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Author Topic: Philip I Sestertius with encrustations  (Read 7690 times)

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Offline Mark Z

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Philip I Sestertius with encrustations
« on: April 14, 2010, 12:20:12 pm »
Hello All!

Any tips on removing the encrustations on the obverse and reverse without damaging the patina and coin?

Thanks!

Mark Z.

Offline Johnny

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Re: Philip I Sestertius with encrustations
« Reply #1 on: April 14, 2010, 08:52:21 pm »
without having the coin in hand,  it's hard to tell, 

can you describe the encrustation ?  pics are great, but with coin in hand what is it ?  soft dirt ? rock hard ?
 
I'm  assuming you've done the soak  and brushing  and that this stuff is concrete hard ?



gavignano

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Re: Philip I Sestertius with encrustations
« Reply #2 on: April 14, 2010, 10:06:01 pm »
Mark - I'd agree with Johnny we need more details - but that's a nice sestertius! Did you buy it as part of a lot? Pretty interesting scratches on the neck - hopefully the owner before you didn't do that during a "cleaning."

Offline Mark Z

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Re: Philip I Sestertius with encrustations
« Reply #3 on: April 15, 2010, 10:20:36 am »
Johnny/Gav,

The encrustations are as hard as rock. They don't come off with my fingernail. I tried an exacto knife on a small area on the margin of the reverse and it was VERY slow going, if that.

I got it in this condition from the previous owner. Didn't even notice the scratches on the neck until you noticed it, but they don't hurt my feelings too much.

Yes, love the portrait but it would be nice to improve the coin if possible.

Thanks for checking in and for your help! :)

mz

Offline Johnny

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Re: Philip I Sestertius with encrustations
« Reply #4 on: April 15, 2010, 06:34:55 pm »
I think the solution is limited in this case, others may disagree,  but  in this case the key phrase in your original post  "without damaging the patina and coin " leads the charge

I don't see anyway of removing this encrustation without damaging the patina,  I think the only solution is to try to " flatten "  or smooth down the encrustation to the level of the coin surface, and I would only try that with good magnification and lots of patience. 

removing this encrustation completely  will more that likely damage the patina ( which I doubt even exists under the encrustation ) ,  or even worse, leave pits, ...:(   

to play on the safe side,  you could leave it as is too,  it's a very nice  coin as is

as always,  this is only my opinion,....  it is your coin  and your choice to make in which way to clean it

cheers
 

Offline Jay GT4

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Re: Philip I Sestertius with encrustations
« Reply #5 on: April 15, 2010, 06:48:11 pm »
Really nice coin.  I agree with what the others have said however why not try letting it soak in Distilled water for a while?  That may loosen up the encrustations and make it easier to use an exacto blade...

Offline Mark Z

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Re: Philip I Sestertius with encrustations
« Reply #6 on: April 15, 2010, 07:55:06 pm »
Johnny,

In the absence of any solutions, it's nice to hear that you (and Jay) believe it to be a nice coin as-is. That reinforces my feeling to NOT try to do anything to foul it up.

Jay,

Soaking in distilled water is a good non-threatening way to give it shot, isn't it? I will give that a try, but only experiment on a small area of the reverse after soaking for a bit. If that doesn't work, I will go back to Johnny's advice with no harm done :)

Thanks to all! :)

mz

p.s. anyone else, please feel free to chime in!

Offline SC

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Re: Philip I Sestertius with encrustations
« Reply #7 on: April 16, 2010, 10:03:54 am »
Is there any difference in the green stuff vs the beige stuff?

I would gently try exacto knife (kept very sharp), under magnification, and see if anything wants to come off.  I would be genlte and not force anything.  I think that way any hard stuff with no patina under it would not come up but anything over underlying patina would "pop" pff or reduce.  I would be happy if any came off and simply accept what did not want to budge as the coin is already beautiful and highly displayable.

Shawn
SC
(Shawn Caza, Ottawa)

Offline Mark Z

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Re: Philip I Sestertius with encrustations
« Reply #8 on: April 17, 2010, 11:28:16 am »
Hi Shawn!

Yes, a little (and I mean a LITTLE) did come off with an xacto knife, but it was VERY slow going and I stopped after a minute or two. I just got scared.

It's currently soaking in distilled water, as Jay had suggested.

I'm looking at the xacto website right now:

http://www.xacto.com/Catalog/Knives/Blades

Something with a convex blade would be the best, I think, or does anyone have a better suggestion with regard to blade shape?

Experts?

Thanks!
Mark Z.

Offline mwilson603

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Re: Philip I Sestertius with encrustations
« Reply #9 on: April 17, 2010, 03:46:32 pm »

Something with a convex blade would be the best, I think, or does anyone have a better suggestion with regard to blade shape?

