Picture of Metal Casting with SUGRU

Please vote! vote! vote! vote! vote! Do it! :) (This is in a contest, you know! :D)

Make sure to check out my blog!

Not to long ago, I started my ventures into metal casting. My early molds were made of plaster, but I quickly learned that silicone epoxy makes GREAT metal casting molds. Unfortunately, the silicone epoxy I was using was not designed for casting metal, and was too soft and flexible. My early silicone molds were not tough enough for lots of repeated use.

But Sugru, on the other hand, is a very durable silicone mold making material. It makes molds just as good as the silicone epoxy I used previously, except Sugru is WAY more durable, and will make molds that will last dozens of casts.

The cast quality of this skull isn't quite exactly what I'm after, but I was in a hurry. Molds need to be broken in before they with make great casts, so the first, second, or even third castings may have bubbles or vacancies. The skull in the main picture is the second cast. You shoulda seen the first one ;)

Ok, this goes without saying (but I'll say it anyway)...
Casting metal involves the use of butane torches. Butane torches have fire. Fire can burn you. So can hot metal. Got it?

If you want to cast high temp metals, just use the sugru molds for wax, then use the lost wax casting process.

There are several people in the comments arguing about fumes. They have not actually done this instructable, so they wouldn't know. Anyway, if you use solid lead free solder, there will not be any fumes. I know this from experience. Please, though, trust your own judgement and use common sense!

TanjaH3 months ago

I'm looking for a durable way to cast many Gallium items. Do you have any experience with using a Sugru mold for Gallium?

gallium melt in your hand or at 30 c so the mold will by used for ever

mcshannon3 months ago
I am wanting to try out casting, but would like to do it with metals of higher melting point. How hot can this handle?
jmyers3 mcshannon2 months ago
If sugru is anything like Silicone, then it will be effective up to temperatures of around 300 degrees C, the best you can hope for would be Pewter or Lead. Make sure you cast in a well ventilated area though, metals can emit some nasty gases. Good Luck!
jupiterhime11 months ago

I'm new to casting, as I'm wanting to test it out with my cosplay. Which would be a better idea to start out with? Epoxy or Sugru??

depends if you want to use metal or just normal silicone
prewon.gurung4 months ago
could you use aluminium/aluminum?
ApexG5 months ago

Is there anyway that I could use some sort of magnetic material as I want to cast something with a magnetic metal. If so any suggestions as to which type of metal?

no, you can't. ferrous (magnetic) metals require heat the sugru can not stand

Dabbles107 months ago
Just a tip pitting, the little bubbles and impurities that occur in the lead casting, can be minimized if you use first a mold cleaner first. I recommend micro mark, and secondly lightly!! Powdering your mold with talcum powder. Please use a respirator mask when working and good ventilation. I cast on regular basis and worked heavily with these materials in similar molds on some pieces for a show a few years ago. Good Luck!

Also using old cans to try to cast is not worth the money you save, unless you want a casting with tons of impurities and pits also be willing to brave the cloud of toxic gasses you will be exposing yourself too.
samark25864 years ago
Can anybody tell me what material should i use to make a mold for aluminium melting? I need a mold to be re-useble.
nepheron (author)  samark25864 years ago
For aluminum you will need to use some kind of clay or oil sand. Molten aluminum will destroy sugru.
doesent tin have a higher melting point? so why does aluminum destroy it but not tin?
nepheron (author)  curvy773 years ago
Nope, tin melts at 232 C and aluminum melts at 660 C.
but iv melted aluminum soda cans in a tin soup can before.

was the soup can thicker than the aluminum

Most "tin cans" aren't really made of tin. Most modern soup cans are made of steel, which melts at approximately 1370 C.
Sand casting? you don't say how big the mold is.
When the weather gets a bit warmer I plan to do aluminum casting using charcoal soldering blocks. You carve your design in one charcoal block, melt the metal directly in the mould you have created then use another block to force the metal into all the crevices of the mould. (place uncarved block on top of molten metal and push down) . You will want to make sure you have a stable work surface so that when you apply pressure you don't end up spilling the molten aluminum. Years ago, when I worked at a jewelry store I used this technique to cast gold jewelry so I think aluminum will be easy enough. I think the charcoal block would hold up to several castings but size may be a problem as the charcoal blocks I have seen were designed to do soldering on and were not overly large. If someone knows how to make a charcoal soldering block I'd sure like to hear how.
jamob2 years ago
I have 2 questions. If this works with lead and tin would it work with zinc from pennies? Just wondering because I find zinc to be safer than lead. Also what stores sell Sugru?
stoobers jamob1 year ago
Zinc melts a few hundred degrees hotter than lead or tin. Sugru probably wouldn't hold up to zinc.

