Win a copy of Permaculture Design Companion this week in the Permaculture Design forum!
  • Post Reply Bookmark Topic Watch Topic
  • New Topic
permaculture forums growies critters building homesteading energy monies kitchen purity ungarbage community wilderness fiber arts art permaculture artisans regional education experiences global resources the cider press projects digital market permies.com private forums all forums
this forum made possible by our volunteer staff, including ...
master stewards:
  • Nicole Alderman
  • r ranson
  • Anne Miller
  • paul wheaton
stewards:
  • Jocelyn Campbell
  • Mike Jay Haasl
  • Burra Maluca
garden masters:
  • James Freyr
  • Joylynn Hardesty
  • Steve Thorn
  • Greg Martin
gardeners:
  • Carla Burke
  • Dave Burton
  • Pearl Sutton

acetic acid instead of horticultural vinegar?

 
pollinator
Posts: 1559
Location: Denver, CO
60
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I can get 1 gallon of 20% horticultural vinegar for $25. I can get 5 gallons of 100% acetic acid for $104, which could be diluted with water. Is there any reason this would be a bad idea for killing weeds? Of course, the acetic acid is probably made "artificially" in a lab; does this make a difference?
 
pollinator
Posts: 2392
86
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
It's the same molecule, whether it was made by fermentation or by oxidative chemical processing.  The only reason to buy horticultural vinegar is for the taste components that are carried along in the process: red or white wine, apple, etc.  If you don't have a culinary end use in mind, might as well buy the cheapest, which is turned out at the chemical plant by the tank car load.
 
Gilbert Fritz
pollinator
Posts: 1559
Location: Denver, CO
60
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I thought as much; it would certainly be a lot cheaper. I'm thinking about using it to kill off cover crops (with a couple of passes) in the same way that agribusiness no-till operations use roundup.
 
steward
Posts: 4666
Location: Cache Valley, zone 4b, Irrigated, 9" rain in badlands.
1550
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
100% acetic acid is much more dangerous than 20% acetic acid... I believe that it couldn't be safely handled at home. MSDS.

 
Gilbert Fritz
pollinator
Posts: 1559
Location: Denver, CO
60
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
You are right; looks like one could get into all sorts of trouble. Its flammable, toxic by contact, inhalation, and orally, and is corrosive.

What percent do you think would be safe?

Strangely, nobody is selling 20% stuff except as (expensive) horticultural vinegar.

Why would diluting it to a safe level make it MORE expensive?
 
pollinator
Posts: 4328
Location: Anjou ,France
240
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Why would diluting it to a safe level make it MORE expensive?
Because its potentially dangerous. Often diluting acids can give off heat lots of heat eqals steam equals explosion if you are not careful .plus  Its cheaper to transport concentrated acids than heavy diltued one because you are paying for transport of the water .

David
 
John Elliott
pollinator
Posts: 2392
86
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator

Joseph Lofthouse wrote:100% acetic acid is much more dangerous than 20% acetic acid... I believe that it couldn't be safely handled at home. MSDS.



I must be showing my age here, but when I was in high school, we could buy 100% (glacial) acetic acid over the counter at the photography store.  Lots of people handled it safely at home.  But that was in the days before MSDSs, before the dumbing down of America.
 
Posts: 696
Location: Porter, Indiana
49
trees
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator

Joseph Lofthouse wrote:100% acetic acid is much more dangerous than 20% acetic acid... I believe that it couldn't be safely handled at home. MSDS.


While 100% acetic acid is a stronger acid, I believe it is still just on par with standard toilet bowl cleaner (20% HCl) which is handled safely in millions of homes. That being said, I wear safety glasses when using toilet bowl cleaner and have a water source near by to rinse myself off if I get any one me.
 
David Livingston
pollinator
Posts: 4328
Location: Anjou ,France
240
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
remember always add acid to water not water to acid

David
 
Gilbert Fritz
pollinator
Posts: 1559
Location: Denver, CO
60
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
What about the explosive/ flammability issue? And the vapor problem?

That said, they are selling the stuff online in 5 gallon buckets with a pour spout. It would be convenient . . .  how much protective gear would I need? Sounds like a vapor respirator, face shield, coveralls, boots and gloves?

