electrolysis

[speedenforcer]

We may have discussed this before, how do you know when and object has sat in electrolysis long enough. I know size and thickness plays a major part. I saw in saint Augustine a large cannon I think it may have been a columbiad not sure it was at a distance but those are unique. it was literally falling apart from the deterioration.

[divedigger]

I don't know about other guys but for me when I am running electrolysis there seems to be matter offgassing from the relic which as the process continues will become less output as time goes on. When the water starts running clear I do a salt test and if it reads good I pull it out and finish it. Your cannon may not have been run long enough or may not have been cared for before electrolysis. The relic has to stay wet after recovery and until the electrolysis is done. Even after electrolysis the metal is sometimes fragile and needs to be in a controlled environment. Chunking it out in the yard is not good

[Pete George]

Speedenforcer asked:
"How do you know when and object has sat in electrolysis long enough?  I know size and thickness plays a major part."

In addition to (1) size/thickness, two other factors are hugely important:
2- the amount of Amperage being used in the electrolysis, and
3- the "soil chemistry" of the dig-site.

Saltwater:
 "Large iron" (artillery projectiles, cannon) recovered from a Saltwater environment needs to be electrolysized for at least one year (sometimes two), AND at extremely low amperage.

Low ground:
Iron which has suffered what Tom Dickey called "Graphitization" due to decades of exposure to Tannic Acid in a swamp or creek or other "low ground" which contains stagnant water (even if there's none shows until you dig the hole) should NOT be cleaned with electrolysis... because that will remove the Graphitized iron's surface and what's left will be ugly.

High ground:
 "Large iron" (such as artillery projectiles) recovered from high ground (soil with good drainage, which produces the typical orangish-brown rust-&-dirt encrustation) should -- in my humble opinion -- be cleaned by electrolysis at no more than ONE AMP, for 36 hours. I'll explain my reasoning in the next paragraph:

Amperage:
   Higher amperage equals faster cleaning. Here's a true story. Forty-something years ago I saw Tom Dickey's electrolysis rig in his backyard.  He used an old HO-gauge model trains transformer, which of course had a variable rheostat (power control dial). Tom had undertaken the massive project of cleaning literally hundreds of the shells he'd dug. Therefore, he wanted speedy cleaning.  He cranked the model train transformer up to the max, which if IIRC was 16 amps. The water in his electrolysis tank almost looked like it was boiling, due to the amount of hydrogen gas being produced. The 16 amps setting cleaned the shells in a few hours... but it was a "violent" cleaning... almost like sandblasting. It didn't hurt extremely solid iron. But iron which was less than extremely solid would get removed. Inspector-stampings and lathe-spin marks disappeared, which could have been saved by the gentler cleaning of a (much) lower amperage setting.  In my electrolysis experiments, I've found that one amp (end even 1/2 amp) is quite sufficient to achieve very satisfactory electrolysis cleaning... it just takes a while longer.  The reward for your patience is, you often save the lettering on a rifle lockplate's "weak" iron skin, or the inspector-marks and lathe-spin marks on projectiles. (I should mention at this point, a rifle lockplate is much smaller than a shell, and even at only one amp smaller objects take less time than shells.)

  In summary... electric power level controls how fast electrolysis cleaning works. You can clean a shell in a few hours at high amperage, but you might not be pleased with the result. I suggest low amperage for a longer time, and I'll testify that one amp will NOT hurt the iron relic even if you left in the tank for 48 hours.

That being said... remember, electrolysis removes metal oxidation (rust, patina, etc.) If you want to keep the white patina on your lead Hotchkiss sabot, or green patina on a copper/brass Read sabot, you must keep those metals at least 1/4-inch above the water in the electrolysis tank.  Painter's masking-tape helps keep the sabot dry from the hundreds of tiny bubble-pop splashes which occur during the cleaning process. 

Regards,
Pete

[Steve Phillips]

On field projectiles I usually run them at about one amp for one to three days until I see the rust and encrustations start to sluff off. I have a voltage regulator that can control current flow. I use baking soda in my water for electrolysis. After electrolysis I boil the projectiles or other iron in fresh water many times to help get rid of some of the sulfides. The boiling and changing the water is important to prevent future problems. I preserve the iron with Gempler's Rust Converter.

[Jim J.]

