Silicone cure-prompts?

[Andyroo]

Folks,
Is there a way and/or to hasten the cure of silicone?
It's been three days and it's hard in thicker spots & where it's doing it's work, but still tacky erring to mushy around the edges.

back-story: I removed the nasty, cracked plastic edging from a couple of hand-me-downs (55 &15gal) and set a glass top-brace; likely/largely redundant yes, but I'm paranoid. Now I'm hanging around waiting to do the final razor-blade tidy-up*. Can I spritz with water, ethanol or acetone or vinegar or a hair-dryer to firm it up & keep it from sticking/smearing the finish?

Mild rush as I've made the classical nitwit mistake of buying the fish before finishing the tank... now living in a Tupperware. I'd just add elsewhere but for the seasonal Ich risk (clown loaches, eels & knives).

 

[tlindsey]

Folks,
Is there a way and/or to hasten the cure of silicone?
It's been three days and it's hard in thicker spots & where it's doing it's work, but still tacky erring to mushy around the edges.

back-story: I removed the nasty, cracked plastic edging from a couple of hand-me-downs (55 &15gal) and set a glass top-brace; likely/largely redundant yes, but I'm paranoid. Now I'm hanging around waiting to do the final razor-blade tidy-up*. Can I spritz with water, ethanol or acetone or vinegar or a hair-dryer to firm it up & keep it from sticking/smearing the finish?

Mild rush as I've made the classical nitwit mistake of buying the fish before finishing the tank... now living in a Tupperware. I'd just add elsewhere but for the seasonal Ich risk (clown loaches, eels & knives).

Normally if that vinegar smell is gone then it should be cured but depends on how dry or humid the area.

 

[Andyroo]

No vinegar smell anymore, still somewhat tacky with mushiness around edges.
Will a spritz of vinegar rekindle curing that tiny last bit? Sooooo close...

The tube's been in the fridge for a couple of weeks but still well within date - I wonder if it's a bad batch? Headache as the clear has been rare in the shops, at least in the smaller formats.

No lid for either tank even in the works yet, so won't be filling more than 2/3ds for a while. Considering this low-strain time, if there's not a rekindle-cure option i may just wipe away the excess & get started.

 

[Rocksor]

Read the MSDS or instructions for that tube of silicone. I remember reading a MSDS sheet that actually said curing time was quicker in a more humid environment for a particular brand of silicone.

 

[deeda]

Room temperature, humidity level and thickness of the silicone beads are the usual factors in how quick the product sets up AND cures. Check that products directions as noted by Rocksor .

I've never heard of keeping a partially used tube in the refrigerator.

How did the product dispense when you were using it? If it took a great deal of effort or came out in clumps or didn't flow as normal as a new tube, that may be part of the problem and may take longer to cure or may never cure properly.

 

[Rocksor]

Yeah if the first several inches of silicone may be too hard already. Need to get to the more free flowing portion in the tube.

 

[kendragon]

Storing RTV, adhesive and epoxy in the fridge are common practice in industry. There's even a few that is stored in the freezer which require thawing when used.
Does your silicone suggest storing under a certain temp?

When sealant don't cure it is a sign of improper mixing. Some are two parts which requires a catalyst to activate the curing. Most home use sealants are one part and cures when exposed to air. Moisture/humidity helps prevent the surface from skinning over and sealing the inside which prevents even curing. For accelerated cure on some aircraft parts, it is cured for 2 hours ambient to allow for it to kick off followed by 4 hours oven with water in the chamber.
Sealants have a work life time meaning once chemical reaction has started you have only so much time to spread it. Perhaps your edges were worked beyond this time. Did you apply it right out of the refrig? Or did you let it warm up to room temp?

There are also different definitions of cure. Many times cure means it is okay to move without jeopardizing the bond or full cure which means full strength. This can be measured with a shore hardness test using a durometer gauge.

Tank builders normally tape edges. Once the fillet seal is applied, the tape is removed. No tacky edges for sure.