 ArtMetalsocial networking for the metal arts |
|
copper sulfate patina to low melt alloy of Bismuth/tin
Francis Baker -
Friday, July 11, 2008 - 12:54am
copper sulphate | low melt alloy | patina I have cast a sculpture of mine in low 281, which is an alloy of Bismuth and Tin. On one side of the sculpture, I used copper sulphate to patina. I have achieved interesting results ranging from a reddish color, rusty, to grey and black. I have not waxed it yet, or sealed it, which I believe will deepen the results. As it is in the raw state, it is a little muddy for my liking. It does not 'pop' the way a great patina does. I guess it is lacking in contrast as all the tones are very, very deep and a bit muddy. The reason I hope the final spray coating of sealer will bring out the colors more, is that when the metal is wet, it looks great; yet, when it dries, there is a whitish coating. I cannot seem to wipe/wash this off. Does anyone out there have any knowledge of copper sulphate? Is there anything I can apply to this patina to brighten the colors? Is there anything that will react with copper sulphate that would be interesting? Is there a way to etch off some of the patina? Any help is appreciated.  copper sulfate time on Metal
Francis Baker -
Saturday, July 12, 2008 - 3:22am
Interesting... I am pooling the copper sulphate on the metal until It seems to completely loose power. I obtain what seems to be a thick layer...I did not even think of it pealing off. Thanks for the tip www.francisbaker.com  Sulfate patinas seem to
Rich Waugh -
Friday, July 11, 2008 - 8:41pm
Sulfate patinas seem to habitually end up having that "haze" when dry, in my limited experience with them. A clear coat over them usually corrects this, though. If you want to get some more variation of tones in your final patina, you can lightly rub the surface of the piece with some fine, dry pumie or rottenstone on a piece of felt. This will cut through some of the copper sulfate layer on the high spots of the surface, brightening them. Conversely, you can ""tint" the patina in select areas if ou wish, using finely ground carbon black and a piece of felt. When doing the highlightin gor tinting, stop from time to timea nd wet the piece to get an idea of how it will appear under a clear coat. When it looks right, dry it thoroughly and apply your clear coat finish. Thank you for the suggestion
Francis Baker -
Saturday, July 12, 2008 - 3:26am
Thank you for the suggestion on abrading the surface. Another friend suggested that and I will try it on one piece. For tinting, that is a great idea as well...I actually make my own carbon black from the burned wood left behind from fires in CA. By tinting the patina with the carbon, does the carbon form a strong enough bond just by loading it on felt and rubbing? Will excessive wetting or washing wash that off again? I will post some work in progress on this... hopefully a before, during and final. Have you used Permalac as a sealer? Thanks, francis www.francisbaker.com Francis, If you seal the
Rich Waugh -
Saturday, July 12, 2008 - 7:03pm
Francis, If you seal the surface with Permalac, (which I have not used), or any similar acrylic lacquer clear coat, it will be permanent. Carbon black is inert, so it won't change color on you later. For interior work, I usually do my patinas and then give the piece two or three coats of Renaissance Wax. That holds up really well and doesn't "wet" the surface so itdoesn't seem to change the patina appreciably, the way that a liquid can sometimes do. I tend to think of the surface of a metal project as somewhat like a bare canvas awaiting paint. Through the use of chemicals, powders and waxes I create the look I want. Some of the stuff I use is: Carbon black, for accenting low areas or generally darkening a surface. Powdered graphite, for much the same uses as carbon black, plus it has a shiny, gunmetal appearance. Bronzing powders, to give a copper, bronze, silver or other appearance to the surface. Talcum powder, to develop a matte finish (over tacky clear coat), to lighten areas and to provide a "weathered" effect on copper patinas. Renaissance Wax, for final finishing and also as a vehicle to bind some powders to the surface. Penetrol, in place of linseed oil/varnish mixtures as a final finish. Has a warm, golden hue to it.  White Coating
warren -
Saturday, July 12, 2008 - 11:07pm
the white coating may be because of moisture......either the metal was not completely dry or excessive moisture in the air. Also certain clear sealers leave a whitiest look. Bad ones are Rustoleum and any enamel base (slow driers). Best to use an acrylic or lacquer base product. warren polishing copper sulfite patina
Francis Baker -
Monday, July 14, 2008 - 12:48am
Thank you for the tip to polish the patina. I went to look for some 0000 steel wool I thought I had and found some plexiglas polishing stuff instead. It is a product called Novus. There is a #3, 2 and 1. #3 being a paste, down to 1 which is very watery. At first I used the #3 with a micro weave cloth. I went through the white haze, continued on and went through the black to get a brass like look. I was more delicate with my polishing in other spots, keeping most of the weathered patina, but removing the haze. I kept some of the yellowy metal look as well as the dull reds. This week I will get some pix up to show. thank you all for your help www.francisbaker.com  finishing copper for a beginner
visitor -
Tuesday, September 15, 2009 - 11:36am
I recently saw a table top covered with copper the finish was beatiful(red and dark brown) i want to try and make my own. I have located the sheet of copper and someone to put it on the table top but i have never finished copper before Is this too big of a project for a beginner and where can i find instuctions on how to do this |
|
.thumbnail.JPG "Duel Aspirations 3")
ArtMetal
I've used copper sulphate on
I've used copper sulphate on mild steel and can testify to the fact that applying a wax or linseed oil mixture after the patina has dried will bring out the contrast and add a sheen to the finish. One thing I have learned is to not leave the copper sulphate wet solution on for more than a minute because it has the tendency to peel. So, I rinse the solution off after about 45 seconds or so. Then I wait for it to dry and reapply to create the desired effect.
Hope this helps.