Metal De-Corroder and its effects

[Ian Knight]

I have used this product on a few swords but use with caution. I too was shocked the first time that I used it. It leaves a horrible dull grey surface.
Be prepared to do a bit of polishing after treatment. I use very fine carborundum paper, used wet, and then polish with Solvo.
I wouldn't use on a sword with faint etching because the polishing will wear it further. Neither would I use it on any sword with blueing or gilding. On a plain blade it is fine but go carefully with the treatment. I apply the liquid with a brush, leave for half an hour and then wash in water using a brass brush on the rusted areas. Repeat if required.
I don't like seeing rust on any sword because it is damaging the metal underneath. Black patches also harbour red rust underneath so it isn't safe to leave that on the metal either.

I contacted the makers of De-corroder a year ago regarding the effect their product had on metal. Surprisingly the were quite taken aback and told me to stop using it.

Ian

[RSWORD]

An important step in all of this process to definitely not forget is to add plenty of oil after any form of etching, polishing or anything of the sort. I recommend WD-40 as the first coat after a good polish or etch as it does a great job of expelling water molecules from the steel and really sinks into the pores of the metal. After a day or two of a good WD-40 soak, wipe away, clean area with acetone and then apply a light coat of gun oil to the area to conserve for longer periods of time.

[Ian Knight]

I would personally recommend applying Renaissance Wax which is used by many museums to protect valuable objects.

Ian

[RDGAC]

I've bee steadily working my way through our collection, applying Renaissance Wax to the hard surfaced objects where it seemed appropriate, and the results are indeed good. It's a very highly regarded product, not least because the coating it gives is both attractive and durable. I'm still unwilling to use it on leather, despite being informed that it's safe to do so, but it's excellent for metal and wood, from what I can gather.

The etching of the metal is indeed troubling. The sword displayed in the first picture was treated with Pre-Lim polish after being treated with the de-corroder, which may go some way to explaining its better finish than the tested area of the jezail barrel, but I remain cautious. Perhaps, if I am to use this at all, I shall have to apply it to each spot of rust individually (which will mean taking about 6 months to get it off); or perhaps there's just nothing more to be done for this barrel, much as I'm very sad to admit it.

[Rick]

Pineapple Juice ??

[RDGAC]

Pineapple juice? I'm lost.

[Rick]

A very gentle way to remove rust .
Immerse and brush daily, then put it back in to soak .

Keris collector's standby .

[Ibrahiim al Balooshi]

Originally Posted by RSWORD

An important step in all of this process to definitely not forget is to add plenty of oil after any form of etching, polishing or anything of the sort. I recommend WD-40 as the first coat after a good polish or etch as it does a great job of expelling water molecules from the steel and really sinks into the pores of the metal. After a day or two of a good WD-40 soak, wipe away, clean area with acetone and then apply a light coat of gun oil to the area to conserve for longer periods of time.

Salaams, For treating rust spots I use aluminium foil ... same as for using sandpaper ... it works at sub atomic levels apparently and the rust does vanish slowly. Use with just fingers and a few foil pieces folded in half... like a small wad.... and rub away. I get the same grey horrible result using lemon salt but the patina is coming back using olive oil and or gun oil . ( sewing machine oil )

[josh stout]

I have been working on a technique with decent results. First I wash the blade with soap and water using a plastic pot scrubber. This is to partially degrease and partially to remove any easily removed rust. Then I degrease with Windex following with a vinegar soak. This gives similar results to the product you are using. After that there is still some patina, the rust is almost entirely gone, and pattern welding shows with high carbon steel darker than the softer parts. The problem is the graying you have mentioned. So I polish the blade with 6000 grit micromesh (http://micro-surface.com/index.php?main_page=page&id=15). The micromesh gently brightens the gray areas without completely obscuring the pattern brought out by the acid.

Josh

[rand]

I have heard that the Met uses kerosene and sawdust in a slow turning barrel to clean mail.

Am very glad you posted these before and after photo's. Am interested in the renaissance liquid decorroder for cleaning mail. From the photo's that does not seem like the best approach because of the dull finish.

rand

[Ibrahiim al Balooshi]

The weird and wonderful cleaning agents and solutions for restoring and preserving ethnographic arms and Armour is a subject perhaps best placed in the margins of Forum activity ...and I respectfully request its placement in Miscellaneous ( Ethnographic Miscellania ) for concise referencing by members..

I suspect this form of aggressive rust remover will tear a good sword apart removing patina and sword blade at the same time. I find it reasonable to know the less dangerous chemicals and apply them first such as light cleaning with warm soapy water...then step up to cold coke cola... but to check every 8 to12 hours removing with soapy water and rinse at the first sign of action. The juices come next and any fruit juice will do ...Then comes the paste with Tomato being quite good...again check every 12 hours... etc The worst stuff is acid... and even worse than that hot solutions ... Hot acid will destroy your item if left too long ...and check every half minute ... its that fast...Dont use it is my advice. I put this de corrosion stuff in the same category...

The action suggested at #22 by Josh Stout is excellent...

[mariusgmioc]

Hello and forgive my late reply as I was very busy with work lately!

I have been using Ren. Met. Decorroder for years and I can confirm it is an excellent product. It is absolutely safe for healthy metal and much better than any alternatives suggested here.

For example pineapple juice that was recommended by some, is quite effective but it is acidic. Moreover, the acidity and thus, aggresivity depends on the brand used. Coca-cola is even more acidic than pineapple juice and definitely less effective than Ren. Met. Decorroder.

Yes, Ren. Met. Decorroder removes etching because etching IS a form of corrosion. Practically etching is a controlled and selective corrosion of certain areas of the metal surface. It's just that the oxidation is not brown and flaky like rust is but dark grey and in the form of a thin film that covers just some areas of the metal.

So after treating either Wootz Damascus or Pattern Welded Damascus with Decorroder, it must definitely be re-etched to get back its patterning.

The dull grey patination that remains after the treatment with Ren. Met. Decorroder is easily removed with Pre-lim or any other very gentle polish. However, the dull grey patination has a protective role as it prevents the formation of rust for several weeks, so if you decide to remove it, you should apply some kind of protection to the metal immediately afterwards (I normally use Ren. Wax and rarely, mineral oil).

And I tried Ren. Wax on leather with great results. I assume that can also be used as shoe polish, but it will be probably the most expensive shoe polish on the market.