Experts?

Thanks!
Mark Z.
I wouldn't class myself as an expert by any stretch, just an enthusiastic cleaner.  But I have had very good experiences using a similar blade to this.
http://www.xacto.com/Product/X216
regards
Mark

Offline Mark Z

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Re: Philip I Sestertius with encrustations
« Reply #10 on: April 17, 2010, 04:28:14 pm »
Mark,

Are you using the entire surface of the blade flat against the coin, or how do you use that one?

At a 90-degree angle or more of an acute angle to the coin? Drawing the blade towards you across the surface or actually pushing the edge sharply AGAINST what you are trying to remove?

I can see how that would be a good one, though, as you can get more of the blade on to whatever it is you're trying to remove as opposed to a regular Xacto blade.

mz

Offline mwilson603

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Re: Philip I Sestertius with encrustations
« Reply #11 on: April 17, 2010, 05:40:57 pm »
Hi Mark,
For your sestertius I would probably use the blade flat and at a 30 degree angle from the vertical, if that makes sense.  So kind of lying flat on the coin, but tilted along its length.  Then I would make very small scrapes on the crusts using a circular motion and see what happens, i.e. flaking, powdering, nothing etc.  The key is to be patient and do not apply too much pressure through the blade initially.  If nothing happens, I would then apply a little more pressure and try again.  Depending on what happens as the pressure increases then I may change the angle of the blade, but try to keep the actual blade flat on the coin at all times to reduce the chance of nicking the patina with the tip of the blade.  Obviously around devices and legends it is necessary to use more of the tip of the blade, and this is where you are more likely to catch the patina, so take these bits even slower.  I know this sounds basic, and I don't mean to sound patronising.  This approach would allow me to understand how to attack the coin, and whether to continue. 
One thing that I have found useful however, and this may go against some other views, is not to use a fresh sharp blade.  Instead I find that using a slightly blunted blade still allows me to remove encrustation cleanly, but with less chance of damage to the patina.  You can kind of use the blade to "grind" the patina a little when it is slightly blunter.
Also, I should say that using a blade on this coin for me would depend on the strength of the patina.  If it is a softer type and easily marked then I may not risk it, however if it is good and hard, then I would be happy to proceed.
I hope that helps,
Mark

Offline Mark Z

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Re: Philip I Sestertius with encrustations
« Reply #12 on: April 18, 2010, 11:50:26 am »
Mark,

That' all great advice!

I'm heading out to the hardware store tomorrow morning :-)

Johnny,

I should've asked this earlier, but you mentioned flattening or smoothing the patina down to the level of the coin. How would you do that?

mz

Offline SC

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Re: Philip I Sestertius with encrustations
« Reply #13 on: April 19, 2010, 01:48:45 pm »
I have tried that concave blade and gave up on it as too risky.  I use the narrow version of the regular pointed blade for sme work but again there is a high risk of scratching the surface given the point.  It is one blade type I would use Mark's advice of perhaps blunter.

My blade of choice is the small curved: http://www.xacto.com/Product/X212

I find the rounded portion to be more forgiving and have far less chance of scratching.  It still has a nice point on the end for when that is required such as getting encrustations out from lettering.  I would also ephasize that you really need magnification to do any of this well and safely.

MZ, you don't really want to reduce the patina but you can reduce the encrustation by going over it with exacto to shave it off layer by layer or with some of Kevin's (mayadigger) dremel heads or diamond dusted dental picks.

Shawn
 
SC
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Offline Mark Z

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Re: Philip I Sestertius with encrustations
« Reply #14 on: April 19, 2010, 11:37:32 pm »
I have tried that concave blade and gave up on it as too risky.  I use the narrow version of the regular pointed blade for sme work but again there is a high risk of scratching the surface given the point.  It is one blade type I would use Mark's advice of perhaps blunter.

My blade of choice is the small curved: http://www.xacto.com/Product/X212

I find the rounded portion to be more forgiving and have far less chance of scratching.  It still has a nice point on the end for when that is required such as getting encrustations out from lettering.  I would also ephasize that you really need magnification to do any of this well and safely.

MZ, you don't really want to reduce the patina but you can reduce the encrustation by going over it with exacto to shave it off layer by layer or with some of Kevin's (mayadigger) dremel heads or diamond dusted dental picks.

Shawn
 

Shawn,

Right, I typed the wrong word there  :-[ I agree with you regarding the curved blade. I picked one up this morning :)

Dremel? Scary, too. I do have one, but I only use it on really uncleaned, and then very lightly at that.

Diamond-dusted dental picks? Where would one get one of those?

thanks!
mz

Offline mwilson603

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Re: Philip I Sestertius with encrustations
« Reply #15 on: April 21, 2010, 04:02:26 am »
Straight-edge blades should never be used for coin cleaning, trust me; curved blades only. Not sure how many times I've stressed 'circular' cleaning with every mechanical tool, but that is the way it should be done. A flat blade will never be as responsive to circular cleaning as a curved blade.

