Delft Clay Casting

Recommended Tools & Supplies:
Safety Glasses;
Kiln Shelf;
Crucible with Handle;
Cookie Sheet (with rim);
Delft Clay Kit;
Ball-Peen Hammer;
Silver Casting Grain;
Paring Knife;
Multipurpose Torch Tips;
Casting Flux;
Storage Containers;
Chopper With Handle;
Baby Powder, and,
Paint Brushes
Purchases made using the Amazon links on the OJA website at: www.onlinejewelryacademy.com, help to financially support the OJA. On our website you'll also find links to products from Durston Tools that we have reviewed. Or, you can access Durston's website at durston.com/oja.
In this video, Professor John Ahr demonstrates how to use a Delft Clay casting set-up to cast dimensional forms in sterling silver. This is an easy bench-top casting technique that can quickly produce fantastic results.
Since we first posted this video to the OJA playlist we have received a number of comments about it. Many people want to know if the Delft Clay casting system will work for other metals. Here at the OJA we have only used the Delft Clay to cast sterling silver. While it may work with other metals, we have no practical experience using the system with anything other than silver. Before you waste time and money trying to cast something other than silver with the Delft Clay, do your homework and research whether or not anyone else it providing a tutorial for the Delft Clay using an alternative metal.
We have also received comments regarding the resulting castings shown in the video. If you look closely in the photograph above you'll notice that one corner of the square grid casting is rounded or incomplete. This may be the result of not using enough silver in the casting or not venting the corners of the mold sufficiently. Either way, this is a process that requires practice and patience. It will take you a while to get the hang of using the the Delft Clay system.
If you like this video there are many more like it included in the Online Jewelry Academy's playlist. You can find the OJA's videos organized by category on our website at: www.onlinejewelryacademy.com.
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The OJA offers complete courses on Udemy.com.
1. Beginners course "Colorful Silver Jewelry"
www.udemy.com/makingjewelry/?...
2. Intermediate course "Making Beautiful Articulated Hinged Jewelry"
www.udemy.com/articulatedhing...
3. Stone Setting Course "5 Ways To Enhance Jewelry Design Through Stone Setting"
www.udemy.com/stonesetting/?c...
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[@jps99]

Mr Ahr is a great teacher. His videos are always thorough and well done, with great attention to detail, yet not repetitive or annoying. Thank you!

[@OnlineJewelryAcademy]

Wow! Thank you for the high praise. I'm glad you find the videos informative without being annoying. Thanks for your support! : )

[@jps99]

I am also impressed that you make the effort to reply to all comments. That takes a lot of dedication and time.

[@OnlineJewelryAcademy]

Thank you for noticing. It's a pleasure to interact with fans and supporters.

[@Atthebench]

The reason you had incomplete casting is because you did not have enough silver for gravity to take into the mold. If you had added an extra 5 to 10 grams then there would have been enough silver in the pouring chanel to force the molten silver into the mold before it had time to solidify. Also, always cut the air chanels regardless because the silver is replacing the air inside the cavity and so the air has to go somewhere.. Nice film though!

[@OnlineJewelryAcademy]

Andrew Berry Thank you for your insightful comments. I'm sure other viewers will find them helpful. And, thanks for watching! ; )

[@cristinaradu5480]

+Andrew Berry - I'd like to learn how to incorporate fire-resistant stones directly into a mold and cast together. Any suggestions would be greatly appreciated. Thanks in advance!

[@willdabeastindy]

Excellent tutorial John. Quick, to the point, and no over-explanation making a longer video. This is something I think is in my scope and will try to do in the future. Thanks, Beast!!!

[@OnlineJewelryAcademy]

+Will Dabeast Thank you for the compliment Beast. I know you're going to love playing with your Delft Clay casting system. It's so much fun to use. Good luck with your projects. Thanks for your support! : )

[@dharleeminter2838]

This is the first time I have actually seen this. I never wanted to try lost wax but this makes me want to attempt a casting in the future. Thank you!

