I assume it's silicone rubber. I have used something similar (EasyMold). The stuff makes great
Some things I know...
• If it will be in contact with food (after curing, of course) make certain it is "food grade".
• Be weary of the cure time. It can be difficult to get it in the right shape within one minute. After about half the cure time it will get significantly rigid. A little planning goes a long way.
...is very difficult to get right. It naturally tends to pull away from other materials. It is not glue or even glue-like. Make certain what it is supposed to "stick" to is very clean.
• It conducts heat fairly well (makes a good sealer for temperature sensors).
• Make certain it is well mixed.
• Make certain it is stable over about double the cure time (don't move it around).
• While curing, it will sag because of gravity.
• If you buy in "bulk", do not accidentally contaminate one with the other or you will end up with a hockey puck.
This is a bit creepy: "This brightly coloured smelly
silicone blob..." None of the silicone rubber I've worked with is "smelly".
I think I paid about $20 per ounce the last time I bought some (came in two equally sized containers).