Purchased green glass ashtray at antique mall and cannot for the life of me get this residue off. So far I have tried hot vinegar soak for 24hours, 409, oil, and just regular dish soap and hot water. Any ideas or tips for how to remove this or what causes this?

Coated the two pans I got from the antique shop on the weekend in yellow cap cleaner and forgot about them in the bag for a few days. The small pan was almost completely stripped, save a few spots. So it got another coat and back in the bag for a day or more.
The second pan was pre-stripped when I got it, but it got the same treatment nonetheless. Rinsed it off, dried it as quickly as possible outside. It got a round of Bar Keepers Friend, another rinse and dry, and then a vinegar scrub before more rinsing and a heat dry. It’s now pre-heating in the oven waiting for me to oil and bake it.
I’ll post the results when I have a few layers on, and when the little one is fully stripped.

Photo 1 - total haul
Photo 2 - mystery boxes, post trades. We had 2 boxes, originally contained 3 ECI pieces & 3 stoneware all in Cerise. I traded from Thurs-Sat to end up with these pieces.
Photo 3 - sale purchases
Photo 4 - my “special pieces” cabinet. Top is my first LC from first FTT attended with grandmas porcelain antiques, middle are grandmas tea cup collection & my salt/pepper collection, bottom are my brasier unicorns from this FTT
I saw a budget breakdown on a FB group and thought it would be interesting to compile my data too. We treated this as a mini-vacation. My budget for purchases was $800, which was winnings from a small jackpot at the casino (& also which I blew past 🙈). I feel very grateful and fortunate for a wonderful experience all around.

Total expenses $1,813

Total LC value $2987

Expenses

Gas $170
Hotel $280
Food/Drinks $340
Experiences $44 (the San Antonio botanical gardens were amazing!)
Spent at FTT $979

FTT mystery box final tally

Stainless steel shallow casserole $228
Turquoise #32 5 qt braiser $415
Caribbean 10.25 in skillet $220
Vapeur heritage square casserole $115
Caribbean 3 piece oval baking dish set $175
Matte sugar pink #28 7.25 qt DO $460

Sale Purchases

L’oven #24 DO $415
Cool Mint #30 3.5 qt brasier $368
Caribbean kettle $100
Caribbean oil & vinegar bottles $60
Square baking sheet $48
Cookie baking sheet $42
Pizza pan $48
Rectangular cooking sheet $36
3 colander set $145
Jewel espresso shot set $56
Spatula $15
Handle cover $20
Replacement knob $21

Edit:
Okey dokey, folks! From the feedback, this one came out a bit jumbled. Here’s a TL;DR of the basic points.

• Minerals = metals.
• Copper and iron are two metals that eat away at (oxidize) most things. They will spoil oils (such as cooking oil or skin oil) and make them stink.
• Metals and fats create new substances when they combine. For example, soap, soap scum, and some kinds of metal corrosion.
• Forcing metal to combine with fat likely helps to dissolve mineral buildup in hair. Putting the right oil on your hair would pull metal out in order to form the new substance.
• The fats capric acid and caprylic acid dissolve copper the fastest. They’re also called C8 and C10. Here’s an example of an MCT oil with just those two fats.
• Treating mineral buildup in your hair will probably only smell weird if there’s oil in your hair, including sebum.

I’m building on info from my last post, so that one may help.
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This post is about my experience testing out medium-chain fats at dissolving mineral buildup in hair, with discussion of how fats have been observed to interact with metals, and odors you might run into along the way. As always, type me a comment down there if any of this goes over your head or you want to know more!
If you need a refresher on the science or any terms, check out my last post for the overview.

