Casting and Mold-making...

[Paul B]

Looking for some information on mold-making and casting. Any one on MR do casting and mold-making?

I have found a couple good websites that sell kits and give good tutorials but I know MR members can be a wealth of knowledge also.

What do you make? Is it as easy as it seems? School me with your knowledge! What is a good kit to use? Any helpful personal tips or tricks? Do I need vacuum kits?

Basically what I'd like to do is mold small pieces from die cast trucks for custom work. Body pieces (roll bars) and interiors mainly so I don't have to buy and then cut up so many trucks just for a couple small pieces while scrapping the rest.

And is it possible to make a mold of a die cast body and interior separately? Then once casted can they be fit back together as if they were from the factory?

Any help would be greatly appreciated!!! Thank you :) If you need photos of what I am trying to explain, I can post some.

Paul B

[kung fu jesus]

I do, but I have to ask why casting when you can print them out from a home office, finish them by hand, and sell?

Even cheap tooling for diecast won't be cheap.

[Paul B]

How would i print rollbars in my home office? 3d printer? Id love to do that. But arent those are expensive...

[kung fu jesus]

Yes. The cost of a 3D printer is waaaay lower than tooling. These are for model cars/toy cars right?

Prices have come down on 3D printers a LOT. Especially for hobbyists and home-use.

[Paul B]

Yes. The cost of a 3D printer is waaaay lower than tooling. These are for model cars/toy cars right?

Prices have come down on 3D printers a LOT. Especially for hobbyists and home-use.

Yes, this is for diecast cars and truck.

I was thinking I could do resin-type casting. Make a mold of a body and/or interior then cast it in resin/plastic or whatever its called.

Any good links to find a home office 3d printer? how much do those run?

[Paul B]

http://www.alumilite.com/store/pg/8-Applications.aspx


Ive been checking out this website.

[revlimiter]

I've done this for years. I'll post when not on a phone.

[revlimiter]

I do, but I have to ask why casting when you can print them out from a home office, finish them by hand, and sell?

Even cheap tooling for diecast won't be cheap.
Sorry. Don't wish to flame or anything, but this statement could hardly be more wrong.

3d printing is great for prototyping and for those who can't sculpt a part by hand. But it's very expensive to buy the printer and refinishing parts over and over is not working smart. We're talking about toys here, not precision 3d cad printing.

Having a part printed and finishing it as a plug for a mold? Sure. But finishing it over and over? No. That's just frustrating.

[revlimiter]

Okay! Molding and casting. Here's a random brain dump.

Firstly - videos. Watch youtube like crazy. Smooth-on has some excellent videos. They make a good product too, but their videos are truly outstanding.

To learn how to mold and cast, I recommend one of the starter kits. It comes with enough silicone and resin to do two or three parts. It won't be great stuff, but it will be better than any class you could take. Consider it Molding 101. I started with an Alumilite starter kit. I think the kit I got was like $89ish. About the price of a continuing ed class at a community college.

For the molds, you'll want a product that can last a long time and take repeated pours. This is usually a more expensive silicone than the starter stuff. It will be more flexible and rubbery. My first love was Alumilite HS3. It's a Dow-Corning silicone that's pink when cured. Not too expensive and available at Hobby Lobby. You can buy it in 10 lb tubs. It lasts a long time.

Equipment needed:

You'll need a gram scale to measure. Target sells them. Amazon sells them. Don't cheap out, but don't pay too much either. A 5 lb scale should be enough to start with. As a bonus, you can weigh your mail with it and print from USPS print and ship.

You'll need something to mix your silicone in. Target has all manner of glass bowls and vases. I recommend glass for mixing your silicone. Something with a pour spout from the kitchen area is probably easiest.

You need something to mix the silicone with. A metal cake spatula (the flat kind that you apply frosting with) is perfect. It lets you mix easily and you can clean the silicone off easily.

You need to make a mold wall with something. I started with lego. I still recommend it to all of my friends. It's super easy and fun to build a mold with lego. They should be DEDICATED lego, because they'll get yucky.

