I've made quite a number of molds using brushed on rubber and RTV silicone for bergens/backpacks to wooden barrels. I poured my resin solution on them with the understanding that the more catalyst/hardener you put the faster it dries. And yes it does harden and dry quickly. But no matter how long I leave it to dry be it 24 hrs (actually is harden quicker than that) or 72 hrs. Once I remove it from the mold, the surface seems to be damp or sticky. I leave it for a couple of more days and some them will dry out completey and some of them will still be sticky. I dont think that I didn't mix it well enough.

Anybody here got this problem?


Or maybe God doesn't want me to re-cast.

Are you using a 1/1 mix ratio resin? If you are, you should not put more of one part than the other in while mixing. While mixing a 10/1 silicone, it is always a good idea to add a drop or two extra of the catalyst, when dealing with resin, it is a different story. Yes, I have had the problem you describe when I measured improperly. Next mix, try mixing it to spec and see what happens. Most resins you can de-mold in a half hour or so. I can't understand you having to wait so long to pull the pieces from the mold??

Oh yeah, use some rubbing alcohol to clean out your molds before pouring the next batch of resin else you will end up with the same sticky mess on the next pieces.

I have to agree - you should mix in exact proportions or exactally to the instructions.

I had a 'sticky' situation a couple of times and realized I had not mixed exact proportions of materials.

I'm using Cast 'n' Craft resin solution which requires a catalyst to harden. The catalyst comes in a bottle the size of an eye drop. It doesn't say how many drops per ml I should mix.

Does it give a mix ratio?

Hello RD!

Please check this link:
Catalyst Chart

Hope this help!

Skipper

It may be the ago of your resin/hardener. I have had this happen when they get old. Also gives inconsistent results such as more yellow/brown color, more bubble and incomplete molds as well.

¡Gracias amigo! I think it will help.

Although it still says in the bottom:

*3-dimensional molds will vary greatly in amount of catalyst required depending on total volume being poured and depth of pour. Refer to mold manufacturer's instructions for proper catalyzing.

I have found that if you try casting parts before the mold has fully cured your going to get sticky parts . I let my molds cure for a couple days after removing the master . Bad mix ratio of resin can be a problem at any time . Also , resin past it's shelf life may not work well .
http://put.url.here http://community.webshots.com/album/30270289huIewaTFMF
Joe

Did you ever figure out what your problem was ????