Imu Posted April 15 Report Share Posted April 15 Hi guys, I'm new here, I seemed to come across this forum a fair bit when researching things so figured it was about time I signed up, its given me some pretty useful tips over the last year or so. Happy to give back what I take, I have more of a technical history than ceramics but there's plenty of overlap. Anyways, my first post I'm looking for a bit of guidance on creating my own gold lustre, there is very little information floating around the Internet and any books I've purchased are more geared towards using lustres than making them so I've been fumbling in the dark. Now I know commercial lustres are available but I have a working project that requires me to make my own to give provenance to the finished piece Now as far as I can work out a gold lustre is simply either elemental gold in a nano/powder form or gold chloride mixed with a carrier oil, lets say pine oil, would this be a correct assumption? I would then use toluene, turps or similar to thin this to the right consistency? Would I pretty much just mix say 10-15% gold with the oil, then boil to ensure it mixes well? I already have some experience in refining gold and do have the necessary nasty chemicals to produce my own powder or chloride so its really just the last step that im fairly vague on Thanks for any input, like I said, information on the process seems very patchy, even a pointer to a decent technical book would be appreciated. Hulk 1 Quote Link to comment Share on other sites More sharing options...
Min Posted April 15 Report Share Posted April 15 Try sending @liambesawa pm asking about this. He hasn’t been on the forum for ages but when he was he was making lustres. Rae Reich 1 Quote Link to comment Share on other sites More sharing options...
PeterH Posted April 15 Report Share Posted April 15 Some plausible-looking advice on techniques and H&S referenced in: Historically there have been two sorts of lustres: reduction lustres and resinate lustres. Your comments seem to apply more to the reduction-fired reduction lustres. While tho commercial oxidation fired products are resinate lustres. Ever wondered why solder is often sold with a rosin flux running through it? When you apply it to the joint the hot rosin reacts with any oxide on the copper surfaces to form copper resinate. The resinates lustres are made by reacting metal oxides or salts with rosin and dissolving the resinate in or another solvent. With luck you finish up with quite a high concentration of metal resinate in the solvent. When these are fired they decompose leaving a thin metal film (and often some pretty nasty fumes). As Min said, do try and get in touch with @liambesaw if you can, but he hasn't visited the here since 2022. A friend used to run a garage industry making resinates and had very strong reservations about many of the solvents used in commercial lustres, sticking to - AFAIK - linseed oil. Manufacture a gold lustre is fairly briefly covered in "Pottery Decorating" by R. Hainbach. Which involves mixing "bright gold" with a bismuth lustre. Bright gold apparently containing resinates of gold and rhodium (and also possibly bismuth, uranium, chromium and iron?). Although a simpler wet process is also described for producing gold resinate from gold trichloride and resin-soap. ... probably much better to find out what people do nowadays. PS The book seems fairly expensive at the moment, change this search to your location and currency. https://tinyurl.com/2d783cv8 Imu, Rae Reich and Hulk 3 Quote Link to comment Share on other sites More sharing options...
liambesaw Posted April 15 Report Share Posted April 15 (edited) 6 hours ago, Imu said: Hi guys, I'm new here, I seemed to come across this forum a fair bit when researching things so figured it was about time I signed up, its given me some pretty useful tips over the last year or so. Happy to give back what I take, I have more of a technical history than ceramics but there's plenty of overlap. Anyways, my first post I'm looking for a bit of guidance on creating my own gold lustre, there is very little information floating around the Internet and any books I've purchased are more geared towards using lustres than making them so I've been fumbling in the dark. Now I know commercial lustres are available but I have a working project that requires me to make my own to give provenance to the finished piece Now as far as I can work out a gold lustre is simply either elemental gold in a nano/powder form or gold chloride mixed with a carrier oil, lets say pine oil, would this be a correct assumption? I would then use toluene, turps or similar to thin this to the right consistency? Would I pretty much just mix say 10-15% gold with the oil, then boil to ensure it mixes well? I already have some experience in refining gold and do have the necessary nasty chemicals to produce my own powder or chloride so its really just the last step that im fairly vague on Thanks for any input, like I said, information on the process seems very patchy, even a pointer to a decent technical book would be appreciated. I wasn't successful getting the gold to reduce with just pine resin, if you buy Greg Daly's book "lustre", he details making it from elemental sulfur and gold chloride. This works well. Commercial lustres using pine resin thinned with toluene use a different gold salt, I'm guessing that's the reason they work. I think the compound is a chlorohexanoic salt of gold. You'll also need a bit of bismuth in there to act as a flux bridging the gold and glaze. I had some luck making a silver lustre by making silver soap. Silver decanoate. But it was difficult to dissolve in almost everything so it was a pain to apply. Was conductive though and I made a few touch lamps using it. Also had success doing a similar thing with copper. Edited April 15 by liambesaw Min, Imu, PeterH and 3 others 6 Quote Link to comment Share on other sites More sharing options...
