Rust

[Nathan Potter]

My first darkroom sink was a lot like yours. But it was a poor grade of stainless steel that would stain badly. I cleaned it thoroughly and did a final surface roughening using coarse steel wool. (I scratched the hell out of it). Then I applied three coats of white marine epoxy paint letting no more than 24 hours pass between coats. Severe roughening of the surface aids with the adhesion of the epoxy paint. I used it for 15 years with an occasional recoat of epoxy.

Nate Potter, Austin TX.

 

[RJS]

There are a lot of brush-on waterproofing things for roofing. I am using one painted on the bottom of my formerly leaking plywood sink bottom. HomeDepot is a good source. Also very elastic waterproof coatings for trailer roofs.

 

[arigram]

All right, so it was time I attacked this problem.

At first I scratched as must of the rest as possible with a sand paper "brick" and a scratcher.

Then I treated the whole surface with a special liquid that is supposed to stabilize rust which turned the whole basin dark blue.

Then I got this paint that not only can be applied on top of rust but is meant to treat it and protect the metal from further corrosion. Plus it came in a "aluminum" silvery gray color which looks pretty close to the original bare metal. I treated the whole inside of the basin along with the top edges. It needs to coats and I am doing the second one tonight, 24 hours after the first one. I am considering another coat just to be safe but the paint is expensive and I am not sure if the two cans I got would be enough for three applications.
The only problem is that it is applied by brush and let's say, my brush work would be fine for a painter but not for a wall painter; really messy looking.

I am also thinking of covering the whole inside with a sticky plastic sheet, making sure the edges have no... edges, but it seems to be mighty difficult to cut the sheet right then apply it without any bumps or imperfections. Another idea would be a thicker sort of plastic, like the PVC you mentioned, cut to size and then cover the edges with a silicone gun (which I happen to have). The easiest of all would be of course to just lay a plastic sheet on top, but that would look really messy and ugly.

 

[archphoto]

At this stage I would apply 2 coats of epoxi paint.
Getting some self-sticking-PVC nicely into that sink is a nightmare, the paint is a lot easier.

My 2 cents...

Peter

 

[arigram]

Peter you are right, I think I won't mess with the sheet.
I went to a couple well stocked hardware stores but I didn't find anything that could be easily be applied or be trusted enough: it was either the thin self-adhesive kind that you would use to cover a table or a drawer, or thick boards of PVC or other plastic that were thick enough to be unwieldy and probably a bitch to cut, cover and glue. And expensive. And no guarantee that they would do the work or that the fuss was worth it.

So, I may do two or three coats of the epoxy paint. My brushwork may be amateurish, but hey, it works for liquid emulsions!

 

[archphoto]

The main thing will be that your sink does not rust away completely, the quality of you brush work will be OK aslong as you treat the seems thoroughly and lets face it: you will be working in the dark anyway............

Enjoy your renewed darkroom !

Peter

 

[RobertV]

http://www.mrboat.nl/EU/index_eu.html

Maybe something for you. Epoxy glass fiber.

Best regards,

Robert

 

[Nicholas Lindan]

buff out the rust with some steel wool

Oh, for God's sake, DON'T.

Using steel wool on soft (read cheap) stainless steel will cause the stainless to rust - tiny bits of the wool embed themselves in the stainless and start rusting sites.

How do I know? - I had a sink that looked just like the one above...and it got that way with a good scouring with a brillo pad. Once the corrosion sites started they just spread and spread.

The only cure I found was to sand the rust away, and to keep sanding it away until it stopped re-appearing. The surface of the sink was cratered and pocked by the time the rusting stopped.

I couldn't find any chemical treatment that would undo the original (m)alchemy.

 

[Eric Rose]

never sleeps

 

[arigram]

http://www.mrboat.nl/EU/index_eu.html

Maybe something for you. Epoxy glass fiber.

Best regards,

Robert

Ha, how didn't I think of that? I live right next to a port!
I am sure I can find something like that here if I look and ask.
Maybe that epoxy paint I got is enough. I'll finish the cans and see if I get the boat paint as I am running a very tight budget.

 

[Jim Noel]

I agree with Tim Vermont - the epoxy paint made for steel should serve you well. It probably would be wise to clean and repaint each year.

 

[ttok]

Just wanted to add that Leedal, a stainless fabricator in Chicago that makes a lot of photographic stuff, uses 18 gauge type 316-LC stainless in their sinks. Not all stainless is created equally! The stuff you get from places that typically make sinks for restaurants is made of a much different grade of stainless that will rust badly when exposed to photographic chemicals.

You have done the correct fix - cleaning the rust, then painting with marine paint - in my opinion.

A.T.

 

[Dave Pritchard]

Stainless steel must be passivated after fabrication and re-work. Passivation baths are sometimes named Irridite, or Alodine. Here is an article on getting the surface of stainless steel electrically passive.

http://www.mmsonline.com/articles/how-to-passivate-stainless-steel-parts.aspx

 

[arigram]

So far it seems that the paint I got was right for the job.
The water and the chemicals that splash out don't "stick" to the basin, they keep together and don't spread and they are very easily wiped even if they had stayed overnight.
I might consider the boat paint later on, but as it is I seem to be fine!
Thank you all again for your suggestions.

 

[AgX]

I wish you all the best with your work. I once used seemingly the same `rust-transformer´ and though I let it drie correctly after some period the varishes I had sprayed over gave bubbles.

 

[Sirius Glass]

I am glad that you have a workable solution to your rust problem.

Steve

 

[Marco B]

So far it seems that the paint I got was right for the job.
The water and the chemicals that splash out don't "stick" to the basin, they keep together and don't spread and they are very easily wiped even if they had stayed overnight.
I might consider the boat paint later on, but as it is I seem to be fine!
Thank you all again for your suggestions.

Well, it definitely is possible to preserve or halt rust more or less using coatings.

This video:

http://www.rtl.nl/components/automo.../week49/vrijdag_13_skoda_1200_1.avi_plain.xml

is of my sculpture lessons teacher Simon Konijn, who is an artist (he's the one with the hat in the video). The car in the video is a rare 1953 Skoda 1200 series. He bought it, and than "repaired" it and even "upgraded" it with a similar old, but slightly stronger engine from another car

The "body work" he did is just a clear super coat of some synthetic epoxy or something, over the rusty parts after some rough sanding. This stabilized it, and it still holds up after a few years in our wet Dutch climate...

Sorry the narration is only in Dutch... The title of the television program "Gek Op Wielen" actually translates to "Madmen On Wheels"

Marco

 

[Edwardv]

Not stainless for sure. I would definitely ask for my money or a replacement.