re-silicon over old silicon

[rostato]

will silicon adhrere to old silicon? Reason I ask is because I have a not so new tank that has some areas that I feel should be re-siliconed before I set up the tank. It holds water perfectly fine, but the 2 front corners of the tank have alot of the silicon scipped away, and have some algae stains on them.

I am just affraid of setting it up and a few months later having a leak. SO can I go over the old stuff, or do I need to rip out all the old and redo it all?

The rest of the tanks silicon looks brand new:unsure:

 

[seedless reefer]

I am in the process of building my new sump.

One corner had very questionable silicone so I cut out about 3" of the silicone and then ran a fat bead from top to bottom and I don't feel uncomfortable with it.

I guess I will know for sure when I leak test it.

The correct way to do it would be to cut it all out, clean it up and run a new bead.

 

[raisingtwo2006]

If it were me, I'd strip those two sides.. not neccessarily the whole thing.. But it's my understanding that new silicon will NOT stick to the old stuff..

 

[drnecropolis]

dawgdude;285484 wrote: I agree with Kim. I would just run a razor blade down each side of the two sides and pull out as much as I couldnt. If you are going to put silicone on silicone then make sure its very very clean and there are no oils or dirt on the silicone when you apply it.

+1

I myself wouldnt feel comfortable glopping new silly cone over the old..

 

[skriz]

As others have said, you have to remove the old silicone before applying the new silicone.

 

[dannybradley]

Use rubbing alcohol to clean the surface before applying the new silicone.

 

[rostato]

Ok, Guess I am going to cut it out. Wish me luck!

 

[raisingtwo2006]

Good luck! You'll be fine- we entirely stripped a 125 and lived A few razor cuts on the fingers later however..

 

[rostato]

All done. It was pretty easy. Hopefully I will have no leaks in two days when I fill it with water...

I only did the front two corners because the rest of it looked fine. Hopefully it holds up!!!!:thumbs:

 

[rostato]

It holds water! Just filled it up. only a few more days untill I make the move! I very excite!

 

[raisingtwo2006]

Awesome! Congrats!

 

[rostato]

Thanks I think Iam going to start a build thread in a few...