Lead is not dangerous unless you dump it on yourself, eat ground lead dust or acid soaked lead, or breath excessive fumes. Probably avoid it if you are a child or are pregnant. Lead toxicity is mostly just a scam. People live their entire lives with lead bullets stuck in their bodies. You don't hear about them whining.

A zinc melt of pennies has WAY more heat in it than lead, so I would rate it as more dangerous than lead, by a long shot. HOWEVER, it pours like silver vodka so it is awesome. You really need to protect against spills, since there is so much more heat - you don't want it to drop onto sneakers or that space between your shoe and ankle.
Don't use a copper pipe endcap as a crucible or ladle. The pool of molten tin will disolve the copper walls of the cap and eventually spill out. While the melting point temperature of pure copper may be higher than your propane or butane torch, the melting point temperature of a copper/tin alloy is not. I have attached some photos that shows what happens when a small amount of tin is melted in copper. I used an ordinary propane torch with no additional oxygen.

An "iron bottom-pour casting ladle" is the best thing to use for this kind of work, but I just use a "4 inch cast iron DWV blind plug" as a crucible and ladle. I welded on steel rods for handles. DWV stands for "Drain Waste Vent". This kind of pipe is also sometimes called "Soil Pipe". Cast-iron DWV fittings are available at any hardware store. DWV fittings don't use threads. In the old days cast iron soil pipe was soldered together with big pools of lead. You can still find "plumbers ladles", which are perfect for tin. Also search for "cast-iron lead pots", "cast-iron lead dippers" and "bottom pour casting ladle".
ithica20122 years ago
oh sorry forgot vasaline (patroulem jelly) should not effect the casting
ithica20122 years ago
hi new here but try heating your mold in an oven till its bout 200 f should help a lot mettel binds up in cold molds
Rowen273 years ago
I realize this comment is extremely late, but in reading this, it occurs to me that the reason your castings are odd for the first few runs is likely due to the mineral oil used in the initial molding process... You might get better results if you use a degreaser in the mold before the first cast. This of course is all speculation on my part, so take it as you will... I'll be giving this instructable a try in the near future, so hopefully I will be able to get back to you with a definitive answer before long...
chamunks4 years ago
Would you not suggest using silver solder?
It would be cheaper to buy silver casting grains - Silver solder is not pure and will contain other metals.

It would also be very expensive.
Foxtrot704 years ago
I like the Instructable. I find that I can use this info readily for a new employment I am about to start which involves prototyping and fabrication of obsolete parts. I also have a silver plated wine decanter set that needs two of three replacement stopper caps, fortunately I can use the remaining one as a my pattern, wish me luck.

As to concerns by folks about fumes, some are real and not immagined. The thing is for anyone do your homework on the materials you are using. Next there are Instructables that show how to build a power ventilated work area that address these very issues. If you have an old range hood vent these can easily be converted to provide a power ventilated work area. Remember, "Nothing, is not impossible... Nothing, just takes longer to accomplish." Keep up the good work!
Be cautious - the solder is in fact largely lead with a small amount of tin added.

