grey-colored patina/oxide of alloy

[jake pogrebinsky]

I'd like to humbly ask for help in tracking down a (somewhat)specific alloy,it's finish,and also,if possible,a reputable craftsman or a shop capable of executing the work itself.

A very old and dear friend has tragically passed away.Her family has asked my help in finding someone capable of casting/fabricating a plaque that will be mounted into the memorial bench at the cemetary.

The required plaque needs to be oval,approx. 12" by 6",and be dark grey in color.

The material needs to be SS or Ti(as i believe that both can be patinated grey,although it is very far from my area of expertise).
Both Cu and the Al alloys are not an option,for a number of reasons.

The inscription will contain a number of symbols,and will have to be fairly detailed.

These are the basic parameters,and i'll greatly appreciate both the thoughts on the metallurgy of the project,as well as any and all recommendations as to a specific person,perhaps specialising in these metals.The location is East Coast,RI,but due to the moderate size of object all locations will be considered.

Many thanks in advance.

[HWHII]

One option would be to sandblast the stainless steel with a copper oxide media. It is pretty popular here in the southwest. It leaves the material a nice medium to dark gray.

[jake pogrebinsky]

Thanks much.It helps a lot by giving me a direction in which to proceed.

[nuge]

Maybe pewter? Fairly easy to cast, you can melt it on your stove. The color is right and it weathers fine.

[jake pogrebinsky]

Nuge,thanks.The general idea of diverse white-metals did cross my mind,but i couldn't recall much about their stability outside,over the long term.Some metals' oxides have a tendency to continue their development,never stabilising entirely(many Al alloys are that way).But my understanding of alchemy is weak,and it is an interesting point.

[jimmy seale]

well years ago i was filling a new motorcycle battery with the acid mix that came with it. and accidently dribbled a little on my wifes ss sink..washed it off and it left a dark stain on it..you may try something like that on a test piece. i know you know but..please be carefull around all types of chemicals.good luck. jimmy

[jake pogrebinsky]

Thanks,Jimmy,but i'm just trying to help the folks in finding someone who would do it,i'm not set-up for ss work,especially raised-work that i envision this to be.
Myself,i'm even lousy with the black oxide finishes...

[John B]

Thanks,Jimmy,but i'm just trying to help the folks in finding someone who would do it,i'm not set-up for ss work,especially raised-work that i envision this to be.
Myself,i'm even lousy with the black oxide finishes...

Just a thought. Why raised work? That implies casting, and all the expense involved with making patterns etc, somone with engraving facilities would possibly be easier to find

[jake pogrebinsky]

That's a very valid thought,now that you've mentioned it.
I'm realising now that i just automatically envisioned this type of work as a deep,solid bas-relief.
Something somber,very intentional,about the depth of such work,perhaps better befitting the purpose.
In contrast with that,the engraving being so much shallower(must specify this subjective instance alone,far from slighting the engraving in general),and "looks" it.
Possibly my impession is from seeing so much of a very poorest sort of engraving around,since the advent of pneumatic gravers and other mechanised means of it.
One has to design carefully,to avoid that "dog-taggy" sorta look.
On the other hand,due to mechanisation,casting now has alternatives.So,with the mention of SS what came to mind was a CNC milling,first and foremost.I'd imagine that the industry uses a number of other tools as well,electro-etching,et c.
But that's just me,and i appreciate your input much,especially since i'm not sure at all that the people,that will be ordering and installing it,actually share my assumption in this matter... :huh:

[bigfootnampa]

Well I will interject a new thought. What about using stainless steel sheet metal and chasing/repousse to form the design? Then it could be treated as suggested by HWHII to get the color desired.

[jake pogrebinsky]

Very true,Clay,it would certainly be a way to accomplish something like this in a classy manner.Thanks for the thought.

I was also thinking that if i was actually up against having to do it myself,with my limited skills,then i'd cut it out of an appropriate thickness sheet with a plasma cutter,true it up with an abrasive bit of a Foredom,and laminate it onto similar(or contrasting)background.

At this point i still hope to find a shop to do it using a CNC controlled end-mill,it shouldn't be too much of a challenge for some moderate-size shop,being practically a 2D project.

[Bentiron1946]

There are alloys of what is called "white bronze" but are really a nickle bronze alloy or more commonly know as "German Silver". The newer alloys are silicon based naval bronzes developed for corrosion resistance and used now for propellers on small craft. These are easily cast and as mentioned before if sand blasted will have a dull gray appearance. If they are cast via the ceramic shell lost wax method they are capable of picking up ones finger prints, so they would qualify for your requirement of picking up fine detail. There is also White Manganese Brass that is used to cast "white" metal parts but I have had limited experience with this metal but it should cast as well as any other brass and pick up detail as well as any other brass.

