large acrylic and glass tank hybrid

[rivan]

I'm looking for any experiance buiding an acrylic tank with a glass front. Something around 300 gallons.

What I'm interested in knowing is how to the bond the glass to the acrylic whether mechanically with silicone or an acrylic frame.

or any other options.

Why? This tank is intended for a reef with the front glass side in a picture window.

I've had both acrylic and glass tanks.

I love acrylic for its weight and toughness but I can't stand its lack of scratch resitance. I'd go with all glass but its empty weight posses a challenge for moving. So I was wondering if anyone has tried this cobination in a big way.

(I had tried a glass cube with acrylic bottom some 12 yeays ago with some success. However to bond the glass to acrylic we used marine goop for all the seams...and when the MH heated it up the glass split apart. )

[rufio173]

hey rivan,

I don't know if this will work, but I think some people have used a lot of silicone to make the seal, but then depend on the water's weight to hold the glass firmly in place. Just support the glass on the bottom with some more acrylic, add an excessive amount of silicone and then add water and I don't think there should be a problem...

I think I saw somebody that did it once, but I can't recall where I read about it. It might have been fiberglass with glass though...

Peace,
John H.

[69vette]

How thick is this piece of glass you have?

[niko5]

I dont know if its possable with any adheasives... silicone doesnt work with glass and acrylic. something you could do is drill lots of little holes around the edges of the glass and into the face of the acrylic. Tap all the holes and make a big washer to fit around it and screw the glass to the acrylic with some titanium screws. Not only would it hold forever but it would look NEAT :)

[nonot8946]

The only silicone I know of that even claims to be able to bond well to glass and somewhat well to acrylic is GE Silicone II. However, I don't think I would personally trust it holding together a glass/acrylic combo tank in my living room, not without a LOT of testing anyways.

Is there any way you could build a metal frame around the tank to support the glass, so that the silicone would only be acting as a sealant against water?

I like your train of thought though - glass for the front window and acrylic to drill through on the bottom and back...best of both worlds.

[H20ENG]

DOW 795 is about the best sealant for acrylic. I would try to do as mentioned above and glaze each piece into a frame, and not rely on the silicone bond for mechanical strength.

[rivan]

The tank might be (if I dont chicken out) 72L*36W*27D.
I am thinking that I could make the bottom 1 inch larger than needed and then bond a 1inch peice of acrylic all around the base to give me some mechanical support on the bottom in front of the glass. Then somethin similiar on top and the sides.

[rivan]

ok I like the idea of screwing the glass to the acrylic...though not the point og drilling the glass. It makes me think however that a big O ring could be cool. Not sure how to do it thought.

[gev]

Ok, so why not do it the ridiculously obvious way: Make an acrylic tank and put a glass pane in front of it.

If they're snug, you shouldn't have any problem with the two. The acrylic won't sweat, so the glass won't fog.

Also, you can use a very thin pane of glass.


Originally posted by rivan
I'm looking for any experiance buiding an acrylic tank with a glass front. Something around 300 gallons.

What I'm interested in knowing is how to the bond the glass to the acrylic whether mechanically with silicone or an acrylic frame.

or any other options.

Why? This tank is intended for a reef with the front glass side in a picture window.

I've had both acrylic and glass tanks.

I love acrylic for its weight and toughness but I can't stand its lack of scratch resitance. I'd go with all glass but its empty weight posses a challenge for moving. So I was wondering if anyone has tried this cobination in a big way.

(I had tried a glass cube with acrylic bottom some 12 yeays ago with some success. However to bond the glass to acrylic we used marine goop for all the seams...and when the MH heated it up the glass split apart. )

[69vette]

Originally posted by gev
Ok, so why not do it the ridiculously obvious way: Make an acrylic tank and put a glass pane in front of it.


The point is, to not have acrylic as the front panel because it scratches when being cleaned.

[gev]

I thought you were trying to avoid scratching it from the outside.

So put a thin glass sheet into the tank. Just design the tank so that the sheet will fit diagonally through the top opening or install it while building the tank. Then press the glass against the front and silicone the perimeter. To prevent the glass cracking when the acrylic bows, use a thick front acrylic panel.

The problem is not that you can't bond acrylic to glass, just that there is no structural strength in the bond that you do make.


Originally posted by 69vette
The point is, to not have acrylic as the front panel because it scratches when being cleaned.

[rivan]

I had already been considering the laminating method of putting a peice of glass before the acrylic front wall.

Wonder why no manufacturer has tried it as an upgrade for reef tanks.

One potential problem I can see is that water could seep between the two sheets as it would still have to be sealed with silicon...which wont bond to the acrylic well over time. Also there may end up being a visual distortion of the light going betwen two materials of differing diffraction. So I though it would be better just to do one material...glass.

I looked into a more scratch resistant sheet of acrylic and the price for 1/2 inch was sky high.

[Acrylics]

The laminating method is done but not for aquaria as the material costs make the tanks impractical. There are several bullet resistant materials that use glass on the outside to cause the bullets to mushroom and then the plastic absorbs the actual impact energy.

You can make the glass on the inside but there are a few problems that occur:
If you dry seal it (silicone the glass in place) then there is a double reflection where light bounces between the two panes.
If you wet seal it (just stick it in there without sealant) then algal growth becomes an uncleanable issue.

The scratch resistant acrylic still scratches and is not repairable as it is a micro-thin coating which will come off.

James