What will this stuff do to the soil long term? Will anything accumulate?
 
master pollinator
Posts: 11352
Location: Central Texas USA Latitude 30 Zone 8
738
cat forest garden fish trees chicken fiber arts wood heat greening the desert
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
It looks like under certain conditions acetic acid can build up in the soil, but I doubt this would be a problem in an annual garden:  http://www.tandfonline.com/doi/abs/10.1080/00380768.1995.10419569

I think it will tend to acidify the soil, but this might be a benefit in an area with alkaline soil.

 
David Livingston
pollinator
Posts: 4328
Location: Anjou ,France
240
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
How much would it cost to get lemon juice? Why not use that instead ?
 
Gilbert Fritz
pollinator
Posts: 1559
Location: Denver, CO
60
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Lemon juice is only 5 percent acid and costs $20 a gallon, so it would be prohibitively expensive and difficult to concentrate.
 
John Wolfram
Posts: 696
Location: Porter, Indiana
49
trees
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator

Gilbert Fritz wrote:What about the explosive/ flammability issue? And the vapor problem?


It's been a while since I've used glacial acetic acid, but from what I recall the vapors and flammability were less than gasoline. Wikipedia states that it's pretty hard to ignite acetic acid at temperatures below 100F, so in that regards it is much safer than gasoline.
 
John Elliott
pollinator
Posts: 2392
86
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator

John Wolfram wrote:

Gilbert Fritz wrote:What about the explosive/ flammability issue? And the vapor problem?


It's been a while since I've used glacial acetic acid, but from what I recall the vapors and flammability were less than gasoline. Wikipedia states that it's pretty hard to ignite acetic acid at temperatures below 100F, so in that regards it is much safer than gasoline.



John has the flammability issue covered, so I'll speak to the corrosiveness of it.  Since it is a weak acid (doesn't ionize very much), it is much less corrosive in concentrated form than the concentrated mineral acids (HCl, nitric, sulfuric).  That said, you don't want to get it on skin or clothing, and eye protection is a must. It's not particularly volatile, so it doesn't go for the nose and throat, but you should still stay on the upwind side when you open the container.  After you pour it and make your dilutions, you will have the unmistakable odor of vinegar around for a while, so be sure you can ventilate your work space.  If any of it splashes around, you want to be able to rinse it down with lots of water.  

The good thing about it is that acetic acid is the most biodegradable compound ever -- all living cells can metabolize it.
 
Posts: 416
Location: Dawson Creek, BC, Canada
32
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Greetings (3 years later).

Yes, MSDS exist.  I don't think they are useful.  They are written by lawyers, for lawyers.  I believe the MSDS starts showing up at about 11% acetic acid.  And yes, acids of any kind can burn skin.  Highly concentrated acetic acids are flammable.  The lower the concentration, the more water is present, and the less net heat can be produced.  Explosion risk?  If you were pumping acetic acid under high pressure, and a pinhole leak developed; such that a "cloud" of very fine droplets was produced, it might be an explosion hazard.  There might be other odd situations which could generate explosion hazards.  But yes, high concentrations of acetic acid will burn.

I am getting so tired of pricing for what the market will bear.

Vinegar comes from fermenting sugars.  Acetic acid can come from other things.  If you want to use acetic acid for a herbicide, it need not be "vinegar", unless you have a reason to distrust the other things that might be in the acetic acid.

I'm in Canada, and about the strongest vinegar I see on the shelves is 9%.  This is meant for "pickling".  They really don't want people to pickle the "proper" way, by using lactobacilii to convert sugars into lactic acid.

A couple of years ago, the cheapest food stores had 4 litre (about 1 gallon) of 5% vinegar for say $1.70.  I see today, that they again have a bottle of 5% vinegar for $1.7 or so, except it is 2.5 litre.  I have no doubt all these companies can justify things, but 60% increase in price over 2 years is just a little bit ridiculous.  But this is vinegar, and not acetic acid.

I think I went through the calculations properly a few months ago, and I believe the world market price for 5% acetic acid (NOT VINEGAR) assuming water is free, is about $0.10 (CDN).

There is a quality issue in talking about vinegar versus acetic acid.  Vinegar is food grade.  Acetic acid isn't.  They can have quite different impurity profiles.