Imu Posted April 16 Author Report Share Posted April 16 Brilliant answer, exactly what I was looking for. Thank you I did have my suspicions that a flux would be needed. I really don't mind spending time experimenting but working with gold has obvious drawbacks. I have allocated a few grams of scrap for this purpose. I've ordered Greg Daly's book so this will be a good starting point. Hopefully I'll have some positive feedback in the coming weeks. Sounds like you've been down this particular rabbit hole yourself with success? Hulk and Rae Reich 2 Quote Link to comment Share on other sites More sharing options...
muddymakers Posted May 27 Report Share Posted May 27 We're you able to formulate a usable luster? I'm headed down the same path and mistakes are expensive lol Quote Link to comment Share on other sites More sharing options...
Min Posted May 27 Report Share Posted May 27 15 hours ago, muddymakers said: We're you able to formulate a usable luster? I'm headed down the same path and mistakes are expensive lol Hi @muddymakers and welcome to the forum. If you want to make sure someone sees your post try either tagging them like I did with you here or send them a private message with your question. (to send a pm click on their name/avatar then on the new page that pops up hit the envelope icon and follow the prompts) Quote Link to comment Share on other sites More sharing options...
Imu Posted July 7 Author Report Share Posted July 7 Hi @muddymakers, apologies for missing your reply. To be honest I've not moved forward much with this, I did pick up Greg Daly's Lustre book which does indeed have details on how to go down the resinate gold route using sulphur. Ive got as far as making my gold chloride and a few other metal salts. I figure I should start with the cheaper ingredients first until Im confident in the process. Green Daly did reference another book which goes into the process with much more detail, this was Industrial Ceramics but Singer & Singer, I did lay my hands on a copy only to realise it comes in two volumes and I have the volume which doesn't cover glazes! So ill be forking out the additional £180 for volume 1 at some point. Recently time hasn't been on my side, but I expect the workload will drop over the winter months and will give me the time needed to get back to this project. As mentioned in all the great answers on this thread there are many different routes I could take to achieve my goal, I fully intend to research them all and find which process will fit with my existing lab equipment For now I fully recommend picking up a copy of Greg Daly's book, if you can purchase gold chloride in your area then the process is fairly straight forward. If not then you would be looking at some gold refining threads on using aqua regia to make your own chloride. Good luck and ill be sure to post back when I've moved forward Quote Link to comment Share on other sites More sharing options...
Imu Posted August 29 Author Report Share Posted August 29 @liambesaw So I'm back to playing with this project, its a rabbit hole indeed. Ive been playing with both the pine resin and balm of sulphur routes. Making up balm of sulphur didn't quite go as expected, a few attempts at various heats resulted in the same outcome. A cheese like consistency which took a bit of work to mix with oil and strain. Cobalt nitrate was easy enough using nitric acid Gold chloride was straight forward enough when I realised it would take a vacuum pump to get it down to a dry weight Bismuth subnitrate is throwing me off a little, as far as I can fathom this is a generic name for a group of bismuth nitrates but I'm assuming it should be a water soluble form which would be H9Bi5N4O22 but cant seem to find much information on buying or making this. I did buy some from a pottery supplier but it doesn't seem as water soluble as I thought, so possibly Bi5O(OH)9(NO3)4, did you use a specialist supplier for bismuth? Was it the water soluble form? Quote Link to comment Share on other sites More sharing options...
PeterH Posted August 29 Report Share Posted August 29 31 minutes ago, Imu said: Bismuth subnitrate is throwing me off a little, as far as I can fathom this is a generic name for a group of bismuth nitrates but I'm assuming it should be a water soluble form which would be H9Bi5N4O22 but cant seem to find much information on buying or making this. I did buy some from a pottery supplier but it doesn't seem as water soluble as I thought, so possibly Bi5O(OH)9(NO3)4, did you use a specialist supplier for bismuth? Was it the water soluble form? 1) H9Bi5N4O22 looks like it's just a short form for Bi5O(OH)9(NO3)4 . Certainly it has the same numbers and types of atom. 2) All the references I'm finding claim that bismuth subnitrate is highly soluble in water. Are you certain that you didn't get bismuth nitrate? Can you share the name of your pottery supplier? 3) I have a lingering memory of having problems dissolving a bismuth compound several years ago. Perhaps related to: https://www.atamanchemicals.com/bismuth-subnitrate_u25219/ bismuth subnitrate slowly hydrolyses in water ... and even vaguer memories of adding "something" to reduce the effect aha! https://patents.google.com/patent/US2142957A/en To a water solution of the sodium salt of the mono-substituted carbalkoxy acetic acid is added a molecular equivalent of the bismuth sub-nitrate, in a water solution containing in sufiicient quantity any polyhydroxy alcohol which aids in holding said bismuth sub-nitrate in solution in the water; for which purpose we have found that either glycerol or mannitol is very suitable. A reaction occurs immediately, and without the necessity for heating; and by that reaction the desired basic bismuth salt of the carbalkoxy acetic acid of Formula 1 is formed. If the monosubstituted malonic ester used is the ethyl ester, which we prefer, R is the ethoxy group. ... for the terminologically confused, like myself: glycerol is also called glycerine or glycerin (IIRC the trade may use different names for different purities) 4) BTW CTM list bismuth subnitrate https://www.ctmpotterssupplies.co.uk/rawmaterialstwo.html Quote Link to comment Share on other sites More sharing options...
