Finishing options

[Buter]

Hi y'all.

Been lurking in the background for a few months, first post. Great forum - loads of info and you folk don't seem half bad either!

The current wife is an artist and is starting to branch out into 3d art. She has bid on doing a sculpture that will be going in front of a posh seaside hotel down in our little bay. I've made her the model for submission along with her sketches and artsy-fartsy drivel and I think she's got a good chance of getting the commission. I'll be doing the fab work if she pulls it off.

I'll be doing the metal work out of mild steel sheet. She really fancies the oxidised copper look, but other than painting it, which she can do, I don't know how to do it. Any ideas?

Another option I pointed out to her was doing a rusted finish which I've seen on this forum. Would anyone care to expand a bit on how to achieve a durable finish using this technique? If so, I'd be grateful.

Salt air, seaspray, winged crap machines, sunshine and force 10 winds are all common over here so the finish needs to be a tough one.

Thanks in advance for any help and I look forward to participating here!

Cheers

Buter

 

[the snooper]

you need chunko for this one he's always rusting stuff up, while the rest of us are trying to get rid of it

 

[chunkolini]

Rusting things quickly?
That is no problem.
Getting them to last in a marine environment might be.

To rust it quickly clean off any oxide such as mill scale, if time is not important dont need to do this.

Scrub the mild steel with a saturated solution of Ammonium Chloride, not as nasty as it sounds and easy to buy off Ebay. Add some washing up liquid/detergent, this helps to break up and grease or oil on the surface.

leave it outside for a few days, ideally a couple of weeks and it will develop a nice bloom of rust. Give it a week or two then scrub it to remove any loose rust.

I paint it with ordinary yacht varnish, put lots of it and use a stiff bristled paint brush. the rust seems to act as a key and it absorbs loads of varnish. two or three coats should do it.
I have pieces of sculpture outside my place for several years with one coats of varnish with no problems.

the big seahorse see pic was recoated after two years, I just washed it between coats and it looks great over a year after the second coat.


This had two years outside before being varnished. it is an unpredictable finish, but does work.
be careful to make sure any loose rust is removed.

if you have mill scale on the workpiece it takes about a year for the rust from the amonium chloride to work it's way beneath it and lift it off. A weird process, it comes like a thin layer of paper and leaves true rust beneath it. Varnish over this and you have a slow moving disaster to deal with.
Done right it looks like this.


The papery layer looks like this a few months after being varnished over.


And like this when it is ready to be brushed off.


Weird stuff.
How will it survive by the sea? probably well if coated properly.

 

[astro_al]

If you want the oxidised copper look, use copper and let it oxidise.

If you want a long lasting rusted steel look, use corten steel.

Al.

 

[Buter]

Hi guys

Thanks for the replies.

Thanks for the info, Mr. Chunk. I've been admiring your work since I began looking into this metal sculpture malarkey. Trying to talk the wife into doing one of your courses so she can do her own fabrication and I can just surf and ride my bikes.

Hi Al. I've never worked with copper so would be a bit leery of doing a sculpture out of it. If successful, the full size piece must be done by December 31st so I doubt I'd get a good patina on it by then anyway.

I like the look of the Corten stuff. Is this left untreated or does it get some sort of clear coat after it rusts over? I'm guessing since it is billed as a weathering steel it gets a thin layer of rust that protects the metal and that's that?

Thanks again and please, anyone else with good info/ideas chime on in.

Cheers

Buter

 

[strada]

Mr chunk ????
prepare yourself

 

[Buter]

Uh oh...

 

[chunkolini]

Chunk? Chunk? Who is this Mr Chunk?
Mr Buter you are new here so I will make an exception.
I have a henchman who deals with this type of thing.
Chunkolini is fine, Chunko is ok in informal situations.
But Chunk, Chunky Chunkums etc are dissapreciated.

On official occasions it is Bennitto Chunkolini Prince of Darkness but that is a bit of a mouthful.

Nice to meet you anyway.

re patination by December would be fine, I reckon if you start with steel with no millscale on it a few weeks is fine. Citric acid will remove it a treat.
I would suggest doing a few pieces and leaving them exposed and keeping an eye on them.

 

[Buter]

A thousand pardons, sir. No offense meant. Lesson learned.

Thanks again for the tips and nice to meet you as well.

Cheers

Buter

 

[Metalsculptor]

Hey Chunko - when you said 'citric acid brings it off' - did you mean the mill scale?
Is this a drastically cheap alternative to blasting???

 

[chunkolini]

Yep!
Soak it for a while , I leave it overnight and it scrubs off with a washing up brush.
I leave mine stood in a length of plastic drainpipe over night. There is a post somewhere covering this.
Much easier/cheaper than blasting or grinding.

 

[Buter]

Well, we won the commission against some other really good entries so I'm pretty stoked and pretty damn proud of the old girl. She actually turned down coming away with me for a little mini-holiday to Vancouver so that she could attend the award ceremony just to applaud another artist when they won; good girl, eh?

Anyway, thanks for y'all's help on this little thread. I'll do my best to make a build thread and post it up, warts and all. I've done quite a bit of welding in my life but it has all been either underwater or structural up til now so the chances of it all going smoothly are slim to the square root of sweet FA.

Cheers

Buter

 

[MattF]

But Chunk, Chunky Chunkums etc are dissapreciated.

If you hadn't mentioned those..., but how on earth could I possibly resist using Chunkums from now on?