Well, in that case Kevin, I guess that I could never have done the following with a flat blade then  ;) .  And in fact, flat blade dry, and with no pre-soaking etc.
I think there may certainly be a certain amount of "it's what suits the individual" in the choice of blade.  I couldn't get on with a curved blade despite trying many times.
regards
Mark

Offline Mark Z

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Re: Philip I Sestertius with encrustations
« Reply #16 on: April 21, 2010, 10:34:12 pm »
Kevin/Mark/Shawn,

Thanks for all your comments.

Kevin,
You know, as I was working on the coin earlier today the thought ran through my head regarding repatination. Using a curved blade, as Shawn and you suggested, the encrustation came off fairly easily, and in fact in a couple of places I got down to the patina, which was uniform, so I'm not sure if it has been repatinated or not. Not sure if it makes a difference, but the patina and encrustation are very different colors, but I suppose that could have something to do with absorption, right?

Happy to say again that it is coming off, though. The curved blade is a godsend, isn't it? I never thought of it before.

Thanks again to all. If/when it gets a lot better, I will publish the updated pics.

Regards,
Mark Zema

ps Kevin, do you carry the JAX Brown solution?

Offline areich

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Re: Philip I Sestertius with encrustations
« Reply #17 on: April 22, 2010, 03:14:57 am »
Straight-edge blades should never be used for coin cleaning, trust me; curved blades only. Not sure how many times I've stressed 'circular' cleaning with every mechanical tool, but that is the way it should be done. A flat blade will never be as responsive to circular cleaning as a curved blade.

Well, in that case Kevin, I guess that I could never have done the following with a flat blade then  ;) .  And in fact, flat blade dry, and with no pre-soaking etc.
I think there may certainly be a certain amount of "it's what suits the individual" in the choice of blade.  I couldn't get on with a curved blade despite trying many times.
regards
Mark

I think I've said it before when you showed them but that is impressive work.
Andreas Reich

Offline mwilson603

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Re: Philip I Sestertius with encrustations
« Reply #18 on: April 22, 2010, 03:28:19 am »
I think I've said it before when you showed them but that is impressive work.
I think that you may have done, and I thank you for your kind words again Andreas,
regards and best wishes,
Mark

Offline Mark Z

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Re: Philip I Sestertius with encrustations
« Reply #19 on: August 07, 2010, 09:50:58 pm »
Hello All!

I thought I'd resurrect this thread as I have been able to work on this coin a bit, mostly the obverse.

A work still in progress, but let's take a look at the results.

(Top is "before," bottom is "after")

I'm feeling pretty good, so far, especially around his nose and on his cheek, which were REALLY bugging me.

Your comments appreciated.

Regards,
mz

p.s. not sure why the colors are different, as I used the same shooting technique both times. Pic #1 is a better depiction of the actual color.

Offline mwilson603

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Re: Philip I Sestertius with encrustations
« Reply #20 on: August 12, 2010, 06:25:55 pm »
Mark, that is good clean work.  I like what you have done with it.
regards
Mark

Offline Mark Z

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Re: Philip I Sestertius with encrustations
« Reply #21 on: August 19, 2010, 12:17:54 am »
Hi Mark!

Thanks!

I had stopped working on it after doing a little more after the pic was posted. Got busy with work :(

By the way, that stuff on the obverse came off much easier than I had suspected it would. It was more like a sticky substance than encrustation.

Thanks for checking in!

mz


Offline Mark Z

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Re: Philip I Sestertius with encrustations
« Reply #22 on: May 28, 2011, 08:27:39 pm »
Hello All!

It's been a while, but I thought I'd show everyone how I was doing with this one.

As you can see, the obverse is MUCH better and the reverse is somewhat better.

Also as you can see, I did 'hit bottom' a few times but fortunately only the patina came off with no cleaning scratches left behind.

Your thoughts appreciated!

mz

1st pic-original state one year ago.

2nd pic-after some initial mechanical cleaning in August 2010

3rd pic-as of 05-28-11

marrk

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Re: Philip I Sestertius with encrustations
« Reply #23 on: May 28, 2011, 08:58:15 pm »
I smeared them with Vaseline few days so the dirt softens
excellent work, Марк Z2

Offline Mark Z

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Re: Philip I Sestertius with encrustations
« Reply #24 on: May 29, 2011, 10:42:30 am »
I smeared them with Vaseline few days so the dirt softens
excellent work, Марк Z2

Hey marrk!

Vaseline? I never thought of it. Has anyone else tried that?

Thanks!
mz

 

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