[@OnlineJewelryAcademy]

Dharlee Minter Thank you for your comments. I'm so pleased that the video has inspired you to try casting. Thanks for watching! : )

[@joychou5115]

Thank you so much. You are really a great teacher ❤

[@OnlineJewelryAcademy]

I’m glad that you liked the video. Thanks for watching! 😀

[@lktruly1]

First example I have seen of this process. I've done some Delft Clay casting without any instructions other then reading instructions. Was nice to see where I was right, and where I was wrong. Thank You

[@OnlineJewelryAcademy]

Linda Koutrulis Wow Linda! Thank you for the high praise. I'm glad you enjoyed the video and found it useful. Thanks for watching! ; )

[@jimbettridge3123]

Again, so well explained John that I would feel confident that my first attempt would have a chance at working out well...thanks!

[@OnlineJewelryAcademy]

jim bettridge Thanks Jim! I'm glad that the OJA videos can inspire confidence. Good luck with your projects. And, thanks for watching! : )

[@Nickscreativestuff]

Nice clear precise video, has a timeless quality about it, except who would’ve thought that scruffy beards would come into fashion… your Delft Clay tips have been priceless nuggets of knowledge to treasure over the years…. Thanks for teaching the way you do…. XXX Nick

[@OnlineJewelryAcademy]

Glad you found the video helpful. Thanks for watching! You should see how luxurious my beard is now. 😜

[@Nickscreativestuff]

@@OnlineJewelryAcademy Luxurious beard!!! …… i’ve not seen one of your videos for seven months…. I hope you don’t look like Captain Caveman now….. look forward to seeing more of your exquisite videos soon …. Xxx Nick

[@nathanaelwiebe7632]

Thanks so much for making this video

[@OnlineJewelryAcademy]

I’m glad that you liked the video. Thanks for watching. 😉

[@nathanaelwiebe7632]

@@OnlineJewelryAcademy where would you recommend buying silver from as a newbie that can’t buy wholesalers

[@OnlineJewelryAcademy]

@@nathanaelwiebe7632 Just go online and search for jewelry suppliers. I don’t recommend any particular supplier. 😀

[@stickytwat]

Delft clay isn't porous like green sand so gases can't escape properly without vents so always worth doing. Also if the height of the sprue is small it can leave unfilled parts, I guess on larger pieces a tall sprue would help 'feed' the cavity better using gravity too. Good demonstration thank you.

[@OnlineJewelryAcademy]

+STICKY_Inventor Thanks for the great comments. I'm sure that they will enhance other viewers' experience (if they read them). And, thanks for the compliment. Thanks for watching! : )

[@lonewolf333]

Nice video!

[@OnlineJewelryAcademy]

+lonewolf333 Glad you enjoyed the video. The OJA has a few more casting videos on its playlist at www.onlinejewelryacademy.com Thanks for watching! : )

[@celticlion9804]

This guy is like the Bob Ross of jewellery making.

[@OnlineJewelryAcademy]

celticlion I hope you're a Bob Ross fan. I am. : ) I love those happy little trees and bushes. And, I hope you enjoy the OJA videos. Thanks for watching! : )

[@agnesphuongart]

Hi John, thanks for this great tutorial, I was wondering is it possible to use wax carved designs ? (I was thinking about making a wax ring for instance to be able to duplicate it with this deft clay casting method) do you think this could work or is wax too delicate ? Thanks

[@OnlineJewelryAcademy]

Hey Miss Dynamite, Love the name btw. Yes, you can use wax carvings in the Delft Clay. I do it all the time. But, just be aware that the details of your carving will be a tiny bit blurry on the finished casting. If you're wanting to make multiples of a wax carving, I suggest that you hire a caster to cast the ring. Then, clean it up and return it to the caster to have a mold made. The caster can then inject the mold with wax and make as many exact copies of the ring as you want. Good luck with your casting projects. Thanks for your support! : )

[@ninanovikova532]

Would you mind to re-publish Amazon link to Multipurpose Torch Tips? The current link in the list of supplies sends you to the paring knife.

