ninhsavestheday
New member
I just got an overflow. What do I use to glue the acrylic to glass?
glue acrylic to glass?
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windsor-aquatic
New member
Agree with javatech; don't mix the two, they require different adhesives/sealants.
WarDaddy
New member
if you want it stick silicone to glass it can be done, the bond is not as strong as you get with weldon, or with silicone when attaching glass to glass.
If you take some sand paper to the acrylic and rough it up a bit. The silicone can hold the acrylic to glass. It does work well enough. I would not try it if you were counting on it to hold water, but as a baffel or internal structure, where there is equal pressure on the seams, there should be no problems.
If you take some sand paper to the acrylic and rough it up a bit. The silicone can hold the acrylic to glass. It does work well enough. I would not try it if you were counting on it to hold water, but as a baffel or internal structure, where there is equal pressure on the seams, there should be no problems.
Silicon will stick to acrylic - period.
Three months ago I built a wet dry/sump from a 30 gallon aquarium and used silicon to put acrylic baffels in place - I could pick the aquarium up by the baffels (which is what I did to carry it in the house). Alas, the tank broke (the bio tower put too much stress on the thin glass), so I built a custom wet dry/sump from acrylic last weekend.
I also, just last night, installed two acrylic overflows in my glass tank (Durso overflows, they are niiice). I was a bit worried with all the "silicon won't stick" mumbo jumbo, but I used it anyway. This morning I was pushing and pulling on the overflows to see if they would budge - nothing.
I've also called a plastic dealer, and they said silicon to glass/acrylic would be plenty strong for what I was trying to do with it. They went a step further and said that if I wanted any silicon aquarium to retain water over a long period of time I needed to silicon the seems - I don't really buy this one.
Now, I wouldn't build an aqurium with acrylic/silicon - but it will stick. It's not as strong of a bond as glass, but it'll do what you need it to do regarding overflows. I think this "silicon won't stick" crap is just crap, even aquarium manafacturers use silicon to install thier overflows from the factory.
Three months ago I built a wet dry/sump from a 30 gallon aquarium and used silicon to put acrylic baffels in place - I could pick the aquarium up by the baffels (which is what I did to carry it in the house). Alas, the tank broke (the bio tower put too much stress on the thin glass), so I built a custom wet dry/sump from acrylic last weekend.
I also, just last night, installed two acrylic overflows in my glass tank (Durso overflows, they are niiice). I was a bit worried with all the "silicon won't stick" mumbo jumbo, but I used it anyway. This morning I was pushing and pulling on the overflows to see if they would budge - nothing.
I've also called a plastic dealer, and they said silicon to glass/acrylic would be plenty strong for what I was trying to do with it. They went a step further and said that if I wanted any silicon aquarium to retain water over a long period of time I needed to silicon the seems - I don't really buy this one.
Now, I wouldn't build an aqurium with acrylic/silicon - but it will stick. It's not as strong of a bond as glass, but it'll do what you need it to do regarding overflows. I think this "silicon won't stick" crap is just crap, even aquarium manafacturers use silicon to install thier overflows from the factory.
Alphabet
Member
I used the silicone to hold the acrylic in place, then ran another small bead on either side of the acrylic. I cut the acrylic just a tad smaller than it needed to be, btw. I personally don't think you need to sand anything, I didn't and it is still fine after 15 months. Good luck with your project.
Pyrojon
New member
How can you make such a strong blanket statement like "Silicone will stick to acrylic - period" with only two weeks of experience in the subject, then go on to doubt your own statement a few lines later?
Here is a better strong blanket statement that is based upon years of experience.
"Silicone will not stick to Acrylic very well or for very long"
Silicone is chemically very similar to glass, that is why their bond is so very strong and lasting, the silicone and the glass are not simply glued together they are chemically bonded forever at the molecular level.
Acrylic on the other hand is nothing like glass, silicone will stick to it but it's not bonded like with glass. The strength of the connection between acrylic and silicone is relatively weak and can very easily be broken. Sure you can make baffles and overflows stay in place for a long time but that's because there is no pressure on the connection, there is water on both sides and no difference in pressure. Try building an acrylic tank using silicone. It may hold for a little while but sooner, rather then later, it's going to start leaking, and probably fall apart under the pressure.
The reason that acrylic baffles seem so strong is because they are wrapped in silicone that is permanently bonded to the glass. You would need to break the weak bond between the silicone and the acrylic while simultaneously tearing the acrylic through the thick coating of silicone. Ever try tearing silicone? It's stretchy and tough, definitely not "easy" to tear in that situation.
