Metal smell/taste

[aessinus]

My son just mentioned something in the shop to jog my old memory.  I've wondered about for several years whenever it's mentioned, but it's never a convenient time to research.  Can any of y'all smell or taste metal?  The lad swears he can distinguish between steel and nonferrous.  I have an engineer that swears the shop stinks when we've been sawing aluminum plate.  I guess I don't think about it most times.

Cutting oil, sure, but not metal.    Back to my brisket, it smells delicious.

[ThomasPowers]

You mean some people don't?

[Ridgewayforge]

Well, I haven't licked my anvil, but.... 

Yes, you can taste steel- its particularly strong when I use my angle grinder without a mask. 

[aessinus]

6 hours ago, Ridgewayforge said:

Well, I haven't licked my anvil, but.... 

Yes, you can taste steel- its particularly strong when I use my angle grinder without a mask. 

@RidgewayforgeJust tried my HB, only thing I get is the honey taste from the beeswax I keep on the face,

 

TP, I must be a mutant.  Never knew anyone could til the lad mentioned it a few years ago.  Seriously, no smell, no taste, I get nothing...

Even way back in college, I figured the guys complaining about canned beer tasting funny were just being snooty about my cheap stuff.. 

I should do some research I suppose.  My sniffer works good in the woods; I can smell a possum & figure out which tree he went up.

[Frosty]

If you walk into a steel supplier the smell is the oils and protective coatings on the steel. However metals have a distinct smell I can easily tell the difference between steel, non ferrous and aluminum. Seriously you CAN'T smell aluminum? Father's shop used to have some really different metal fragrances but we worked with a lot of exotics for aerospace. Titanium is one of the more neutral, IF it's one of the more pure alloys. There are so many jet and rocket engine alloys and some are very distinctive, some distinky. The engine hot parts had to be spun hot, one of my early jobs was to hold torch while Dad spun. The lubricant we used to spin smoked a lot but you could smell the metal easily.

Copper alloys come in an array of scents, when I was a kid I could tell bronze from brass like it was strawberry compared to mint and even different grades of bronze. We didn't spin much brass but bronze has a lot of apps. Silver is REALLY obvious where gold has as much smell as a shadow. My sense of smell is WAY less sensitive now than when I was 15 even not counting what the birch did to my smell and taste.

So yes, you can indeed smell metals.

Frosty The Lucky.

[Foundryman]

The gunmetal (a leaded bronze I think) we occasionally use at work smells of rotten fish immediately after casting.

[Frosty]

Rotten fish? Are you sand casting in a resin or oil bond sand? That's a new one on me but my experience in a foundry is very limited.

Frosty The Lucky.

[Kozzy]

It's a curious subject.  Apparently the smell of metals isn't smelling the metal at all but organic compounds that are from metallic reactions.  Here is one source of info http://chemistry.stackexchange.com/questions/7916/why-can-we-smell-copper  and here is a study of "iron smell" that is referenced in the previous link  http://phys.org/news/2006-11-metal.html

Noses are weird, though.  There are certain chemicals that some people genetically can't smell at all while others smell them strongly.  One example is the chemical compounds that come out in urine after eating asparagus --only about 25% of people have the gene which allows you to smell the compounds (and they really stink!). To the other 75%, there is absolutely no smell at which is detectable by their noses from those specific compounds and they can be stymied when you mention it (think you must be crazy...and maybe you are for telling them about the smell of your urine   )

Wondering if similar happens with some of these metal smells--whether some people do and some don't genetically, not just in sensitivity to smells.

[Foundryman]

50 minutes ago, Frosty said:

Rotten fish? Are you sand casting in a resin or oil bond sand? That's a new one on me but my experience in a foundry is very limited.

Frosty The Lucky.

When casting gunmetal it will either be green sand or petrobond (oil bonded sand) depending on the component being cast.

[aessinus]

10 hours ago, Frosty said:

If you walk into a steel supplier the smell is the oils and protective coatings on the steel. However metals have a distinct smell I can easily tell the difference between steel, non ferrous and aluminum. Seriously you CAN'T smell aluminum? .....

So yes, you can indeed smell metals.

Frosty The Lucky.

