I wouldn't call Alumalite crap. It has worked very good for me. It is also easy to get, and relatively inexpensive.
I use legos or something similar to make a mold box. Build up the walls, line it with some clear plastic packing tape and you are good to go.
I'm only quoting what others have said about it. I can't make a valid judgement on it as I've never used it, but I
was going to use this for my models until I read some negative reviews from other members here, and on other forums. This is what started my search for other resin makes from different vendors. One person on the rpf said: "I've used alumicrap - I hate it!" He also said that on Starship modeler. That didn't leave me with a good taste in my mouth at the time since I was unaware of any other vendor that sold resin products!
Do you use the Model-Pro or Model-Pro Slow resin?
I'm using the Model-Pro in clear, which is called Color-Pro. It's the same stuff. I can't get good enough results with it, as it won't fill the tiny recesses of my moulds. I'm going to go with the Fabri-cast 50. This is ultra low viscosity so that I can get better results without wasting product. The moulds I made are very thin, and have tiny pin head sized rivets that won't fill without a lot of cohersing. If you're planning on using something that needs a two part mould, and has little detail to worry about, then use the Model-pro. It kicks (starts to cure) in two minutes. So if you have a few moulds of the same vehicle, use this to make them with. It pours easily enough, and can be sanded, painted, primered, etc. The slow version is only if you need a lot of working time to get the resin into small crevices. All resin starts out clear before curing. It turns white, or creme when it starts kicking so that you can see the chemical reaction. This way you know when it's close to the time when it can be pulled from the mould. (I'm sorry - I didn't intentionally make that rhyme!) It'll cure hard enough that you can remove the part, but until the entire time required for a durable cure it will be soft.
It's best if you want to get the parts out right away to use something that cures within 10 - 15 minutes. You can remove it and make more parts in a shorter amount of time. It's about 4 minutes for a 10 minute pull, and 8 minutes for a 15 minute pull when you can remove the parts and have them hard enough to handle. However, I DO NOT recommend that you remove them before the alloted time required as I've done. This resin will be tacky until it's ready to be removed from the mould. It'll be dry, and hard when ready. I lay the parts on a table once I remove them from the mould to keep them from distorting. You can use tape over windows if you want to make a two part mould. You can also tape off the wheel wells to keep silicone from filling the inside of the body. I'd just fill it until you get most of the mould filled over the vehicle. Once cured, you can remove the formers, or box for the mould, them put the entire mould, and vehicle in a slightly larger box (upside down), then brush the silicone with petroleum jelly (Vaseline) to keep it from embedding your car, or truck. Once the silicone cures, you can remove the body, or master, and cut a vent tube, and a pour spout into the mould halves. This will allow you to fill the mould, and leave a space for air to escape. I take the moulds from the box, and tape them together to keep the resin from leaking out.
Most resin is made from polyurethane. Diisocyanate is the main ingredient in it - be careful when sanding. The stuff I use is purported to not have this in it - I don't know how since it's polyurethane! Either way, it's fairly easy to use once you get the hang of it. It just takes a while to get used to the properties of it, and knowing when you can, and can't remove it, and NEVER wipe your moulds down with anything other than mineral spirits, or dish soap, and warm water!!!! Sometimes you'll have sticky uncured resin stuck to your moulds when you're first learning to mix this stuff. Use THREE cups to mix - NEVER just ONE! This is so that if you pour too much resin into it - side B, or too much hardener - side A, you can pour each one back into the bottle without contaminating it. I've poured a little more of the hardener in, and sometimes resin before to balance out the measurement. But I've wasted more than I wish I had to by doing that way because it kicks to fast for me to pour all my moulds, and I have too much left over that sits in the mixing cup making a white, or clear paper weight.
I use polyethylene cups that my mom gets some cheap Jell-O knock-off in. These work perefectly, and I can remove the hardened resin from them, and use them over and over. I make sure that they're perfectly clean before I reuse them. It'll take a while to get used to casting, but once you get the pattern down, you'll get better and better, and you'll produce better results when you're more relaxed, and comfortable with it. I added some thinner to my resin - I don't recommend that you do this, but I needed more working time than what it's formulated for in this hot weather. I feel like I'm in the desert all the time! It's unbearable, but the only benefit from it is that my moulds don't take as long to solidify as they would if it were a lot colder outside!
If you're worried about resin sticking in your moulds - use petroleum jelly thinned with mineral spirits (white spirits in England) brushed into the moulds sparingly. Let this sit for a few minutes to air out a little so that you don't get wet spots on your resin. I've used it with, and without corn starch to get the resin to flow, but in big parts I've had no trouble making excellent copies! This stuff is 80 cpds (centipoids) meaning surface tension resistance. It's as thick, or thin as everyone else's resin from all the research I've done on Yahoo, and other search engines. I use Yahoo because it's far more comprehensive, and I get better results. There are a lot of resin vendors out there, but most of them use the exact same manufacturer for their resin. From what I learned, Alumalite is made by Dascar plastics - now known as Specialty resin. They bought the industrial portion of Dascars' operation, so now as Specialty resin they only make the modeling resin and nothing else. This is what I've heard from the owner of Specialty resin. They changed their name now that they don't have the heavy plastics division of their company.
Nothing wrong with Alumilite.
You may find a cheaper price or or variety of rubber/resin that is better for your application but Alumilite's quality is as good as you will get anywhere.
You got very good results with that despite it being so small! I've been having trouble getting resin to flow into all the tiny recesses, and details in my moulds, but I'm going to a lower viscosity so that I can get more pulls successfully without wasting a lot of resin. Most companies sell 80 cpds viscosity, even Smooth-on. This makes it more difficult for me to get the results I need without going to a single vendor that specializes in resins only. This is why I use Specialy resin - they have more variety of resins than what I've been able to find anywhere else. Otherwise, this would work for most of the projects that I'd cast in resin.
~ Chris