I have a sister who works at a cleaning supply place.  They have VINEGAR in their store, they do not have acetic acid.  The prices they charge for vinegar are ridiculous.  But, I live in an economy dominated by the "oil patch"; and the feeling is that everybody in the community has too much money; and so you can charge whatever you want and people will still buy it.

A few years ago, my local Coop Agro store had 20% vinegar.  The price was "okay".  To use acetic acid (or vinegar) as a herbicide, you really need to know what it is you are going to be killing.  There is no sense using 20% acetic acid for something which can be killed by15%.  What using "over-concentrated" acetic acid gives you, is a faster kill.  If there is a chance of rain later today, the stronger acetic acid solution may give better results if it does actually rain.

Acetic acid in the soil eventually turns into water and carbon dioxide.  Every organism in the soil comes across acetic acid at some point, and has some way of dealing with it.

---

Using 5% acetic acid vinegar as a herbicide may work where you live, it no longer makes sense here.  It probably didn't make sense when it was $1.7 for 4 litres.  It does not make sense when you only get 2.5 litre for $1.7.

I would have thought a cleaning company would have the option of clients buying acetic acid, instead of buying vinegar.  They don't.  I've looked periodically into the possibility of buying things like a barrel of vinegar (food grade) or acetic acid; and there is no savings.    One oil patch company sells 53% acetic acid for something or another; minimum order is something like 1300 kg.

High concentrations of acids (or bases) which need to be diluted are trivial in the lab, when you are making something like 100-1000 ml of solution.  If you are working with multiple gallons; things are not so easy.  Diluting concentrated acids or bases generates heat.  If you do it wrong; you can get localized boiling.  If the acid you are diluting is flammable and you do it wrong; you could start a fire.  If you are using plastic vessels and you do it wrong, you could melt holes in the vessels.  There are lots of ways to get into trouble.

It would really be best; if you could purchase the strength you need.  But that doesn't seem to be what business is providing; unless you want to pay LOTS of money.

----

If you make acetic acid (or vinegar) over the course of a year, and live someplace that gets significantly below 0C in the winter, you may be able to increase the strength of acetic acid by  freezing it.  You need to use a vessel design that won't break when things (involving water) freeze.

It seems likely (I haven't tried (yet)) that you can concentrate acetic acid by pouring your vinegar (or acetic acid) onto a tall column of activated charcoal.  Activated means the carbon (charcoal) is amenable to adsorb things (adsorption is to become attached to a surface; absorption is to become attached to a volume).  Biochar (which includes burning trees) is carbon.  It may be activated out of the kiln, or you may need to do something else to it.  But, if you pack a column with fine activated carbon; and start pouring acetic acid (or vinegar) onto it, it seems the acetic acid preferentially adsorbs onto the surface of the carbon, letting whatever else is in the acetic acid (or vinegar) to (possibly) pass on through the column.

Maybe there are components of the feedstock, which adsorb onto the carbon better than acetic acid.

But, absent that point, to deliver acetic acid (or vinegar) onto the top of such a column; the acetic acid adsorbs at the first opportunity it s presented with.  Leaving the rest of the contents to travel down through the column; and eventually leave.  Perhaps the pH of this first liquid is 7.  If so, it means that all pH related things had adsorbed onto the charcoal in the column.

A person keeps adding more and more acetic acid (or vinegar) to the column.  Adding more acetic acid, might mean that something adsorbed onto the column, desorbs and travels further down?   Nominally suggesting that acetic acid is the preferred species to adsorb on the column

At some point the column will become "loaded".  If we are monitoring pH at the bottom of the column, we are expecting the pH to drop when the column is filled.

https://www.sciencemadness.org/whisper/viewthread.php?tid=5528
https://www.sciencemadness.org/talk/viewthread.php?tid=10545

----

The above is to be interpreted as a book report.  It should not be considered expert opinion.  The engineering society in Alberta, Canada decided it needed to make a diversity statement.  It considered gender and ethnicity.  It would not consider things such as autism.  I told them where to stick their P.Eng.
 
Morning came much too soon and it brought along a friend named Margarita Hangover, and a tiny ad.
Switching from electric heat to a rocket mass heater reduces your carbon footprint as much as parking 7 cars
http://woodheat.net
  • Post Reply Bookmark Topic Watch Topic
  • New Topic
Boost this thread!