Making Solid Copper Mugs, but should you drink from them?

In this video, I make a solid copper mugs in my home foundry. I designed the mugs in fusion 360 and the 3d printed the patterns in a plastic called PLA. Then I made a mold using a material called Suspendaslurry. After casting, I carved Walnut handles to fit onto the mugs.
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[@michaelbelman1064]

I'd suggest using brass screws to secure the handles instead of steel. Those steel screws will react with the copper and cause a layer of corrosion to form over time which could make it impossible to get the screws out later should you need to replace the handle.

[@chuckaddison5134]

Not to mention copper, brass, or bronze screws would be more pleasing to the eye.

[@TG-zd9de]

Electrolysis between stainless and copper is fine for a mug. Copper reacts with aluminium and zinc.

[@bobkin611]

That and steel screws with such a nice mug just makes it look cheapish. Idk, I’d still love to have those mugs tho

[@CLCasual]

Say no to nonsimilar metals, not even once

[@capnlardo748]

Great looking mugs, if you wanted a totally smooth surface could you sand the marks out or would you just chase them around? I like the “antiqued” look though

[@cglynne]

These look great. If you plan to try and make them again, before you start applying slurry, finish your blanks with wax and make the finish as you would like to see the final product. You can eliminate the printing striations and seams with the wax filling in the ridges. The slurry will take on the smoothness of the polished waxed mold and when you melt the PLA the walls of the mold will be smooth. Your finished product will be dolphin smooth.

[@MartinodePueblo]

This is exactly what I thought when we was smoothing out the edges of the glued on part!

[@heobay807]

great idea, i hope he sees this

[@marksworkshop8724]

I second this!

[@taviusjhoson6331]

Damn solved a problem for thank you

[@johnnguyen396]

Also, exporting the initial CAD model with a higher precision in the STL file or even using a slicer that accepts STEP files will help greatly with the grainy circles. It is a cool look on the finished product for this project, but if you want nice smooth circles it is perfectly possible to achieve with a normal 3D printer.

[@stumccabe]

Traditionally copper saucepans were plated with tin which of course is food safe. I would suggest tin plating the interiors either electrolytically or possibly by filling them with molten tin and pouring it out to leave the inside plated.

[@westonmalone3205]

Flux, heat, melt tin, wipe. Please tell people to do this more. Copper poisoning sucks.

[@alden1132]

Excellent advice.

[@KellyPKramer]

I think the copper looks great as it is...wouldn't worry about copper poisoning since most houses still have copper waterlines.

[@davedoessomestuff8176]

​@@KellyPKrameryes but they're in contact with water, not acidic food or drinks, which can cause a lot more leeching to occur. There's a reason people tin copper.

[@RaffyMaBoi]

You dont really want a more conductive material for a mug. This will just make the energy flow better and make hot things cool faster and cool things heat up faster.

[@alecasone]

Was about to say this lol. Copper would be terrible for any drink you want to keep at a certain temperature. It will reach equilibrium with the environment too quickly.

[@TheMinecraftReloaded]

Yeah, you should keep these in the freezer, instant cold drink. Super cool for that (get it?) Otherwise, the opposite of what you want

[@timmer9lives]

Yeah, very, very attractive mugs. But horrible for all the reasons you give. If you pour cold drink in a mug, you want the mug to NOT get cold. That’s called insulation. But, very cool looking mugs. It would be neat if you make the mug the exact size of a disposable plastic cup. That way you can slip a plastic cup in the mug to insulate your drink.

[@ExarchGaming]

until it reaches a thermal equalibrium

[@guacre2675]

Copper is unmatched (other than silver) for certain cooking purposes, but pretty bad for other purposes.

[@jfirebaugh]

I worked for an artist who used this method for casting aluminum. He would put the hot shells into a pit filled with vermiculite. It would keep complex shapes upright, help retain the heat and hold the shell together if it cracked during casting.

[@wafu6058]

If you’re not planning on using some sort of coating, I would be very careful drinking anything other than water. Particularly stuff with acids like lemon/lime juice that you demonstrated can be very bad as it will leech the copper off and straight into your drink. Heavy metal poisoning is not very difficult to get if you’re unaware so be careful.

[@BraxtonHoward]

Also, it warms up cold drinks much faster than a normal cup would. Overall not very useful.

[@douglasboyle6544]

I was thinking about this too, A great follow-up video would be plating the inside with a protective coating - I think they use aluminum?

[@matrix626]

@@douglasboyle6544 they typically line a copper mug with a Stainless steel liner. Kind of like the inside of a tumbler.

