# non-toxic hot glue????



## gmoney1585 (Apr 13, 2009)

I am thinking about hot gluing a bunch of my rocks together, so that i can make my own design of caves, tunnels, etc. They are mostly 5 inch assorted rocks, some round, some flat, some both round and flat, and I am getting sick of my cichlids flashing off of rocks and knocking rocks over and collapsing the whole thing. Plus would make for easy gravel cleaning!!!!!! Also, i would be able to stack higher and use the top half of my tank and caves would be larger for when they get larger. My question is, if i use a hot glue gun, with non-toxic glue, will my fish be safe???? all opinions would be appreciated. oh, and its a 55 gal setup with mostly juvenile malawi mbuna. also, would my magnum 250 canister filter be able to keep up when i start to "overstock"?? currently at about 15. Or should I look at getting another 250???


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## under_control (Jan 9, 2008)

Why not just use silicone.


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## gmoney1585 (Apr 13, 2009)

i could, but the silicone would take alot longer to dry. it wouldn't dry as hard, so might be pretty wobbly and more delicate when moving due to all the uneven surfaces. Also, i all ready have a hot glue gun. Dont wanna have to run to the store if i dont have to.


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## under_control (Jan 9, 2008)

But hot glue being brittle is more likely to make it not stick. Plush, in my experience hot glue just pops off.


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## mithesaint (Oct 31, 2006)

I've used the hot glue before, and never ran into any problems with it.

That said, silicone is known to be aquarium safe, and it should dry hard enough to make things stable. If you're relying on the adhesive for structural stability, I'd redesign the structure :thumb:


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## Toby_H (Apr 15, 2005)

I've made many rock structures out of silicone, hot glue as well as several different aquarium grade adhesives...

I didn't have any issues with the hot glue being toxic. Although I must confess this was quite a few years ago and I didn't do the proper research... just took the chance. I also have no clue what brand I used or if some brands are okay while others are not...

Having the experience of using several matuerials... I currently use silicone to make rock structures... it has helpd up the longest and simply has worked best for me at this application.

I have personally given silicone a 24 hours cure time then put it right into an aquarium with no issues... Would hot glue really be that much faster?

Note: If you do choose to use silicone be sure to avoid anything that says "mildew resistent". Both GE and DAP make versions that are both safe and unsafe for aquarium use. DAP's "plus" series is not safe... GE Silicone I is safe (II is not safe). I'm not sure about DAP, but GE has somewhat recently added "BioSeal" to all of their GEII line.


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## under_control (Jan 9, 2008)

Toby_H said:


> I've made many rock structures out of silicone, hot glue as well as several different aquarium grade adhesives...
> 
> I didn't have any issues with the hot glue being toxic. Although I must confess this was quite a few years ago and I didn't do the proper research... just took the chance. I also have no clue what brand I used or if some brands are okay while others are not...
> 
> ...


errr... GE II is actually safe as well. it just releases ammonia during curing and thus you must ensure it is fully cured before putting it into the tank...


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## Toby_H (Apr 15, 2005)

under_control said:


> errr... GE II is actually safe as well. it just releases ammonia during curing and thus you must ensure it is fully cured before putting it into the tank...


Previously... this was truly... more recently they have changed... All GE Silicone II (both Kitchen & Bath as well as Window & Door) have BioSeal which is mold & mildew resistent...

But don't take my word for it... http://www.gesealants.com/sil2_window_door.html

GE Silicone I Window & Door is still aquarium safe...


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## bntbrl (Apr 23, 2009)

GE has said that the Silicone II is the same formula as before. *** used the BioSeal and I havent had fish die. You MUST let it cure as it releases ammonia during cure. It offsets ammonia until cured. I read and read and read about it being "bioseal" and everyone said to ue it but according to what I read the msds has no herbicide in it that I can tell. My tank is a month old and nothing is dying. Plants are good also. I used the II for years until they changed the logo. Still used it and nothing bad happened. I want to hear more testimonials though on silicone II


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## mithesaint (Oct 31, 2006)

bntbrl said:


> GE has said that the Silicone II is the same formula as before. I've used the BioSeal and I havent had fish die. You MUST let it cure as it releases ammonia during cure. It offsets ammonia until cured. I read and read and read about it being "bioseal" and everyone said to ue it but according to what I read the msds has no herbicide in it that I can tell. My tank is a month old and nothing is dying. Plants are good also. I used the II for years until they changed the logo. Still used it and nothing bad happened. I want to hear more testimonials though on silicone II


Hmmm. I'd love to hear more if others have used Ge II. I have a 135 that needs totally redone, and noticed that GE II comes in black. I'd love to redo it in black silicone as that takes away the problem of algae growing on the clear silicone.


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## jstntlvr (Apr 20, 2009)

The DAP silicone comes in black as well and is safe just don't get the silicone plus


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## Toby_H (Apr 15, 2005)

I may be wrong in my thought that the BioSeal found in all GE Silicone II products makes it not safe for aquariums... If it is not the ammonia releasing agent similar to what is found in the Kitchen & Bath product, then I don't understand why they claim it is "mold & mildew resistantâ€


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## JALOOS (Sep 6, 2008)

Been using hot glue on my DIY filter media plates forever. Nothing is dead yet and on porous surfaces it works great.


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## gmoney1585 (Apr 13, 2009)

thanks for all the info, i ended up goin with DAP auto/marine silicone sealant. it is not mildew resistant, and if its good for boats, then it must be good for my tank, right? I am building my structures in seperate sections, and will be put together in the tank. I will be sure to wait at least 24 hours before putting anything in. Everything seems to be going well. (except for the brain cells im losing from all the silicone smelling) Ill post pics when finished


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## jstntlvr (Apr 20, 2009)

ventilate sum of those fumes can cause permanent damage to your lungs


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## gmoney1585 (Apr 13, 2009)

thanks for the tips guys. here are some pics. what do you think??
the third pic is actually 3 dif segments. ended up taking the top off and put pic 4 on top


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## CutieSusieQ (May 12, 2009)

Just speaking from experience....I just made some caves with black PVC pipe and crushed shells and also made a rather large center piece out of several layers of flat rock to create some caves and cliffs. My experience with using the PVC pipe and the flat rock is that is it IMPOSSIBILE to get stuff to stick together without using both; the silicone and the hot glue. The hot glue will hold the pieces together suddenly unlike the silicone, but once it dries the glue is very hard and easily breaks off the surface (especially smooth surfaces such as flat rock and pvc). Hot glue is best for porous surfaces. Using only silicone seems to work best for smaller projects b/c it simply does not dry fast enough to hold heavier projects together; it lets the rocks slide and does not "grab" it like the hot glue does. Since my surfaces were smooth, I used both. I use the hot glue as my "holder". It holds my pieces together long enough for me to apply silicone to them. The silicone drys and feels like rubber.

I have read that hot glue is safe and cures much faster than silicone. When using silicone just make sure it is aquarium safe; I buy mine in the fish store that way I know for sure its made for tanks. I always let my caves air dry for 48 hours and then I soak them in water for another 24 hours before adding them to my tank. Not real sure why you are suppose to soak them in water for 24 hours before placing in tank, but I do it anyway out of precaution.


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