You also need clay. Some silicones are platinum based and require a certain type clay. Tin cure silicone can work with just about any clay. HS3 is a tin cure. The clay is used to make the mold floor and seal the edges of the mold. It can be reused a billion times.

You need mold release spray. Alumilite has some of this too.


Consumables:
Little medicine cups. They're like 40 or 50 ml. Buy a sleeve of them.
Craft sticks also known as popcicle sticks. Buy 1000 of them from amazon for cheap. You'll have a lifetime supply.
3oz paper cups are perfect for mixing your resin. Buy a box at your grocery store.
Paper towels - always have a roll with you when you're casting.
Rubber gloves - I like the Kimberly Clark KC100 purple ones. Very thin. They fit well and keep your hands clean. It sucks having your nails caked with resin for days.

For resin, you'll want a fast cure one. A resin that kicks in 2-5 minutes is optimal for small toys. Alumilite White is a great starter resin. It's very strong, flows pretty well, and is inexpensive. And you can dye it before you mix it. You'll probably still need to paint, but it's nice to start with a black/blue/red/whatever object and paint it a little bit rather than having to completely color-change your new robot head / wheel / rollbar / whatever.

What else.... hmmm....

I own a pressure pot and a vacuum chamber. I only bought them last year. You can mold for a long time before really needing expensive tools like that. If you do the "bombs away" pour, you can pour an extremely bubble-free mold very easily. Smooth-on has a video about this.

Cost:
You'll probably spend around $200-300 to get all the stuff you need and a goodly supply of resin and silicone. It's a LOT to pay for a single small part. But if you continue with the art and keep making small parts, the cost goes down very quickly. 5 lbs of silicone will make a ton of different molds. 2 lbs of resin will make 2 lbs worth of little 1/64 rollbars. You'll only have to top up your consumables and plastics once in a while.

If you wanna make just one or two parts, I highly suggest Sketchup (3d drawing software) and Shapeways. It's a 3d printing service on the internet. They have a ton of different types of plastic. Making a single toy robot will run around $30-40 depending on the plastic required to print it. Way less than a few hundred to make molds and cast yourself. But... it's $40 per bot. Once you make molds, you can make 20 bots for about that same price. Cost per part goes WAY down the more parts you make.

I hope that helps. You can always email me about this stuff too Paul. I love talking about it.

[revlimiter]

And is it possible to make a mold of a die cast body and interior separately? Then once casted can they be fit back together as if they were from the factory?


You can re-mold anything.

ANYTHING.

Any object that can have silicone poured over it can be perfectly duplicated. either a car body, interior, multi-piece action figure, real car part, or a hot girl laying on a table for a live-mold. Any object that can exist in the real world can act as the plug for a mold. One mold produces one piece. Anything with a joint will need to be done in multiple molds. Or several individual objects in the same mold.

As far as a hot wheels, a squish mold works pretty well. You have to make a two piece mold, but yeah... you just fill it up with resin, squish the two halves together, and a few minutes later you have a body or interior.

PS - you might not want to watch live casting videos at work. There are usually bubbles or blurry areas over the nude women, but... not always.

[Phatmiata]

ill post up here when not on the iPad......... to hard to link stuff like photos

[Paul B]

Yes my uses will be 1/64 scale roll bars for little monster trucks that I custom make. Some to keep for myself and some to sell. Might get into molding old bodies, interiors, and chassis of trucks that are no longer made.

Thank you, Adam, for the great write up. What you're saying confirms with what I had in my head but was pretty unsure of since I know nothing about this. I will definitely start with the alumilite kit from hobby lobby and go from there. Thank you for the product recommendations too. Sounds like HS3 is a good start too.

I think I will try the squishy mold for any bodies I make. And I do have plenty of Legos !!

May have to send you an email once I gather supplies and attempt my first mold.

What have you made with this stuff? What have other MR members made??

Now this may sound bad and I know companies get in trouble for molding stuff and selling it; but what is involved in custom die cast molds ? I know plenty of customizers sell cars on commission using company decals and liveries and molded bodies and stuff. Do people get in trouble for this? What are the rules and laws governing this? I am looking to possibly make some old school trucks that are not produced or were never produced. Many people are interested in buying my works. It's a hobby but if I make them to sell am I gonna get attacked and sued? If that's the case I will use molds strictly for personal collection trucks. Or not at all. Can I mold a piece and then tweak it, remold it to create my own to save my ass?

