Resin Casting Supplies?

[Nells250]

HI folks... does anyone know of alternatives to Micro Mark resin casting items?  They are a bit pricey and was wondering if there are any other suppliers of smaller quantities out there.  I used Micro Mark's stuff a long time ago with mixed results...

JD

[wisdonm]

,I have had very good service and results from Specialty Resin in MI. I love their Ultra 4 mold release, Model-Pro-Slo resins, and Cast-A-Mold 30TF silicone.

Edited January 7, 2020 by wisdonm

[crazyjim]

Google ooh moo.  Smooth On products.

[Ace-Garageguy]

In years past, I used materials from Freeman Supply extensively for a wide variety of industrial prototype and marketing model presentation projects. The costs were reasonable, and materials were available in quantities down to a quart. They also have a bunch of instructional videos to help determine what various products do, and to better explain the processes. Never had an issue with "old" materials not performing because they'd been sitting on a shelf for 5 years, as sometimes happens with materials sourced in small quantities from hobbyist resellers.

https://www.freemansupply.com/video.htm

Edited January 8, 2020 by Ace-Garageguy

[Nells250]

THANKS so far!

[Casey]

There are many different brands and types of resin-- too many to list all the options.

What specifically are you planning to mold and cast, how many pieces are you wanting to produce, etc? That might help narrow things down a bit, and also help us guide you toward a product which would increase you chances for success.

Do you have any resin casting experience? Do you own a vacuum chamber? A pressure pot? 

[Nells250]

If I go through with it, it would be making a set of wheels, possibly with tires on them... So I may have to make two mold halves, with channels to pour in resin.  Not totally sure yet.

I tried it a long time ago with very mixed results, though I was using clear resin and I think that was a mistake.  I also remember only making a one-side mold for some items.  

Here are two photos from 2002:

[jas1957]

On 1/8/2020 at 9:08 AM, Ace-Garageguy said:

In years past, I used materials from Freeman Supply extensively for a wide variety of industrial prototype and marketing model presentation projects. The costs were reasonable, and materials were available in quantities down to a quart. They also have a bunch of instructional videos to help determine what various products do, and to better explain the processes. Never had an issue with "old" materials not performing because they'd been sitting on a shelf for 5 years, as sometimes happens with materials sourced in small quantities from hobbyist resellers.

https://www.freemansupply.com/video.htm

www.miapoxy.com is the hobbyist   DIY division of Freeman Supply.  

Edited January 11, 2020 by jas1957

[Ace-Garageguy]

18 hours ago, jas1957 said:

www.miapoxy.com is the hobbyist   DIY division of Freeman Supply.  

Thank you. Most useful.

[Casey]

On 1/9/2020 at 2:40 PM, Nells250 said:

If I go through with it, it would be making a set of wheels, possibly with tires on them... So I may have to make two mold halves, with channels to pour in resin.  Not totally sure yet.

I tried it a long time ago with very mixed results, though I was using clear resin and I think that was a mistake.  I also remember only making a one-side mold for some items.  

Yes, one part molds are far easier IMHO. If you don't have a vacuum chamber to remove air from the mold rubber when first poured, you will probably be fine if the mold depth is shallow (1" or less) and there are no deep undercuts. I have made many single part molds without a vacuum chamber, but you have to be diligent regarding manually removing any trapped air bubbles before the mold rubber cures.

I use Smooth On's Mold Max 10, and have been very pleased with it. There are smaller trail size kits available, which sounds like it might be a good match for your needs: https://www.smooth-on.com/products/mold-max-10/

I think Smooth On's Smooth Cast 310 would be a good choice if you do not have a pressure pot, as it has a longer open time, again allowing you to manually chase out all air bubbles. yes, it can be done, but you're going to have to pour and cast in smaller batches and be patient. Probably not a big deal if you're planning to cast small items like wheels and such as seen in your image. A small 2-3 gallon pressure pot is not that expensive, and if you already have a pancake air compressor or larger (not a tiny, constantly running airbrush style compressor), you're already halfway to having  a decent casting setup. https://www.smooth-on.com/category/urethane-resin/

Honestly, there are many different companies producing mold rubber, urethane resin, and other molding and casting products, and each person has different experiences and preferences, so factor that in when you read people's suggestions. I like predictable, repeatable results, so I use the above mentioned products and follow the same techniques each time and get, well, predictable, consistent results. I would NOT recommend using Alumilite products (which, admittedly, are easily available at box craft stores), especially not their trial kits, as both the resin and mold rubber included set up way too quickly for what you are planning.

One other tool you absolutely will need is an accurate scale which reads in grams. I use the Jennings CJ-600 scale, which I purchased from Old Will Knott Scales here: https://www.oldwillknottscales.com/jennings-jscale-cj600.html Very pleased with the scale and company's service. Don't cheap out and try to use a low quality kitchen scale from the thrift store. If you want accuracy, invest in a good, accurate scale.

One other suggestion based upon what I see in your image. Use a smaller mold container so there's less waste. For smaller items like wheels you don't need that much mold material around the cavity, but maybe you simply used whatever you had nearby. Various lengths of PVC pipe (which is available in multiple diameters) or unions/collars are nearly ready to use or can be cut to whatever length you need, and the cut ends can be made flat and square to the side walls with some sanding on a planar surface, too. Here's an an example of that, using a piece of 3" pipe cut to 1-14" in length (height, as shown). I have several former Corian countertop material sample squares which I use as as the base, and double side carpet tape to keep the mold ring and parts in place while the mold rubber cures. Rather simple, but easy to disassemble and clean up, to allow for re-use. These are all parts which can be made with one-part molds, so again, for consistent and repeatable results, follow the K.I.S.S. method whenever possible:

 

Some Chevy Rally wheels, vintage style CMUs, and a 1/20 scale Hurst wheel, ready for mold rubber to be poured over them:

 

The above mold ring is used for various different height items, so it's a bit too tall for even the tallest item inside of it in the image above, but you can see how the parts can be efficiently placed to maximize space and minimize the amount of mold rubber used. Trail and error will determine what works best for you, but this seems similar to what you have planned.

Here's a cured (slightly dusty) mold similar to what you'd get after filing the above mold with rubber and allowing it to cure:

 

One final tip: ensure the are you rest your mold(s) upon while they are curing is level in all directions. That will ensure the cured mold is a consistent thickness and the parts which come from it are level and even, too.

[Nells250]

Hmmmmm.......

Maybe I should just pay Casey to do it for me!  ?