Got the 900 high-tensile stuff to make wheels. After ordering it I found out that it cannot be mixed with pigments and comes out looking whitish.
Any ideas on how I can color it black or rust color? If I just paint it, the paint will likely come off on the rails.
Any tips appreciated.
Look at this document from Micro Mark. I have never done this as I paint my castings afterward.
http://www.micromark.com/html_pages/instructions/82708mrrresinart.pdf
rich
What have you used for pigments? Have you tried Micromark’s dyes? And why are you casting wheels in the first place? Have you considered casting them with low-temp metal (also available from Micromart)?
thanks, all. from that pdf it appears that one can coat the mold with paint. They mention lacquer. Has anyone tried latex or other types of paints to coat the mold. I’m guessing oil paints are out.
I did speak with a technical advisor at MM and had considered metals but for wheels they’re a bit brittle unless you wish to machine steel to turn some brass or other metals. I’m not set up to do that. IOW $$$
For painting silicone molds prior to casting, you can certainly use oil or solvent based paints, (they won’t affect the silicone), but it’ll still wear off from the treads.
You didn’t say why you’re casting your own wheels, I would think there’s a wide enough varity of wheel types out there to avoid casting them yourself. The toughest part is going to be getting an axle dead-center with no wobble, unless you’ve got a lathe and then you may as well turn them from brass or ns stock.
BTW micromart carries another product, I can’t remember what it’s called, something like Liquid Steel or something, it comes in a tube and i believe you can use it to cast with and it’s silver in color.
Jay,
Reason didn’t say is that when I mention 7/8" scale people’s eyes glaze over and I don’t get many replies. Wheels in this gauge are about $9 an axle. I just don’t have that kind of money.
I might experiment with JB Weld in the mold too.
I’ve never done anything in that particular scale, but modeling is modeling, right?
Have you thought of using bands of aluminum tubing for tire treads and embedding them in the molds before pouring the resin? You may have to adjust the wheel size to match the nearest tube diameter. Just a thought.
FYI: J B Weld also comes in large 5 oz tubes. The stuff does get pretty hard and it is grey, but the CR-900 is harder and tougher and you already have it.
You might also check: http://www.alumilite.com/checkout/index.php?cPath=24&osCsid=9e6e98cedde8f34597768b5340e62a25
If your thinking about trying JB Weld, there are some industrial epoxies like that out there. A company called Mavadon makes a 2 part epoxy that’s really strong and would work well for pouring into molds. You can buy it in quarts and gallons. It pours like thin batter so it’s good for molds. It’s aluminium impregnated so it’s strong and conducts electricity to some extent. (like JB Weld) Sorry, Don’t have a link.
The best way to make sure that the wheels don’t wobble would be to cast them solid, then chuck the castings in a lathe and drill them out, assuming you have access to one.
Short of that, you can pour the rubber around the wheel with a piece of rod stock through the axle hole, long enough that it will embed in both sides of the mold. When casting, just put that same length of rod back into the mold and it will create an axle hole in the casting.
thanks for the innovative ideas; I’ll try them; I’ve converted my trains to R/C so conductivity isn’t an issue
Mix tempera powder or aluminum powder into the resin (actually you mix it with part A or B then mix the other half of the resin with the filled half.
It does make the resin thicker.
Dave H.