[@OnlineJewelryAcademy]

I've updated the link on the description page. Here it is: amzn.to/2VCW8bk

[@Chucker69er]

Great tutorial! Is it possible to create your own silver shot by pouring molten silver into water? I am picking up all of the equipment you showed in your video and look forward to trying this. Right now my source for silver is a coin shop that sells 1oz silver “rounds” for just a little over spot; any suggestions about procuring silver for these types of projects? Thanks!

[@OnlineJewelryAcademy]

Hi Chuck, While it is possible with basic equipment to melt silver and drop it into water to make small grain, the results will never work as well as commercially produced casting grain. This is because professionally produced casting grain is made under very controlled conditions that keep unwanted oxides and other impurities out of the casting grain. I recommend that you just purchase your casting grain. You can anneal the silver bullion coins and run them through your rolling mill to produce fine silver sheet. But, items made from fine silver are very soft and are easily dinged and scratched. I've used fine silver I milled myself to create thicker bezels for some designs. Good luck with your projects. Thanks for your support! : )

[@private91205]

Thank you for detailed explanation in plain and simple terms. My question is can I use resin for jewelry instead of silver using delft clay casting mold?

[@OnlineJewelryAcademy]

+private91205 NO! Resin would just get delft clay stuck in it and on it. The Delft Clay system is only for casting metal. There is another video on the OJA playlist about casting paper in quick set silicone molds. The silicone molds can also be used with resin. Take a look at that video. Thanks for watching! : )

[@corndogg4279]

will this work if you do it like a ingot mold I have a few ideas I want to try and think it might look better if I did it like that? also I have seen the delft clay alternatives online do they work the same or should I stay away from them? Thank you for the great videos as I have been looking into this your tips and videos have by far been the best I have found

[@OnlineJewelryAcademy]

+john cates Hi John, Thank you for the compliment. In the video I demonstrated the most commonly used approach to working with the Delft Clay system. I have been working with it for years. And, I have all sorts of crazy ways of making it work for me. The trick is to safely experiment with it until you determine if it will work the way you want it to or not. The delft clay alternatives that you mentioned are probably the same product with a different name. The delft clay material was originally developed as a means to remove grease and oil from garage floors. If the alternatives are more affordable and you think you can use them, why not try them out and see. I try to only recommend products that I know will produce results and that are readily available to the public. Good luck with your projects. And, thanks for being a loyal viewer! : )

[@brendawhite243]

Hi. Great video. This might be a stupid question but say it goes wrong the first time and you want to do it again. Do you have to empty rings out and start from scratch or can you just top it up after removing the blackened bits? Thanks in advance of your reply. 😊

[@OnlineJewelryAcademy]

If the casting fails, you will need to remove the burnt delft clay, empty the mold frames, and repeat the packing process. If your castings fail, be sure to add vents to the mold for your next attempt. Have fun casting. : )

[@weirdlywiredjewelry]

I've watched many video's on Delft casting, and this is a good one - very thorough! I am curious about the water you used to cool the casting as I hadn't seen that done before... you didn't address any moisture in the sand when you returned to the studio either. Can the water cause issues with the oil used in the clay? Are there other benefits? Do you still do this step?

[@OnlineJewelryAcademy]

Yes, I always cool the Delft clay castings with water. It does do anything to the clay. 😀

[@ElGatoLoco698]

What's the point in using scrap versus shot? I've seen you add enough shot to cast the item but then you add scrap for the overflow. It's all going to blend together and there is no difference between the two, is there?

[@OnlineJewelryAcademy]

+ElGatoLoco698 Professional casters only use casting grain because it is refined, clean metal that won't cause porosity. But, when you work in Delft Clay, you can add some of your "dirty" metal or scrap to the crucible. You should only blend a 50/50 mix. I added the extra metal to ensure that the weight of the metal would flow into the void and create a sprue button. Good luck with your projects. Thanks for your support! : )

[@lindafountain7783]

Hi professor, could I use a small piece of brass tubing to punch out the hole?