This would not be suitable for food use.
evindrews4 years ago
You know... I wonder if you could make key "molds" so if you lost your key to your house, you wouldn't need to buy a new key..?
The metal in use wouldn't be strong enough.
tinker2343 years ago
wow thanks is there a way i could use a tin soda can as a source of metal
Your soda can is either steel or Aluminium!
FrozenIce3 years ago
okay so i wanna make a mold for a hotwheels car, and i only need the top metal part. how do u sugest i do it using sugru?? (yes i will dismantle it first
klayla4 years ago
So you're casting with solder? That doesn't seem like a very good idea as solder tends to pit when casted. Just curious, interesting instructable though.
larryihnots4 years ago
Simple and motivating for beginners as I !! Definately on my way to the blog now. Thanks for your innovativness !.
small skull bead is an understatement. look at that thing! its like the size of an led head!
jimmiek4 years ago
How high a temp will this material stand before it won't work (in degrees F please, I don't do Euro measurements)
You can use google for many things including unit conversions. for instance if you type the following in to google's search bar; "204.44 degrees celcius into degrees fahrenheit" you will get the conversion. or go here for even more google awesomeness; http://www.google.com/help/features.html I even use google to translate languages into english, and if you use google chrome as your web browser, it will ask you if you would like a foreign website translated in the browser...... Hope this opens up some doors for you Jimmiek! Rog
nepheron (author)  jimmiek4 years ago
A naked flam will instantly wreck the Sugru.However, the Sugru website says it can withstand 400 degrees F or so. It certainly withstood molten metal being poured in...it's pretty tough stuff!
TIP: if you make semi-random cuts in the sugru to split it it'll go back together a lot more accurately!
stormende4 years ago
Nice ible, you got my vote.
I do lead castings for solders as a hobby, and there are always little things that I would love to add on, but most DIY casting kits cost about $60 and will only make one or two good molds. This method is awesome. As if I didn't need yet another reason to get Surgu.

One tip for this. Where you have a space in the back of your skull for the pour to go, you can always just place a spacer there and mold around it.
nepheron (author)  atombomb19454 years ago
I'm really glad you like this!
All those lead casting kits are is an ''epoxy-silicone'. Nothing special, but at the prices they sell it for you'd think it made of diamonds or something.

Sugru is the same material as the silicone in the soldier casting kits, except sugru has a solvent that evaporates instead of a chemical reaction. The end result, in either case, is just plain old silicon.
Just as a friendly correction, silicone rubbers aren't epoxies. Epoxies are specific family of organic resins. Silicone polymers are a different kettle 'o monkeys entirely.

This is the second time I've seen mold making silicones referred to as "silicone epoxy" or "epoxy silicone" here on Instructables. Never seen that miss-term before anywhere else, dunno how it came about.
nepheron (author)  nepheron4 years ago
ahem, the last word 'silicon' was meant to be 'silicone'. Silicone is not equal to silicon LOL
quote: Where you have a space in the back of your skull for the pour to go...

firstly you'd have to drill a hole in your skull, you'd need a mirror, but usually such procedures are handled by a neurosurgeon, and the person is under general anesthesia... LOL!  Gotcha!  :):):)

I use Freeman V330 / CA45 silicone rubber with a shore A30 for my low temp castings and epoxy resin castings. The 1 kg (2.2 lb) kit only cost $35 US and holds up great for many many castings. Also you can use Amazing Mold Putty for low temp metals as well and you get 1/2 lb for around $20 US and is very flexible for those bad undercuts.

@nepheron - Great instructable and LMAO at all of the Lead issues people are talking about. I say if your afraid then you should not be doing this in the first place :)
Man! That is awesome!!!! nice job!!!
handprints4 years ago
your clamp is adorable. did you make it? if so, how??
nepheron (author)  handprints4 years ago
Yep, I made that clamp :D
A lot of my tools are handmade out of junk. It's sort of a fun challenge for me to figure out how to make a $20 set of tools out of junk or cheap parts instead of buying it :)

Anyway, here's a schematic of the clamp:
The brass rod is just soldered onto the end of the bolt, so I have some leverage.
Mindhunt3r4 years ago
Got my vote :)
nepheron (author)  Mindhunt3r4 years ago
Thanks x1000!
Hey Best Friend!
You got my vote!
nepheron (author)  Greasetattoo4 years ago
best friends fo-eva!! :D Thanks!
darkclaw424 years ago
Great instructable!

