Hi Everyone

Discussion in 'New member introductions' started by purpleparachute, Jul 20, 2022.

  1. Hi there,

    New to the forum (though lurked for a bit) but not really new to casting - coming at it from the hobby/sculpture side of things and primarily interested in lost wax bronze casting. Been working with commercial foundries for a while, getting rough castings to finish etc.

    Done bronze, alumnium, lead and iron many years ago when I was at uni and had access to the full foundry works and large contingent of strong men and women to help with running pours (ah those were the days!)

    however when it comes to setting up my own kit, there are areas of knowledge sorely lacking, which is where I hope to be able to find direction/help in thehomefoundry.

    Happy to offer my own knowledge, for what little it's worth and to contribute to discussions - I may disappear from time to time and am very bad at checking messages (PM's etc) but do ping me if you want to.

    Anyone here from the old sculpture.net forum? I miss that place!

    Am south UK based, anyone up for creating a pour team??

    PP
     
  2. Mantrid

    Mantrid Silver

    Love to hear about your experience with patination and If you can share any techniques especially doing the more unusual effects and colours.
    I remember sculpture.net. It was a good forum. Do you know when it disappeared and why?
     
  3. Hi Mantrid,

    Patination wise, it's another area I need to play around in more - I've done fairly standard french brown (LOS), black (LOS) red brown (ferric) and greens (Cupric and ammonium chloride) it's all quite unexciting and any funky colours or effects are usually unintentional haha!
    I do remember that ferric on LG3 bronze turned it red and then when heated more it went purple and finally black. doesn't seem to get the same colours on sil-bronze though so I guess it depends on what you're trying to do. It was all incidental and I have no idea about temperature of the metal unfortunately.

    Can tell you more about my methods if you'd like, what have you done yourself?

    Btw on the subject of LOS - what are your disposal methods for this stuff? And is it really ok to be able to smell it just avoiding breathing it in when it's steaming off the sculpture? I wear a FFR (full face respirator) all the time when patinating as I don't want to take chances but it may not be 100% necessary? (sorry lots of my questions are boring H&S ones!)

    The sculpture.net forum was fantastic, I have no idea what happened to it but I'm sure I was posting on there until at least 2015-16 maybe? I guess whoever ran it just decided it wasn't something they wanted to do anymore but my god it was FULL of amazing tips and knowledge for the hobby sculptor! I saved some of the older pages but I don't think it's archived anywhere unfo.
     
    Last edited: Jul 20, 2022
  4. Mantrid

    Mantrid Silver

    I have experience of the usual patinas. I m looking at more unusual patinat to replicate the colours found on a coral reef which is the current sculpture Im working on. I have found techniques for reds and blues but i am looking for others such as purples and yellow greens and whites that will stay white after wax is applied. I would prefer to stick with a traditional wax finish rather than spraying with lacquer.

    Regarding disposal, Ive never hdto dispose of it. Ive used the chunks of LOS dissolved in water. I tend to paint it on ith a brush and just make up what I need. I think you can neutralise it with baking soda. However I dont think it damages the environment in the same way as other chemicals. If I had to dispose of the fractions of a litre I make up I would probably just tip it on the gravel path of my garden.

    I dont wear respirators, as I usually use brushes to sapply the patinas on the small sculptures I make. I have used small spray bottles and wear just a simple dust mask to trap droplets. From what Ive read the usual patinas you have mentioned are not carcinogenic which is my main concern. I think they are mostly irritants at best. I also spray patinas outside.
     
