Aquarium silicone sealant comparisons

[Gaspergu]

I resealed a 30 gallon Hex, a 55 gallon rectangle, a 55 gallon sump, and a 180 gallon tank. They were 10 oz caulking gun size.

About the GE that used to say aquarium safe if it says 100% silicone it's safe. silicone is silicone. The problem GE was having is that they were taking on liability. If the product were to fail or if someone put it in the wrong way. A lot of people were not cleaning the glass properly with alcohol and scraping it all off before they tried to reseal. By saying it was aquarium safe they just opened themselves to lawsuits. But like I said silicone is silicone it all depends on the stiffness how much it shrinks and the adhesion properties of it how strong it is to hold glass together.

 

[Gaspergu]

DOW 999A ACETIC ACID CURE

LIMITATIONS
Dow Corning 999-A Silicone
Building & Glazing Sealant is not
recommended for use in applications
involving:
• Structural silicone glazing or joints
where physical abuse or abrasion is
likely to be encountered
• Prolonged water immersion or
adhesion to porous surfaces, such
as masonry
• Building materials that might
bleed oils, plasticizers or solvents –
materials such as impregnated
wood, oil-based caulks, green or
partially vulcanized rubber gaskets
or tapes
• Totally confined spaces, because
the sealant requires atmospheric
moisture for cure
• Surfaces sensitive to corrosion by
acetic acid vapors (a byproduct of
sealant cure)
• Surfaces that will be painted (paint
will not stretch with the extensions
of the sealant and may crack and
peel); complete all painting prior
to using sealant


*******************************
DOW 832 PURE SILICONE RTV NEUTRAL CURE

Features
• 100 percent silicone RTV rubber
• Superior unprimed adhesion to a
wide variety of surfaces, including
glass, metal, masonry, concrete,
most rubber and plastics, including
ABS, PVC and polycarbonate
• Low odor
• Neutral (alcohol) cure

How To Use
Apply to clean, dry, frost-free surfaces.
Typically, no primer is necessary; however,
for best adhesion to concrete, use a
primer such as Dow Corning ® 1205 Primer.
Dow Corning 832 Multi-Surface Adhesive
Sealant will dry to the touch in 20 minutes.
Limitations
• Not intended for food-contact
applications
• Requires atmospheric moisture to cure
• Not for use in submerged structural
or adhesive applications
• Not designed for high-movement
joints
• Not for application to oily or dirty
surfaces
• Most paints will not adhere to sealant

Have you just said it quote: 8226; Requires atmospheric moisture to cure
• Not for use in submerged structural
or adhesive applications. That's exactly what it's doing in an aquarium it's being used as a structural adhesive and it is fully submerged. Same problem GE has with their old school stuff. 100% silicone is 100% silicone it's the additives in it that makes it bad. They leach into the water. You know the fish in the ocean you can't eat because of Mercury content in the fish. But the fish don't die. But what does that do to the babies when you breed them? Just like all the dogs with hip dysplasia, bad breeding chemicals inside them, bad breeding just different reason.

 

[Cecropia]

How about ASI sealant? has a 4 1/2* rating on amazon

ASI Black 11oz tubes are usually strong adhesion, and quick, but last few months has had issues not curing hard. GE1 is consistent, but weak adhesion, and slow; very smoothable tho.

Interestingly, the Biosphere reef system was run by Adey who invented the first algae scrubber in 1980.

I know these were posted years ago, but I just redid a 90 and 180 along with overflows and new trim. The curing thing appears to have been solved. It recommends 7 days til full cure, but the adhesion comes QUICKLY, like 15 mins so work fast with the stuff.