[@OnlineJewelryAcademy]

Linda Fountain Hi Linda, You could use a piece of tubing to punch a hole through the Delft Clay. But, you'll capture a small amount of the clay in the tube. I suggest that you use items like wire segment or toothpicks to punch small holes. Good luck with your casting projects. And, thanks for watching! : )

[@glycerinwtf]

Great video. I just ordered some Delft clay and will give casting a try for the first time. One thing I'm hoping you can answer is, how can I tell how much metal to use? Thank yoi

[@OnlineJewelryAcademy]

glycerinwtf There really isn't a great way to determine how much casting grain you'll need. What I usually do is I make an "eyeball" estimate of how much I need to go into making the piece and add a bit more for the sprue. You need to have a sprue so that enough metal goes into the mold. Practice will teach you what to do. Remember, if you melt more metal than you actually need you can always pour the remainder into a bowl full of water to create a few water castings. Good luck with your project. And, thanks for watching! : )

[@glycerinwtf]

OnlineJewelryAcademy Thanks for the reply. Using a bowl of water is a great idea. Almost makes me want to melt a tad too much to see what shapes the water will form

[@lonewolf333]

+glycerinwtf There is actually a way you can get a ballpark determination of the amount of metal you will need, but it involves finding the specific gravity of the material you use as the mold, and the metal you are going to cast with (gold, silver, etc.). You then have to weigh the piece you are using for the impression and this is where you'll get the estimate to calculate the exact amount of silver or gold for that piece. Then, you have to add enough silver/gold for the sprue. The way I suggest getting the estimated weight for this is to do a few castings and then average the weight of the cut sprue after each cast, then add this number to the one you get for the impression piece. I know this sounds like a lot of work, but alternatively you will also learn how much to use when you get more experienced, like John says. I did a casting today of a sterling baby shoe pendant, and used a little too much silver as some splashed outside the mold (I was too lazy to calculate the metal I needed, and just eyeballed it). Once I'm near my reference material again, I'll post the calculations online. It's pretty simple math you'll be able to do on a calculator.

[@ThomasJoseph315]

This guy is one KZbin channel away from starting "Fun with Flags" hehehe

[@OnlineJewelryAcademy]

***** "BAZINGA!" Glad the OJA could make you smile. Thanks for watching! : )

[@ThomasJoseph315]

OnlineJewelryAcademy Next video you do,.. please end it with a "BAZINGA!" that would be so funny! I actually came to your channel to see about the kit and clay you're using. I am in the process of making my first mold and I am going to be using Aluminum. I was wondering how high of detail you can get with casting. Is their anyway you could do a close up or something high detailed?

[@OnlineJewelryAcademy]

***** Hi Tom! You can get extremely good detail with the Delft Clay system. But, castings made in Delft Clay always have a slightly grainy surface texture on them. If you want your pieces to have a high polish, you will loose a tiny bit of the sharpness of the detail. The system works best with gold, silver and pewter. White metals like aluminum can be cast in the clay. But casting aluminum is very different from casting silver (as I did in the video). I suggest that you do further research on casting aluminum before you invest in tools and materials. Good luck with your project! : )

[@ThomasJoseph315]

OnlineJewelryAcademy Yes,.. I am looking into foundry's. So what would be the best fix for the slightly grainy surface? I can polish the surface and then I plan on using enamel on some parts. And for some area's I wouldn't mind actually for the grainy surface as it would not only help the enamel stick better, but give texture as well.

[@ninqiniccistratton2082]

Can this be done successfully with a model bust/relief of a face? Or would the necessary details be lost for sure? I want to make a ring that is the face of wolfman.

[@OnlineJewelryAcademy]

Yes! It can be done. But the details will be a bit softened by the process. 😀

[@cleverkimscurios3783]

I have worked with casting a couple of times but only with silver. I have lots of copper scrap- can I cast that?

