New "acid" to remove calcite from specimens

I was able to find a product called Barracuda 10k which is the same as Barracuda concrete stripper just faster working. 25% faster.
I used it to clean quite a few copper pieces from Keweenaw and it worked great. Except for one piece. It turned dendrite copper crystals gold toned. It looks beautiful but why would that happen? I was thinking may be the dendrite crystals have silver or another mineral that reacted with the barracuda 10k? Anyone ever have experience with this stuff?

Hi Phillip,

Does the Barracuda product indicate what it is, specifically what type of acid, i.e. sulfamic acid or muriatic acid?

In my limited experience with cleaning copper with acids, it seems if you leave the specimen in the acid to long it can discolor the piece. Also, once the piece is removed from the acid, rinse it thoroughly with water and once rinsed towel dry followed by a hair dryer - be sure to remove all water as any remaining water seems to tarnish the piece.

Also, one trick is to soak the specimen in water after the acid bath - it helps take away the "new penny" shine that comes with acid cleaned copper. The length of soak time is strictly based on your taste.

I must compliment you on that Central piece you found in the stream - gorgeous! Any chance that piece is available?

Hope this helps a bit!

Ben

Should have registered before posting (the post from horsecore is my post).

Feel free to drop me an e-mail Patrick - I always enjoy making contact with fellow Copper Country enthusiasts!

Ben

horsecore Wrote:
-------------------------------------------------------
> Hi Phillip,
>
> Does the Barracuda product indicate what it is,
> specifically what type of acid, i.e. sulfamic acid
> or muriatic acid?
>
> In my limited experience with cleaning copper with
> acids, it seems if you leave the specimen in the
> acid to long it can discolor the piece. Also,
> once the piece is removed from the acid, rinse it
> thoroughly with water and once rinsed towel dry
> followed by a hair dryer - be sure to remove all
> water as any remaining water seems to tarnish the
> piece.
>
> Also, one trick is to soak the specimen in water
> after the acid bath - it helps take away the "new
> penny" shine that comes with acid cleaned copper.
> The length of soak time is strictly based on your
> taste.
>
> I must compliment you on that Central piece you
> found in the stream - gorgeous! Any chance that
> piece is available?
>
> Hope this helps a bit!
>
> Ben

The barracuda k10 product I used is a synthetic acid, the formula is patented and no information is available on it. It does have a 000 health rating on it, but they say to not drink it as it may cause loose bowels. It is kosher too. It works great for cleaning minerals, I plan to post before and after pictures as soon as I return from a trip to Drummond Island, Michigan. I'm hoping to find some nice fossils at Marble Head and the Fossil Ledges. As far as that Central copper piece- it's not available. It belongs to my wife, I give her all my good finds, mostly because I don't want to sell or trade them, if they belong to her I'm not allowed to do so. I've talked to a professor at MTU and he recommends searching the same area for similar pieces, so next year I'll be hopefully finding some more crystals like those. Be looking next week for my before and after cleaning pictures this weekend, I'll use hydrochloric acid, soap and water, and Barracuda K10 for everyone to compare the results.
Phillip

>The barracuda k10 product I used is a synthetic acid, the formula is patented and no information is available on it.

This makes no sense. If it is patented then the information must be available publically in the patent application documentation, and will probably be online. The whole point of patents is that you can't keep your invention secret.

If it's just a "trade secret" rather than a patent then there's no reason someone can't test it to find out what it is.

In any case I wouldn't suggest anyone put good mineral specimens into an unknown mixture of chemicals.

Jolyon

They are getting sued for patent infringement for using urea hydrochloride (or some equivalent).

[patft.uspto.gov]

What is "urea hydrochloride" ? [Note: it's certainly not urea hydrochloride]

This is replacing a trade name with a trivial name that doesn't make any sense either ....

According to the filed patent it is just a mixture of urea and hydrochlorid acid. The branded products refered to probably also have surfactants or other components added. I would personally not risk trying such a mixture on specimens with minerals known to be soluble in hydrochloric acid (like apatite, tephroite, trimerite etc.) In such cases I will stich to acetic acid as described by others.
Knut

Well, if you mix urea with hydrochloric acid, you'll end up with ammonium chloride.
Urea will not survive being brought in contact with mineral acids in any conditions. It even hydrolyses in demineralized water; reaction will be complete within a couple of minutes at less than 60 °C. Acids considerably accelerate decomposition (H+ catalysis).

