Your Casting Epic Fails

[lastspartacus]

Surely others have had these? Here is hoping. I'll share how my day went yesterday.

I receive some exciting master parts in the mail from the 3d printer, some 'flying bases' for a flying ship miniatures game I'm designing. I know in theory not to mess with master parts, but I want to see how the flight stems fit into the bases, and promptly jam one in and have it break off in the base.

Now its a perfectly tight fit, so the square peg at the bottom of the stem is pretty much fused to the base, and I have a broken stem. I think ok, I can just replicate anyway and glue on for proof of concept, and I have two other different height stems anyway. As I walk to wash the parts of any residual oils, I lose the smallest stem. No idea how, it must have fallen out of my hand somewhere and just can't be found. Then the other drops out of my hand in gets washed out of the sink.
There I am just minutes later with one broken stem left out of three.

At this point I'm having a bit of a moment. This isn't like me, I have no idea what gravitational earth flux happened to warp my luck this way. Nevermind, I'm going to cast these bases! I've spent months slowly learning, tinkering, gathering parts, but its going too slow!

So without getting any kind of proper procedure or setup in place, I set about for my first mold making. Mold Max 30 part A turns out to be [b]incredibly[b] viscous without any good way of pouring it out of the gallon container it came in. I ruin a squeeze bottle and have to clean up the bottom of my sink by hand to prevent it from slopping into the drain. I break a few untensils trying to stir part A and B together after setting up a mold box around my bases, being sure to build a few bricks higher to account for vacuum bubbling. Obviously this was not high enough, probably because of the incredible amounts of air I kneaded into the mixture from exertion in stirring and time lost trying to sort a power issue which, turns out, was a cable that simply wasn't plugged into the wall.

After a tank full of splashed out silicone, I was stressed and with a neck intensely messed up from the stress. To put a final cherry on top of a delicious fail ice cream sunday, the pressure release valve goes off when I bump the tank. Scares the crap out of me and I completely ruin my neck from tensing and jerking. I miss the next day of work.

It was a humbling experience, and I knew this was the place to share my sorrow

[mangozac]

It may have been a humbling experience, but the important thing is whether it was educational

I've never had any catastrophic issues (touch wood). I did try using up some old silicone 2 years back that never cured. Also I think more than once I've mixed up some resin only to realise that I haven't prepped the moulds (boards and rubber bands)!

[lastspartacus]

It was very educational. The molds turned out satisfactorily so it was encouraging

[lastspartacus]

I can honestly say without this site I don't know what I would have done. But with the helpful tutorials and commentary this thing has become much less daunting than it first appeared, though there is still much to learn.

[mangozac]

I'm always glad to hear that!

[paulson games]

I've had a couple minor material related fails.

I used a combination of micro-mark silicone and smooth-on resin. The two had some sort of reaction and the resin bound with the silicone like it was superglued in place. I tried and cut the parts out but they were stuck so tightly it was no good.

When I was using stuff printed on the objet printers I'd molded a couple parts without sealing them in primer and they bound up with the silicone due to the layer stepping on the part. Effect was like being glued to the mold with some serious work I was able to get the parts out but it tore chunks of the mold face off so the molds were worthless and I had to spend several hours carefully cleaning the masters and then sealing them in primer.

Another small disaster was using some of the platinum cure from Tap plastics (which is expensive as hell) Stuff is supposed to set in 90 minutes but a full day later it was still complete goop other than a very thin cured layer on top. I go back and read the directions to find that it says not to use with wood. Apparently the wood's natural resin/sap impeads the silicone from curing and I'd used my wood popsickle stick to stir it. Took hours of work to get the silicone gel off as water did nothing to help it rinse off and I had to get into every tiny crevase with Q-tips and a hobby knife.

Rather recently when pouring resin into a measuring cup I managed to get a splash of resin in my eye, fortunately it was just the A side and not the mixed combination. Didn't burn but it wasn't pleasant, it left my eye ball feeling like I'd had a blast of menthol or peppermint in it and my eye kept tearing up for several hours.

[lastspartacus]

Now that's what I'm talking about! Man, that sounds awful. Motivates me to read the directions and wear my safety glasses.

[mangozac]

Great to hear from you Jon. I knew you'd definitely have a couple of stories to add

[chromedog]

I had mould making fail a number of years ago (around 1993 or so).

Was using a Dow Corning RTV silicone (heat resistant, because I was going to be doing both pewter casts AND resin casts out of the same mould at the time).

Didn't realise the chemical reaction that would happen between some RTV silcones and PVA.
Rubber permanently bonded to part of model and I lost both the model and the mould.

[Hiflt4]

[SSB]

After vacuuming, I went a bit fast putting the air back in the pressure pot : KABOOM !

[mangozac]

That looks awesome at least!

[Fleafa]

Please make a cast of that.

[SSB]

Of which side ? ^^

[Fleafa]

Both!