Molasses rust removal solution pH notes

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Picked up a crusty Dietz Little Wizard lantern for under $25 last week. Good condition except for the typical coat of crud. Bought it for the red globe was is original to this 1939 lantern. One side has Little Wizard and the other side Syracuse cast into the glass, not just etched or printed on the glass. The globe alone is worth the price I paid for the lantern.

Learned something new and important about using molasses to remove rust from objects. Anyone trying to use molasses to remove crud and rust from metal needs to remember what I discovered about the process.

Made a 4 gallons molasses solution and dropped the lantern into it. 3 days later, nothing happened. I thought it was because I used soft water. Dumped the solution and made a new one with rain water, soft water but without the sodium form softener water. After 3 days, nothing happened in the new solution.

Did a bit of research and discovered two items used to remove rust, vinegar and molasses, have acidic pH's - 3 to 4 and 4 to 5 respectively. Seems the soft water, pH of 7, was too neutral or a bit basic, above 7, to get the molasses' sugar chelation process going. Dumped a half cup of white distilled vinegar into the molasses solution, stirred it up and within about an hour, started to see the gas bubbles created by the chelation process appear on the surface. The water in my last home was hard and possible below pH 7 so I never had that problem. Now, with better water, the solution has to have its pH adjusted for the rust and crud removal process to proceed.

The sugars in the molasses have to "work" on the iron in the surface rust to remove and and if the pH of the solution is greater than 7, it won't work, the rust won't be removed. pH has to be between 4 and 6. A half cup of vinegar in 4 gallons did the trick.

The first pail image is the solution after 3 days at a high pH. The next pail image is showing chelation bubbles after one hour. The last image is the bubble image annotated to show the lantern handle, air tubes and the cross wires of the glass globe cage.

"After" photos to be posted when the lantern is finished.

[paul-f]

Nice project, John. Looking forward to the results.

Thanks for the chemistry refresher. It's been a loooooong time since I thought about subjects like that. The process sounds like it's a lot more cost-effective than some of the hardware store alternatives. Definitely worth a try.

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Having learned to adjust the pH down to about 6 with vinegar, the chelating process began and is continuing.

Molasses has complex sugars that work as chelating agents. These sugars are molecules that are shaped a bit like the claws of a crab (the word chelation comes directly from the Latin word chele which means claw). They work by enveloping the metal iron atoms on the metal's surface as rust (iron oxide) doing 2 things: 1) breaks the iron oxide apart by capturing the iron atom in a water soluble sugar, and 2) release the oxygen part of iron oxide which floats to the surface. The first image below is a very simple drawing of a claw shaped sugars which has captured on metal atom.

The second image is the surface after about 9 hours of reaction, lot of oxygen bubbles rose straight up to the surface to nicely show what is in the pail. By tomorrow morning, the bubbles will be covering the top and the lantern image gone.

There are 4 things in the pail: 1) the lantern, 2) the burner cone, 3) the burner itself and 4) the fuel cap. The burner cone is on its side and it looks like the burner is upside down. The wick adjuster is attached to the burner by a straight wire.

The cone, burner and fuel cap are about 1 foot below the surface as is the fuel tank on the lantern. The wire cage is about 7" below the surface. The top cap is about 1" below the surface and the air tubes about 1.5 inches below the surface.

I'm always amazed at how the gas released in the chelation reaction produces bubbles that rise slowly and straight up in the molasses solution to make what looks like an X-ray image of the water.

This is a slow process taking 3 to 7 days but it is very effective in removing the rust and leaving the tin-sulfate patina in place. Kerosene contained a lot of sulfur 80 years ago as as the sulfur combustion fumes hit the shiny tin plate surface, it reacted with the tin producing the very nice light to dark grey patina on the tin plate surface. Lanterns used more than others ended up with a darker patina than those hardly ever used.

As such, this slow molasses process removed metal rust (oxides of metals) from any item leaving the aged patina placed on the original metal over time. This can be used on anything from car parts go firearms to wood working and mechanic tools to lanterns. If I can find a rusty tool, I will put it into the current solution after the lantern is done.