Peter, would calcite be soluble in ammonium chloride solution? Or is the patent application simply not telling the truth about the ingredients? (which would sort of miss the whole point of making a patent application)

Urea hydrochloride seems to be stable enough to have a CAS # (506-89-8), and to be offered for sale by a number of companies. Example 1 in US Patent 5,672,279 gives a fairly detailed description of how to make it. The patent states that there is a slight exotherm, when the reactants are mixed. The only detail that is omitted is the maximum temperature that the mixture can be allowed to reach, before the urea starts to hydrolyze. . This may seem to be a minor detail, but when a reaction is done on a large scale, it is very important. Based on my years of experience in the chemical industry, there is a finite possibility the the procedure described in the the patent is total bogus, however if another company was able to infringe the patent, it is probably fairly accurate.

So, in removing calcite, what's the advantage of urea hydrochloride over plain old dilute HCl? Considering that HCL is very cheap and very widely available, why switch?

The chief disadvantage of hydrochloric acid is the corrosive gas that the aqueous solution gives off. This can cause severe damage to to the lungs and will also corrode any metal it contacts. These other acidic solutions do not have this problem. The weaker acids may also not react with some other minerals, such as sulfides and some silicates, which are attacked by hydrochloric acid.

A trick I learned from Rock Currier was to use nitric acid when taking carbonates off of sensitive silicates, like dioptase and inesite - Nitric doesn't hurt most slicates anywhere near as much as HCl does.

Nitric acid however should never be used for cleaning sulphides. Dilute HCl works fine on most sulphides. Almost all the abundant pyrite and sphalerite specimens from Peru on the market have been cleaned with HCl and, contrary to many peoples' expectations, the pyrite remains stable; the HCl does not cause it to decompose.



Edited 1 time(s). Last edit at 09/12/2009 06:30AM by Alfredo Petrov.

Rory:

EMS does make a product that is very effective on rust stains.
It is called Players Choice. The link is:

[www.enviromfg.com]

I suggest you try it.
EMS has over 100 products and can make custom formulations to meet a wide array of needs. We have used a number of them with great success. And they are totally GREEN.

Ed Drown and all others,

Please see attached. One must know how to read a civil filing prior to passing judgment.

PSL "accused" EMS of this and never tested Barracuda nor did they ever make Barracuda or any of the other accuse products for EMS. This case was dismissed after investigation, depositions and a strong 40+ page order from the judge in Rome Georgia.

Our formula for Barracuda and many other products have been tested by NSF, certified as DfE worthy, have been evaluated by FDA experts and such. I can go one and one with valid governmental documentation such as a 96 page test from the US Department of Navy.

EMS has since file against PSL for patent invalidity. EMS sells in BULK thus I realize none of you would be paying customers however, if anyone wants a FREE sample of our Barracuda; please email me direct at jmac@enviromfg.com.

Thanks

"jmac"

Apologies for not responding sooner, it is good when a representative (I presume) for a company can answer questions about the use of their products. With regards to the documents referenced herein, they were located via a Google(TM) search and are believed to be but not necessarily represented as true copies.

coby.nixon.googlepages.com/PeachStateComplaint.pdf
shumakerindustries.com/pdf/Barracuda Literature.pdf

The filing by Peach State Labs, "PeachStateComplaint", dated November 26, 2008 is fairly clear. Bully for you in getting a dismissal. I do not recall, however, any assertions made in this forum as to the validity of PSL's claims. In their filing PSL did disclose their patent and therefore their active ingredient(s); which was germane to the topic under discussion, i.e. what type of "acid" is in "Barracuda". That question was not definitively answered in the PSL filing. It does appear, however, that they believed it to be urea hydrochloride.

It is all well and good for you to have NSF and FDA approvals for "Barracuda", do you have any documents from the US patent office (or WPO) that you can cite? The above referenced version of your product literature does have on its first page the claim that you have patented this "acid," quoting:

"Independent tests confirm that Barracuda, formed with EMS’ patented SynTech®, the world’s only synthetic acid, dissolves nearly 15% more concrete than Hydrochloric acid."

Which patent(s) covers "SynTech®"?

It seems to me that in this forum, marketing terms will not get one very far in having your product accepted by all as suitable for mineral cleaning and preparation. The statement in your brochure "It is safe on paint, chrome, aluminum, wiring, plastic and even glass." does not begin to cover the diverse chemistry that is encountered in this field. If your "synthetic acid" contains chloride ions, those that wish to use it to clean native copper for example, would want to take that into consideration when determining its suitability for use.

That is why the composition of "Barracuda" was and still is it seems, an open question and a concern to those who may wish to try it.

Any clarification that you can provide would be greatly appreciated.

Cheers,


Ed


Reference herein to any specific commercial products, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement or recommendation. Product names are for identification purposes only. All trademarks and registered trademarks are the property of their respective owners.

My favourite acid for dissolving carbonate minerals off slightly sensitive minerals, in particular off fluorite and native silver, is phosphoric acid. It is not as hazardous as hydrochloric but the usual precautions should still be taken. Not sure that it would be safe to use on apatite though, danger of soluble calcium hydrogen phosphates forming.