Can BD penetrate plastic?

[daverino]

Trace contamination of the coin's patina  with water-absorbing salts like this will make it vulnerable to corrosion. Removing them as much as possible is the object of the water soak. Obviously they are easily washed away from the surface but if they are embedded in or under the patina there is no way to ensure that they are removed even by very long water soaks.

Hi Dave,

Are you implying that it is necessary to strip a coin's patina in order to more fully stop the spread of BD?

Is it possible to fully treat a coin without stripping the patina?

With regard to my diseased coins, it is a moot point (and question). After just 2-3 soakings, the patinas were all pretty much 80-100% stripped anyway. But, then again, is that the intended idea? By stripping the patina, you are ensuring better treatment.

Meepzorp

I certainly don't think it is a good idea to strip the patina. Very few coins have BD, many more have some level of external corrosion, others have more-or-less "green patinas'  others really have no problems at all, just a few green spots which you would likely never notice except for the high magnification we can get so easily these days. Sometimes it is hard to tell the difference and unless you know I would suggest a kind of general treatment that would hurt none but help the ones that need it. 1) Wash 'em; 2) Dry 'em out; 3) Wax 'em up real good and; 4) keep them in a dry environment.

[Meepzorp]

Hi folks,

Last night, I ended my soakings. I rinsed off my final batch of coins. Then, I baked them in my oven to remove any water. Hopefully, the soakings will be permanently done. If any of my coins relapse, I may need to start soaking them again. That has already happened a few times.

My plan is to wait a while (perhaps 2-3 months?). For that time period, I will keep my formerly diseased coins "quarantined" (set aside in a different place than my non-diseased coins). I will temporarily store them in an open-air environment (not in their mylar flips) so that they can "breathe". I am hoping that it is also a low humidity environment, but I admit that I don't have much control over that.

During that time period, I will regularly check my formerly diseased coins for signs of re-activated BD. If all goes well and there are no signs of new and/or re-activated BD, then I will take the next necessary steps. That will probably entail artificial re-patination (at least for some of my formerly diseased coins) and/or sealing them with some type of wax (Ren wax?).

Meepzorp

[areich]

Painting your coins may make it harder to detect a relapse of BD.

[Meepzorp]

Painting your coins may make it harder to detect a relapse of BD.

Hi areich,

I know. But, for some of my formerly diseased coins, NOT "painting" (re-patinating) them is not an option. After numerous soakings, some of them are so ugly that they are a horrendous mess. They literally are an ugly, mottled mess. I can't leave them like that. And some of them had beautiful patinas (glossy green, etc.) before the soakings. I would like to restore that look to them.

However, I am still considering not "painting" (re-patinating) some of my coins. I am open to that. These are coins that (a) are NOT an ugly, mottled mess after the soakings, and (b) that didn't have beautiful patinas to start with. In particular, some of my formerly diseased Augustus AE As coins fall into this category.

Of course, you do realize that NOT "painting" my coins may actually promote more BD growth. Most schools of thought out there seem to feel that re-patinating them will significantly slow down the growth of more BD. But the jury is still out for waxing them. Some people feel that it seals in the chlorides, making the situation worse. And some people feel that it seals out the moisture, preventing the chlorides from converting into HCl, thus protecting the coins.

Meepzorp

[Joe Sermarini]

I think that waxing a coin after treating BD is the correct choice. 

[Meepzorp]

Hi folks,

It has been a little more than 3 weeks since I ended my soakings and baked my previously diseased coins. My plan was quarantine my coins and let them sit for about 2-3 months. I would check them periodically for signs of re-activated BD. I purposely did NOT put them back in mylar flips. I left them out and exposed to the air so that they could "breathe".

Today, I was looking at one of my Augustus AE As coins. It is the one that had really bad BD, probably the worst case of it out of all my diseased coins. It appears that the BD is returning. Along the perimeter where the BD previously was, I am seeing traces of light green stuff.

I wish that I could take a photo of it, but I can't. I'll have to wait until I have access to my niece's cell phone camera.

I am re-posting the photos from page 1 of this thread so that you will know which coin I am referring to. This is what this particular coin looked like before I started treating it a few months ago.

Meepzorp

[Meepzorp]

Hi folks,

This is what this particular coin looked like after quite a bit of treatment. It looked even better than that (more BD cleared) when I stopped treating it.

These photos were also previously posted in this thread.

Meepzorp

[SC]

Some days I think we could have an entire forum devoted to BD.

Here is something I have been thinking about for a while.

There are many ways to "treat" BD but most boil down to: reduce the chlorides in the coin or prevent moisture from getting to the coin.

