Can anyone help with sump build?
- Thread starter jesterns2
- Start date
cloakerpoked
New member
I don't think the OP will need weld on, since the impression I'm getting is its a glass sump with acrylic baffles. Weld on won't bond acrylic to glass very well 
cloakerpoked
New member
Just didn't want to cause any confusion for the OP since he was asking for help. The last thing I'd want is the poor guy trying to use weld-on for his purposes
acer
New member
Ok - I have been following , "Weld on" is not available at Home Depot. I have two things using acrylic I need help with . #1= sump build -which means acrylic baffles sealed to glass sides= 20 high sump/refugium build. #2 = I am also building a overflow box to use on Nates 37 cube tank (one center drilled hole) that I am getting = acrylic to acrylic then acrylic to glass. . Help please. I have a sheet of 1/4 inch think blue acrylic.
cloakerpoked
New member
To bond acrylic to acrylic, you will need weld-on. Nothing else will work. To bond acrylic to glass, you have to use silicon (GE#1 silicon available at Lowes will work fine.) As a matter of fact, I've read on here that AGA uses repackaged GE #1 silicon in their tank builds. Your best option would be to use all of one, or another for the overflow box (i.e. use glass to build the box, or use a hang in the tank overflow box like the one on the 90 gallon tank upstairs that I showed you.) To have an acrylic box hanging on a glass tank by silicon seals is a recipe for disaster. It not only stands a better chance of leaking, but also of just falling off completely.
As for the baffles, just silicon them in place using GE#1 silicon to the glass sides. seal the leading and trailing edges and they'll hold and be water tight. Silicon DOES bond to acrylic very lightly, but will peel off very easily if allowed to. Baffles experience very little forces that would cause the silicon to fail, so it works a lot better that way. Even overflow boxes are held to the glass mostly by water pressure into the corner of the tank. The silicon seals well to the glass too, which also keeps them there, but you should never think that your overflow boxes in the tank will remain sealed for the entire length of the tank. They might, but its far from a sure thing.
As for the baffles, just silicon them in place using GE#1 silicon to the glass sides. seal the leading and trailing edges and they'll hold and be water tight. Silicon DOES bond to acrylic very lightly, but will peel off very easily if allowed to. Baffles experience very little forces that would cause the silicon to fail, so it works a lot better that way. Even overflow boxes are held to the glass mostly by water pressure into the corner of the tank. The silicon seals well to the glass too, which also keeps them there, but you should never think that your overflow boxes in the tank will remain sealed for the entire length of the tank. They might, but its far from a sure thing.
cloakerpoked
New member
*edit to the above...not so much an edit as further clarification I guess...
Acrylic and glass can never be bonded together. Silicon will hold to acrylic, but not firmly. Weld on chemically fuses acrylic sheets by essentially "melting" them together, forming, in essence, one piece of acrylic like welding metal together. Weld on would have no effect whatsoever on glass. It is an industrial solvent, so is not available at regular home improvement stores. Shipping is also strickly controlled of weld-on because of hazmat regulations. Your best bet is to go to the places listed above. Personally, I'd either...
1.) Drill the tank if you can
or
2.) Purchase an over the back overflow box
for your new tank.
Acrylic and glass can never be bonded together. Silicon will hold to acrylic, but not firmly. Weld on chemically fuses acrylic sheets by essentially "melting" them together, forming, in essence, one piece of acrylic like welding metal together. Weld on would have no effect whatsoever on glass. It is an industrial solvent, so is not available at regular home improvement stores. Shipping is also strickly controlled of weld-on because of hazmat regulations. Your best bet is to go to the places listed above. Personally, I'd either...
1.) Drill the tank if you can
or
2.) Purchase an over the back overflow box
for your new tank.