[@douglasboyle6544]

@@matrix626 ah. That's harder to plate.

[@MichaelKunz-mt2oo]

Don't worry about it. The copper used in the scrap pipe and wire is pure copper. Where you might need to be careful of the source of the copper is placer metal you find in the ground, or copper you refine from an ore yourself, where arsenic is definitely going to be present. But the video shows copper tubing and copper wire. Ever drop of water coming into your house that goes into your cooking and drinking comes through copper pipe, and there are purity requirement on it for exactly that reason.

[@MarcsYoutube]

The Vornoi pattern that emerged by accident is really something nice to look at. I like how you made the wooden handles also faceted and now they kinda match the smaller pattern on the mugs.

[@Thoron_of_Neto]

These mugs are neat, for sure I think my favorite part of them, is the primitive handles. It adds so much character to the copper I love it!

[@AlexanderGee]

You should use natural PLA for investment casting. The colorant in your black pla is a good part of the ash you observed.

[@stevencunningham4680]

I always find your videos fascinating , especially these copper mugs. I really like the handle it looks very natural to hold.

[@pirobot668beta]

Copper-tin or copper-silver can look a lot like pure copper and resist acids. They are types of Bronze; they form a patina (metal carbonates, mostly) that protects the base metal from acid leaching. Recycled Bronze can be risky; arsenic, antimony and beryllium Bronze are becoming rarer, but are still found in the electronics industry and old Sculptures. Beryllium was widely used in contact-pins for connectors; flexible, corrosion and abrasion resistant. A tiny sliver of beryllium Bronze under the skin can lead to ulcerating sores that take weeks to heal!

[@HLBNZ]

That's the most interesting comment I've heard all year. I know that in my trade of steam fitting we install bronze valves a lot.

[@Syrkyth]

Very neat! Though, you might want to consider plating the lip and inside of the mug with silver to keep the copper from leaching into any drinks with citric acids (most sodas) or anything above a fruit-juice. Apparently it only takes 27 minutes for a Moscow Mule to leach more copper than FDA regulations allow in safe drinking water. Silver plating the inside would also save you from having to clean off the inevitable oxidization/patina! At least on the inside =D

[@ThePeaceableKingdom]

I thought similarly also, that the insides should be tinned in some fashion to prevent contamination, especially if used with wine, which also has a high acidic component

[@ZAPATTUBE]

BS - it same as a copper pot, NOT TOXIC!!!

[@johannaverplank4858]

I love the way the mugs turned out. I especially like the rustic, hand carved walnut handles. Great job!

[@paulh5429]

Its been a year or so since I last saw your videos, and you've really refined your techniques! Love to see a channel growing like this, keep up the great work

[@Serbianguy432]

The creation of these mugs was, as usual, an interesting look into the mind of the creative genius behind Robinson Foundry. I'm always amazed at what you come up with as, step by step, a concept evolves into a concrete product. And regarding the information you impart, well, my cup runneth over...

[@hunterrees]

Your videos are so interesting to watch. I’d love to see a tour of the shop in a future video!

[@kaibroeking9968]

My grandfather was a coppersmith. Copper and foods do not mix - tin the inside with lead free tin, i.e. soft solder, and it'll be fine. Coppersmiths used dilute hydrochloric acid as "soldering water" to prepare the surface for this. A more modern solution would be to use lead free soft soldering paste, i.e. ground up solder (e.g. 97% Sn, 3%Cu) in flux paste, brush coat the inside of the mugs with it and the heat them gently untill the paste melts and you get a silvery tinned surface. Rinse well before use to get rid of any flux residue.

[@wientz]

and yet every drop of water that you drink comes into your mouth via a copper pipe. Ask gramps about that.

[@TheHalfDecentGamer]

Hey, it was really cool to see this project go from start to finish. It was a bummer that there was some cracking and air pocket holes left in the end product. I've worked with diecast molds and I would recommend adding a few "vent holes" in the sides of the design of the 3D print next time, so most (if not all) the imperfections can be pushed out to the sides of the end product.

[@donaldhoot7741]

I love the green "flame" of copper in the forge! Cool video!

[@TheDreadGazeebo]

I like how you left the imperfections from the cooling, and the lines from the 3d printer. it's a satisfying contrast.

[@user-ml1fr8kk4c]

You're an artist! Everything I've seen you make turns out super cool!

[@paulojrg]

Great work. One note, copperware has to be coated with tin when will it be in contact with any acidic substance either food or drink, to prevent leeching while still preserving the thermal conductivity of the material.

