Resin Addict Forum

I made an unfortunate mistake while calculating the amount. I have a 5% mixture RTV (Silastic 3481) and I made a mistake, I have used in the mix 1 ml less of the catalyst while i needed to use 3 mls...

As a result, while the mold should be ready in 24h, now 48h have passed and it has not completely cured. It is somewhat fluid.
What should I do? Wait for more, till it finally gets its final mechanical attributes and check if it still fluid then? Or remove it, spill 1 more ml of the catalyst, mix it again and then try to reuse it?
I really don't have any idea...

I once had the same thing happen and I left it, it took about 6 months for the rubber to set.

I have also poured the second half od a two part mould while forgetting to add any catalyst at all! In this case the only thing to do was pour it out and clean the mess up with white spirit. Either way your in a spot its quicker to clean the mess up and start again. Always best to use too much catalyst than too little in my experience.

I tried to remove the rubber in another container and mix it there with the catalyst but it does not move much. It could not be dropped, just moves some cm in the centre. I think it is gonna dry after all in some days. Either way there is nothing I can do..

It happens to the best of us sometimes - just cut your losses and move on

Yeah, it sounds like it is too far gone.... probably cured by now.... Info I got was if it was still in that liquid where you can pour it, I would add the extra catalyst, remix and repour. If it is too far gelled you can spray more catalyst on the surface of the mold. It should proliferate through andeventually cure the mold. Some humidity would help - not direct water but water vapor in the air like from a humidifier.