RTV 103/108 cure time?

[mcoomer]

I used RTV 103 and 108 to install an overflow box and coast to coast in my tank and I'm a bit concerned about how it's curing. The coast to coast overflow has only been in about 12 hours but the box has been in for nearly 36 and there is still some tack to the RTV. It's a pretty thin bead of RTV so I'm not concerned about having too much in the joint. It hasn't been very warm and it's been wet so I maybe it's going to take a bit longer to fully cure. My only concern is that I used acetone and a rag to wipe the glass after I removed excess RTV with a razor blade. I was very careful to avoid touching the sealant but??? I think that if I go home today and it's not fully cured I'm going to rip it all out and do it again with a fresh tube of 103 that I got yesterday.

Any guidance is appreciated.

Thanks,
Mike

[uncleof6]

It takes ten minutes give or take, for the product to skin, however full cure will not occur for up to 7 days, possibly longer, depending on temperature and relative humidity. Full strength will definitely not be reached for at least 7 days to 2 weeks. My suggestion, is find something else to mess with for a couple of weeks. Longer if you can stand it. Mess with it too much, and you WILL be redoing it. Patience.

Jim

[mcoomer]

Patience?!? I'm screwed! Seriously though, will directing warm air into the tank aid in curing? BTW...for reference, this is what I built. the coast to coast overflow is kind of hard to see due to the black on black construction but it's there.

http://img.photobucket.com/albums/v638/mcoomer/Aquarium%20Pics/224.jpg

http://img.photobucket.com/albums/v638/mcoomer/Aquarium%20Pics/231.jpg

http://img.photobucket.com/albums/v638/mcoomer/Aquarium%20Pics/230.jpg

http://img.photobucket.com/albums/v638/mcoomer/Aquarium%20Pics/002-7.jpg

[uncleof6]

Patience?!? I'm screwed! Seriously though, will directing warm air into the tank aid in curing? BTW...for reference, this is what I built. the coast to coast overflow is kind of hard to see due to the black on black construction but it's there.

http://img.photobucket.com/albums/v638/mcoomer/Aquarium%20Pics/224.jpg

http://img.photobucket.com/albums/v638/mcoomer/Aquarium%20Pics/231.jpg

http://img.photobucket.com/albums/v638/mcoomer/Aquarium%20Pics/230.jpg

http://img.photobucket.com/albums/v638/mcoomer/Aquarium%20Pics/002-7.jpg

Warm air yes will help, also AFTER A FEW DAYS, an 1/8" of water in the overflow box to raise the humidity. BUT do not get impatient! I know how hard that is, trust me: I have a power amplifier sitting here, incomplete, with a 9 week lead time for 12 fricking resistors...........your week or so wait time, pales by comparison......

Jim

[mcoomer]

The thing that worries me is that it doesn't seem to have much of a skin. I can touch it and it's tacky enough that it sticks to my finger and leaves a residue on my skin. The tube that I started with I purchased and opened at the end of April. I just pulled the dried RTV out of the end of the tube and used the rest of it to attach the overflow. Does RTV go south once the tube is exposed to air? I'm beginning to wonder if I shouldn't just pull the entire thing off, scrape and clean the glass with acetone and start over with the tube of RTV that I bought on Thursday.

Mike

[mcoomer]

Just checked the Momentive site for this RTV and it's supposed to be tack free after 20 minutes with a full cure time of 7 days. Mine definitely isn't tack free, and it's been more than 48 hours for the overflow box.

Mike

[Jsin]

I just resealed a tank and made a sump with RTV 108 today and it was setting up within 10 minutes, and tack free within 20-30min. I would say you may have a problem if it has been 48hrs. I am in FL and it was in the 90s today but 48hrs seems like a long time for it to still be tacky.

[tibob32]

what's the best before date on the tube?

[mcoomer]

I didn't see a "best before" date on the tube, just a batch number. I pulled the overflow out last night and went to pick up some more acetone. I'm going to clean everything up, wipe the glass down with acetone a few times, and try again. Some sections were curing nicely while others weren't so something obviously wasn't right. I'm going to mask the edges of the overflow with painters tape this time instead of using a razor blade and acetone to cleanup. Maybe some of the acetone bled over to the RTV while I was cleaning up last time. I dunno, but if I don't use acetone for cleanup this time I can rule that out.

I'll let you know how it turns out this time.

Mike

[JTL]

You need to call the phone number listed and give them the batch number. They will tell you the expiration date.

You will need to restore the surface of the glass to a virgin condition. I had to use a lot of steel wool and razor blades. Even the very slightest of film will cause a bad seal.

[mcoomer]

Good news! The new RTV that I applied is curing much better than my first attempt. There is a good skin over the entire length of the seam and I don't see any of the separation from the glass that I was seeing before. Much mo betta!

Thanks for the advice.

Mike