I actually used this to make a bat keyring for a friend of mine, if you live in Austin TX, who really enjoyed the 'Bridge bats'. :)

Winner in my opinion!
now i would predict this to be the winner..
but anyway i am sure you would at least be a finalist
rated 5 stars
nepheron (author)  michaelgohjs4 years ago
Thanks! I just need votes when voting starts, then I'll have myself a leatherman and some more sugru!!
ya i'll vote for yours and i have 2 things in the contest
i got the free sugru pack..but because my SAT test is right before the closing date and i just got my sugru few days ago, i wont be able to do an instructable..
so my vote goes to you
nepheron (author)  michaelgohjs4 years ago
Thanks!!!!!!!! :D
SwiftLegend4 years ago
Where can I find/buy Surgu? I live in Manhattan. Is it sold in Lowes or Home Depot?
Easiest is to order here, really affordable shipping... around $1,50 to the US

not sure about retailers though, especially in the US since I live in sweden.
Alt-Horizon4 years ago
Disregarding any/all Trolls, debaters or just average wiseguys in the comments I really liked this 'ible. it was the first Sugru 'ible that caught my eye and after reading half I took a break and ordered me some sugru.

This will be great for making custom hair ornaments and beads. and since the grains of important info regarding different types of tin isn't really relevant for me (I live in sweden and it's a different terminology) I will use my common sense and ask two people I know: A licensed electrician and the owner of a toy store and tin soldier afficionado (sorry for any lack in grammar/spelling, my neighbours kept me up all night).

In closing though... Common sense isn't all that common.
mmh4 years ago
Looks like the Mad Scientist is having too much fun!
nepheron (author)  mmh4 years ago
i would like to just say.... DONT DO THIS INDOORS! the misses will pretty much destroy you on the spot. not to mention all those fumes aint so great for you iether. but still very cool idea for using sugru :]
nepheron (author)  kyle brinkerhoff4 years ago
Have you actually done this ible? There are no fumes. Please don't say bad things about this before you try it.
Eirinn nepheron4 years ago
The problem isn't the lead fumes, afaik lead fumes do not arise during normal soldering since led vaporizes at a much higher heat.

However the problem is the flux Core fumes which is into standard solder - and may i add it's embedded into lead and lead-free solder. It smells perfumed and.. actually has a rather pleasent aroma - it is also poisonous (afaik).

In this case you're using a torch and it might actually heat up to where fumes are released from lead. However you state you're using lead-free so this shouldn't be a problem.

For casting, a flux core isn't needed which you don't seem to use either since you say there's no fumes. This is, in reality a warning to people thinking about using flux core solder.

Also lay down man, he only wants to help and being agressive jsut because you want to win a contest doesn't help you :)
nepheron (author)  Eirinn4 years ago
His argument is not based on fact. Winning the argument or contest is irrelevant.
yes it is, I work with electronics every day ( part of my job) we are required now because some guy jacked up his lungs, work under a fume hood. and seriously, nephron who cares.... its still a great instructable but you just want to make people aware of the risks they have to take to attempt this...
limerick Eirinn4 years ago
adequate ventilation is never a bad thing. fume extraction/filtration/redirection is even better. not sayin you have to have a fan blowing over your project, in some
cases, too much positive ventilation can cool things down too much to work effectively.
its when you use LEAD solder is when you get into trouble... chances are if your using stuff thats normally used for pipes or is the super cheep crud from an auto store theirs pockets of foreign material in the solder that can cause these fumes
It has also been confirmed that lead gets into your system through ingestion and very, very rarely through the skin.
bpfh Pazzerz4 years ago
Melted lead will get through the skin very quickly - by burning a hole (327°C/621°F)...

I make cast bullets with it and I treat molten lead with even more respect than mains electricity...

Heavy leather gloves, wooden handled tools and eye protection (face shield) are an absolute MUST! Metal tools heat up and wooden handles insulate, the gloves stop severe hand burns, and eye / face protection is self explanatory - A drop of any molten metal in the eye is a guaranteed trip to ER, and very great possibly a trip to the glass eye store when you get released...
Pazzerz bpfh4 years ago
I do the same work, have been splashed with lead, too. It hardens instantly without burning through unless you're dumping is wholesale onto your hands. Another thing is that solder, even leaded solder, is low temp enough that it hardens even faster with splashing. Sure, you use eye protection, I do too. My gloves are more for protecting me from the heat off the crucible than for anything else. I'm not advocating doing things hap-hazardly, but I think if anyone who has an inkling on common sense will take basic precautions with hot metal and whatever else is needed by their conscience. Oh, BTW, I've been shot six times in my life, with lead bullets and by golly, I don't have any signs of lead poisoning.
bpfh Pazzerz4 years ago
Very good point kenbo regarding small splashes, though my personal respect with molten lead actually started when I used to use a large ladle and make 2lb diving weights years and years ago, and slopping half a pint of molten lead around is not the same as 2x 120 grains!!

