5 Ways to Ruin a Mold Making Project




Introduction: 5 Ways to Ruin a Mold Making Project

About: I'm a maker with a penchant for art and a love of sculpting the unsettling. I also appreciate the history of deep craft traditions and would be a good part of any post apocalypse survival team.

Do you ever have one of those moments where you think, "I know exactly how to do this correctly, but I'm not going to do it that way." Either cost or time or hubris gets in the way and you make a bunch of rookie mistakes and end up with a failed project. A failure that your logical side saw coming from the very beginning, but you kept going anyway.

Okay, so replace "you" with "I" in that last paragraph and that is exactly what happened with this casting project. I wanted to do a quick project using only materials I had left over in the studio and I decided to just improvise the rest. 

I did, however, get the 10K achievement for doing every cardinal sin in mold making. A sort of triple crown of failure. And here's how you too can ruin your project, waste materials and add a trophy to the wall you'll want to bang your head on.

Step 1: Use the Wrong Materials

First, think of what you'd like to make and the best possible materials for it. Now, use the exact opposite. 

For a successful project, I would have used silicone for something small and highly detailed. So, to ensure failure, I used Dermagel, which is great for life casting since it sets up quickly, is non toxic and easy to use. It is, however, very soft, prone to air bubbles and not durable, making it ruinous for a small detailed projects like this one.

Step 2: Say "Good Enough" on Your Original Sculpt

Once you rough out your sculpture, be sure to stop there before adding detail. Maybe beat it up a bit or move it around the room so it stretches and warps out of shape. As soon as it's a hollow shadow of you original idea, say "good enough" and stop working on it. Not only will it look like a drunk child did it, but it will also not fit onto any other part of your project. 

Step 3: Use the Wrong Size Container and No Mother Mold

To guarantee failure in your project, be sure to use a container that doesn't fit your object. This will ensure that the final mold has thin walls that tear easily and other areas that are dense, heavy and waste materials.

Also, to aid in that effort to create walls that tear and warp, do not under any circumstances create a plaster mother mold to keep the soft material in place. Registration marks are key to precision and success. Avoid these at all cost. 

Step 4: Run Out of Materials

Be sure to have too little mold making material, panic and try to displace excess material with whatever is around adding unnecessary holes in the mold and weakening it further. Once it sets up, be sure to cut far to close to the object. You should end up with a pile of goopy gelatinous mold material is barely recognizable as something man made. 

Additionally, If you need two sides of your project to match up perfectly, do not create a two piece mold. Create a one piece mold and just toss in a half hearted attempt at the reverse side when you go to cast. Again, do not use registration marks or any other indicators of where this piece should go. 

Step 5: Ignore or Poorly Patch Weak Spots

After guaranteeing that the mold will have holes, tears or at the very least weak spots, be sure to fully ignore them or poorly patch them with ridiculous materials, like cellophane or tape. After an abysmal patching effort, go ahead and pour the mold making material anyway. While I had a layer of cellophane under the mold to catch most of what spilled out, you can take it to the next level and have plastic spill all over your workbench and floor. Once it sets and hardens, it will be nearly impossible to remove from some surfaces. Consider this your well deserved merit badge of terrible planning, execution and decision making skills. At this point you should either vow to all that is good that you will never make anything again, or try to regain your self respect as a maker, and just do it right next time. 



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    58 Discussions

    These are common mistakes many people make with mold making. Good to keep in mind when you get started.

    ROFLMAO! That is nothing! Try casting molten aluminum into a still damp plaster shell! The water flashes into steam, and you get to wear some of the still molten aluminum! I think I earned the dumbass of the year award that time, I still cringe thinking about it. I am damn lucky that I did not burn my house down. No one got hurt, and you only had a little cleanup and a few dollars of wasted material. I call that "Learning Expenses". So long as there are no doctors or lawyers fees, you are on the right track. Keep up the good work.

    5 replies

    I spent almost 3 years working for the Anaconda Copper Co in the early 70's. The Copper Refining Furnaces could hold 250 ton. We used compressed Air 90 # to raise the rest of the Slag left from the Converters Dept. Then big - (often wet and frozen in winter) - logs to hoist with a swing boom, and electric Hoist on a track on the boom and chains with 6" links as big as a finger and 3/4 " cable on a pulley to persuade logs to stay under the Copper to burn out the air that had been blown under the surface of the copper, - making it like a sponge. The "Safety" asbestos aluminum suits wore out in 6 months on a 1 pair a year allowance. SNIVVLE = ~ So day after day, week after week, Etc, Molten Copper Splatting out the furnace door of about 3' X 4' - past the "Smoking Ol' - Flip Down - Green Plastic - Face Mask" (I've had some get so hot they curl up and droop all around, If You could get one to solidify just right It could last a couple weeks counting any day's off. Copper enjoys spattering down the front & back of the neck, and some choice surprise spots! I woke up one morning in Yuba City with a Gal standing over Me with a meat fork, She should have knowen from the night before that I was no cigarette burning Pervret. So back to molten metal. it seemed that wherever You weren't standing seemed to be safe Ya' know. And whatever was left of Your 2 X a year Bib Overalls "Pay-Days" was always hanging threads like the rich kids do to their new jeans now days, these "former holes" were catching fire quite often The only job where I didn't pay attention if a fella I was working would slap My donkey..! Hot, You wouldn't believe how hot. They had to keep the cement lined 4' X 20" X 4" thick "Dipper - above the 3,000 # Molds around the 50' Casting Wheel". Upon finishing a charge We would get a 3/8 pipe burning "Clint Eastwood" style except on 90 # air, then walk out on this ramp about 4' above that 4' X 20" red hot dipper and burn a tap hole thru the fire mud plug and then form a "Pouring Lip" under the tap hole, quick as possible but not so quick that You have to do that a second time, "It scorched the bottom of the socks brown, So I know about those quick surprises, they happen so fast there is no avoiding them, like You have thank the Lord for protection Drunks & Dam Fools, I can wear them hats. They water to keep the dust down in a wide isle of big chunks of waste Slag & etc, being shoved around by Cat between the Reverbs Department on the West, the Converters Departments on the East - once in a while an Over Head Crane Operator would mess up and drop a 60 ton ladle of molten, - It's worse than Dynamite.! I agree. Sorry I went long, old thoughts, I was sure glad when I was finally able to transfer to the Local Tram, etc, and that You must be faring well. Luck.

