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View Full Version : What to Use to attach Plexi to Plastic????


ensquire
04-29-2011, 05:54 PM
I have a cross brace on my tank that blocks out my light and I want to cut it and glue a piece of plexiglass in it's place. I have tried epoxy and it didn't bond well enough. What would be the best product to use ?
Must be somewhat safe as the brace is just above waterline in tank.
Would another clear product work better than plexiglass ??

Thanks

cale262
04-29-2011, 05:56 PM
...Would another clear product work better than plexiglass ??

Thanks


Ummmm...Glass?


I have a glass cross brace in one of my rimless 90's and I don't even notice it...

GMGQ
04-29-2011, 06:36 PM
Are you talking about attaching the plexi to the top frame of the tank?

Dont people normally use clear silicone for that?

ensquire
04-29-2011, 07:07 PM
I thought plastic to plexiglas with a little stress would be to much for clear silicone?

ensquire
04-29-2011, 07:31 PM
Ummmm...Glass?


I have a glass cross brace in one of my rimless 90's and I don't even notice it...

Had the plexiglas handy and thought it would work. Was looking for glass.
Would silicone hold it to plastic?

GMGQ
04-29-2011, 07:39 PM
Silicone actually dries pretty sturdy. Just squeeze a good bead along the bottom, and press it down, and squeeze some more around to fill in the edges, and let it cure overnight.

I used it to put lucite baffles in my sump, holds rock hard. It was actually a PITA to remove when I wanted to change the layout of my sump!


I thought plastic to plexiglas with a little stress would be to much for clear silicone?

sphelps
04-29-2011, 07:55 PM
I assume the tank is glass with a black plastic brace around the top. You removed the black plastic center brace and are looking replace it with clear. Best solution is use glass, have it cut to fit exactly from inside front pane to rear pane (same length as side glass panes). Install the glass brace with silicone underneath the plastic brace so you have glass on glass contact. This will be the strongest. Another alternative is to remove all black plastic trim on the top and Euro brace the whole tank, this eliminates the need for a center brace all together.

ensquire
04-29-2011, 08:15 PM
I assume the tank is glass with a black plastic brace around the top. You removed the black plastic center brace and are looking replace it with clear. Best solution is use glass, have it cut to fit exactly from inside front pane to rear pane (same length as side glass panes). Install the glass brace with silicone underneath the plastic brace so you have glass on glass contact. This will be the strongest. Another alternative is to remove all black plastic trim on the top and Euro brace the whole tank, this eliminates the need for a center brace all together.

First problem is that it is a bowfront tank so some real custom glass cutting involved.
Secondly, tank is full of water and I would not be sure it would hold withouit plastic rim. It is an All Glass Aquarium.
I have ordered a piece of glass and will try to seal it as tight at both ends as tight to the glass as possible.
should have just went this route at the start, was looking around for material and the only thing laying around was plexi. Cheap never works........

sphelps
04-29-2011, 08:18 PM
ahh bow front, lame! :wink:

Should note that modifying any bracing on a tank should be done with no load so the tank should be empty.

cale262
04-29-2011, 08:19 PM
I had a corner bowfront and had Crystal gals in Edmonton cut me a curved peice of glass for a top, they just asked me to cut them a template out of cardboard and they did the rest, it was a perfect fit.

ensquire
04-29-2011, 08:19 PM
In the middle of remodeling my sump right now also, but it is glass on glass and I didn't think it would work with glass and plastic.
Should have asked question here first LOL. Would have saved the " Why do you always have to modify things " Question from my wife...............

Silicone actually dries pretty sturdy. Just squeeze a good bead along the bottom, and press it down, and squeeze some more around to fill in the edges, and let it cure overnight.

I used it to put lucite baffles in my sump, holds rock hard. It was actually a PITA to remove when I wanted to change the layout of my sump!

monocus
04-30-2011, 02:54 PM
try gorilla glue-this stuff expands so make a couple of dams with masking tape(the green plastic type)

apexifd
04-30-2011, 04:13 PM
Would have saved the " Why do you always have to modify things " Question from my wife...............

still better than "I told you so" from the wife

Samw
04-30-2011, 05:21 PM
This is what I've seen before. Weldon and nylon bolts.

http://www.thereeftank.com/forums/showpost.php?p=1612873&postcount=10

http://www.reefcentral.com/forums/showpost.php?p=18077825&postcount=6

ensquire
04-30-2011, 08:12 PM
Wouldn't you know it. I went and had a piece of glass cut to fit. Came home to replace the plexiglass so I had to cut off last of the black plastic brace. One end wouldn't come apart and the other end only released after applying a lot of pressure. So I finished the trimming, added more epoxy, clamped it together. Went to it this morning and it is bonded. I have the glass as a backup if it fails, but maybe I got lucky and have solved this problem.

As for the two links, I was kinda wondering what fastening device would work in this environment. Nylon screws would be perfect.
Thanks for all the good advise and ideas, If there are any changes I will report them...