[@DieterDuplak314]

and carbonated drinks are acidic so watch out

[@TG-zd9de]

You would die from alcohol poisoning before copper toxins😅

[@paulojrg]

@@TG-zd9de After a good night sleep and a bad following day your alcohol will be gone, copper will stick a bit lonnnnger and is a bit harder to diagnose. You can try both 'till death, in the name of science of course.

[@michiganprospectors]

That is so cool!!! Metal and wood shop in one!! The flaws in the metal and the rough finish on the handles match perfectly. I hear that copper is actually an antimicrobial so they are often used in water pipes.

[@KrakenCasting]

Gotta love a functional cast! And what great character!

[@SystemX1983]

Seeing the "imperfections" on the outside at the end, especially on the left mug, made me think they look like a maze. Imagine this random pattern all over the surface instead of a perfectly smooth surface. It kinda fits to the rough handle 👍😎

[@sirfer6969]

Just gorgeous. Nice work.

[@cosmicinsane516]

Those handles are perfect. Very cool mugs. Lol I learned the hard way coffee and solid metal mugs usually hurts.

[@thunderbasilisk1352]

What awesome mugs! Though you may want to plate the lip and insides with Silver to avoid copper leaking into any citric acid drink like most sodas are. Other than that I cant wait to see what you make next. Also glad the Cardboard tricks working for you.

[@sebastiannielsen]

are hot coffee in the "danger zone" for copper leaking out?

[@amarzzata]

You sure that's an issue? They sell copper mugs for moscow mule drinks and i have never seen any of them plated with anything.

[@dankboi42069]

​@@amarzzatabecause they expect you to drink the Moscow mule fast ofc

[@dominicbrissette4433]

@@dankboi42069 🤣🤣👍

[@wafu6058]

@@amarzzata they have coatings inside

[@badendowie4889]

Brilliant Project- Thanks for sharing

[@moshebron2105]

You're an Artist. Beautiful work,

[@narancs5]

The texture on the handle is a really nice touch. Feels like old times :)

[@Dilldough.]

My southern grandmother might throw hands for that act of sacrilege you brought upon that cast iron skillet.😭

[@vikingslayer34]

Nice work! I love the “rustic” look. It adds character. Not “perfect” like the ones you buy from China. If you ever make a set of these and sell them I would be interested.

[@iidremzii]

Great job! Looks like when you sliced the stl, you have low polygon sides. You can see them in the cast. You can increase the deviations and number of sides to make it close to a perfect circle

[@alanpreston3111]

Love this , your patience working through the processes of making these mugs is admirable.. not a quality I possess 🙄😂😂🙏🏻👏🏻👏🏻

[@brownranger1797]

Love the finish on the copper cups.

[@dommyboysmith]

These would be fun to do some engraving on. Thanks for the idea!

[@diyfireking]

Nice work. The mugs looks fantastic. 👍👍

[@copperkingrecycling634]

Awesome casting video. Thanks.

[@mpccenturion]

Nice work! I enjoy the process. One off is art in my book and this is art!

[@johnsumner2987]

I really like how those cracks look. Can't wait to get my furnace so I can make stuff like this.

[@westonmalone3205]

If you do make cookware, do tin the inside. It's not difficult

[@wearetheremnants1615]

The most satisfying process to watch .

[@look4lec]

Very cool, I'll never do this but this will never be recreated in a lab so it's your slice of eternity. It's awesome for people to see how timely and difficult this is and know their item is a one of a kind ... Imagine buying one and finding out someone else has it too! Buy the pair! :)

[@aserta]

PLA wasn't completely cooked out of the mold. You need as little PLA in this as possible. Basically, you'd need to print the inside and outside of the mug as vase mode shells that you'd then glue together using as little glue as possible (probably modeler's thin glue). The pouring spout and the handle knob, also glued on separately (tho you'd need to print only the outer shell of the handle knob and the spout.

[@jackmclane1826]

Did you watch the video before giving advice? There is no pouring spout!

[@PATRIK67KALLBACK]

Nice muggs! However, there is a reason you tin the inside that is with contact with the cupper. If you use them daily it will release cupper ions into the liquid and you will be sick.

[@rachelg552353]

Great project! Cheers! 🍻

[@chromatophore881]

The mugs look fantastic. What I would suggest though is keying the shaft for the handles or using two screws to hold the handles on. I think over time they will loosen on one screw then spin and dump your drink in your lap!