 

[hiplecoman]

How about a RTV 4500 by Silco Inc.?
Acetoxy cure
High performance
UV stable
excellent Weatherability
Non Yellowing
VOC Compliant
Non Flammable
Water Proof
Excellent adhesion
25% movement capability
Non-Shrinking
Temp Range -62 F to 350 F Continuous
Meets specs:
ASTM C920 TYPE S NS
Class 25
TT-S--00230C
TT-S-01543A
MIL-A-46106A
FDA 21 CFR 177 2600
USDA Approved

 

[Gator]

How about a RTV 4500 by Silco Inc.?
Acetoxy cure
High performance
UV stable
excellent Weatherability
Non Yellowing
VOC Compliant
Non Flammable
Water Proof
Excellent adhesion
25% movement capability
Non-Shrinking
Temp Range -62 F to 350 F Continuous
Meets specs:
ASTM C920 TYPE S NS
Class 25
TT-S--00230C
TT-S-01543A
MIL-A-46106A
FDA 21 CFR 177 2600
USDA Approved

That's almost three times the price of DAP 100% silicone which has a nearly identical SDS.

 

[SantaMonica]

It probably has a ISO9001 listing or similar, like having a UL listing it will cost much more.

 

[Ulu]

Whatever you use, test a small sample first and make sure it cures.

It's the pits to do a big tank and have it still sticky a week or month later.
I had one sample that never cured, but fortunately it was a very small project.
I didn't have to scrape and wash for 8 hours to get the glass clean again.
I just tossed it out.

When I said it never cured, I kept a test sample on cardboard in my shed over 6 mos before I tossed it.
It was dusty on top, but still sticky, and would leave residue on your finger. It was about as liquid as the day I placed it.

 

[Fishlover420]

ge construction is the strongest sealent availble for fish tank use. i work as a n aquarium builder and its what i use.

I’m interested in what you said. I have horribly managed to re seal this 23 gallon but now I’m looking at a 55 gallon job any advice on how to come out with a clean seal and not some mess that’s by luck holds water in all honesty!!!!

 

[fishguy1978]

I’m interested in what you said. I have horribly managed to re seal this 23 gallon but now I’m looking at a 55 gallon job any advice on how to come out with a clean seal and not some mess that’s by luck holds water in all honesty!!!!

Tape your seams. Get a small paint brush and some alcohol in a small dish. Once you have laid all your beads of silicone dip the brush in the alcohol and use it to smooth the beads. This will also allow you to more smoothly feather the edges to the glass and where each seam meets. Acid brushes work really well.

https://www.amazon.com/Solder-Plumbing-Handle-Inexpensive-Brushes/dp/B07KKH5N8K/ref=asc_df_B07KKH5N8K?tag=bngsmtphsnus-20&linkCode=df0&hvadid=79852149837930&hvnetw=s&hvqmt=e&hvbmt=be&hvdev=m&hvlocint=&hvlocphy=&hvtargid=pla-4583451676289788&psc=1

 

[jjohnwm]

Tape your seams. Get a small paint brush and some alcohol in a small dish. Once you have laid all your beads of silicone dip the brush in the alcohol and use it to smooth the beads. This will also allow you to more smoothly feather the edges to the glass and where each seam meets. Acid brushes work really well.

https://www.amazon.com/Solder-Plumbing-Handle-Inexpensive-Brushes/dp/B07KKH5N8K/ref=asc_df_B07KKH5N8K?tag=bngsmtphsnus-20&linkCode=df0&hvadid=79852149837930&hvnetw=s&hvqmt=e&hvbmt=be&hvdev=m&hvlocint=&hvlocphy=&hvtargid=pla-4583451676289788&psc=1

I just watched a friend do this last year, first time I have seen it done this way. It works, for sure; takes a lot more time than I have when putting a tank together, but gives nice clean results as long as the tape is removed immediately.

With practice, you learn how to lay down the correct size of sealing bead...or, better yet, eventually how to apply the correct amount when laying down the original structural bead to have the proper amount squeeze out when placing the glass. Then just stick your finger into your mouth to moisten it, and quickly run it along all the interior seams to spread them and "concave" them. The job is finished before the guy with the tape has even managed to find the beginning of the roll and started to pick it off with his fingernails...

Tip: make sure you lick your finger before you get any silicone on it. Don't ask...