Bad silicone

[aquaman49504]

I originally posted this in the DIY forum but upon further thinking, decided that this forum may prove more useful.
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.

 

[lafster]

You have to mechanically remove as much of the uncured silicone as you can. This happened to me on some windows. I don't believe there is anything that will really disolve it. I found some info on the GE (I think) website that talked about what to do for silicone that won't cure. It happens when the chemical that causes the caulk to cure leaks out.
Lynn

 

[BeanAnimal]

Most petroleum based solvents will work with silicone. WD-40 may even do the trick. However the same solvents may cause acrylic to craze. 100% mineral spirits will work. You will just have to be careful. Most marine supply houses carry 3m silicone solvent (prep solvent 70). I am not sure if it is safer with acrylic than mineral spirits or not.
http://products3.3m.com/catalog/us/...ospace_3_0/command_AbcPageHandler/output_html

Remove as much as you can by scraping it off. The less you have to disolve the better off you are.

 

[aquaman49504]

Thanks

Thanks

Thank you for the info. I feel better now that I know that it won't be too bad to repair, just messy.

 

[Bowman]

If your working on glass acetone will work well, if your working on acrylic I would go with denatured alcohol just as if you were gluing acrylic. Remember though that silcone will not stick well to acrylic and the joint will fail, just a matter of time. HTH

 

[Randy Holmes-Farley]

I've not heard of this before, but I'd be very careful about exposing the acrylic to any solvents.