Peter et.al.,

Before leaping into the breach and going after your rust problem with various "recipes" you should have a professional assessment done by a metals conservator (preferably one whom has worked on industrial objects).  There is no way anyone, including those of us with a fair amount of experience, can make recommendations sight unseen!  (Just try that one with your physician!)

Most preservation problems are complex and require some measure of sensitivity - such as the preservation of signs of use, patina, paint & other coatings, and even industrial residues (if stable and non-toxic).  I would not recommend sandblasting with aggressive media as this will refinish the surface back to bare metal and will also alter the surface texture (ie., microcraters).

The main question I would ask, for pieces exposed to the outdoor elements, is whether these tanks retain water or if there is the ability to let them drain.  Also, do they tend to stay wet ,such as objects under a shed roof, or are they exposed daily to the sun?  I would desire to have similar answers to various preservation problems for any artifact in an indoor environment as well (ie.," is it kept in the basement?") This is the type of local environmental information that a conservator will need to have to formulate the best treatment and preservation options for your problem.  

Cheers!
Dave

David Harvey
Associate Conservator,
Metals & Arms
The Colonial Williamsburg Foundation
p.O. box 1776
Williamsburg, Virginia  23187-1776
Voice:  757-220-7039
E-Mail: [log in to unmask]

-----Original Message-----
From:   Museum discussion list  On Behalf Of Alex Avdichuk
Sent:   Thursday, June 25, 1998 12:48 PM
To:     [log in to unmask]
Subject:        Re: Rusty Tanks

Peter:

I have had success with a polymeric rust converter which I used on outdoor
wrought iron.  The chemical called "Conquest" converts the rust to a stable
tannic oxide and then the polymer seals the metal against moisture
penetration and forms a base coat which can then be painted over.  Any
rusted area that comes in contact with the metal turns black, while in all
other non-rusty areas, the chemical dries clear.  Keep in mind that this
process is NOT reversible, but in my case, it was a choice of having the
wrought iron rust away to nothing or preserve it through this
non-reversible process.  Another advantage of this product is that the
rusted metal does not need to be sandblasted or even sanded down, because
the presence of rust is required for the chemical reaction to take place.

The company I purchase the product from is a Canadian distributor, but the
original company, Liner Rolpanit, is in Europe, unfortunately I'm not sure
exactly where.

If you would like to contact me off-list, I can find out from the Canadian
distributor where in Europe the parent company is located.

Alex Avdichuk
[log in to unmask]


Question: Are there methods to your knowledge on how to (1) stop the
rusting process and (2) preserve the "looks" of the tanks.
If we cannot find a suitable method, we would have to clean them via
sandblasting. Then they would look new and neat - but that's not the
intention.
Thanks in advance
Peter, the Rebernik