[revlimiter]

Of course you can email me! I mentioned it above. I love talking about this stuff.

First thing I ever made: robot feet.
https://farm4.staticflickr.com/3274/2622567999_ed723f4a75.jpg (https://flic.kr/p/4ZKm6D)

which grew into this.
https://farm4.staticflickr.com/3220/2702939784_bb86cb03f6.jpg (https://flic.kr/p/57RgQ5)

which became this.
https://farm4.staticflickr.com/3110/2764593324_f3b702e998.jpg (https://flic.kr/p/5digh9)

https://farm4.staticflickr.com/3209/2764594262_4e228cb740.jpg (https://flic.kr/p/5digyj)

Revoltech Shockwave was a recast of a super rare garage kit. A guy on a TF board commissioned me to make a copy for him. I learned SO much. There was 14 molds for the figure. I made several different heads and hands. I think there were 20 molds total.


I made a plug for my cut up rear airdam. I did a blog post about it. http://revlimiter.net/blog/2010/07/rear-air-dam-restoration/
http://revlimiter.net/blog/wp-content/uploads/2010/07/DSC_1443.jpg

The plug is in the center.
http://revlimiter.net/blog/wp-content/uploads/2010/07/DSC_7016.jpg

And my window switch frames are molded and cast pieces. I've upgraded the mold 5 times. I'm now on the mk.v window switch frame. It's stamped on the bottom of each.

http://revlimiter.net/store/switch/switchna-01.jpg

My dash pod gauge cups are molded and cast.

http://revlimiter.net/blog/wp-content/uploads/2015/06/cup7.jpg

[revlimiter]

Now this may sound bad and I know companies get in trouble for molding stuff and selling it; but what is involved in custom die cast molds ? I know plenty of customizers sell cars on commission using company decals and liveries and molded bodies and stuff. Do people get in trouble for this? What are the rules and laws governing this? I am looking to possibly make some old school trucks that are not produced or were never produced. Many people are interested in buying my works. It's a hobby but if I make them to sell am I gonna get attacked and sued? If that's the case I will use molds strictly for personal collection trucks. Or not at all. Can I mold a piece and then tweak it, remold it to create my own to save my ass?

Copyright law is tough. I am not a lawyer, but here's a few key bits of info.

Every company defends their property at a different rate. Take concerts for example. You can record and redistribute Pearl Jam concert footage and bootleg recordings to your heart's content. The band is completely behind it and even sells their own recordings of their own concerts. Fans are free to trade them, even the official ones.

On the other hand, you have Janet Jackson. If you so much as post a 15 second video clip of her on your instagram, her lawyers will attack and you'll lose your entire Instagram account due to copyright infringement. They go after people sharing photos of her too. I can't imagine the legal reaming a poor fan would receive if they had a bootleg of an entire Janet Jackson concert out for trade.

Some companies defend their "property" far too much. Others are pretty cool. Since the HW customizing community is so vibrant, I'd say there's a near zero probability of being legally punished. However, you never know. I'd not let a little fear get in the way. If you become big enough for the big boys to notice, that's pretty huge in itself.

[Paul B]

Copyright law is tough. I am not a lawyer, but here's a few key bits of info.

Every company defends their property at a different rate. Take concerts for example. You can record and redistribute Pearl Jam concert footage and bootleg recordings to your heart's content. The band is completely behind it and even sells their own recordings of their own concerts. Fans are free to trade them, even the official ones.

On the other hand, you have Janet Jackson. If you so much as post a 15 second video clip of her on your instagram, her lawyers will attack and you'll lose your entire Instagram account due to copyright infringement. They go after people sharing photos of her too. I can't imagine the legal reaming a poor fan would receive if they had a bootleg of an entire Janet Jackson concert out for trade.

Some companies defend their "property" far too much. Others are pretty cool. Since the HW customizing community is so vibrant, I'd say there's a near zero probability of being legally punished. However, you never know. I'd not let a little fear get in the way. If you become big enough for the big boys to notice, that's pretty huge in itself.