Nope, nor taste.  My paying shop machines aluminum & composite honeycomb for aerospace mostly.  If a cutter gets glowing hot (dull) I can smell the burning adhesive where the aluminum foil is bonded together easily, as in before other folks notice there is an issue.  All the composites I can distinguish by the resin odor when they are machined.

Son's work shop machines honeycomb in SS, Hastex, etc.  It's all spot-welded together on site, but no smell for me.  He says he tell what general type is running by the smell.  The wire EDM's and spark erosion grinders apparently smell really strong, but all I get is the funky electrolyte and cutting oil fumes in the machine shop.

Dunno, maybe I am am a throwback

[aessinus]

Very interesting research Kozzy.  Thanks for posting.  I'll have to do some more looking tonight. 

Apparently my skin does the right thing to metal because the boy, and his mom, can always tell if I been "hands on" all day.  At work, we use primarily use bandsaws or similar, produces very fine dust that must be pungent.  Our material is not touched without gloves during processing.  Our customers insist their parts be clean & ready to bond, but the dusts go everywhere, even with big dust collection systems.

8 hours ago, Foundryman said:

When casting gunmetal it will either be green sand or petrobond (oil bonded sand) depending on the component being cast.

The fish smell I do recall from AFS(American Foundry Society) college days.  We had a very well equipped foundry for green sand, different core methods, a permanent mold machine, two big gas furnaces & two brand-new induction furnaces.  I remember one of the cores smelled like sardines when you opened the molds.  I don't recall which core type it was though.  Good times, but just too many years ago.

We had an 80# brass melt get away from the instructor/club mentor; when everybody bailed, I ran the length of the shop (100' feet?) to kill the furnace & get all the roof purge blowers going to evacuate the smoke.  I held my breath mostly, but have been gunshy of zinc ever since.  Made me pretty sick

[SLAG]

Aessinus  please define EDM,

A net search defined EDM as Electronic-Dance-Music. I do not believe that is the correct meaning in this thread's context.

Kozzy

thank you for the metallo-lipid-carbonyl references, they are wonderful. (& I have "bookmarked" them for future reference / research.)

SLAG.

[SmoothBore]

Anyone who has worked in a shop doing Zinc or Aluminum Die Casting knows the odor associated with "Heavy Metal Toxicity".

Whether that is the odor of the base metal, or one of the trace alloys, ... like Arsenic or Antimony, ... is unknown to me.

Also, Iron Oxide, on Steel or Cast Iron, has a very noticeable odor and taste.

Copper Pennies are widely regarded as having a noticeable flavor.

 

The variables in human sensory perception are intriguing, ... as well as extensively documented.

[aessinus]

6 hours ago, SLAG said:

Aessinus  please define EDM,

A net search defined EDM as Electronic-Dance-Music. I do not believe that is the correct meaning in this thread's context.

Sorry Boss.  Try wire cut electrical discharge machining.  Somewhat the same results as waterjet, just closer results.  Is the shizzzbomb!...

6 hours ago, SmoothBore said:

Anyone who has worked in a shop doing Zinc or Aluminum Die Casting knows the odor associated with "Heavy Metal Toxicity".

Whether that is the odor of the base metal, or one of the trace alloys, ... like Arsenic or Antimony, ... is unknown to me.

Also, Iron Oxide, on Steel or Cast Iron, has a very noticeable odor and taste.

Copper Pennies are widely regarded as having a noticeable flavor.

 

The variables in human sensory perception are intriguing, ... as well as extensively documented.

Once again, I find myself to be a mutant.  Sigh.

[Smoggy]

Regardless of the cause of the odour, the odour is accosiated with the various metals, be it steel copper. aliminium etc, this is also true for the taste which can sometimes be tasted "in the air".....it's akin to smelling approaching rain or snow fall. Yes we all have differing sensitivities to various odours and tastes and it often changes with age. I can smell a hedgehog that passed through the garden last night, but I've never managed to sniff out a good deal on an anvil yet!

[SLAG]

Aessinus,

Thanks for the definition of E.D.F. There is no need for an apology.

(incidentally, your technical knowledge is impressive).

Kozzy's two cited references explain what is going on. Metals are not being smelled, they do not seem to have a smell by themselves.