Benzotrizole is one of the second types of treatment.  It creates a barrier in the very surface of the bronze - a barrier which keeps out not just moisture but the sulphuric compounds.  However, Benzotrizole is very, very bad.  Highly poisonous and carcinogenic and usually not available and definitely not for anything but chemistry lab use.

However, I thought of this treatment while using my frustrating brass bristle brush.  My frustrating brass bristle brush is a typical large brass brush and when I brush a coin it starts to leave a brassy tinge - hence the frustrating part.  This brassy tinge is clearly a very fine layer of brass being deposited on the coin surface.

So what on earth does this have to do with BD you ask.  Well I only use this brass brush for tough cleaning, I use a silver bristle brush for my fine cleaning and my polishing.  Thus I use the brass brush for cleaning coins with BD, for removing the dusty green, etc.  

I have noticed that where I use this brush and leave the brassy tinge the BD does not seem to come back or at least re-appears in very limited ways.  I think that this is because the thin brass film being left acts as a barrier the way the Benzotriazole does.  Now it is not a liquid like Benzotriazole is and so is less efficient.

Anyway this is all just anecdotal observations so far but I think it is worth pursuing.  It is certainly not an answer to all problems.  It would only work where you can use a largish brass brush on the coin.  But I think for example that Meepzorp's Augustan as would be a candidate.

Shawn

 

[Joe Sermarini]

I think wax is more effective than brass brush film.

[Meepzorp]

I think that waxing a coin after treating BD is the correct choice. 

Hi Joe,

Thanks for the input on 8/2/14 and today.

Are you advising that I should wax my formerly diseased coins immediately? Or should I wait about 2-3 months or so to see if any coins relapse, and then wax them if they don't relapse?

What happens if I wax them, and then the BD re-activates under the wax?

This is uncharted territory for me.

Meepzorp

[Joe Sermarini]

I would wax them immediately after treatment. You could dip them in acetone and heat them to dry (just very warm, not burning hot) to help ensure all the moisture is removed before waxing.

[Meepzorp]

Hi folks,

Well, it's time to bring this thread back to life again. The last post was late Summer 2014. At that time, I decided to suspend my BD treatments, which I had been doing for several months. I figured that I'd just let my treated coins sit for a few months exposed to the open air (not in my mylar flips) and see what happened. In September, I also got very busy helping my niece with her homework again (what else is new?).

Now that I am all done helping her with her homework (permanently, I hope), I have more free time. Since September, I've been routinely giving my coins very cursory examinations. They all appeared to be fine, except for one. Today, I decided to examine my BD coins much more thoroughly. All total, I treated 21 coins for BD last Summer. After treatment and then sitting for a few months, 14 of them are fine. I see no trace of BD returning. 6 of my BD coins show very slight (if any at all) evidence of BD returning. And one of my BD coins is a horrendous mess. The BD came back with a vengeance. That coin is one of my Augustus AE As coins, the one that probably had the most severe infestation of BD in the first place. It is the coin in the photos in a post that is a few posts above this post (my posts from 8/25/14). I wish I could take a photo of it right now (before re-treatment), but I can't because I still don't have a digital camera or a cell phone with a camera. I hope to address that issue in the near future. So, I am now (as of today) soaking 7 coins.

On Monday, I ordered a Jax 4-pack of chemicals to artificially re-patinate my BD coins with stripped patinas. I also ordered some Renaissance wax. The package is on its way to me now.

My plan is to re-treat these coins as long as necessary. I will stop when the BD is cleared. At some point, I may just need to make an arbitrary decision to stop. Where does it end? How far is far enough? At that point, I plan to take Joe's advice and re-patinate and wax the coins immediately after re-treatment (within a span of less than 24 hours) to seal out any moisture. That way, in theory, there won't be any hydrogen available to bond with the chlorides to form HCl. That's why I ordered the Jax chemicals and Ren wax before I started re-treatment. I wanted to make sure they would be here when I decided to stop re-treatment so that I can immediately re-patinate and wax them.

Once I am all done treating, re-treating, artificially re-patinating, and waxing my coins (which, hopefully, will be within a span of a few months), my next big project will be to take photos of all my ancient coins (all approximately 2,000 of them). At the very least, I want photos for my own records. I may also post the photos online. I haven't made up my mind yet. I've been wanting to do that since last Summer, but my BD issues pushed that project back by at least 9 months or so. Hopefully, I can start doing that in the early Spring. But let's not put the cart before the horse. Right now, I need to re-address my BD issues.

As always, I'd like to thank everyone for their input and advice here. Please feel free to continue to do so as this project is progressing.