Guys,
If you would like to read the standard "treatise" on electrolysis, please follow the link below -
http://nautarch.tamu.edu/CRL/conservationmanual/ConservationManual.pdf
If you read down the menu on the left, you will see chapters on Metal Conservation, Iron Conservation I & II - these are the ones you need to read to learn the science behind ER.  I run the day to day operations at a large conservation lab, where we have ~ 40 ER vats, from about 5 gallons to ~ 3,000 gallons.  Currently we have a IX inch Dahlgren and a 6.4 inch Brooke single band rifle in ER, with another pair still to go.  They came from the CSS Georgia, we have about 120 tons of iron to run through ER ~ 9,000 artifacts.
We generally use sodium hydroxide as the electrolyte, but there are a whole slew of other chemicals that will work with varying degrees of success - sodium carbonate, baking soda, sesqui-carbonate, washing powder, etc.  You can also use formic acid if you are cleaning brass artifacts in ER. 
How do you know if the artifact is finished in ER?  In an ideal situation, you would have a high $$$ digital probe that would give you a reading on conductivity, that can then be applied to a chart to get salt ppm - parts per million.  I do not really care for the probes, as they are expensive, need constant calibration, and usually die after 2 to 3 years.  We use a wet chemistry titration method, Yes it is old school, but it is simple, relatively cheap and it works.  When an artifact gets down to less than ~ 20 ppm salt, we take it out of ER and boil the what-not out of it over a five day period, changing the water everyday.  This will take you down into the region of < 5 ppm, which is "pretty good" from a conservation point of view. 
Okay, in the field, what do you do?  If an artifact comes from a land site, and is in good condition, I would run it for a minimum of 1 to 2 weeks (trigger guard), a 3 pdr shell I would leave in for a minimum of a month or more.  The artifact needs to be cleaned at a slow pace initially, and later you can turn up the amps more.  I do not care for this method, as why put the time and effort in when you do not know what the end point is going to be.  For artifacts that come from a marine environment - TEST for salt ppm, there is no guessing here or you will lose the artifact.
After the boiling rinse, a rust preventative is a very good idea - tannic acid, ospho (?), Gempler's, Gem, etc.  It is a very good idea to coat the iron in microcrystalline wax as a final sealant, as this is a good water barrier and slows the onset of corrosion.  Polyurethane is not such a good idea, is it seals "out" and well as seals "In".  What I mean here is this, if there is water still present in the iron when it is painted, then it will continue to corrode under the urethane which is not as easy to remove as the wax when you are redoing the artifact. 
"Soil chemistry" - Yes, important.  Is it basic or acidic -  that affects the iron in differing ways.
Comments on amperage are all good - take your time, it is worthwhile in the long-run.
Thanks for taking the effort to help preserve some of our past, for our future!
Regards, Jim J.

[emike123]

I have found the microcrystalline wax to be an absolute bear to get off whereas the spray polyurethane comes off easily with lacquer thinner or by re-running through electrolysis.  Both methods seal in as well as seal out moisture.  Maybe in your lab you all have a better method for getting the wax off.  Is it merely heat? -- I have taken blow torches to waxed projectiles that look like candles they were so ugly from the wax job.

[Jim J.]

Wax is best applied by boiling the artifact submerged in in molten wax at ~ 325 degrees F, over a few days.  The high heat drives off any air bubbles, AND the water vapor left in the pores of the iron.  When the stove is turned off overnight, the iron / brass cools, the wax is pulled further into the metal.  The following day, melt the wax and remove the artifact (as soon as the wax melts) and wipe the surface clean with a cloth to remove any excess wax.  If you paint on / wipe on the molten wax, you will seal in water vapor and air.
To remove the wax, place in a container of water and boil for a few hours.  The wax has a lower specific gravity than water, so will melt and float.  Allow the water to cool, the wax hardens on the surface of the water, skim it off and remove your "clean" artifact.
There are pros and cons to both methods - wax versus polyurethane.  We find the wax is easier to apply and remove, and gives a more natural feel and look to the artifact.  But - the acids on your finger (with handling) will break it down over time, so will UV light if left in the outdoors environment.  Polyurethane yellows with time, has too much of a sheen (even satin finish), and we feel is harder to apply and remove easily.  It is a personal thing really.  If you are going to display your artifacts in a good climate controlled case, and NOT handle them, you can get away without a surface sealant - if the artifact has been conserved properly .  .  .  .
Jim J.

[emike123]

Good stuff.  Glad you all are conserving things so thoroughly.  Please send pics of some of the Brooke or Tennessee sabot projectiles you gave preserved this way.

Are you suggesting, lacking access to a lab such as yours, our forum members try this at their homes employing their significant others' kitchen pots?   I have personal experience with the fallout from ruining a rangetop boiling shells...

[redbob]

Or your significant other coming home and finding one in the oven.