But they chemically react with skin compounds and that produces chemicals that do have a smell.

The reaction products of skin oils and low molecular fats with metals that are being perceived. The oils are short straight chained hydrocarbons with 6 through 10 carbons that react with phosphorous compounds that smell. They found on the skin. The metal ions promote the reaction. come of those chemicals are e. g. phosphines, methyl-phosphines, dimethyl- phosphines, and oil octenes (skin oils) such as octene aldehydes and ketones. The latter two groups of chemicals are odorous. etc. etc.  (some of them have been used as perfume ingredients in the past).

Different metals create different odorous compounds. (e.g. Cu., Fe., Zn., etc.) .

I have a sneaking suspicion that I am not being terribly clear.

So if you are interested, in the subject, please  read Kozzie's two cited references. They are short reads, & not too complicated for non-chemists.

The fresh smell of the ground, after a dry spell, is called petrochore, (that would be the preferred search term.) and it does not involve metal ions.

I don't know about hedgehogs. Perhaps they don't bathe.

SLAG.

[ausfire]

Brass stinks. Polish brass on a buffer and you can smell it on your hands and taste it in the air.

Don't know about hedgehogs but possums are a bit on the nose. They like my shed.

[gote]

I do not believe that anyone can smell a clean piece of metal at room temperature. There is nothing that can get into the air. It has to be some kind of gas or aerosol if we shall be able to smell it.

 There are many ways for this to happen; some mentioned above. One easy way to distinguish limestone rock and silicate rock in the field is to hit it with a hammer and sniff at the hammer. The limestone has next to no smell but the silicate rock will smell "gunpowder". It seems that we can smell minute particles of SiO2.

If we grind silica wet in a ball mill, it is customary to increase the pH by adding lime to decrease chemical attrition of the balls. If the lime is forgotten there is a very strong smell that I associate with iron but I do not know what it really is.

I do not doubt that experienced persons can smell the difference between different metals. I would like to know more about circumstances. Buffing is one. Polising is another. I smell something that I believe is the polishing compounds reacting with the metal oxide that is removed. I assume metal spinning works in a similar way. I would assume that working metals cancreate dust that is so fine that it oxidizes immediately. Metal oxide way react with the humidity in the nose and create more or less soluble hydroxides that the receptors in the nose can detect.

[aessinus]

13 hours ago, Smoggy said:

... it often changes with age. I can smell a hedgehog that passed through the garden last night, but I've never managed to sniff out a good deal on an anvil yet!

Smoggy, my lack of smell thing has been at least since I was 19 & worked in an oilfield repair machine shop.  Carbon-arc gouging never bothered me with the odor, so that task always seemed to fall to me.  My mother insisted I shower before even leaving work because I smelled like "that nasty place".  btw, there was a hedgehog as a pet several years back.  It didn't smell much, certainly not like a musky old possum or rats.

Slag, you are perfectly clear in all your posts.  You seldom throw me off with innuendo or sly jokes.  There are other folks that post & I have to read several times or get son to interpret.  Jokes tend to go over my head the 1st time though. 

I did read thru both references & discussed with the lad.  His organic chemistry is fresher (30 years more current too) and he went much deeper as a pre-vet.  He's as baffled as I that I don't get the odors.  Who knows, I could have damaged something in my nose or the circuits along the way.

Ausfire, brass is a no go.  Ammonia in the polishes I smell, but nothing from mechanically grinding or polishing,  Y'all's little possums don't smell much, but they wouldn't make much of a Sunday dinner like our big guys.

gote, check Kozzy's reference articles about metal odor & the reactions.  Very interesting.

Edited September 7, 2016 by aessinus
added response to gote

[SmoothBore]

16 hours ago, Smoggy said:

 I can smell a hedgehog that passed through the garden last night, but I've never managed to sniff out a good deal on an anvil yet!

Well sure, Hedgehogs are real, ... while that other thing is an "urban myth".

--------------------------------------------------------------------------

My lifelong hunting buddy has much better eyesight than I, ... but I can smell a deer in the woods, before he can see it.