Background

The most basic kind of lipid (fat) is called a fatty acid. Its molecule has a tail, and one of the ways to tell apart fatty acids is by the length of their tails. Fatty acids can be pure and unattached (free fatty acids) or in little clusters (e.g. a triglyceride). Oils and fats as we know them are actually a mixture of multiple kinds of fatty acids, mostly clustered and long-tailed ones. Metals can form compounds with fatty acids. I’ve been calling these substances scum. Chemically, they are known as soap^\), often called metallic soap. I’m fairly sure that this is the gunk that shows up on the scalp for some of us with very metallic or hard water. As sebum is produced, the mineral buildup slowly turns it into scum/soap.
^\)^{This is where normal bar soap gets its name, because it’s made of sodium or potassium—metals—which are chemically connected with fatty acids. Soap scum forms when metals in hard water steal away the fatty acids from the sodium in bar soap.}
There’s a lot that’s still unexplored about how metals and fats interact. This topic is particularly relevant when it comes to conserving artwork and other historical items.
One example came from a museum in Denmark that kept some personal papers and effects of a celebrated sculptor from long ago. When designing her sculptures, she would make little wax models over a metal base.
A pale wax figurine that is turning light green in sections, and an x-ray of the same figure showing the metal stand inside holding it upright (Gramtorp 2013)
Her models, now around a hundred years old, were taking on weird colors and smells, and starting to dissolve in places.
A close-up of a piece of wax that is dark green and slimy-looking (Gramtorp 2013)
The museum wanted to figure out what was happening chemically so that they could stabilize the collection. They found in her notes recipes for modeling wax that called for olive oil and butter. Aha, maybe there were fats going rancid and that was the scent. Chemical analysis of the green wax found soaps of copper and zinc bound to stearic/palmitic acid and oleic acid. Copper and zinc means that the metal wires inside were brass. But they weren’t sure what oil she wound up using because she tweaked her recipes over time, nor why the metal was liquefying the wax.
Another museum in Canada experimented with the best way to clean and restore a beaded leather belt, where the blue-green corrosion actually formed a crust over whole sections.
A section of the belt’s design with brass beading, and the same area completely encrusted with turquoise corrosion (Werner 2012)
They settled on using mechanical cleaning to get as much crust off as possible before carefully using a solvent, and they spent time discussing their research on the volatility of copper in the context of preservation and storage. Copper will rancidify oils, which mostly have the triple triglyceride compound instead of the single fatty acids. And because the belt contained leather and sinew, they pointed out how coppeiron will break down leather, collagen, and even cotton. Of course, we know that copper and iron do this to hair too!
A recent study tested each fatty acid with copper and brass to see how quickly soaps form. They found that the longer the chain length of the tail, the longer the conversion from fatty acid into soap took. Stearic acid with an 18-carbon tail, C18 for short, fully reacted with copper in 20–24 days and with brass in 30–40 days. C6 evaporated so fast that it couldn’t react with copper, but it did react with brass for about 30 minutes. For pure copper:

Fatty acid	Full reaction time
C18	20+ days
C16	18+ days
C14	5½ days
C12	8 days
C10	4 hours
C8	3 hours
C6	--

So the fatty acids 8 carbons long (caprylic acid) and 10 carbons long (capric acid) are in the sweet spot.

Hypothesis

C6, C8, and C10 are considered medium-chain fatty acids, with medium-length tails that are six, eight, or ten carbons long. They’re somewhat uncommon in nature, but they are in coconut and palm kernel oils, and in lanolin. My hypothesis was that the C6–C10 fats are active metal-binding ingredients in lanolin. My goal was to compare coconut oil, MCT oil, and lanolin to see if their medium-chain fats give them similar binding properties in my fine, 2b/2c hair. Frustratingly, my tools for making lanolin treatments were delayed. In the meantime, how did the first two stack up?