[speedenforcer]

Information over load here. I think ill just do something easy like go find a drug dealer to lock up or something. Any way great information. Reckon Ill just pay the professionals lol. on a serious note those that do the electrolysis, can yall post pictures and label showing the different outcomes of different methods.

[Steve Phillips]

For many years I used the melted wax process with good results until I found how dangerous it is. I've unloaded and preserved over 2000 complete artillery projectiles and thousands of pounds of other iron relics. The dangers of melted wax are a couple. The biggest danger is having an unknown air cavity that the heat creates very high pressure similar to a scuba tank and can explode blowing the melted wax all over. I had this happen twice before I quit using the process. The first was a James shell that had been drilled by someone else and I thought it had no air cavity. It had a small drill hole ,about a quarter inch and had not been cleaned out good and the rust and powder residue resealed the drill hole. When the pressure got high enough it blew the several gallons of melted microcrystalline wax out with enough of an explosion to break a four burner stove with down pressure. The explosion blew the wax all over the ceiling that was twenty feet high. If anyone had been near they would have been killed by the wax. The second and last time I had a Dalhgren blind projectile. I knew it didn't have black powder and couldn't blow up but I forgot about the air cavity with black sand that is in it. When it blew it was about like the first time. I think just a bubble in the iron could blow up. Another problem is the microcrystalline wax can be heated high enough to actually melt lead. I ruined a beautiful CS Borman fuse when it melted. I now use Gempler's Rust Converter. It is a tannic acid based product and works great. Much easier to use and if you have removed as much of the sulfides by boiling many times in fresh water before applying the Gempler's the end result is better than the wax treatment. If someone is using paraffin wax it is even more dangerous because it can easily catch on fire and the fumes of a large volume at high heat are dangerous.
I've never been a fan of polyurethane and get rid of it on any projectiles that I buy. All I've ever seen polyurethane do is hold a shell together while it falls apart from the inside.

[pipedreamer65]

I use baking soda and a dc power source that has amp adjustment built in with meter.  Sub-amp and I have run salt water shells for up to 3 years.  Other items range for a day or two on up to 10 days.  Very gentle.  It will not "burn" up your artifact, esp. if you are trying to see markings or engraving, etc...  I only use battery charger on iron items like chains, gun carriage parts, or ax heads.

A propane turkey fryer and vat come in handy for the bigger salt water projectiles to boil.

I'd stay away from the wax.  Just my personal opinion.  There are so many other great things to use as sealer/finish.

[Jim J.]

Steve, and others,
Yes, wax can be a problem if not used correctly.  By the sound of things, you may have had a shell that was not properly cleaned in the first place.  The first shell you admit possibly having a small hole that was blocked.  In effect, what you may have had was a sealed pressure vessel that you heated up.  Secondly, you may also had a black powder explosion, as a small air cavity does not have enough force to damage a four burner stove.  I think that the person who "drilled / cleaned" the James shell did not do what he told you!  With the Dahlgren shell, you may have had some water present in the shell cavity, that turned to steam and blew!
When placing artifacts into a wax container, do so when the wax is solid.  You then melt the wax slowly, and the artifacts heat up and sink into the wax.  If the are any openings to the artifacts, like fuze holes, place these so that they face upwards - and any air / water can vent off.  If there is any water present in the artifacts, this will start to boil off slowly as the artifact heats up. 
Lead - the melting point is over 600 degrees F.  You do not want to use wax over 350 degrees F, as you will boil off all of the low molecular weight waxes that seal the surface of your artifact.  You are perfectly correct in saying that the wax can catch fire, and at higher temps it will smoke and then burn.  A small oven thermometer helps here, and you keep the temps at around 300 to 350 degrees F.  If fumes / smoke are coming off the wax, then your temperature is way TOO high.
Remember, when boiling artifacts - change the water out multiple times to get rid of the excess salts and chemicals.  Also, to keep the "Lady of the House" happy, do this outside on the gas grill!
I will try and find some time later this week, to post images of some of the 240 rounds of Dahlgren and Brooke ammunition that we have from the CSS Georgia. 
All the best, Jim J.

[divedigger]

thanks for the information Jim. I would like to try the wax. What would I be looking to buy and where might I buy it. Thank you

[Jim J.]

The last time I bought wax was from a distributer in Houston, Brenntag Southwest, Inc.  The contact info was (713) 433-6771.  The wax is called Multiwax 180M, "M" being for aMber (color), or you can used 180W - for white.  It comes in a 60 pound box, with 6 - 10 pound slabs, and the last quotes was $2.98 per pound.  The item number was PC#647467.  Heat to a range between 325 and 350 degrees F. 
Jim J.