    Last edited: Jul 21, 2022
  5. If you can control your LOS use to the point where you have no wastage then that's great, I am paranoid about my health after a few issues (may or may not have been sculpture related) and as I tend to be less accurate in my mixing I normally have some left over. I used to use lump form and now use the gel which makes it much easier. When finished I usually pour it into sand, wait for it to stop being smelly and to go white then I chuck it out. Sometimes with older lumps it would deteriorate very quickly and be unuseable in minutes so I'd need to junk it and start again. very hot water adds to this deterioration.
    I'd be careful with how you use it as my bottle says 'toxic by stench and skin absorption'. It's the steam coming off the sculpture you have to watch out for. I wonder if I'm using something different. (potassium sulphide, yellow sulfur smelling lumps, or dark yellow gel)

    With the colours you want to get you could try ammonium chloride for white/very light green (is it sil-bronze?)
    Otherwise titanium white? I haven't tried this one. https://www.shutterstock.com/video/clip-16973659-laying-patina-titanium-white-on-bronze

    Using cupric and ammonium chloride together gets you a very bright blue-green. cupric on it's own gets you a very bright grass green. don't overheat it though or it will go salmon pink!

    and this method may give you a blue - can't remember where that is from, it could be here somewhere.
    For a blue patina, mix one part Miracle-Gro with three parts water for a solution that you can spray or wipe onto the copper. For a green patina, mix one part Miracle-Gro with three parts red wine vinegar. A patina will form within 30 minutes and become permanent within 24 hours.

    Pretty sure it would be the ammonia in the Miracle Gro that would cause this reaction.

    Yellow, I've had gold-ish from ferric, it's very temperature dependent and can burn easily - not sure what happens when waxed though.

    If you don't mind other methods have you looked at the dye oxides by sculpt noveau? Or pigment in finishing waxes?

    Or there are a couple of patina recipe books around.
     
  6. Mantrid

    Mantrid Silver

    Thanks for the patina tips. Never thought about miracle grow. I suppose it has many different salts in it.
    The only white patina ive tried is bismuth. It was along time ago. I think I reacted the metal with acid. Cant remember which. It formed a bismuth salt. Its made a white patina but when waxed it lost its colour.
    I have achieved various interesting colours with los but again they fade or disappeared when waxed.
    Using pigments might be an option if I cant achieve a chemical effect.
    I have alot of experimeting to do. I have a failed casting that I will use for experimenation.

    http://forums.thehomefoundry.org/index.php?threads/coral-pinnicle-with-shark-and-conger-eel.2035/
     
  7. Possibly of use, this is a shot of the inside of an A25 crucible after casting pure copper deoxidized with phosphorous which shows some nice colour of what should be a reasonably tough oxide layer. Maybe baking bronze in a kiln will give a similar result assuming you could arrest the oxide formation at the desired point (CO2 gas purge?).


    Photo without flash
    copper oxide 2.jpg

    Photo taken with flash:
    copper oxide.jpg
     
  8. That looks cool - another vote for this idea - watching casting videos online, down a rabbit hole as you do, found one where pre-heating for patination was done by putting a small sculpture on a coil heater - it went all kinds of funky colours. Not sure how to keep that colour though.
    I wonder if any of the heat treating for copper ideas would work too? One other idea though I know you are still looking at chemicals - indian drawing inks, very vivid and have used on alumnium before with some success. Not sure if you need a rough sanded or mirror polished finish for this but as they are sort of transparent you get the metallic sheen coming through as well.
     
  9. Mantrid

    Mantrid Silver

    Ive had colours like tht when heating bronze with a welder however they seemed to fade with time. I didnt put wax on then but they were quite transluscent so I suspect they would fade
     
  10. Sounds a bit like the interference colours on hot polished steel formed by a thin clear oxide layer.
     
  11. Petee716

    Petee716 Gold Banner Member

    I was just goofing around with one of my "failures" one day. I just chased around the surface with a rich burning oxy/acet torch till the colors started coming up. Quenched in cold water. Still looks about the same as it did almost 2 years ago. My buddy saw it over my workshop doorway and was enamored by it so I gave it to him. I had him snap a picture of it today. Alloy is everdur. Spray lacquer.
    2 years ago
    652933887.jpg

    Today
    680302200.jpg

    Pete
     
    Last edited: Jul 23, 2022
    Tobho Mott likes this.

Share This Page