In any case, as you say, common sense is king (but how many times have we tweaked the devils tail to get things done a little quicker ;) ).

As long as you go easy, with care and respect - and use about 5-10 bucks of PPE, you are golden.

Oh, and please don't get shot again. The instructables community is a small and nice one, and we don't want it getting any smaller!


Pazzerz bpfh4 years ago
It was a hazard of the job. I don't do that kind of work anymore. I realized I wasn't indestructable somewhere about 30 or so.

Common Sense, that's it. ;)
nepheron (author)  kyle brinkerhoff4 years ago
There is no lead used in this instructable.

The solder I use is the Oatay brand. I've had samples of this solder density checked and emission spectrum analyzed by a friend with an electron microscope. This solder is tin, and antimony, and that's it.
OK this is an extract from the MSDS sheet from the Oatey web site for their lead free solder.

I guess they know their product!!
MDS sheet.JPG
nepheron (author)  rickharris4 years ago
Oatay make solid solder wire and acid core solder wire. This is the MSDS for the acid core wire, which I do not use. Acid core wire is very smoky because it has resin in it, you would never want to use acid core wire for this project
Actually, Oatey makes at least three kinds of solder:
solid (no core)
acid core
rosin core

Acid core is NOT rosin (resin) core.

Use acid core for plumbing work.
Use rosin core for electrical work.
Use solid for this 'ible.
Actually that was an extract from their MSDS for lead free plumbing solder. BUT it makes no difference the warning is the same.

For me you can do as you like but the advice to do this outside was good.

A neat moulding solution, as a matter of interest you might want to try plain ordinary plasticine- this will produce some smoke but should work OK with the temp range you are using.

MDF will also work - even with Pewter -
im talking about when others attempt this....
OH MY GOSH! You mean you might come near lead? Yawn. The only terminal instantaneous lead poisoning comes from bullets. Most solder these days is pure tin and antimony. Even if there were trace lead in it, you get more from your environment than that.
The 'foreign material' would normally be an acid flux used to clean the metal and prevent oxidation.
nepheron (author)  jtobako4 years ago
Hopefully no one would use acid core for metal casting...that stuff spits and spatters like hot grease!!
Seriously guys. This is NOT complicated, for safety, you should always be soldering in a well ventilated space, and a fan in your work area to pull any potential fumes away isn't a bad idea. Why argue about this? I recommend that you be safe, if you don't want to be, that is fine, but don't tell others not to be because you FEEL it is ok. That said, this was a great instructable. I would really like to give this try. Thanks so much for making it!
Edgar4 years ago
I didn't knew about Sugru, thanks!
Bismuth is a substitute for lead, and I bet is melts at about the same temperature,
Also Aluminum melts at a higher temperature, but not much more than solder, there are tons of how-tos on that.
CRKeizer Edgar4 years ago
Ah...you might want to read the MSDS for Bismuth before you play with it.

See this one: http://www.sciencelab.com/xMSDS-Bismuth-9927101

Notice the warning about washing after skin contact.

I'd rather play with Tin, for safety, as a low melt temperature metal.

There are about two centuries of experience with "tin soldier" casting for us to review for potentially interesting issues. Notice, however, that even Tin may cause skin irritation: http://www.sciencelab.com/msds.php?msdsId=9925265

Have fun and play safe.

havent read the msds for bismuth but in terms of handling it more than briefly (washing hands should suffice for this), use nitrile or latex gloves for longer term handling of it, or at least that's what common sense tells me... i'm certainly willing to stand corrected! :)
Edgar CRKeizer4 years ago
You do not know me, so don't tell me to "play safe". Don't be paternalistic.

The world is not yet a Global Police State, and God willing, it will NEVER be.

