Hi all,
Just looking for some tips and advice for resin casting for parts. I have never worked with resin before. I am planning to make masters of my models by 3D printing them, then making moulds and casting with resin. Any tips would be appreciated.
Thanks,
Anthony.
The URL below is from a google search on the phrase “resin casting model railroad” that turned up several useful links. And there’s a whole lot more if you’re willing to watch videos of non-train-related castings. Micro Mark has a complete starter kit for doing resin casting. But those same materials can probably be had for much less at another source.
There is a Yahoo group devoted to resin casting, but am not a member. Heard it’s useful.
Casting materials are usually available at your local art supply store (Michaels, HL, etc) as jewelry makers, among others, use it.
I’m very interested in 3D printing and resin casting as I wind up needing detail parts that are not available from neither Details West, Details Associates or other vendors.
I found this interesting YouTube clip.
https://www.youtube.com/watch?v=_Kn3LBiFBZo
3D printing looks promising but is currently expensive.
But before jumping into resin casting, I’m definitely going to continue reading about it and asking for feedback from other modelers that perform it before trying it. [8D]
I recommend that you start out with the Mircro Mark starter kit.
http://www.micromark.com/complete-resin-casting-starter-set,8174.html
I have seen several videos on resin casting but this one is by far the best
http://www.micromark.com/easy-casting-techniques-dvd,9265.html
It is well worth the investment. It is very important to apply a slight coat of talcum powder on the mold before casting. This will prevent the air bubbles on the surface of your final product.
Once you the hang of making molds and castings then you can find the same, or similiar, materials at a lower price as suggested by csx_road_slug.
I have been doing resin casting for a number of years. Here is a link to my process and materials.
http://waynes-trains.com/site/NeatStuff/ResinCasting/ResinCasting.html
Enjoy.
Heres a few tips Ive learned, or, that I garnered from some of the mainstream companys like Accurail, Bowser and Athearn etc…
Dollar store glass panes taken from their $1 picture frames are great assets to have. They make clear and perfectly flat surfaces when used as part of the mold. Acryllic also works and is workable into 3d aspects where glass cannot.
Dollar store tooth brushes make great parts cleaners. Also very handy to clean your molds, and originals with before each use.
At one point atleast in your part making, you will need a perfectly flat surface for the molds to cure on. For a multipiece mold, some say this is not needed. If you are worried about air bubbles and even dispersment of resin, get a flat surface!
Next time your out at your local feed bag, grab some extra togo ‘plastic trays and lids’ that seal. Not styrofoam! Use these to store your molds in. Keep in a cool, no sunlight, place. Air tight is the key!
If you are not casting at least once a week or more, then you need to physically handle your resins to keep them mixed, and from setting up. Kinda like inkjet printer ink after 6 months… dried up. While resins arent as bad as ink, they do go bad just sitting.
Next time at McDonalds, grab handfuls of their togo soufle cups with lids. These are clear and make great small cups to mix resin in. And are free! These also can be used as molds for small parts. Many uses here for this item. And they toss easily. You’ll find resin clean up to be a royal pain in the patute.
Metal lids from cookie cans (or similar) make great molds too! Especially when paired with glass panes. Think ‘smooth, and flat surfaces’ !
In conjuction with the McDee cups, you will need some sort of weight scale. Your mix of resins needs to be as close to 1:1 as you can get. If your off (doing by eye), your plastic will either be brittle, or rubbery. And therefore - unusable. Hand scales wont work, has
There are three parts to resin casting, one is making the master, the second is making the mold and the third is making the casting itself. Each step has its own little tricks.
The master is the most important part, since resin castings EXACTLY reproduce the master. If the master is badly done, every casting will be an exact duplicate of the badly done master. The master should be created with idea of how it will be cast in mind. Will the casting be flat, solid, hollow, have undercuts, etc. Every minute you spend planning how the part will be molded and assembled will pay huge dividends later.
There are 3 general types of molds, flat molds, multiple piece molds and “squish” molds. A lot of model RR parts are made in flat molds. The part has a flat back that you attach to a pane of glass, you build a dam around it and then pour RTV over it. Classic uses, are car sides, building walls, coal piles for hopper cars. A multiple part mold casts a “3D” object. The object is embedded halfway in a material (modeling clay), mone half of the mold is cas, the material is removed and the second half of the mold is cast. There is a two part mold with a void in the middle. Car has to be taken to include a sprue to pour the resin into the mold and vents to let the air out of the mold. Figures, air brake cylinders, detail parts are often made this way. A squich mold is a two part mold to make a hollow casting, such as a boxcar or gondola body. The master is made and attached to a flat surface with the “open side” down. A dam is placed around the master and the female half of the mold is made. The cured mold is turned over, the flat surface is removed and the male half of the mold is pored. The master is removed leaving a voild between the two halves. Its called a squish mold because you pour resin into the female portion the