Meepzorp

[areich]

Painting your coins will not do anything form them, as far as BD is concerned. It will probably make it harder to see what's going on with the coins.

[Meepzorp]

Painting your coins will not do anything form them, as far as BD is concerned. It will probably make it harder to see what's going on with the coins.

Hi areich,

I know. You've advised me of this previously in this thread. But leaving my coins with stripped patinas will only make them more susceptible to BD in the future. And besides, many of them look very unsightly now. I want to restore their original colors.

As Joe advises, by sealing the coins with Ren wax immediately after soaking them in sodium sesquicarbonate will, in theory, prevent the hydrogen in the air (from water vapor) from bonding with whatever chlorides are left in the coins. And I can't apply the Ren wax over a (now ugly and unsightly) coin with a stripped patina. Doing so will prevent them from re-toning naturally. I must artificially re-patinate them first, before applying the wax. It's a "catch 22". By applying the Ren wax immediately after the final soaking, I am eliminating any chance of the coin re-toning naturally. Therefore, I must artificially re-patinate them. I don't have a choice in this scenario. I don't have the option of not artificially re-patinating them, unless I don't immediately wax them. But. if I don't immediately wax them, then this cycle can go on forever, endlessly. In theory, I can be treating my coins for years, especially the one stubborn Augustus AE As. If I just leave my coins out (exposed to the air) so that they can re-tone naturally, they can keep on developing more and more BD for 10 years or more. Then, what do I do? Where does it end? I think that is what Joe was trying to imply. At some point, you just have to draw an arbitrary line and say, "I'm done treating". And you have to apply the wax. But you can't apply the wax over a stripped patina.

Meepzorp

[areich]

Painting them will not help with treatment though. A layer of paint will not protect them from BD and will make it very hard to monitor them. Sealing them with wax is something completely different.

[Meepzorp]

Hi folks,

As I mentioned above, one of my Augustus AE As coins has relapsed badly. The BD came back with a vengeance. I wish I could have taken a photo of it before I started re-treating it, but I couldn't. Today, my niece briefly stopped by. She has a cell phone with a camera. So, I took photos of it. She was in a hurry, and I literally had less than a minute or 2 to do everything, including taking the photos. I had to take the coin out of the sodium sesquicarbonate soaking solution, wash it under running tap water, set it up on the paper towel, and take 2 photos really, really fast. And then she was running out the door. I didn't even have time to think. I was on auto-pilot. I did a bang-up job. And they may not be clear. But it was the best I could do under the circumstances. As I said, she was in a monster hurry.

As you can see from the photos, the coin is still wet. She was in such a hurry that I didn't even have time to dry it before I took the photos. I just threw it on the paper towel and took the photos as fast as I could, with the coin still soaking wet.

These photos were taken today, after soaking in sodium sesquicarbonate for over 24 hours and after scrubbing it manually with a brass Dremmel tool under running water (before soaking it yesterday). Obviously, the BD was much worse yesterday.

Here are the photos:

Meepzorp

[Meepzorp]

Hi folks,

I figured that I'd keep everyone posted, like I did in the Summer.

Today, I started my second soaking (day 3). There is nothing remarkable to report.

The sodium sesquicarbonate solution turned blue, just as it did in the Summer.

Meepzorp

[Meepzorp]

Hi folks,

As I mentioned above, on Monday, I ordered a Jax 4-pack and Renaissance wax.

On Thursday, it arrived. But the package is damaged. The Priority Mail box is smashed. And the white cardboard is dyed green, right where the box is smashed. I suspect that the jar containing the green dye is broken and/or leaking. But I am not sure because I haven't opened the package yet. It is still sealed.

Off-site, Nick suggested to me that maybe the extreme cold weather did it. In his theory, maybe it froze and burst. He may be right. The box is smashed, but not that much. I won't know exactly what happened until (or if) I open it.

Here are photos:

Meepzorp

[Meepzorp]

Hi folks,

Today, I started my third soaking (day 5).

Things are "chumming along". The BD is clearing nicely, even on my stubborn Augustus AE As. On that particular coin, the BD is about 65-70% cleared, after only 2 soakings.

Meepzorp

[Meepzorp]

Hi folks,

Today, I started my fourth soaking (day 7).

My stubborn Augustus AE As is now about 80-85% cleared of BD.

As per the merchant's instructions, I opened the damaged package containing the Jax 4-pack and Ren wax. The situation looked worse from the outside. When I opened it, I was pleasantly surprised. The invoice and metal Ren wax container were dry. There was some blue/green fluid in the ziploc bag containing the jars (outside of the jars). But none of the 4 plastic jars appeared to be broken or leaking. However, there was some solution missing from 3 of the jars. Maybe Nick's theory is correct. It could have been the extreme cold that did it.

