Rust removal from enlarger column?

[David Lyga]

I just got a Bogen 69 Special enlarger in excellent shape ... but the column has a considerable amount of rust on it. The bellows is excellent as are the negative carriers (35mm and 6x7), but the rust on the exterior is annoying, at best, to look at. This does not affect functionality at all but I am wondering who knows the best way to get rid of this rust? Is naval jelly the best here? Thank you. - David Lyga

 

[ic-racer]

Light surface rust comes off with WD-40. I'd go with naval jelly for more severe rust.
An example of naval jelly on chrome, (not mine) from the internet:

 

[David Lyga]

Yes, the rust is rather severe. And, if and when rust has been removed. should the bare metal be coated with anything? - David Lyga

 

[ic-racer]

Yes, the rust is rather severe. And, if and when rust has been removed. should the bare metal be coated with anything? - David Lyga

From this picture, it looks like the column is chrome, and in that case, we hope the chrome will remain, rather than bare metal. WD-40 protects chrome but also gets sticky, which may alter free column movement. If the column is really bare metal, it was probably originally coated with grease (or should have been ) to prevent rust.

I'd think good design chrome column should not have metal-to-metal contact. It should have nylon or other plastic in contact with the chrome. In that case I'd probably not put anything on the clean rust-free chrome.

Can you tell if there is metal-metal contact between the column and the head?

 

[David Lyga]

The column seems to be chrome, but a worn chrome, tending towards bare metal. Of course, the column supports the head and that head glides along the column as you turn the crank. The actual gliding contact is via plastic washers. - David Lyga

 

[Truzi]

I'm not really sure what you would want to do with chrome, aside from polishing with 00 steel wool, or aluminum foil. This would not help much if it is extremely rusty, but might be a good way to see how bad it is - sometimes the rust "blooms" and appears thicker than it truly is.

If you can remove the rust to the point it looks presentable, perhaps coat it with a museum or coin wax (such as used by numismatists) to protect it - thought it will likely wear off with use.
Perhaps boards related to gun-metal may offer you some different ideas.

On the chance you may expect to refinish the column (paint it), you might venture into some automotive boards. Of course, your enlarger will not be exposed to the elements, but there is some information that might be useful to you.

Specifically, I'm talking about "rust converters;" typically, you don't actually remove all the rust when using these, aside from a wire brush to remove the scale. SEM Rust-Mort is one example, but there are other companies with similar products:
http://www.semproducts.com/rust-and-corrosion-rust-converters-sealers/rust-morttm

They are expensive, though, and may be overkill for your application. It is also more involved than simply using a can of rustoleum. If you go this route, use thick rubber gloves - I know for a fact it will seep through vinyl

 

[Rick A]

https://www.youtube.com/watch?v=z7OdX42NjWQ

 

[chip j]

Try a very, very thin coating of vacuum grease to protect the chrome--it never wears off.

 

[Old_Dick]

I would first use Bar Keepers Friend. It removes rust and polishes. Maybe even use the product with one of those Mr. Clean sponges, works for me.


Principal Unix System Engineer, Yoyodyne Propulsion Systems(retired)

 

[Truzi]

Naval Jelly and Coca Cola contain Phosphoric acid - in differing amounts. I believe this is the main ingredient responsible for the rust removal.

As suggested above, you can try Coke, it may be a cheap and safe experiment.

 

[Bill Burk]

Steel wool and oil (like WD-40) is my recommendation. Take your time and give it a good rub. If you are lucky it will clean up like new since most rust over chrome is removable.

Then I use a light oil (like 3-in-One) to protect from future rust.

 

[Paul Howell]

I would just replace the column with a new length of chrome pipe, ought to be able to find one on the internet. My first thought was that you could make the column taller, but Bogens columns are not off set or slanted so you can only raise the head to the point that the head cuts of the projected image.

 

[DWThomas]

I tend to use a very fine abrasive pad ("Scotchbrite" - synthetic steel wool equivalent) and WD40 (or motor oil on cruder things). For something like an enlarger column I would then most likely use a couple of good rub downs with an automotive polish, that is, a dry silicone lube. I suspect if it's once cleaned up and kept in a less humid atmosphere it will probably outlast any of us.

 

[John Koehrer]

Coke, the car restorers friend.
Like Truzi says, it's the phosphoric acid that does the work. Protect it with a good waxing.

Advantage Coke, you can drink it to finish the bottle.

 

[Rick A]

Advantage Coke, you can drink it to finish the bottle.

Just think about what it does to the rust as you pour that toxic brew down your throat. And, oh yeah, it's a great toilet bowl cleaner too.

 

[GRHazelton]

I'd suggest using copper scrubber pads with whatever. The copper is softer than the metal you're trying to clean up, and won't scratch it. Most grocery stores carry it. We use it on Cuisinart Multiclad stainless, since it won't scratch the metal.

 

[bdial]

I've used a product called "Evapo-rust" recently and it worked very, very well. Note that it is a thin liquid and the part to be de-rusted must soak in it, a brush-able product may be easier.
For protection afterword a good automotive paste wax would probably do well.

 

[wiltw]

I would first use Bar Keepers Friend. It removes rust and polishes. Maybe even use the product with one of those Mr. Clean sponges, works for me.

^^^

 

[mgb74]

http://www.amazon.com/Flitz-Polish-Paste-1-76-Tube/dp/B000T9LZDI

 

[David Lyga]

Thank you all for your profound diversity in the matter!

I had never heard of Coke doing the job, but that drink is so 'mysterious' (at least, to me) that it is worth giving a try. Again, thank you all. - David Lyga

 

[Paul Verizzo]

Away from this forum for a couple of years, came back to search for David's work with dilute C-41 developing.

I saw this and am compelled to comment due to some inaccuracies and not spoken facts.

Phosphoric acid, whether in cola or Naval Jelly and similar products does not remove rust. They convert the iron oxide to iron phosphate (I think that's the end product.) The difference is critical because as someone above called it, rust "blooms." When the iron oxidizes it becomes thicker.

Therefore, it's imperative to remove the rust via abrasion, such as with steel wool of fine sandpaper before any chemical treatment. After treatment, it's your choice to protect from further oxidation, but since the column has the enlarger head running up and down it, all coatings and paints will ultimately deteriorate in one manner or another.

 

[cowanw]

And, after the cleaning, it may be necessary to let the rust come back ever so slightly (and/or treat several times), as Iron Oxide is necessary to start with

 

[bobwysiwyg]

I have to disagree. Ferrous rust is not like copper or other non-ferrous oxidation that creates a protective layer. Once started it continues. Once removed do everything possible to prevent its return.

 

[Loren Sattler]

David, one option would be to remove the column and take it to a chrome plating shop and have it re-chromed. It will look like new, but process can be expensive. If the column is round tubing you could buy a new aluminum or stainless steel tube and replace it. A third option is the abrasive process mentioned earlier. Maroon colored Scotch Brite or fine sandpaper (start with 220 or 320 grit) would be appropriate products to remove rust and the chrome plating. You could then prime and paint the column to prevent further rust.

 

[David A. Goldfarb]

The column seems to be chrome, but a worn chrome, tending towards bare metal. Of course, the column supports the head and that head glides along the column as you turn the crank. The actual gliding contact is via plastic washers. - David Lyga

If the movement depends on friction between plastic washers and the column, I wouldn't oil the column as some have suggested. Oil might cause the carriage to slip, and could cause those plastic rings to deteriorate.