Imu Posted August 30 Author Report Share Posted August 30 Yeah, I've been finding conflicting information on the subnitrates, I am under the impression this is just a a very generic term for a group of compounds. https://www.pccarx.com/products/BISMUTHSUBNITRATEUSP/50-1145/APIS-EXCIPIENTS#:~:text=PRACTICALLY INSOLUBLE IN WATER AND,ACID OR BY NITRIC ACID. (Practically Insoluble in water) https://www.americanelements.com/bismuth-subnitrate-1304-85-4 (Very soluble in water) I believe I made my own Bismuth Nitrate by trioxide & nitric acid, which was only very slightly soluble.I then tried hydrolysing using a low heat and looked over some info on adjusting the PH of the water to precipitate subnitrates, but this was the rabbit hole I fell into. As you mentioned above you can hydrolyse the nitrate at 60C and adjust the PH to above 1 to precipitate nitrates. In the end I thought it safer just to order some subnitrate from a supplier, and indeed it was from CTM as you linked above. I assumed this would be the correct one. But again, this doesn't seem fully soluble. At this point I already had some cobalt resinate made up, so went ahead and used CTM's bismuth, I figured that the pine resin would be acidic and therefore aid in dissolving the powder, so dropped it in and gave it a good mix and heat, but I don't believe it dissolved fully, now when I let the resinate stand overing there is slight separation, a thicker mix on the bottom of the container. So I believe the bismuth is falling out of suspension, I could be wrong, it may just be the nature of pine oil and eucalyptus separating, as I don't have the experience I couldn't say for sure Interestingly, I washed off some of this bismuth in a beaker, let the powder fall out of suspension and syphoned off the solution. This stuff behaves as I imagined subnitrate should, very hygroscopic/water soluble, wouldn't dry out easily with heat alone, left in a vacuum overnight to get still slightly sticky powder. So today ill run the process again and use this. Just to compare with the first batch, see if it remains homogeneous after an overnight stand. Within the literature I've been reading, the bismuth has been referred to as Nitrate, Subnitrate and Basic Nitrate (Older term for subnitrate), but no reference to its characteristics. Just a general overview that working with lustres uses the water soluble forms of the metals. With very little modern information available on the resinate process I know its just going to come down to my own testing, Quote Link to comment Share on other sites More sharing options...
PeterH Posted September 1 Report Share Posted September 1 On 8/30/2024 at 7:39 AM, Imu said: Just a general overview that working with lustres uses the water soluble forms of the metals. Both the wet and dry processes use metal salts. But surely only the wet process requires the salt to be water soluble. Not least because the dry process doesn't add water and is carried out above the boiling point of water. Daly, Hainbach and Parmalee all recommend the dry process for bismuth resinate lustre. Probably worth trying it before worrying about the ambiguities of "bismuth subnitrate" solubility. Quote Link to comment Share on other sites More sharing options...
PeterH Posted September 2 Report Share Posted September 2 I've not had many dealings with CTM, but their website has always looked competent. So I sent them an email Hi, Having a confusing discussion on the web at the moment over the solubility of bismuth subnitrate. Lots of sources on the web say that it's highly soluble, while lots of other sources say that it's insoluble. One possible explanation is give in https://en.wikipedia.org/wiki/Bismuth_oxynitrate (apparently yet another synonym). Bismuth oxynitrate is commercially available as Bi5O(OH)9(NO3)4 (CAS number: 1304-85-4 ) or as BiONO3·H2O (CAS Number: 13595-83-0 ). Do you know the CAS number of the bismuth subnitrate you sell? Regards, Peter Their reply (within minutes) was Soluble in acid, insoluble in water like most of the heavy metals, Kind regards Graeme CTM Potters Supplies - Doncaster Branch Simba Materials Limited Unit 7/8 Broomhouse Lane Ind Estate Edlington Doncaster DN12 1EQ Tel: 01709 770801 Fax: 01709 770803 PS I'll remind you when I was making a "lustre" decades ago (water, bismuth, iron, probably CMC) I think added glycerine to aid solubility/suspension. If it was aiding solubility it might be worth trying with the wet resinate process. If it was aiding suspension it probably wouldn't help. Min 1 Quote Link to comment Share on other sites More sharing options...
Imu Posted September 4 Author Report Share Posted September 4 Thanks for this Peter, very much appreciated, I've just moved onto some practical testing using the bismuth I have. I guess, if it works, it works, try not to overthink it until I see results. Quote Link to comment Share on other sites More sharing options...
PeterH Posted September 15 Report Share Posted September 15 (edited) @Imu Just found a very old jar in the garage labelled Bismuth wash 100 water 25 Bismuth Subnitrate 18 Citric acid Not a published recipe, but something I knocked together to increase solubility/dispersion. Probably for a raku party. Edited September 15 by PeterH Quote Link to comment Share on other sites More sharing options...
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