Commercial rust removers range from gentle to harsh. The citric acid based removers as gentle while muratic and other acids are harsh. Depends on what the desired end result is, how much of the original patina is to be preserved. Harsh removers are great if one doesn't care about maintaining the patina. Shiny original metal is easy to get with acids and also with sand or bead blasting.

Only thing to remember when making the molasses solution is to make sure it is acidic in nature, pH 4 to 6, for the chelating process to work. Seems 1 to 2 cups of distilled white vinegar in 4 gallons of pH 7 to 8 water does the trick..

I've found the condensate from high efficiency furnaces has natural gas combustion components in it lowering the pH of this otherwise distilled water to about 6. This is a good source for making the molasses solution during the heating season. My furnace put out about 1 to 2 gallons in 24 hours with outside temperatures below 35° F.

pH (litmus) paper can be found for cheap on eBay and always good to have around the shop.

[david@london]

John,
that is very nice lantern, love the embossed red globe - I will be following this thread with anticipation of a great end result.
You are the Molasses Maestro!

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In the meantime, with the lantern out of the molasses bath, I found the most rusted tool I had and threw it into the pail. Wasn't badly rusted but some areas had rusted through the outer layer which seems to have been a silver colored metal. The wrench was painted blue originally. It's so old, I can't remember what it looked like 50 years ago. Seems the molasses process does work for any metal that's been oxidized

This image below shows the molasses working on the rust with a bubble image of the wrench some 14" below the surface after 6 hours, and more defined after 24 hours. The large wrench (spanner) image at the bottom is the "after" image showing the tool free of rust but missing its original coating where the rust had taken over, had eaten through the original metal coating.

There are a lot of stuff on the internet about using molasses to clean old tools, metal parts and engine blocks by machinists and others.

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This is a "how to" on lantern fuel tank cleaning and sealing.

With the lantern structure crud removed, work on the fuel tank began. The inside of the tank got a final cleaning by putting a half cup of white distilled vinegar into the tank, adding a 1 foot long piece of sash chain into the tank and roughly swirling the chain around inside the tank. While the molasses works on rust inside the fuel tank, a piece of sash chain will "knock" off the loosened crud leaving a relatively smooth surface on the rust areas inside the tank. This was repeated until no "debris" was seen in the vinegar when it was poured out of the tank.

The tank was leaking from the left side, the side which had all of the solder on the bottom. To fix this, the tank was flushed with water a few times and then dried out using 3 applications of acetone, swirling about 20 ml of acetone each in the tank and dumping it out (a "lot" of polar acetone mixes with a "little" polar water to carry the water away when the acetone is dumped, which after 3 cycles leaves the tank free of water). After 3 acetone rinses, the tank was dried using a vacuum hose in the burner opening and shooting compressed air into the fuel tank spout. After the acetone smell was gone, the tank was heated to about 120° F with a hair dryer and then left to cool. That leaves the clean tank water free and ready for sealing.

Blue painters tape was applied to the seam over the leaking area to keep the sealer in the tank. About 15 ml of POR-15 Fuel Tank Sealer was carefully poured into the tank. The lantern was tipped on its side and rotated 360° several time clockwise and counter clock wise to coat the entire inside of the tank with the sealer. The lantern was then tipped upright and the sealer swirled around the bottom to make sure the entire flat bottom was covered.  This sealer has a strong, organic solvent odor so the lantern was placed in a covered 5 gallon pail to "cure" for 2 days.

After 2 days the tape was removed only to find a mess I had not considered. I've used tape on other tanks to seal leaks but didn't think about the uneven surface of the soldered and how that would fill with the liquid tank sealer. With the tape removed, about a 4" long section of the solder on the bottom was covered with the hardened sealer. Some of it also crept up under the tape on the outside of the fuel tank getting onto the patina'd tin, the side of a quarter. This had to be removed before a second coat of the sealer was applied. In the future, I would use melted bees wax to seal irregular surfaced metal.

Removing the sealer was not easy. Ended up using a 150 grit Dremel scour pad wheel and pressing quite hard. Went through 2 pads. The debris cast off required using a mask. Not only was the sealer "dust" being thrown off but also the process created friction which also removed a thin layer of solder. That sealer that got onto the tank side was removed but the tin sulfide patina was also removed leaving the quarter sized spot as shiny tin plate. Some of the patina next to the solder on the tank bottom (which was not as dark as the lantern structure) was also removed leaving a bright shiny tin plate streak.

