Help - Silicone not curing

[aquaman49504]

I am making a sump with compartments for skimmer, baffles, prop, and fuge. I have made it out of plywood and lined with acrylic. I have leak tested the sump itself and all is ok. After I used solvent to glue the partitions in, I went over the seams with silicone to help fill in any voids due to warpage, as I have done other times. I used two tubes of silcone. The silicone from the second tube has not cured at all after 48 hours. I am not sure why, but I need to move on. Has anyone had this experience or knowledge of what I need to do. Obviously I need to remove the uncured silicone (which will be a messy ordeal) but I am unsure how to remove the slick residue or will the new silicone bond with the residue in place.

 

[Abysswater]

How old is it?? And does it have a more sour smell to it? it could be bad.

 

[aquaman49504]

It is definatly bad, it was expired by a year and a half. I was not aware that it has an expiration date. Anyway, I am looking for a remedy for my problem, how to best get adhesion of new silicone. Do I need to clean up the existing silicone and prepare the surface in some way or will the new silicone adhere to the residue of the bad silicone?

 

[areze]

should try to clean it.

it is a pain in the ***, but unfortunatly quite common. I get a bad tube about 20% of the time. gotten good about spotting it, old tubes are ussually lumpy IME.

clean it off, use a little rubbing alchohol maybe. since your just looking to fill holes, whatever left should cure eventually, wouldnt want it for holding a tank together, but just as a sealant, itll hold fine.

 

[coralguy1]

I go through a LOT of silicone in my job. I agree with "araze". Clean out the worst of it with paper towels and rubbing alcohol. Don't knock yourself out over it as you are not glueing a tank together. Put new silicone over the top of it.

 

[windsor-aquatic]

Agree with above advice. I would advise leaving for a couple of days for the silicone to cure.

 

[aquaman49504]

Thanks for the good advice. I will pickup some denatured alcohol and clean it up tonight.