and dyeing since ancient Greece, probably since ancient Egypt. They have been used in food preparation for at least several centuries.

These are all separate chemical compounds, though. Are you claiming they all behave the same as refined aluminium? I'll readily sprinkle soluble sodium chloride salt over my food. I still very much prefer to keep both substances away from it in elemental form. Note that I'm not claiming aluminium were dangerous, just that your argument is deeply flawed.

It's not that my argument is flawed so much as that it depends on some basic background knowledge about processes like corrosion and solvation. Lacking that knowledge, you're better off taking my word for it that humans are not exposed to aluminum in the environment in a different way since we started refining the metal.

Re: Aluminum foil (2021)

#133

Post by kragen »

bluGill wrote: post #128
cperciva wrote: post #46

Earlier quoted context omitted.

the oxide to pure aluminum ratio is high For some definition of high? Standard foil is around 20 um thick while the oxide layer only goes about 10 nm deep.

When you melt thin al that creates more oxide as well.

Only if you do it in an oxidizing atmosphere. Though aluminum is very liberal about its definition of "oxidizing atmosphere".

Re: Aluminum foil (2021)

#134

Post by roughly »

IshKebab wrote: post #125
roughly wrote: post #50

Earlier quoted context omitted.

The trick to being a good hacker is acquiring a sufficient supply of useless information, such that when that information is suddenly not useless, you have it at hand. Which is to say, it's your job to figure out what the cool applications are.

Yeah fine, take notes. Why post them here?

To share with a community of like-minded individuals, many of whom found it interesting enough to both upvote and comment?

You understand the rest of us do actually exist, right? That we’re, you know, real people with thoughts and opinions and feelings, right? This isn’t pinboard or something.

Re: Aluminum foil (2021)

#135

Post by kragen »

br0ceph wrote: post #66
badc0ffee wrote: post #49

Earlier quoted context omitted.

"Plastic" in general isn't toxic as a liner. It's used in plumbing, and in zillions of containers for potable water and foods. When you get food from even a nice restaurant, they probably marinate meat in a plastic container, and squeeze fruit juice into a plastic container. They sous vide items in plastic. I've also never heard of a plastic/Alzheimer's connection, only one claimed with aluminum.

i didnt mean those contaminents cause Alzheimers, just that its a risk to general health. food grade plastic is not considered toxic at these doses, but u def dont want it in your body if u can avoid it within reasonable effort. i use freezer bags made from plastic , and reuse plastic ziplocs from some food stuffs i buy to marinate meat, its really convenient to be able to remove the air and have the marinade fully c…

"Plastic" is not a material; it's a property or state of many unrelated materials. It doesn't make any more sense to say that plastic is a risk to health than to say that liquid is a risk to health or that crystals are a risk to health.

Re: Aluminum foil (2021)

#136

Post by kragen »

InitialLastName wrote: post #24
1970-01-01 wrote: post #16

>Alternatively, though, it might be possible to stiffen the foil by making the equivalent of corrugated cardboard out of it, maybe using aqueous boric acid (US$1.70/kg according to Potential local sources and prices of refractory materials) or borax as the glue. The surface tension of water is ample to hold aluminum foil in place until the water dries. Hello Amazon? Billion dollar idea here. This needs more attention…

That would be hell on everybody's box-cutters (and fingers). I already cut myself too often on shipping boxes.

I wasn't suggesting using it for shipping boxes, but rather for things like robot arms.

Re: Aluminum foil (2021)

#137

Post by kragen »

IshKebab wrote: post #125
roughly wrote: post #50

Earlier quoted context omitted.

The trick to being a good hacker is acquiring a sufficient supply of useless information, such that when that information is suddenly not useless, you have it at hand. Which is to say, it's your job to figure out what the cool applications are.

Yeah fine, take notes. Why post them here?

By "here" do you mean "the internet"? Are you trying to discourage people from sharing their calculations and observations with one another if they don't personally interest you?

If so, what is wrong with you?

I didn't post my notes on HN; in fact, I didn't even post them on dernocua.github.io.

Re: Aluminum foil (2021)

#138

Post by IAmBroom »

1970-01-01 wrote: post #105
hilariously wrote: post #58

Earlier quoted context omitted.

Cardboard is very recyclable already.

75% of it, aluminum can get to 99% https://www.afandpa.org/news/2024/how-much-paper-was-recycle...

Solid aluminum, not foil. Foil is terribly wasteful, due to oxidation (existing and created by the melting process).

Re: Aluminum foil (2021)

#139

Post by Ferret7446 »

mishellaneous wrote: post #89
kragen wrote: post #85

Earlier quoted context omitted.

It does not, but aluminum oxide is even more of a "forever chemical" than teflon is, though less so than, for example, the nitrogen that constitutes 78% of the atmosphere.

i guess in that case the question would be if one should be as worried about the biological effects of PFAS as much as these two other forever chemicals you cite

The irony is that the more 'forever' (non reactive) the chemical, the less effect they have on the body, generally speaking. You do not want something with a short half-life in your body

Re: Aluminum foil (2021)

#140

Post by burnte »

Nifty3929 wrote: post #117
jacobgold wrote: post #113

Earlier quoted context omitted.

> " There's no risk to leeching, there's no data proving any link at all between Aluminum and Alzheimer's. " EFSA (European Food Safety Authority) says acidic or salty foods can increase aluminum leaching from pans and foil into food: https://efsa.onlinelibrary.wiley.com/doi/pdf/10.2903/j.efsa.... This review found mixed evidence and a positive meta-analysis signal for aluminum exposure and Alzheimer's: https://www.s…

"Aluminum (Al) is a widespread environmental contaminant " - they lost me right there in the very first sentence. Already using charged, non-neutral language ("contaminant"), giving away their pre-existing bias and forcing me to disregard the rest of their opinion on the matter. Aluminum is no more "environmental contaminant" than any other extremely common basic element in the Earth's crust, like silicon or iron. Ar…

Yeah, it's the third most abundant element on the planet. If that's a contaminant, then so is iron and oxygen and nitrogen. Did you know Dihydrogen Monoxide is found in 100% of cancers?
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