( A "dry" Whitetail Deer, smells much like a wet dog. )

 

[Frosty]

I've read some brief articles about the skin oil hypotheses of odors be they metals or other reactive chemicals. It's plausible and maybe even "proven" since I read anything. There's another hypotheses that is as or even more plausible. taste buds and . . . smell buds(?) work by having neural receptor sites of specific shapes a molecule that fits a receptor site it closes a circuit so to speak and the signal is sent to the brain which interprets it as a smell or flavor.

I like the hypothesis that some metal ions fit some of our smell taste receptors and many metals are reactive enough they don't require outside stimulation beyond the presence of oxygen to react chemically and release ions. Even sunshine is enough to make iron sheet's scent plain to my nose and it doesn't have to be in sunlight long enough to even warm up, just the sunlight striking it  is enough.

I thought the yummy aroma of cooking asparagus was due to the sulfur compounds in it like so many of the REALLY healthy green veggies say Brussels Sprouts, spinach, kale, etc. I know it isn't just the sulfur there's a lot going on there and the aroma is very different if you saute, sear, broil or bake them.

I am surprised that anyone can't smell sulfur compounds though it's a prime ingredient in most "danger or warning" odors. Sulfur is a major player in biology so evolution has tuned us to recognize it first as a necessary nutrient and secondly a main ingredient in toxins. Being able to smell sulfur compounds is a survival trait. I'm thinking an injury or illness as the logical cause of loss of such an important sense as smell. I know the TBI really messed with my senses, I'm still adjusting to what thing smell and taste like NOW.

I'm liking this thread, I'm picking up lots of good reading subjects. Man I LOVE Iforge.

Frosty The Lucky.

[SLAG]

Frosty,

I believe you are onto a good idea.

Smell and taste receptors often work in concert together.

For example, a blindfolded person that has his/her sense of smell blocked cannot tell the difference between  pureed apple and macerated onion.

The nasty cooking odor of brussels sprouts, cauliflower, broccoli, etc. (that is found in all the members of the Brassica family). Are caused by the breakdown of proteins that have sulfur amino acids, such as cysteine, cystine, methionine, etc. have sulfur atoms in their make up. Those amino acids are essential for life. Proteins are composed of amino acids. Sulfur compounds often have a strong smell when boiling, etc. breaks down some of those proteins 

For example, a prominent sulfur compound found in nature is diethyl-mercaptan, the main constituent of skunk odor, & a host of others, stink.

Frosty, a few people barely or do not smell skunk odor. They are rare. For example. one such person is Dr. Dragu who is the Worlds foremost authority on skunks. (figures).

By the way, one way to suppress the odor when boiling brussels sprouts is to put a slice of sandwich bread in the water.

Regards,

SLAG.

[Stash]

Try cutting the sprouts in half, toss with oil, s and p, and mebbee some hot sauce, roast in the oven at 350 till done. Now, there's a good smell. You'll never boil them again.

Steve

Getting hungry now

[Frosty]

I like marinading asparagus in Bernstein's cheese and garlic Italian dressing then tossing them on the BBQ or under the broiler. a fast sear in a HOT pan then cover and a dash of water to let them steam finish are ALL good ways to eat the things. One of my favorite ways to fix Brussels sprouts is trim the stem halve them lengthwise and sautee them in garlic butter in a searingly hot pan. When you smell the nutty smell that says they're reaching golden brown and deliciousness kill the fire, splash in a 1/4 cup of white wine, cover and let them steam finish. Another REALLY good way to cook Brussels sprouts is on a toasting fork over a fire, a little garlic butter, salt and toast them till a p inch says they're done.

A good saute on Cauliflower takes a really good pan, cast iron works best but my new 12" ceramic saute pan works nicely, it's heavy enough to not cool to fast to broun the little Florettes. Oh, did I mention garlic butter? It's much better sauteed in garlic butter.

Oh, if you haven't noticed, when I'm cooking if it doesn't have garlic and probably onions in it it's desert.

Frosty The Lucky.

[aessinus]

When I posted this, I was expecting it would devolve to recipes.   Thank you all.  Now I'm hungry.  

So I'll throw this out.  What do you each stuff your possums with?  Brussel sprouts,including all the Brassica family or just traditional celery, onion, garlic and cornbread crumbles?

Ausfire, do you all(spelled out so he don't have to figure out texan) eat your possums?  How do you cook them down south?