[@Steinmetal4]

I think just gluing it would be fine

[@TheBeerBox80]

I think all the pits and imperfections make them look awesome.

[@rescobar8572]

GREAT VIDEO!! Love the mugs!!

[@tonyb7748]

I found a really thick copper "bowl" inside an old Eastman Kodak facility being demolished around 1997. It measures 15" across and is relatively shallow with a rise of 3". Weve used it for a firebowl ever since and has some great coloration after hundreds of fires.

[@egoalter8745]

Very cool looking and those cracks give nice touch. Just found your channel and video is very well made

[@alden1132]

Do you use any kind of flux when melting your copper? It helps in a lot of ways, like making it easier to skim floating slag of the top before casting.

[@petercopley1242]

Brilliant they look really good 👍

[@sharonwilliams3484]

I wish I could make my own. I live in an apt so no tools for me. You did a beautiful job!

[@wolfgangstitz2852]

Great job. They looks pretty nice 👍

[@timscollectibles520]

Nice job that was a fun watch.

[@VetvsWorld]

Being an utter novice in casting, but trying, this was an excellent video as well as idea. Thx for sharing bro.

[@neilkennykenny4113]

Brilliant looking mugs, defects and all I would consider rounded edges on the top edge would make it more comfortable to drink from perhaps.

[@thejoshman4883]

I love this design super cool

[@carlp4353]

If you plan to drink Moscow mules from these, I suggest a protective coating on the inside of the mug. The acid from citrus leeches the metal into the contents of the food/drink.

[@dangerousandy]

They came out great!

[@johnquijote7194]

Great looking mugs!

[@nelsonofpilipinas]

Absolutely gorgeous! ❤

[@redfailhawk]

I had a mule for the first time today... in a copper cup. Interesting to learn that this is traditional!

[@CommunityGuidelines]

Beautiful work! I imagine dwarves drink their mead out of mugs like these.

[@justsluiceit]

Awesome!! Cheers Robinson

[@EmanonEcafon]

RF, shut up and take my money! Those mugs are superb, and I need them for fully enjoying my bourbon! Great channel; I love your presentation, and ingenuity. Keep up the excellent work. ;)

[@sportsman1824]

Beautiful , not for coffee. Great video.

[@dbhunter79]

Yes! Another awesome video!

[@emillioheredia6253]

Looks amazing!! The time and craftsmanship you put in reflect the finished product.That being said, next time if you ever make a mug, refine the connection point from the handle. A slimmer attachment would feel more natural holding the mug.

[@westonmalone3205]

And tin the inside....

[@vagishgpatil3013]

Most beautiful and perfect casting I feel

[@TMFXLLC]

Clean process and cool design. If you're modelling with Fusion, check your .stl output settings, you can get rid of those facets in the mesh by increasing resolution. The build line texture doesn't transfer but the facets kind of did so just FYI you can control that if you're making the original model with parametric CAD software. A pair of screws, a small non-concentric set screw that gets covered by the concentric panhead screw, would keep the handle from clocking or indexing out over time.

[@samuelschneider9067]

Cool project!! It's fun when you get copper or brass hot enough to start seeing the crystalline structure. Answering the question from the video... I'd say treat it like you're drinking out of one of those old lead tankards they used back in the day. Especially if you have a hot acidic liquid in there. I used to fix musical instruments. Some folks have allergic reactions with the metals in the instrument and we'd electroplate it with silver or gold. You'll end up with silver with a copper undertone similar to plating phosphor bronze . Very pretty to look at and safer to drink out of. Best to use a brush electro plating instead of dunking it into a solution since the hard edges will collect more silver and appear inconsistent to the rest of the mug.

[@jasongrinnell1986]

Those cups look awesome.

[@sandqwert]

As a decoration, they look great. As mugs, I think they won't do it. I mean, they will make a cold drink warm fast and a hot drink warm fast. Awesome to drink natural water at room temperature though =)

[@killergames391]

It looks like some of the surface finish issue on the mugs themselves could be caused less by shrinkage, but dissolved gasses in the copper melt affecting viscosity and forming bubbles. liquid copper readily accepts dissolved hydrogen but it doesnt in the solid form which can cause pitting, cracks, and porosity as it solidifies. I recommend degassing the Copper by adding in a small amount (

[@benjaminmargulies1853]

fresh copper surfaces can't be leached by non-oxidizing acids since copper metal can't reduce protons to hydrogen

[@MeleeTiger]

This is a random thought but, would a large one of those ultra-sonic bath things work for removing the shell after?