Thanks for that advice. I had never heard of any die cast customizers having issues like that but you never know. Im not trying be big...just want to make cool toys for peoples collections.

[Paul B]

15194

Picked this kit up today. Originally $70...my amazing wife gave me a 40% off coupon. Brought it down to $45.

[revlimiter]

Yup! That's the Molding and Casting 101 class. Good luck and have fun! Post some results.

[Paul B]

Yup! That's the Molding and Casting 101 class. Good luck and have fun! Post some results.

Will do!! Excited for this!

Another question... If i were to cast a hot wheels body, does it cause any damage to the original piece?

[revlimiter]

Re-casting rarely damages the plug. If you damage it, you're doing something with silicone that few people in the world ever have. You know, because silicone is really really soft. :)

The worst that can happen is the original (the plug) gets yucky from being half buried in clay. Careful cleaning after removing it from the clay is a good thing. You can spray it with some mold release before claying to make it easier to pull out. And, of course, you'll have to spray it again before pouring the 2nd half of the mold.

[Paul B]

Awesome!! Gonna try my first stuff this week.

Thank you so much for your help!

[Agent☣Orange]

I have to say...

I didn't know about any of this but now I'm learning a little bit and eager to experiment!

[Paul B]

Ok, here is my progress so far. Made the mold last night. Used the alumilite calculator online to find the proper amount of silicone mold/catslyst to use since its 10:1. I used an empty baby food container for my mold. Made a base in it out of clay and place my little monster truck roll bar face down in the clay. Let the silicon sit and cure overnight. Mold seems good to go today. Probably could have been made better so i will address that in the future if this piece doesn't come out usable. I will most likely go the different route for the mold box; one that has a complete flat bottom. I i think that will help the front of rollbar come out better and more crisp.

So a half hour ago I mixed tiny (about 1/2 tsp each) amounts of resin mix and poured into the mold. Let it sit about 15 minutes (instructions say 5-10 minute demold time). Pulled it out and here is my first effort. The cast rollbar is missing the back legs , so resin mix must not have seeped into those holes.

Attempt two of casting is happening right now. I used a dull poking tool device thingy to try and open up the holes in the mold for the back legs of the roll bar in the mold. Once i poured the resin mix back in i also used that tool to try and make sure the mix gets down there. Poured real slow and tried to clean up the exposed part of the resin.

These tiny rollbars are such small pieces that i will probably end up getting a mix that cures a bit harder for more strength. We shall see.

The picture shows my mold, the piece i casted without the legs and what it is supposed to look like.

15200

[Paul B]

Second attenpt failed. This tome, no back legs and it broke in the middle when i was trying to remove from mold. It had set a few hours.

I guess ill try a stronger resin for tiny part but still dont know how to get resin into the holes for the mold for the back legs of the rollbar

[Paul B]

Need some advice... Would it be better or easier to mold this whole piece instead of just the tiny rollbar?

If I were to mold the whole piece would it come out of the mold better? Is it even possible? Lol

15204

[revlimiter]

You used way way too much silicone for that mold. You want far less. The thinner the mold, the easier it is to massage it while you're pouring the resin and get bubbles out.

And you need a method of evacuating air from the far parts of the mold. An air tube or something.

And if you demold while the resin is still pretty flexible, it won't bend and break. It'll just bend.

[revlimiter]

Anything super tiny, thin, and delicate is really hard to mold. I'd not start with that. Start with something easy like a Star Trek communicator badge or rubber ball or a Testors model paint jar or something. Something not too high on detail. You'll drive yourself crazy trying to learn on a piece you actually WANT to duplicate.

[Paul B]

Hmmm I feel this ending without the results I'm looking for.

Thanks for the tip Adam, Ill make a smaller mold box. Luckily I pick up my legos from my parents house on thanksgiving lol ill make a smaller mold box and try this rollbar again.

What is the process of getting the air out?

Only other thing other than this that I would want replicated is a truck body. Maybe Ill start with that.

Only other option I can think of to make these rollbars is 3d printing.