[@OnlineJewelryAcademy]

+Clever Kim's Curios Hi Kim, Unfortunately, copper does not flow well like other metals for casting. I suggest taking your copper scrap to a recycling center for cash. Then, you can put the money toward silver casting grain. Thanks for being a loyal viewer! : )

[@cleverkimscurios3783]

Aw shoot. I have been saving it for scrap but it sure would have been nice to cast it into other neat stuff. Thanks for the quick response!

[@JosetteRedwolf]

you can cast copper jus make sure its pure copper ..make your channel wide enough for air to escape and use an extra 5 to 10 grams over your piece to make sure gravity takes it into the mold before solidifying

[@nancycarreau6740]

Do you give classes I'd like to go and take one

[@OnlineJewelryAcademy]

Unfortunately, the school where I was teaching closed their jewelry program with the advent of Covid. If I start teaching again, I will be sure to post where on Instagram. Thanks for watching!😀

[@raylenekinyon]

Hello. How do I re-hydrate delft clay?

[@OnlineJewelryAcademy]

Hi Raylene, I've never know anyone who has tried to "re-hydrate" delft clay. Here's a link to a discussion that you might find helpful: orchid.ganoksin.com/t/delft-clay-goes-crumbly-etc/18494 If you have had your delft clay for quite a while and have used and abused it, I would recommend that you simply replace it. Good luck with your creative projects. Thanks for your support! : )

[@raylenekinyon]

@@OnlineJewelryAcademy Hi, My clay is not dirty and used, except for about 5 times. I haven't used it in awhile and it is dried up (hard). I used it just for pewter pouring flat, one sided, Thank you

[@thinge27]

You can buy Delft Clay in a special "Extra oiled" version. You can mix that with the old used Delft clay to make the mixture like new. There is no real recipe for that, so you must do it by try and error. I normally mix 20 to 30% from the extra oiled stuff to my old clay and the results are good enough for me. I am using the Delft Clay for sterling fine silver casting with ultra fine details.

[@danietkissenle]

how dose delft clay differ from green sand/ oil sand

[@OnlineJewelryAcademy]

+danietkissenle Delft Clay is easier to work with. It is easy to maintain a small set-up to work with. The castings are a bit smoother. And, it can easily be used to make impressions of existing objects to be cast into metal models. I hope this helps. Thanks for your support! : )

[@thinge27]

@@OnlineJewelryAcademy That's correct John. I am experimting for a year with all sorts of clay, make my own mixes....but Delft Clay gives the finest results. I have used finer sands like some Petrobond versions, and yes, they give me more details, but getting the master out of the clay is a real pain in the head. Everytime the delicate corners broke out and the sand mould was useless again......it is so difficult to find the right mixture of oil and the right mesh of sand......

[@stevenedwards4470]

HI. Is there a specific formula to gauge how much flux to use per amount of silver? Or something visual to look for to when you've added enough?

[@OnlineJewelryAcademy]

Hi Steven, If you're working with a "seasoned" crucible (one that has been pre-coated with flux), you add the flux a pinch at a time. What you're looking to see is the silver feeling moving on top of the flux with a little on top of it. It's going to take some experimentation to get it right. You don't want too much flux in the crucible. Because, if you have too much flux it could pour out and occupy space in the mold that needs to be filled with metal. Good luck with your projects. Thanks for your support! : )

[@grossleg123]

7:30 now I am going to take my chopper , ( I turned off fast )😂

[@OnlineJewelryAcademy]

+grossleg123 I'm not sure that I understand your comment. But, it appears that this video didn't appeal to you. Well, the OJA has over 150 other videos that might appeal more to you. Thanks for watching! : )

[@grossleg123]

+OnlineJewelryAcademy hi it was a joke in the U.k. a chopper is slang for something else 😀your tuition was great

[@silvercity1347]

Where is hole for air ? Air should have their own roads to geting out ! Sorry for my English !!!

[@OnlineJewelryAcademy]

Silver City Channels cut from the molded impression lead to the holes made in the Delft Clay. This helps the air to escape. This is discussed toward the end of the video. Good luck with your projects. And, thanks for watching! : )