[@taviusjhoson6331]

A random good thought .👍👌

[@readthetype]

Thank you for speaking like a normal person, and not a spastic KZbinr that feels pathologically compelled to turn everything they say into the most exciting catch-phrase ever.

[@dave_s_vids]

They look great!

[@MarkHahn]

Very cool 👍 I want to buy them!

[@d3w4yn3]

I've been 3d printing for a couple of years, and this is a great project!!! What kind of filament did you use? Was it straight pla? I only ask because there are a lot of variations and I've never thought about what would completely burn the best. It feels a bit devious 3d printing something that I will literally destroy, but yet I'm excited to try this!!!

[@billjenkins5693]

Turned out great

[@stanislavdezman2756]

To je prava mojstrovina. Čestitke.

[@DanteYewToob]

I agree with everyone saying to use brass screws and maybe make some walnut dowels to hide them. You don’t need to glue them in, just make them a pressure fit and if you need to disassemble, you can put a dab of hot glue on them and pull them out. I’ve done this before and it works pretty well. I just heat the tip of the glue stick itself, stick it to the plug, and then when it cools you just pull the glue stick to pop the plug out. Anyway, they look awesome and I’d absolutely never use one because I hate metallic taste on stuff.. lol I’d buy them to just use as pencil cups or something…

[@Absaalookemensch]

They look great. Can you coat them to prevent the patina from forming over time?

[@danhase8904]

Link to ceramic mold liquid ?

[@BionicleFreek99]

Moscow muels are actually fairly controversial. The thing that help give them their destinctive taste is the copper basically being leached into the drink by the acidity of it, which needless to say, probably isn't great for you!

[@oldnubbins8060]

Unless it takes you a month to finish a Moscow Mule, you are not going to ingest any measurable copper.

[@I.____.....__...__]

@@oldnubbins8060 Or less than an hour. 😒

[@H0mework]

Is there any taste copper imparts? The copper pan I had was excellent at conduction and it was coated with zinc, neither should be with acidic foods because it leeches and gives a taste. If that happens to you, and you'd like to try plating, it be cool to see them gold plated. I love the warm look of your cup.

[@vincesangmeister1075]

Beautiful piece of artistry. Question........can you tell me where I might find the model you used for your variation on the theme?

[@joepearson9704]

Those are amazing.

[@user-vx4pk8cl1h]

good stuff. Why does it take so long in the slurry curing process? can you heat it to speed up? curious.

[@hjfcoco]

After dipping the part in the slurry 2 or 3 times, can sand be added to the slurry to make it thicker and stronger? Im making a more complex part and cant really sprinkle sand in some areas of the part after dipping

[@willmartin4477]

That was awesome thanks

[@brandt-heiss]

Beautiful Cups. Like them really much. My question is, do they hold the color or are they changing into brown with the time? Please let me know this. Greetings from Germany.

[@justinlcosby]

Dude I want some of these. Lol you should make a bunch and sell them. You could make two kinds the copper like you made plus copper just like that with clay on the inside to insulate it for coffee and hot drinks.

[@glenncain]

very nice product with a distinct rustic look, i quite favor that, tho perhaps you would like to look at the topic of copper utensils and moscow mule by adam ragusea to decide how you would like to use copper utensil in a way to minimize any metal consumption issues that might happen

[@ammcd2012]

Gorgeous ❤

[@that1guy82]

I love my aluminum cup. It cooks stuff pretty well. I can cook 3 ramen in it if i did it right and I've always wanted my own copper cups.

[@mikethespike7579]

I have a few suggestions to make: Beakers are usually made of an insulating material not one that conducts heat like copper does. That's why glass or ceramic is often used, because these are not good conductors. For example my titanium camping beaker, already a better insulator than copper, has double walls and a vacuum in between to hold the temperature of my drink longer. I'm not sure that copper is a healthy material to drink from or keep food in. My great grand father, who was a copper smith, used to coat the insides of his vessels with tin. In fact most copper vessels I've seen have been treated in this way. I'd have used wax instead of plastic to make the positive forms for the beakers. Most plastics leave some ash behind when they are heated up to their melting point. Wax just turns to liquid and then evaporates leaving a pristine negative form. Personally, I find the rims on these beakers not ideal and not really inviting to place my lips on. They will also possibly make drinking difficult without dribbling. There's a good reason why the rims of most drinking vessels are round and smooth. Otherwise, all in all, an interesting project.

[@dougsmith747]

Very nice! 😎