    Hahaha! Brings back all kinds of bad memories! Molten metal is dangerous. I will share a secret though: There is a trick to make your clothes damn near fire proof. You treat your clothes with HI-Temp Silicone sealant! It is flexable, able to withstand 900+ degree metal splashes, easy to apply, and it makes your clothes last forever. Found this out by accident, but it is a handy tip to have if you work with any kind of hot metal.

    Naw, thats from all the brick laying you do! LOL. No, it doesn't stain much surprisingly. I had one pair of pants last me 5 years and anywhere the silicon was just wouldn't wear out. Make sure to work it into the fabric as well as you can.

    Great idea that would even work better in underground mine where big patches and "Tug O War" were the general solution.. Har.! Thanks Again. G-G

    Ok, Lmao like a dang loon, over here! You see this is particularly timely for me, having just yesterday opened a package with the first of my molds in it. Granted, they're purchased molds which I'll use with airdry clay or resin or some such for jewelry, but I'm still rather nervous and reticent about the whole thing, as I'm totally broke, and materials are a danged fortune! lol Crossing fingers that you've got other 'mold tip related' instructables... if not and you have any resources you particularly recommend, I'm all ears! Dying to start making my own molds, as that's really the only cost effective way to make the sort of jewelry I aspire to. Anyway, thanks for the chuckle and exactly what moronic steps not to take. Its inevitable I'd have 'put my foot in it' in at least one of these ways and ruined my first go round. ;)

    ...still chuckling
    Rachel of OddModicum

    7 replies

    I have no direct experience, but somewhere I saved a thing on molding with Silicone, so the way I gathered Hardware Store Silicone "Calking", etc, when setting up, forms a "Skin" then turns dry from the outside in. A responder replyed that by mixing some Baking Soda to this "Grease Gun" Silicone will make It set up all thru. Fairley pronto if I recall. Get Em'.?

    Ooo, new molds! Fun! If you're just getting started making molds for jewelry, I'd recommend checking out Quick-sil. It's super easy to use and you get a nice silicone mold that's great for resin. Also, Smooth-On has some really cheesy videos about mold making and resin casting, which can be helpful if you can get past the elevator/porn music.

    rofl.... lauging like a loon again. Are you a blogger, by chance? I have a feeling I would VERY much enjoy your tidbits on a regular basis. ;) And I have no objections to mondo cheesy elevator/porn soundtrack if the info is good and it saves me making costly mistakes, and bursting into tears surrounded by expensive materials I've screwed up, covered in goo, in a big pile of mess that I've created. Thanks so much for the suggestions! I hadn't gotten as far as coming up with what to make my molds OUT of, but that's a huge hurdle I now no longer have to research. You don't have any suggestions for particularly good cheap clay (thinking something air dry?) or resin, by chance, do you? Thinking paintable, of course, and strong enough for jewelry. I'm sorta leaning toward 'diamond' resin, because of all the reviews, or Annie Howes version of same. Thinking its gotta be self doming, and relatively low on stink factor, since I've got gnarly fibro and am crazy sensitive to smells and such. Anyway, thank you SO much for your help, and your two very entertaining instructables, today. I was so intrigued by the existenZ game console, btw. My guy is a mad gamer, and he'd love same, but mostly games with pc, so not applicable. Could do an existenZ-esque mouse though, I suppose! Your idea is just creepy and fun enough to be totally marketable. If you ever get into selling those consoles, or 'sleeves' to put over em, give me a yell out. I know a group of gamers who would fall over themselves to get at em. ;)

    Thanks! I don't think I'll go into production, but it's nice to know there's an audience for it! Hmm. Mold making materials can be pretty stinky, and I always wear a mask with organic filters (like this one) when working with any two part resin, but it looks like you may have alternatives. Hope you post what you make!

    Note to self.... obtain respirator to avoid asphyxiation. Good tip, for sure! lol I'm grabbing some Ice Resin today (it is a 2 parter, but supposedly on the 'less stinky' side, great for jewelry from my research)... but I'll definitely need a respirator, for sure. Thanks for the tip, cause I knew that, but had forgotten to budget for one. ;) Showed my guy the console and he officially had palpitations over it, btw. Definitely cool! And yep, I'll be sure to show it off iffin I make anything show off worthy. ;)

    Never done any casting now I never will, just kidding, this reminds me of a fiber glass peice I did in which I had 100 bucks worth of glass and resin but the supplier sold me hardener in the resin can so I mixed 4 to 1 hardener to hardener obviously it never set and I had a pile of glass soaked in hardener
    Thanks for the what seems now obvious

    They said be positive!!!
    Well this "positively" Sucks

    Very cool anti-instructable,