All I need to know is this:

"It is relatively stable and does not corrode in the atmosphere, unless attacked by strong acids. Bismuth is not known to have any role in either plant or animal life functions. Importantly, bismuth is non-toxic (not poisonous), unlike lead and most other heavy metals."


EVERYONE should wash their hands after any Metal work, and avoid any eye contact with uncleaned hands, that's why washing your face and hands is for.
I was just wondering how anybody here gets ANYTHING done???...You all waste much too much time trying to be an authority figure where it is not needed...HERE!!!...Do something and get a life.Either you want to do this,or ya don't.Either way,we all take whatever risks may need to be taken when we opt to do anything posted here!.If it is a good job,say so...if not,simply do not do it!!! Otherwise...save the comments for BIG BOY THINGS;unless you are his Daddy!!! Thank you for your time in this ongoing farce!!!
tool... man, just let folks express a bit of concern for safety of others.. not everyone
here is sophisticated enough to have enough common sense for safety.
nepheron (author)  reverendbubba14 years ago
big-jamie4 years ago
you know...the best bit about this instructable for me is the fact it uses solder as the casting metal. it has never ever dawned on me to use solder like this. so i thank you for that ^_^

and what is Surgu ? whats it used for ? and i live in the UK can i get it here ?
Sugru is a British product.
Take a look at Sugru.com and treat youself to some.
I can't remember when I last ordered a pack of 12 of anything and paid only 74p shipping. Its only 91p ($1.37) shipping to the USA!
nepheron (author)  big-jamie4 years ago
I'm glad you like this! it's in a contest, so please rate it :D

Sugru is a moldable silicone. It's for modding and hacking things (check out their website)
It's really just a more clay-like window caulk, I bet I could synthasize it at home and post an 'ible after this contest finishes up.

I used Sugru for this because that was a requirement in order to enter this contest. Any silicone epoxy would work the same, except Sugru is pretty dense and will probably last more casts.
Mistwalker4 years ago
Nifty guide. I might have to try this out. Also, that Buddha looks like he's happy to see me.
evindrews4 years ago
omg awezome!! best instructables eva!!!!!
CyborgGold4 years ago
Nice Instructable! Great thinking finding this use for Sugru as well. I would recommend people NOT use lead based solder however, seeing as how the stuff is poisonous and what not, its just a safer way to go.

Will the Sugru mold hold up to use with other metals? i.e. something with a much higher melting point.
nepheron (author)  CyborgGold4 years ago
I mentioned lead because there still is a thriving community of lead-casters around today. People who make replicas of tin soldier and lead toys of that era often use the same materials of the originals (which is lead).

Sugru won't hold up to much hotter metals, but you can use Sugru the cast wax into. You then use the Lost Wax casting process using plaster (and then you can use any metal you want.)
Great instructable, but I'm not familiar with the "LostWax" casting process. I will try to google it, but could you maybe make and instructable about that too, since you're so good at it.
Lost wax casting is one of the oldest methods of casting metals. The Internet is rife with tutorials and how to's on the process. Basically you would cast a wax copy of the skull, then add sprues (long wax rods) and a pour cup all in wax then embed it in plaster or some other investment material. then once it's set up, you heat the investment, melting the wax out. Once the wax is gone, you pour your metal into the cavity left by the wax and you have a perfect copy of your original.
Wasagi4 years ago
Great Job!

Could you potentially use this for melted down lead?
bnmelech Wasagi4 years ago
Yup. Also ok fo AL, CU and other soft, low melt temp stuff. Some alloys of PB, CU and PB might give a hard time. Not recommended for casting bullets with Antimony. Well, my experience with trying wasn't too happy.
nepheron (author)  Wasagi4 years ago
Thanks! Please rate this 'ible if you liked it :)
Yes, lead should work fine. Due to some of the comments, though, I must recommend that you don't eat the lead or grind it up and inhale the dust XD
Wasagi nepheron4 years ago
haha. Can do!
vandal11384 years ago
Carved firebrick really looks like a rice crispie treat....
nepheron (author)  vandal11384 years ago
I did a presentation in school about metal casting, and I made a similar correlation XD
Hahaha then you sir, are a genius
alcurb4 years ago
Very cool project. Seems simple enough to replicate. I would have never dreamed of using a polymer-based mold to cast metal into it. Very clever.
Is there anything that Sugru cannot do? Hmmm....maybe it could fix the economy (comment nannies: it's just a joke).
nepheron (author)  alcurb4 years ago
It was quite a surprise to me, also. I figured this out when I was trying to melt some silicone. In my inexperience, I though It would melt like plastic. It didn't melt, but it also didn't burn. So I poured metal into it as an experiment, and whalah! it didn't melt, and the metal wasn't repelled by the surface. I bought some silicone epoxy and was able to shape it around objects, let it cure, pull it off, and cast metal into it.