The bright spots were darkened with the use of Novacan for Lead and Solder, a dilute solution of nitric acid. Nitric acid turns (oxidizes) tin creating SnO2, which is a dark grey to reddish brown patina, within a second or two of application. These colors were noticed after application and came close to matching the original patina.

Novacan was also applied to the solder used to seal the bottom of the tank seam. That darkened the bright shiny polished solder to a shade that was close to the dark gray lantern patina. The shiny, polished smooth lead on the bottom as not treated with Novacan.

Unfortunately, applying Novacan to the bottom strip of bare tin plate turned the tin plate much darker that the adjacent natural patina.  In hind sight, might have been better if left alone. Just a bit more character on the bottom due to that oops. The nitric acid patina is thin and not a hard as hard as the mineral tin sulfide patina so the darker strip could be easily removed with 0000 steel wool, and might be done as I think about it.

In all applications, it was noted that the nitric acid had no affect on the original patina, the rock hard, insoluble Tin sulfide mineral. Only the bare original tin plate was affected.

After all that was done, a second layer of tank sealer was applied. For a second coating, about 10 ml of the tank sealer poured into the tank, slowly swirled about the tank as above and left for 7 days to fully cure before filling with fuel.

Images below show the taping of the bottom seam, the bottom issues annotated and the inside of the tank before and after sealer.

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The lantern is now restored to a working condition, a 1939 Dietz Little Wizard with character once owned by a New York Water Department (someone scratched "Water Dept" into the bottom of the lantern which can be slightly seen on the left of the first image below, upside down at the bottom).

The tank leaked caused by water getting through the tin plate to rust the steel. 

First image below shows the bottom after the first cleaning where most of the surface crud was removed but the typical red iron rust of the steel was still present. The image to it's right is after 4 soakings. The light frosted area where the red rust had been is pitted tin plate, an area where the patina was removed by the rusting process.

Second image shows the bottom with most of the red rust gone. Seems the molasses converted the red rust to a black iron mineral and then that iron mineral was removed by the molasses chelating the iron out of the mineral. The yellow rings show the black mineral after 3 soaks. The lighter "frosted" areas around the yellow circles are shiny pitted tin plate which were all black before the last soak.

I did not take an image after the second soak showing what is now all of the frosted light areas covered with the black mineral. After 4 soaks, almost all of the iron mineral had been removed. The final condition of the tank bottom can be seen in the bottom image in the last reply where sealer removal was discussed.

The last restoration step was to go over the lantern gently with 0000 steel wool and then apply a thin coat of 25% linseed oil and 75% mineral spirits. Takes about 3 days for the top coating to dry.

When dried, it was noticed the solder bead around the bottom was quite shiny being a shiny polished solder surface to before coating. The shiny bead was gently rubbed with a small piece of WypAll X60 (now available in Advanced Auto Parts stores off the shelf for about $9.50 a box) backed by a cotton ball. The extra bite of this man-made fabric nicely reduced the gloss shine on the bead to a satin look matching the fuel tank. The WypAll was a lower grit poor mans micromesh that worked nicely for this. It might also work nicely to take the shine off of other items and will keep that in mind for future phone projects.

The original red globe turned out to be a very nice darker, ruby red not seen in repro glass. That globe alone was worth restoring the lantern.

The last images are the before (as I received it) and after restoration and a glamour shot of the finished lantern.

[david@london]

John,

an amazing transformation on that lovely 80+ year-old lantern.

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Just another example of what molasses in water will do to rust on tin plate.

This 1945 Blizzard spent a lot of time hanging in the rain. The top cap and front fuel tank near the spout have been well corroded. After the first 24 hour soaking in molasses, the red rust has been turned into the black iron mineral which over time, a week probably, will be chelated off by the molasses sugars. It's all surface rusting on the tin plate so it will be interesting to see what the patina will look like on this lantern.

You can see the front (fuel spout side) has a lot more corrosion than the back side which was against a wall protecting it from some of the rain.

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The intent of this topic was to cover everything about lantern restoration. One of those steps was wick replacement.

This is the way that works best for me (some lanterns have the burner cone as part of the globe plate so just the burner is removable).

