Defective smooth-on silicon

Anakin Starkiller

Master Member
So a bought three boxes of silicon OOMO-25 from smooth-on a while back and when I opened them up yesterday all of the part A material had gone bad. I contacted smooth-on and they told me they only warentee their products for 6 months.:angry


Well-Known Member
Just been fiberglassing, and I hate fiberglassing, it never turns out the way I like it to.

Oh yeah,,,,, Defective smooth-on silicon, what took you so long to use it?.


Sr Member
Sorry man, but you can't really blame the manufacturer if you didn't follow the instructions. It's not like they keep the shelf lifes a secret or anything.


New Member
yeah smooth on had alot of trouble with people getting free sample kits at tradeshows then taking them home and putting them up someplace and then contacting smooth on whenever later after they finally decided to use it complaining about how they wanted a new sample because it had dried Ship me new free product cause I forgot to use the first free one you gave


New Member
Just the luck of the draw unfortunately, when I worked for Home Depot (gold mine for prop building components sometimes) we had contractors and construction workers coming back to replace silicone, liquid nails, etc. because it had gone bad and there wasn't a date on things. Afterwards, we got into the habit of marking the dates of when we received them....
Just check dates before you buy/receive anything


Master Member
Usually in the data-sheet that´s provided with the material.

I had the same thing happen to me as well.
One -the blue- part of the OOMO30 was just a gooey mess, while the pink was still pourable. I had luck on using some thinner to make at least some of it work, but the rest had to be thrown away :unsure
Other -more expensive- silicone is useable after months, even years if you´re lucky.


Rhett J Martin

Sr Member
Did you mix the seperate part back up? It tends to seperate, but can be remixed. I'd warm it up a bit in some warm/hot water . . . but I bet it's fine.

Sorry to ask, but I've been there.


Sr Member
Always happens to me with mold rubber - I get a giant bucket, then go back to use it for a third of fourth project, and one of the parts is rock solid.


New Member
I willl say on one last note as well that it appears to be a platnium silicone, there are two types of silicone platniumn and tin cure silicones. platinum is a finer quality less shrinkage(which is minimal even in tin cures)but contains a chemical solution of platinum which is expensive. Its expensive which means its picky(as all pricey women are) Platinumn silicone's and their cataylsts are picky, im buddies with one of their reps. First off platinum grade silicones will have curing issues if any of the following occures
-exceding shelf life(which is short and temperature sensitive)
-contact with sulfer containing products
-contact with aloe containing products
-in the same room as anything with orange citrus oils( dont eat a orange while molding it will find it I know....:(
-sealing a sculpt in clear coat wont matter if sulfer containing products are present

And on a last note i will defend smooth on further to say that there is no way it could be defective product, they make this stuff along with all their products in hugh batches which under go quality assurance. If they messed up you and everyone who ordered oomo-25 woulda had the same problem and a recall would have ben issued. Sorry not trying to pick on you by any means but i literally talked to my sales rep(great guy) about that same issue because people where bad mouthing them because they didnt take the time to learn the chemicals they were working with.


Well-Known Member
... it appears to be a platnium silicone,

Oomo is a Tin (condensation cure) silicone - hence the short shelf life. Platinums remain viable much longer on the shelf (I've pulled from stock 3 years after opening with no problems), but the rest of your info is correct on their temperamental qualities.
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