If you like this ible, it's in a contest, so please rate it :D
How well would this work with resin? For most projects I'd use it for, I'll need to do resin casting, not metal.
nepheron (author)  The Mighty El Rondo4 years ago
If you use the appropriate mold release for your resin, then these molds should work fine. These are silicone molds, and silicone should not react to your resin.
Thanks, that helps. Now to figure out where I can get that stuff around here, lol, I haven't seen it anywhere.
nepheron (author)  The Mighty El Rondo4 years ago
Sugru won't be in stores-near-you for awhile to come, so you may have to order it online. Silicone epoxy is also a good mold making material, and is usually cheaper than Sugru (but the advantage of sugru still stands: it's durable and more rubber-like than the epoxy).
RVogel4 years ago
Great idea and well written. I would however advise NOT using anything with lead content that could be in regular contact with the skin. I am not one to preach on this. I often over-look material choice in favor of the effect. But lead is a heavy metal and there is a reason for the whole RoHS movement.

I will shut up now and again say that the skull looks awesome.
nepheron (author)  RVogel4 years ago
Thanks! I agree with you, lead is bad and should be avoided. I mentioned lead as an alternative to tin because some hobbyist prefer it (and are very aware of the hazards involved). I personally eradicated all lead items from my workshop since I started making jewelry awhile ago, eliminating the danger of contamination.

If you like this tutorial, please rate it :D

wagelda4 years ago
very good, simple & fast. No other comments needed.. great job.
nepheron (author)  wagelda4 years ago
Thanks!!!!! if you like it, please don't forget to rate! :D
kscott4 years ago
I've never used this stuff so I've got a few questions -
1) It looks like the sugru is molded & then "hardens" - How long does that take?
2) How well does the mold hold up? About how many replicas will it make and how long will the mold stay "fresh"? How precise is the replica?
3) Will it cast plastics?
nepheron (author)  kscott4 years ago
It takes 24 hours for the Sugru to harden. Shrinkage is pretty much unnoticeable.

The mold feels like the rubber from a car tire.

I don't know how long the mold will last. Expect several dozen casts.

The replicas are pretty darn good after the fourth cast. Do not get water on the mold.

I have never used plastic for casting, so I don't really know.

IF you liked this ible, don't forget to rate! (it's in a contest :D )
Ninzerbean4 years ago
Brilliant! Great instructions as I have done metal casting myself and this is a stupendous idea.
nepheron (author)  Ninzerbean4 years ago
I'm so glad you liked it! This is in a contest, so don't be afraid to rate this ible :D
stever_sl4 years ago
Half of the great state of Missouri has lead in the soil, lots of it (a large amount of the country's refined lead comes from mines here), and everybody in the country eats the corn and soybeans that are grown in that soil. Half a century ago we used to crimp pure lead fishing sinkers onto lines with our teeth, and I haven't know a single person in my lifetime who ever died of lead poisoning or was even diagnosed with it, except for a kid who ate flakes of old paint. The hysteria about lead is comical in a society that saturates its yards with MUCH more direct and fast-acting poisons just to kill weeds and bugs. I wouldn't worry about using ordinary lead/tin solder for this or any other indoor project - that's what I've been using for 30 years in making stained glass. Whoever said it was the flux fumes that stink was exactly right, and they do irritate the lungs (though they're not really poisonous as such) so that's where to take your precautions.
a good reason to preheat any molds when pouring metal (especially metal ones!) illustrated here (A LOT of cursing!)
only funny because no one was hurt.
david5474 years ago
The lung is not a digestive organ. Use a centrifugal blower to pull any vapors, smoke, dust of any kind away from the working area. Even a shop vac will work to keep stuff out of your face. I work in heat treating and metallurgy and have a degree in Biology. I encourage everyone to enjoy these activities and learn to be Makers, but do take care of your health with an ounce of prevention. I don't know if there is a laminar flow or exhaust hood "-ible", but they are easy to make out of common stuff and can be used for other activities as well. ( exhaust paint fumes from model building activities in winter )

thanks for the interesting explanation and suggestion of Sugru.
I will look forward to trying this out at home. You get my vote.

