What's a safe silicone other than the one they sell at your local fish store. I want to glue some rock together and I I have some clear silicone already but one small tube won't be enough from my LFS. Any tips?
silicone question
- Thread starter johnrigu
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fagundespavinp3
Active Member
I just Picked Up some DAP Reef Safe 100% water proof silicon from my local Home Depot Paint Department
It was Like $5 for a small tube.
It was Like $5 for a small tube.
ngvu1
Valuable Member
No silicone is going to adhere and work w/ rock well.
I agree, either epoxy or preferably drill your rock w/ a cheapo $5 masonry bit and insert acrylic rods or PVC, this is what most of us do to go up w/ structure, and maintain integrity.
I agree, either epoxy or preferably drill your rock w/ a cheapo $5 masonry bit and insert acrylic rods or PVC, this is what most of us do to go up w/ structure, and maintain integrity.
DAP
GE Silicone I
RTV 100 Series
SCS1200
Dow Corning Silicone
RTV108 12C
"The MSDS for Silicone II does not indicate that there are any additions other than siloxanes, of which there are literally hundreds, (polymers) common to all silicones, without getting to complicated about it, The MSDS also does not indicate any proprietary additives either. Where such is present, the law requires that they be included in the MSDS. This raises serious questions as to the validity of the advertising.
What differentiates Silicone II from Silicone I is the latter is an acetoxy cure silicone, and the former is a neutral cure silicone.
Silicone II does not take longer to cure; published cure times are about the same. However the cure times pertain to a specific amount of silicone, usually given in a bead size, generally 1/8" or 1/4". Hardly have I ever seen an aquarium application use that little. As the amount increases the cure time increases, a week, two weeks...RTV100 series' 7 day full cure time is for a 1/4" bead!
I would say that neutral cure silicone is a bit more toxic in its "uncured" state than acetoxy cure silicone, but that is as far as it goes. It is better to malign a product for what it does not do well, rather than internet rumor.
Acetoxy cure silicone excels at bonding to glass and ceramics; acetic acid is corrosive, so it is not suited for metals, and it does not bond well to other materials (acrylic included.) Neutral cure excels at bonding metals (non-corrosive) and other materials (acrylic not included.)
Co-polymers, are another category (not 100% silicone) and are out of the scope of this thread.
Within the two general categories, there are several sub-categories: sealant, adhesive, high temperature, etc. Obviously we are only concerned with sealants and adhesives. the choice of which to use, really takes little thought. Sealants seal, adhsives hold stuff together.
GE Silicone I (Momentive) is, easy to work with, but is a bargain basement low end sealant. RTV100 series (Momentive) or SCS1200 (Momentive) are high end adhesives, not so easy to work with."
"Uncleof6"
eww
Community Member
Never use anything other than pure silicone with no additives on anything that will come in contact with your water column. Most everything available at the local box or hardware stores is NOT pure silicone and therefore not reef aquarium safe. If there are any mold or mildew inhibitors they will most likely kill your aquarium. You should only use a high grade quality silicone like Momentive RTV 103/108 or similar. These are not as easy to find however and cost considerably more but it is what you need to use. I agree with one of the other posts here that silicone is not going to hold your rocks together and it needs a clean surface to bond to. You should use an epoxy like Water Weld or if you are completely adverse to epoxy then simply drill the LR and zip tie it together. You can get pretty creative with zip ties and they hide really easily.
For small pieces there are types of crazy glue that work well, but that stuff can be bought cheaply and w/out concerns at LFS that is specifically for reefs
As to the post on silicone MSDS, I have seen that before, and I'm not positive what is being pushed now, but for many years we used the GE1 because there were no added mold inhibitors or anything, and while MSDS must show if that is used, it has to be a certain percentage for them to HAVE to label it, or this has been the argument I have seen over the years.
Personally I have used GE1 doors and windows for sump baffles and similar needs for many years w/out issues.
Personally I have used GE1 doors and windows for sump baffles and similar needs for many years w/out issues.
