Sealant suddenly turned yellow on new tank?

[impur]

No, a couple are ACE. One is DAP. I found this info:

100% silicon
Generic Description; Silicone elastomer
Physical Form; Paste
Color; Colorless
Odor; Acetic acid odor

NFPA Profile; Health 2 Flammability 1 Instability/Reactivity 0

Note; NFPA = National Fire Protection Association

2. OSHA HAZARDOUS COMPONENTS

--------------------------------------------------------------------------------
CAS Number Wt % Component Name
4253-34-3 1.0 - 5.0 Methyltriacetoxysilane
17689-77-9 1.0 - 5.0 Ethyltriacetoxysilane


And for the 100% silicon mildew resistant the contents are:

Methoxypolydimethylsiloxane, Dimethypolysiloxane, Treated fumed silica, Hexamethyldisilazane, Methyltrimethoxysilane. VOC (excluding water and exempt compounds) is less than 50 g/L


I also find on the 100% silicon(not mildew resistant) it claims:

This product is appropriate for incidental food contact in federally inspected meat and poultry plants.

So thats what i went with. I do find the GE 100% silicon with mildew resistant so as far as GE goes, they do not differentiate between the 2 even with added contents. So you are right there.

 

[jeff1733]

Here's what I'm talking about. I used SOMACA clear AquariumSilicon. As i mentioned before GlassCages.com gave it to me, I assume it's what they use. Notice the silicone under the sand is still fairly clear and also above the water line. I let it cure for about a week before adding water. Then waited another week before adding rock. It discolored when the rock went in.

 

[brian3]

The thing that concerns me (and it may be unfounded) is what they say when you call GE Silicone. They say it is not recommended for aquariums. It it was truely exactly the same why would they not just say to use it - more business for them. I think all 100% silicone is not the same and has to do with the way it is processed. Obviously some manufacturers add to their compound even though they still say 100% silicone on the tub. Some manufacturers may want long life, 25 - 50 years. Others may want durability to abrashion while others in the aquarium trade would want strong adhesion under pressure of water. Slight variations to meet the desired specifications. A tub of caulk goes a long way and paying $3-4 more each is worth it for me, maybe not for everyone though. Some may get away with it for years, it is just not worth it for the little savings vs. the chance (even if only slight) of a flood and loss of the tank contents.

 

[chipmaker]

I think what the labels are stating is the silicone used in the "stuff" in the tube is 100% pure, its not a meaning of 100% of the stuff in the tube is the only ingredieint and totals 100% of the tubes content. Just like alchohol is labeled.....40% 100% etc.....So you could still have a 100% pure silicone product with a mile long list of additives to make it mildew resistent, UV resistent etc etc, and it would not change it from being 100% pure silicone "USED" in the manufacture of the product.

I have to agree there is certianly nothing wrong with the GE silicone big box stores sell. I have never had a problem with it in many many years of use in aquariums. Why pay high bucks for what in all reality is going to be the same stuff in a different tube and pay $8.00> when I can get it for 3 or 4 bucks a tube.....even though it has no suggestins on using it in aquariums...

 

[BeanAnimal]

brian your partialy correct, but your missing some major facts.

1.) GE labels the material "Not for aquarium use" for liability reasons. Their "aqurium silicone" is labled for use on aquariums 10 gallons or less (or something like that). This again is a liability issues.

2.) They sell the same stuff for "aquarium use" for a much higher price (presumably to help balance the liability and turn a higher profit). This is a simple matter of understanding niche markets. They do not sell this stuff to end users, rather they sell it to profesionals. This simply removes them from the liability chain and places the burden on the tank manufacturer. The manufactuer presumably has better knowledge, tools, techniques and training to use the product to produce safe aquariums.

Regarding all silicone "not being the same"... I would suggest a google search and some phone calles to the different "aquarium silicone" manufacturers. I would suggest some deep diging and you may just find that almost all of the stuff comes right out of the GE process line and is packaged for sale to many different companies under many different names.

You may also find that many of the products you see on shelves are distributed this way..... there are only 2 or 3 carpet manufactueres in this country, yet 40 brands of carpet. Appliances? Electronics... you name any sector and I can show you dozens of different brands that are made in the same plant or factory but pasted with different labels or paint.

Bean

 

[Atomahawk]

Bean is right on all counts, private label or made to measure is big business for a manufacturer that has the equipement and want to boost production to keep people employed. As long as it's not cutting into their main business or is a niche market that a large company like GE can't bother with, most will private label if the money VS repackaging time, (packaging change on the assembly line), component swapping etc. is worth it. Most of the time these products do cost more since the company requesting private label has no were near the numbers that the main has, plus the runs are usually fairly short compaired to the main, so downtime costs money.

There are lots of Asian companies that make products based on the private label principle and don't have a label for themselves. All they do is show you what they can make for you, example of this is air pumps. I actually sat at a meeting with one Chinese manufacturer who showed us all the models they can make and was surprised to see quite a few models that were being distributed in N.A. for different companies we all know. Yet I could buy the exact same mold and guts with my own name brand and model name.

If you need 100,000 of anything I'm sure I can find the people that will private label it for you.

 

[BeanAnimal]

And by all means... if anybody can show me a 100% silicone product that is stronger than the GE silicone and show me proof, then I will gladly buy it, recomend it, and help spread the word that all 100% silicones are not equal.

I have read several "tank makers" assertions that the "blah blah brand of silicone" is made for aquariums and MUCH stringer than the GE stuff. I just have not found anything to back this up.

Maybe some testing is in order

Bean

 

[BeanAnimal]

BTW you may want to post his question in Randy's Chem forum... he might have an idea as to what chemical reaction caused the silicone to change color.

Of course a call to GE may yield some answers also. You just need to ahold of the right person, not the one who reads from the laminated answer sheet.

 

[impur]

<a href=showthread.php?s=&postid=6605236#post6605236 target=_blank>Originally posted</a> by chipmaker
I think what the labels are stating is the silicone used in the "stuff" in the tube is 100% pure, its not a meaning of 100% of the stuff in the tube is the only ingredieint and totals 100% of the tubes content. Just like alchohol is labeled.....40% 100% etc.....So you could still have a 100% pure silicone product with a mile long list of additives to make it mildew resistent, UV resistent etc etc, and it would not change it from being 100% pure silicone "USED" in the manufacture of the product.

I have to agree there is certianly nothing wrong with the GE silicone big box stores sell. I have never had a problem with it in many many years of use in aquariums. Why pay high bucks for what in all reality is going to be the same stuff in a different tube and pay $8.00> when I can get it for 3 or 4 bucks a tube.....even though it has no suggestins on using it in aquariums...

Good point, i hadn't thought of it that way.