At some point in the near future, I am just going to draw an arbitrary line and make a decision to stop treating by soaking in sodium sesquicarbonate. Besides, I am getting low on sodium sesquicarbonate, and I don't feel like ordering another pack. I am already on my third or fourth pack of it.

Now that the re-patinating chemicals and Ren wax are here, at that point, as Joe advised, I will immediately start artificially re-patinating and waxing my BD coins. I think I am going to start with my Augustus AE As because that coin had the worst case of BD from the very beginning. It was absolutely infested with it. I will "experiment" on that coin and use it as my "test sample". I think it is smart to seal that coin with wax first because I think it has the greatest likelihood of of the BD returning (again, for the third time) rapidly, more rapidly than the other treated coins. I think the other coins can wait a few days. That coin cannot.

I hope all goes well.

At this point, if anyone has any advice to give me about artificially re-patinating and/or waxing coins, now is the time to speak up. For example, do I dip them in the chemicals, or do I "paint" them with a cotton swab? If I dip them, do I dip them sideways (flat side down) or vertical (edge facing down)? Do I dry them (or paint them?) by standing them up on edge in the bristles of a toothbrush? Do I restore a green-black patina by applying the green solution first and then applying the black solution over the green solution (or vice-versa)? Does applying the Ren wax over the dried Jax solution restore a "glossy" look? How much Ren wax do I use? Should I wear rubber gloves during any part of this process? I've never done this before, just like I had never treated any coins for BD before last Summer. I would appreciate any advice.

As always, thanks to everyone for advice.

Meepzorp

[JBF]

Never done this either, although I have friend who has toned coins before, so I get some sense from him.
My guess is that if you dip, it will be pretty uniform and so to the experienced eye, it will look like it was dipped.
You might find a nice bronze and in painting a damaged coin, try to imitate the nice bronze's patina.  Not totally imitate it, but get the nuances of how an authentic coin's patina looks.  But, if you don't have the feel for doing it, it is still going to look artificial.

Like I said, I have not done it myself.  What I said above at least superficially makes sense, however, I would love someone with more experience to say if it actually works that way or not.

[Meepzorp]

Hi folks,

Today, I started my fourth soaking (day 7).

My stubborn Augustus AE As is proving to be stubborn again. It seems like I hit a plateau with that coin. It is about 85% cleared of BD. And that last 10-15% of BD is just hanging around, being stubborn. I only have enough sodium sesquicarbonate left for maybe 2-3 more soakings, and that's it. And I don't feel like ordering another pack. I went through 3 or 4 one-pound packs of it already.

Meepzorp

[Carausius]

Meep:

Are you brushing/picking-off the bright green between soakings? When I have treated BD, I've used a toothbrush and dental pick between soakings to remove as much of the visible BD as possible.  Also, don't forget to heat dry the coin (oven or toaster oven works nicely at low heat) before patinating and waxing. Good luck.

[Meepzorp]

Hi folks,

Today, I started my fifth soaking (day 9).

There is nothing remarkable to report.

I only have enough sodium sesquicarbonate left for 1-2 more soakings. Then, I'll wrap everything up.

Meepzorp

[Meepzorp]

Meep:

Are you brushing/picking-off the bright green between soakings? When I have treated BD, I've used a toothbrush and dental pick between soakings to remove as much of the visible BD as possible.  Also, don't forget to heat dry the coin (oven or toaster oven works nicely at low heat) before patinating and waxing. Good luck.

Hi Cara,

Yes, I am brushing/picking off the light green stuff between soakings. Actually, I'm doing both. I am manually scrubbing the coins with a brass Dremel tool attachment. And I am picking at the BD with a metal pin. It's interesting that you should ask that question now because, just today, for the first time (at least since my re-treatment started), I really scrubbed the hell out of my stubborn Augustus AE As. I exerted much more pressure while scrubbing this time than I normally do. I scrubbed it so hard that, in certain spots, I had it right down to the shiny metal. In those ares, it looks like a shiny brand new penny now. But it did the trick. I got off some more of the stubborn BD, maybe 5-10% or so more. That coin is now about 90% cleared of BD. There is a really stubborn spot right where Augustus' forehead is. There is a "line of green" there, and it recessed, sort of like down in a valley. So, it is not very accessible.

Yes, I will heat dry the re-treated coins before I artificially re-patinate and wax them.

Thanks for the reminder and well wishing.

Meepzorp