Hopefully it is OK to ask this here, this was the first forum I found that it might be appropriate to ask this here.
Trying to replicate a hard to find and possibly no longer in production cast rubber part.
The original material would have been most likely been clear, as the product has been avaiable in a myriad of colors over the years and my suspicion is that they would have used the same material for all.
The product is b/w 25 and 30 durometer, and will absorb water and get harder when it does (this is not a desired feature, just thought it might help ID). The product I'm working from has been colored solid black, which at one point I was told was "carbon black". The product is not super UV resistant and breaks down over time.
The product also has a plastic backer plate that was also pour cast and is permanently attached to the rubber.
Sorry if I'm being too vague, this is far from my wheelhouse.
Does the portion your trying to replicate melt? If it won't melt then it is most likely a cross-linked rubber. If it does melt then it's probably a TPE (Thermoplastic Elastomer). Fortunately, there are a ton of TPEs out there with a variety of chemical and physical properties. My advice would be to find one that fits your application needs rather then trying to replicate an unknown polymer. Your only other option is to send the material to a lab and have it analyzed. A simple FTIR can give you a basic chemical analysis.
Post by carol - Alumilite Corp on Oct 9, 2018 7:59:39 GMT -5
Robert's correct if you want it sent to be tested you could find out through the analysis what material you have and probably if it is still available.
We have a transparent (platinum cure) silicone rubber (Trans40) with a 40 durometer that can be dyed. We have a Flexible Urethane Rubber with a 30 and 40 durometer that can also be dyed black. These two products are not UV resistant either but with the dye they do have a tendency to hold the color longer than in their natural state of the caramel/honey color of the FLEX. These materials do not take on water and the durometer/hardness should not vary.
Our rigid resin AlumiRes RC3 is used for hand holds and the Flexible Urethane is attached to it for the wall attachment on the hold to rock wall. I don't know if any of this is of help or if you can use this information, but I though perhaps you could look at the Technical Data Sheet listed next to each of these products and see if it can be substituted for the original material ... if you are unable to find it.