[jake pogrebinsky]

Ah!Thanks for that info,sir,very interesting.
In a way,i've always felt uncomfortable for neglecting the non-ferrous metal casting side of things.
Certainly in terms of information,especially the specific stuff like this.
I have a 2-buner set-up built for an A-6 crucible,(even have one kicking around,a SiC kind,that i've EVEN forged tongs for...).
But certainly no investment materials.Pattern-making,too,would pose a serious learning-curve challenge.
All surmountable difficulties,and the ones that a wise metalworker would be best to get even a little experience with.Handy stuff.
Thanks again,Jake

[Bentiron1946]

I learned by reading a book or two on how th Egyptians and Incas did it and they didn't have much to work with compared with todays tooling. My first setups were very primitive but worked out very well. I figure that with the Internet and all that is available today it'd be easy to find all the necessary information on how to scab together a makeshift investment(think plaster of Paris and sand) and for a pattern use beeswax and paraffin wax to adjust the hardness of it. Something else for you to play with during the long cold winter I guess. :blink:

[jake pogrebinsky]

Oh,but let's not forget that the ancient Egyptians and Incas had this one great tool...Slaves!
All the successful,productive cultures did,from the Kingdom of Zimbabwe to the Tsimshian culture a bit s.e. of here.It's a great way to get stuff done!(Not our crowd here,though,life was too rough).
Unfortunately,my ethnic background predisposes one toward a slightly different position on slavery(as the etymology of a term "slavic" indicates... ).
Come to think of it,i can really picture myself a couple of thousand years ago as an artisan-slave,maybe i'd have even been a good one!(Alas,all the craftsmanship has fled the slavery nowadays,maybe that's why when i was a minimum-wage slave i was such a bad one...).
The artisan-slave in modern times is more of a beggar(i.e.grants,from the wealthy and/or the mighty),as the artisan still has to make ends meet,somehow.
OK,enough of silliness,sorry about that.
Yes,very true.Investment also is an old,and simple trade,and not a "rocket science",it can,and it SHOULD be practiced on some level.
(What you wrote vividly brought back memories of a few glorious explosions of some (incompletely dried)plaster molds of my misspent youth!
And it's the lack not of slaves but rather of self-discipline that prevents me from better utilising the winters,it's very true.
This is a lovely time of year,the spring is,in part because one can entertain such high hopes for the next winter!
Thanks for encouragement,you're very much right.

[K. Bryan Morgan]

Just a thought, but, something that I have experienced with making metals grey is sand blasting. It gives a very soft grey sheen to the steel. I've sand blasted quite a few cars and even a Rolls Royce as prep for painting. The finish, before we did the priming, was actually quite a nice color. I don't know if that would be a process you could do, or if you have a sandblaster available. But I think it would give you the look your wanting.

[Bentiron1946]

Just last week I got some of my cast iron pieces back from the sand blaster and there were such a nice gray color it almost seemed a shame to start the rusting process by spraying them with white vinegar.
Now back to casting metals, yes, a Slavic salve would be nice, maybe if it were a compliant one but I haven't meant to many compliant Slavs of late. I made some casting using clay tempered with large amounts of sand over the wax and did a very slow burn out to cook the clay and then went hot to eliminate all of the wax. It turned out reasonably well for the experiment I was working on at the time but it sure took a lot longer than using some nice Kerr T-64 investment in a good gas fired burnout oven. When in collage the professor use a mix of 1/3 plaster of Paris, 1/3 hydro-cal & 1/3 fine sand, it work OK but the jerk never mixed it throughly enough nor did he put any reenforcement in the cardboard boxes he had us use along with the garbage bags to hold the waxes. The students had a nearly 60% failure rate in their castings. He also had them use little tiny sprues and risers. One night he was absent and I took over and did things a bit different, we put on 3/4" sprues, hardware cloth reenforcement in the cardboard boxes, mixed enough investment to fill the whole box at one pour using a power drill and a paint mixer in a five gallon bucket. That group of molds went to a 100% success rate. Having a PhD in art doesn't guarantee success in casting but a good background in practical experience does and the professor didn't have that. He had been doing casting the way his professor had taught him and having failure, they just had never tried to figure out what it took to be successful in casting, they just knew they had problems. I had been working for several years to make a success of my castings and knew that tiny sprues were not the answer by studying ancient examples of the founders art and modern foundry practice. I tried a lot of the ancient methods by trial and error. Those ancients knew their stuff and just look at all that wonderful stuff they cast and we are still in awe of it today and feel that we can only accomplish it with fancy vacuum casting machines and other modern devices, they did it with mud, charcoal and their own hands, not machines. Well I guess that I have ranted enough. :mellow:

[bigfootnampa]

Jake here is another idea: I got some monel at the scrapyard last year and made myself a MONDO ice cream scoop (whew, some HARD stuff). I liked the thin dark scale and left hammer texture on it. I sanded it to clear any loose scale and to highlight the texture by polishing the high parts. It came out very pretty and the color has proven to be extremely durable... surviving unchanged through a year of heavy use and many hand and machine washing cycles. The color is more charcoal than grey but maybe done thinly it would be just right as the base metal is bright steel colored. This stuff lasts nearly forever in weather too... it represents the ultimate stainless steel. HEAVY stuff, more nickel and copper than iron... UNBELIEVABLY HARD!!!!

[MattBower]

This is a fascinating discussion, but since you originally were looking for a reference, Jake, take a look at this site. They're in Rhode Island. Click around on their photos and see if it looks like they might be up to what you envision. http://www.maleylaser.com/

I don't have any first-hand experience with these guys. Your description of what you want reminded me of stuff I've seen on the site of a similar place around where I live, so I started looking for a place like that in RI.

Anyway, just a thought.