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After 18 days, the lantern shown in Reply #8 is finished. I paid $16 for the lantern and restoration cost me $37. Total of $53 and a lot of time.

Two of the top posts, the ones that were to the front of the lantern when it was hanging in the rain were rusted to the point of having rust out holes and the tabs at the top of them to hold the top cap on were ready to break off, and they did as I restored them by cutting and soldering thin brass sheeting to the inside of the posts and then added a brass piece that was then shaped on the lantern to the correct height and width or the original tabs to be the 2 new tabs. The brass was tinned with solder and the solder turned black with diluted nitric acid to match the two original tin plated tabs. The top is now secure and needs to be because the loop on the top cap is used to raise the chimney (with its strong internal spring) to tilt the globe back for removal and cleaning.

This was one of the most crudded up lanterns that I have worked on and could not get the black crud off of the front top of the tank, the top cap and some of the sides of the tank. Since it wasn't loosening up any more after 14 days, I called it a project with what's left being the character of this lantern, sealed the tank, fixed the posts and put it together.

Looks quite nice. The back is just like new old stock tin plate but the front took a beating from the rain and its character shows. I have a strong feeling that someone bought this lantern for emergency use and hung it outside a back door where it stayed for many years never being used once. That put the rain on the top cap, the top front of the fuel tank and the sides, more on the front that the back. It was dropped on the top at some point and that bend could not be taken out of the chimney. The air tubes were bent upright. There are a few dents in the fuel tank that are just more character.

Probably light it up next Christmas to see the original ruby red globe color which is a deeper red than the modern reproduction glass that sells for the same price. I think this is the longest I spent on one lantern but it was worth it and it is a very relaxing and rewarding hobby.

Have 6 more lanterns in the cue right now. Might post the more unique or unusual ones but only before and after images. This topic covers everything anyone would need to know to restore a crudded up tin plated kerosene lantern so I'm leaving the blow by blow steps out of any future posts.

[FABphones]

Thanks for adding this topic. Good to have it all detailed in the one thread, makes it easy to follow. Thanks also for the info on reply 9, that will come useful to many of us.

I will certainly now be on the lookout for a lantern with a red globe. Very nice.

[shortrackskater]

That lantern looks great. Thanks for posting.
I'll eventually get to mine!

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Ever since moving, I've had a problem getting the molasses mixture to generator bubbles with the lantern in the solution. I've tried soft water, distilled water and hard water. I've added vinegar to reduce the pH a bit. I've filled the sink around the 5 gallon pail with hot water. None of this generated the amount of bubbles I was seeing in my last residence.

With a comment from david@london about the lantern he is working on, I realized my problem was more basic than the solution itself and a lot easier to fix. My basement is year round in the low 60° F range. Even filling the tub around the pail with hot water didn't do much to raise the temperature of the molasses from the low to mid 60's high enough to get the chelating chemical reaction to start and continue.

The simple solution was putting two aquarium heaters opposite each other in the pail near the bottom. These are cheap and are made to heat the liquid and hold it at a constant 78°F.

The first image is 1 hour after adding the heaters with the molasses about 71° shows the heaters and the image of the lantern is starting to show. The second image is 24 hours later with the solution at 77°F. Bubble (aggressive chelating chemical reaction) problem solved.

I monitored the temperature rise over time and noted that the temperature at which the reaction starts is in earnest is about 72-74°F. Occam's Razor in action. The solution to the problem was the simplest to fix, temperature. Right now the solution is staying at a constant 77°F and the molasses is working just fine.

Now I'm thinking about removing the boiled linseed oil from the lantern in this topic and putting it back into the molasses to remove the crud that did not come off of the top of the fuel tank when soaking in the mid 60°s.

Thanks to david@london for having his lantern solution in a warm shed.

[FABphones]

Another option to heat might be to carefully wrap the outer of the container using an unwanted electric blanket?
These usually have temperature controls (heat range at hottest is usually over 100°F, often timers too). As a Beekeeper, this method is sometimes used to warm honey (extraction tank exterior) making it more 'runny' for easier filtering.

ETA: Thinking this through further for this application, the tank would need to be sizable so as not to cause issues with the heating elements. Honey Extractors can be somewhat larger.