'lil D
JJ Joseph4 years ago
The solder warning also warns against "ingesting" (eating) the solder. Users should be warned not to eat the solder. From the comments, it sounds like some users might accidentally eat the solder.
TIGID4 years ago
ZINC I just love zinc So I wanted to say that. You can get it free eveywhere as well old junk like draw handles, and toys (broken) Lots of stuf is laying around made from zinc.
ireneoleary4 years ago
There are products available in the dental supply industry at much larger quantities for about $30 or so w/varying tear strength/flexibility that would be perfect for this project and they require far less time to set up and be pourable, my fav is ivoclar-vivodent's "siltech" a putty gel combo whose setting time you can control by the proportion of accelerator to putty (we're talking minutes to set), there are others that are putty to putty mixes whose set times and properties you can also tinker with by adjusting proportions.
Awesome. Thanks. I will look into those when I get around to giving this a try.
suckrpnch4 years ago
Curious. What is your crucible made out of? Thanks again.
GWJax suckrpnch4 years ago
He stated in the instructions that it was carved out from a fire brick.

suckrpnch GWJax4 years ago
I see. It is on the photo. Missed that. Thanks.
justkim4 years ago
Is there a substitute for Sugru? Great tutorial!
yomero4 years ago
i wonder how sugru would work to make a handle of a cook's knife, any thoughts?
nepheron (author)  yomero4 years ago
Sugru would make a great handle because it's vary firm, not soft or spongy. However, the cost of Sugru is a prohibitive factor.

I think Sugru would make a great, albeit expensive, knife handle.
yomero nepheron4 years ago
I've done pewter casting in silicon molds, I wonder if this would be the similar? Tin solders fine but pewter is definitely better then lead solder, with that whole pesky "heavy metal poisoning" part!
nepheron (author)  iminthebathroom4 years ago
I use tin solder (lead free) because its cheap. Pewter is hard to come by, and I personally avoid lead but some people make re-creations that are made with dated materials (like lead).

Lead is not all that dangerous as long as you don't eat it, or rub it in an open wound. Absorption through skin is not a significant hazard. Besides, most lead-tin-soldiers are painted, and this is yet another layer of protection. Just don't give them to your kids ;)
True enough, best place for pewter are salvation army stores, value village etc... all those college grad tankards with engravings no one wants.
nepheron (author)  iminthebathroom4 years ago
Oh, and yes to the mold part of the comment :) . This is the same stuff as silicone molds, AFTER it's dry. It has bad solvents in it, but when they evaporate, its just regular silicone.
Great idea, but don't most people making metal castings want to use things like silver, copper, or aluminum? I'd imagine those would wreck the sugru mold due to the heat they require to become molten.
nepheron (author)  supersoftdrink4 years ago
You can't use these mold for casting high temp metals, but you can:
Cast wax, instead of tin, into the mold. When the wax hardens, pull it out of the mold and submerge it in plaster. Then when the plaster cures, just melt out the wax and cast your molten gold, silver, or brass into the cavity.
Show us that! Show us that!
I agree, I agree! But overall, this is a very nifty 'ible, sir.
nepheron (author)  kellygreen4 years ago
An 'ible on Lost Wax Casting can be found here

Or just leave in the wax and make sure you have a runner and a riser.
Cool... that's a really good idea.

I hate working with the liquid silicone for molds because it's a pain to make sure there aren't any leaks in the mold holder before I pour it.
Jayefuu4 years ago
Fantastic as normal nepheron! Can't believe I wasn't subscribed already :)
nepheron (author)  Jayefuu4 years ago
Thanks, Jayefuu!!!