"Silicone won't stick" crap is definitely not crap, it's real. Do yourself a favor and understand why something is or is not crap before making a statement like you are some kind of expert.
To answer the first person's question, yes you can use silicone to attach an overflow to your glass tank, everyone else does. You will want to rough up the acrylic and ensure that the glass is very clean before applying the silicone. Wipe the glass with some denatured alcohol first.
Good luck
I went on to doubt my statement a few lines later because of all the hype I've read on this board about silicon not sticking to acrylic "well enough" to be used for baffels and overflows. On every post about attaching acrylic overflows to glass tanks there are lines and lines of post about how it won't work, which is bogus.
Yeah, I tested my theory and carried my tank around by the acrylic baffels that were put in place with silicon because I wanted to know if they would hold.
Experience?? You're right, I don't have much experience (with glass and plexi), but looking at the things I've built you wouldn't be able to tell. However, I did call Oceanic (the manufacturer of my tank) as well as a large plastic dealer in Houston, both have more experience than any single person on this board. Oceanic told me they have been using silicon to attach overflows for years and years without one reported failure. A&C Plastics told me that WeldOn alone wouldn't make an acrylic aquarium watertight, but silicon will adhere "well enough" to create a water tight seal (even though I've never heard of this approach).
I think they know what they are saying.
So, maybe I should reword my statement - silicon will adhere (not bond) good enough to be used to stick acrylic overflows to a glass aquarium. Is that better?
Yeah, I tested my theory and carried my tank around by the acrylic baffels that were put in place with silicon because I wanted to know if they would hold.
Experience?? You're right, I don't have much experience (with glass and plexi), but looking at the things I've built you wouldn't be able to tell. However, I did call Oceanic (the manufacturer of my tank) as well as a large plastic dealer in Houston, both have more experience than any single person on this board. Oceanic told me they have been using silicon to attach overflows for years and years without one reported failure. A&C Plastics told me that WeldOn alone wouldn't make an acrylic aquarium watertight, but silicon will adhere "well enough" to create a water tight seal (even though I've never heard of this approach).
I think they know what they are saying.
So, maybe I should reword my statement - silicon will adhere (not bond) good enough to be used to stick acrylic overflows to a glass aquarium. Is that better?
windsor-aquatic
New member
Well said Pyrojon!
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Black Mammoth
Premium Member
I don't have tons of experience with glass & acrylic. But IME I've never had a problem attaching acrylic to glass. It worked very well for me. I have very strong bonds and has been attached for a long time.
I used the DAP Aqarium silcone seal. I will not say it will work, but I've never had a problem. Maybe others had problems because of different adhesives, dirty materials, or improper use/installation.
I say go for it. It's cheap.
I used the DAP Aqarium silcone seal. I will not say it will work, but I've never had a problem. Maybe others had problems because of different adhesives, dirty materials, or improper use/installation.
I say go for it. It's cheap.
jnb
Premium Member
For what its worth
I am having an acrylic tank made and the issue of needing to bond a tunze magnet to this tank came up as a possible solution and James at Envision Acrylics said there was a silicone made for acrylic if I understood him correctly - not to say it will be as strong as glass to glass by any stretch - but if you are going to move ahead with this maybe you should give him a call
I am having an acrylic tank made and the issue of needing to bond a tunze magnet to this tank came up as a possible solution and James at Envision Acrylics said there was a silicone made for acrylic if I understood him correctly - not to say it will be as strong as glass to glass by any stretch - but if you are going to move ahead with this maybe you should give him a call
IME, the best silicone for what you are trying to accomplish is Dow Corning #795. It is technically considered an industrial adhesive but is a silicone nonetheless. It sticks to acrylic well and is the standard for public aquaria where you have inlayed acrylic panels and the silicone works as a gasket. I've used it for many years with no complaints. I would not try to use it for any structural application however.
I would think for your application, it could work quite well. You can find it at most roofing or glazing supply houses and costs about $6-8 per tube. I've used several other silicones and this one is by far the best I've found.
That said, I wouldn't say anything else wouldn't work, just that this is the best I know of. Many folks have had good success with various silicones for just what you are doing. Some have also used Marine Goop as well with good results.
HTH,
James
I would think for your application, it could work quite well. You can find it at most roofing or glazing supply houses and costs about $6-8 per tube. I've used several other silicones and this one is by far the best I've found.
That said, I wouldn't say anything else wouldn't work, just that this is the best I know of. Many folks have had good success with various silicones for just what you are doing. Some have also used Marine Goop as well with good results.
HTH,
James
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