#1 Coconut Oil

Coconut oil is about 7% C8 and 8% C10 triglycerides.
I used refined, deodorized coconut oil. It had virtually no scent, just the impression of a rich fat, like melted butter.
I briefly steamed my hair in the shower to lift up the cuticle, and rubbed in the melted oil bit by bit until the hair was saturated. I wrapped my head in an old cotton pillowcase and put a beanie over the whole thing. I left it for 90 hours (3.5, almost 4 days) before washing.
Under my hat I discovered a very distinctive odor that didn’t fully wash out. I associate it with the spicy sort of smell that you get from using stale moisturizer. Not quite nail polish remover / acetone, but maybe a distant cousin. It reminded my spouse of mineral oil lubricating a sewing machine. It must be the smell of oxidized^\) fats, meaning that metallic buildup did start decomposing this typically stable oil. I wondered if a virgin, unrefined coconut oil containing the original antioxidants would be more resistant to that. I had chosen refined coconut oil to try to limit confounders.
There was some scalp buildup but not much. Possibly just the normal stuff generated by my own sebum. My hair seemed to last the normal amount of time, about a week, before looking greasy.
^\)^{If you’re not familiar with oxidation, you can just think of it as a kind of spoilage or destruction. Oxidation is what converts iron into rust, and fuel into fire or explosions.}

#2 MCT Oil

MCT oil is typically a mix of C12, C10, and C8 triglycerides.
I skipped the C12, and used a fractionated MCT oil that was pure C8 and C10 at 60% and 40% each. It had no smell whatsoever, and was liquid at room temperature. I had high hopes for this one because there are stories of MCT oil dissolving polystyrene (Styrofoam) and other plastic containers, similar to lanolin.
I followed the same application procedure as above after my one-week waiting period. The spicy smell was mild by then but still detectable. I had been concerned that any oxidized oil left in the hair could spoil fresh oil, but I wasn’t sure how to fix that without postponing indefinitely. Unfortunately, in spite of the hat, I was already getting generous whiffs of oxidized oil by the next morning. Only 48 hours (2 days) in, I convinced myself to give up. C8 and C10 are supposed to work within hours, per that study. I compromised the experiment by not getting the old coconut oil out, or I was wrong about MCTs being tough on metals. Just admit to Reddit that you’re not so smart; maybe find something else to try.
The MCT oil shampooed out just as easily as the coconut oil, but AH THE STENCH as I washed it. In fact, I was combing a lot of buildup off my scalp, much more than the first trial. Was my last wash less thorough? Then it hit me.
Metal has no smell.
The scent that we associate with metal is actually a reaction of the metal with our skin. I read this factoid as a kid and tucked it away safely. With our skin? Does that mean… skin oils?
Yes.
The first stage of lipid/fat oxidation is when it turns into lipid peroxides. Air or bacteria can do this, so we’re already carrying around some sebum peroxides on our skin. The second stage turns these peroxides into aromatic aldehydes and ketones (like acetone!), which is what happens when skin comes into contact with, say, metal coins.
I brought my science and my freshly laundered head over to my roommate, who took another sniff and revised his assessment to corroded copper.
So: the scent of metal, corroded or otherwise, is a subset of the scents of oxidizing oils, chemically speaking. My expired moisturizer, his sewing machine oil, Antique-Scar’s metal, Disastrous-Sea’s petroleum (?), presumably silky_string’s farm animals, and in fact blood with its iron, are on the same spectrum of scents. A theory is that humans are very sensitive at detecting these chemicals because smelling blood was important, such as on a hunt.
Well, we got the privilege of detecting those smells the rest of that week. WAS there still oil under the hair scales somehow? The smell sharpened when my hair accumulated enough sebum to start looking greasy, and still after only one week. While I was deciding what to do, I noticed that the greasy hair… didn’t really get greasier. By two weeks, it still had the seven-day clumpy texture, but the sebum wasn’t building up past that.
Perhaps due to my acid mantle helping me out, the next shampoo did cut a lot of the smell. I skipped conditioner like I was doing throughout the trial, and this time it turned out very dry and frizzy. Maybe there had been oil left on or in the hair shaft after all.

