How many folks here are mold makers for simple plastics and stuff? I made my first set a while back but it seems like there are not many folks making basic molds for old plastics these days? Jdee
I make molds for lenses, knobs, shifter knobs, and other small parts. The wife does a lot of similar stuff only with jewelry. This is just a sideline for me but it is something that I could really get into if there was a market for it.
I just bought this dvd on ebay 10 bucks, and it is very informative from simple to industrial;Making Silicone Rubber Molds & Casting Resin Parts
I just bought this dvd on ebay 10 bucks, and it is very informative from simple to industrial;Making Silicone Rubber Molds & Casting Resin Parts
I've been making molds for over forty years. First there was fiberglass, then I moved into thermal plastics making medical products. Rubber molds and components where next. Then silicone molds pouring plastic parts. You can make almost anything if you learn these different processes. The reason you may not see many on this site making old reproduction parts in plastic is because most of the guys are metal knocking guys. Plastics, and mold making is another median used in some forms of aircraft and others relating to various crafts. Many of us are what's called well rounded and have been involved in multiple disaplines. Not that the metal knockers aren't well rounded. Many are so talanted they scare some of us. Some of the work displayed on this site is spectacular. The time, energy, and cost to make molds and plastic parts sometimes doesn't make it worth while. If you need help, or have questions about different processes relating to molds, and plastics I'm only an email away. If you would like to see some of the different items that I've built over the years. Check out my picture albums on my profile. There is no limit to what can be made in plastic. The limits of your imagination would be the determining factor.
Been making molds since 1980.Never ran across the term "Metal Nockers".Been building lots of short run prototype molds latley.Its pretty easy to get into the 5 to 10 grand range in price even the most simple products.That there limits what most people would get into to reproduce parts.
I was sitting in the dentist chair, and this cuty whipped up some rubber mold for my teeth. It was a powder that she added water to, and took just a minute to set. I asked the doc to get me some and ended up with 2 quart containers of the stuff for about $10.oo a piece. It worked pretty good, but starts to shrink, and dry up with time. I use it for one time only castings. a WHOLE lot cheeper than the Hobby Shop stuff.
Jdee: What are you trying to mold? It is possible to make very cheap molds and cast replacement parts for just about anything small pretty inexpensively.<?xml:namespace prefix = o ns = "urn:schemas-microsoft-comfficeffice" /><o></o>
I was using one of the Mold resins for that nasty clear casting resin like in the video. I guess some call it death in a can. Bad stuff I wont be making another set. If I do send flowers and and some beer! LOL Jdee
Metal knockers is a term for guys that shape metal. I was one over fifty years ago before I attended General Motors Institute and learned how to sculpture car body's in clay. It's not a term used in the composite, or plastics industry. Sorry, my mistake.
Your absolutely correct. Platinum cure Silicone will last longer than other materials. It is more expensive, but if a guy intends on keeping his molds for years. It's the only way to go. I built molds for the Ford Flathead engine in 1988. It's a full size plastic model of the 59AB with all the trick stuff. Finned heads, four 2 intake with the 97 carbs. I sold around 125 units over the years, and built around 400 heads for guys that made clocks out of them. The platinum molds are as good today as when I built them over twenty years ago. The inexpensive urethane molds only where good for around five years. A good supplier of these products is Smooth Cast out of Eaton Pennsylvania. These are a few of the display engines that I have built out of plastic, and fiberglass.
While trying investment casting , I needed to mold parts to make them out of bee wax . I tried silicon , the basic silicon we use around bath , mixed with 2 drops of glycerin oil and a few acrylic paint . The glycerin avoid the silicon to stick to the parts . Silicon cures with water . So you could just use water in the mix . Acrylic paint is water based , so when you mix , you see a color when it s homogen . With water it s more difficult . And the cherry is you have a mold pink , red , yellow ... It will cure in about 30 or 45 minutes , and after several coats you have a really strong mold . Silicon can support quite temp , so maybe pouring pot metal directly should work . Not as precise as dentist thing ( this is alginate , made from algua ), but for a hobbyist with no money it works perfectly . I found this trick on a taxidermist forum ..... Here s an example : The dark grey part is made of plaster of Paris , with Krylon paint on it . The Krylon paint avoid humidity in the plaster with it s in the wet sand , cost peanuts , doesn t leak and dry in 10 minutes ... The pink is the mold I made to use bee wax . I tried to cast with plaster FGR 95 , it didn t work , so I did it with the basic way sand / clay . So the alu part part is the result . For the curious , I m building a wood + alu shifter ( acajou ) for a Olds 79 , an OT car The picture is quite uggly ( this is the best I could have ) , but silicon gives a decent result for a really low cost .
Another plastics molder here. I use products from http://www.polytek.com and smooth on and like others have said if you want the molds to last you have to use Platinum cured silicone. I started making parts about 15 years ago when I could not find any replacement parts for my Junior car available. I also have 3 vacuum formers the largest being 27"X27" that I use for making replacement lenses for powered promotional cars. For anyone that wants to make cast metal parts they can use the silicone rubber molds to make the wax masters used in lost wax casting. or shell casting. there are a lot of good informative videos on youtube so you do not need to buy the DVDs on Ebay. The silicone rubber does an excellent job with detail and has even picked up a fingerprint I left on a part I was molding so that fingerprint is faithfully reproduced in every part that comes out of the mold. The most I have ever spent on molding materials was $300 for one large mold and I had to recreate the mold master from scratch since the only available original was broken and warped. The process is more labor intensive and not effective for high production but it allows you to make parts that are otherwise not available. Some of my bumper guard molds I have only made one part out of but I will have it available if someone ever needs another one. http://www.jrcentral.com/resources.html this page shows most of the parts I make
Metal casting is quite off topic here , since it s plastic casting . The pb with investment is the ceramic is hard to do , or overprized . In Canada .
The Jalopy Journal