Final Thoughts

Oil-based binders have the potential to be the very smelliest option. But does that make them the most effective?
My open question is whether the scent of oxidation means that soaps have been formed (buildup is dissolving! progress!), or whether the smells simply happen anytime metal and oil touch including but not limited to soap-making.
Antique-Scar smelled metal when using a vinegar treatment, and vinegar does not contain fat. There were no odors from apple cider vinegar or citric acid for silky_string, up until a combination of citric acid and ascorbic acid, likewise fat-free. Importantly to note, acetic acid (vinegar) tends to grab metal with only one of its hands, and is thus not a bi-handed, true chelator. Ascorbic acid (vitamin C) does have the possibility of being a chelator. But in the presence of metals like iron and copper, its antioxidant abilities paradoxically can increase—prolong, I’m guessing—the total amount of oxidation and its accompanying scents!
In comparison, the study on oxidative scent compounds found that using a three-handed iron chelator suppressed the development of the typical smell of blood. Treating hair with the strongest chelator, EDTA of the Five Hands, is also reported to have faint or no smell.
This leaves us with a few theories:

1. Hair may have to be perfectly clean of sebum to avoid smells during treatment of metal buildup. Sebum or sebum scum wedged under the hair cuticle could make this impossible to achieve.
2. A true chelator (minimum of 2 hands) may be required to avoid smells during treatment.
3. A strong chelator (minimum of 3 hands) may be required to avoid smells.
4. Oxidation smells may be impossible to avoid with an oil-based treatment.

Your turn!

Which chelators or metal binders made the most (or least) intense smells for you? Do you remember how much sebum was in your hair at the time? And where else in your life have you encountered metallic odors? (Coming in from the cold outdoors, anyone??)
​

Sources and further reading

• Investigation and conservation of Anne Marie Carl-Nielsen's wax models. Gramtorp (2013)
• The removal of metal soaps from brass beads on a leather belt. Werner (2012)
• Infrared spectroscopy reveals the reactivity of fatty acids on copper surfaces. Boyatzis (2023)
• But aren’t all soaps metal soaps? Russo (2023)
• Rancidification at Wikipedia
• The Two Odors of Iron when Touched or Pickled. Glindemann (2006)
• Oct-1-en-3-one at Wikipedia
• Old person smell at Wikipedia
• Two Faces of Vitamin C—Antioxidative and Pro-Oxidative Agent. Kaźmierczak-Barańska (2020)

Picked this skillet/griddle up at the antique store for $8. It’ll go motocamping soon! Yellow cap easy off and a vinegar bath. 2 seasonings down. Now it’s time for some bacon. Can someone ID it?
Had this cornbread mold around for a while, a quick dip in the vinegar (it was just rusty, looked unused) and note it’s ready to cook! I guess I missed a kernel or two when wiping and the oil pooled on the surface in two spots.
I’m a “function over form” user of CI, so although not perfect, I’m happy and will use them, allot!

We’re getting ready to install this mantle pulled from salvage. Originally we thought about stripping and painting. While the finish is rough, it’s kind of growing on us as old and worn. I did clean the surface a couple of days ago with a light vinegawater solution and scotch brite pads. Rinsed very throughly with warm water multiple times and dried.
Restore options I’ve thought of: 1. I like the idea of boiled linseed oil and beeswax (use it for woodwork) just to rehydrate wood and buff on finish. Problem with that is the smell, my wife would not like the linseed oil smell at all. I guess I could do mineral oil and beeswax.

1. Restore a finish (not so sure about that one, don’t need to get rid of cracks exactly, but a little more color could be good.
   
2. I see this product called Kramer’s Best Antique Restorer that’s available, but anyone using it and posting videos either work for company or have no idea how to shoot a video. The stuff in antique mall with it applied looks nice. If anyone has experience with this stuff I’m interested.
   
3. Other ideas (oil soaps, products, etc.)?
   

Bought two pans years ago at an antique mall. Yesterday I soaked them in a white vinegar solution for an hour, then scrubbed with baking soda and dish soap until I could see a solid silvegray surface. (I could NOT strip the outside of either pan even after scrubbing forever.) Dried over a low burner, then rubbed with an extremely thin layer of canola oil, popped them into the oven upside down for an hour at 450, and left in the oven overnight. Both are splotchy. Is this normal? What's my next step here?