Building a 620 gallon acrylic stingray tank

[rdbrown]

I didn't take any photos of the welding, it took two of us to weld them. The way that I did the welding was I started with the front of the tank down and welded the two sides onto the front.

Very similar to this one.

After I had both ends welded and set, I turned it over and placed it on the back of the tank and put a board in the center to keep it from bowing while I welded the back to the sides. The board sometimes needs to be higher then the sides of the tank. What you are trying to accomplish with the board is to make the sides square to the back so that you get full contact on the joints for welding. Once the sides are welded to the front and back I turned the tank right-side up and used a square and tape measure to adjust it to the bottom and welded the bottom on. I always try to use oversized acrylic sheets when I make a tank. I literally have at least an inch of overhang on all joints. When the welds cure, I go back and route the overhanging pieces off giving a perfect joint. This is really critical to getting a good clean weld by allowing me to apply solvent from both sides of the joint.

I don't use a jig. The welds cure in a matter of minutes, enough at least that you can move them.

 

[Ramcharger]

excellent work can't wait to see them set up !!

 

[JK47]

Amazing tank man. Really nice work and I especially like how the top of the tank has so much open space to put in large wood etc... I wish I had that much to work with. That is a seriously monster DE filter!

 

[zennzzo]

Weld-on#4 and not solvent to do the corner joints?! right on...

do you have a close up pic, of these optically perfect joints please?

nice size and Kudos for the project...

 

[rdbrown]

Weld-on#4 and not solvent to do the corner joints?! right on...

do you have a close up pic, of these optically perfect joints please?

nice size and Kudos for the project...

It is weldon #4 (which is a solvent), I don't have a close up photo of the joints, but I will get one taken and post it.

 

[zennzzo]

It is weldon #4 (which is a solvent), I don't have a close up photo of the joints, but I will get one taken and post it.

I should have said water thin solvent, #4 is thick like rubber cement consistency right?
They all have to actually be a solvent, to chemically weld the joints, I worked with the needle type applicator and water thin stuff.
I like the thicker stuff, it stays where you put it, but I seemed to have a hard time with bubbles in the joints... Any tricks to that?

 

[vamptrev]

what kind of uv r u using?

very nice build!!!

 

[GiangNOOO]

sweetness

 

[rdbrown]

I should have said water thin solvent, #4 is thick like rubber cement consistency right?
They all have to actually be a solvent, to chemically weld the joints, I worked with the needle type applicator and water thin stuff.
I like the thicker stuff, it stays where you put it, but I seemed to have a hard time with bubbles in the joints... Any tricks to that?

Weldon makes 4 commonly used solvents/resins. Weldon #3 and #4 are both water thin.

I personally don't like #3 as it evaporates to quickly which means it doesn't soften the acrylic enough to give a good strong weld. I use #4 for all my joints.

#16 is a solvent with acrylic resin in it. It comes in a tube and reminds me of plastic model glue. It is used when you have a joint that is uneven. It doesn't soften the acrylic much, so although it may appear to make a good joint, it is a weak joint. I only use #16 to fix problems such as a small pinhole leak.

#40 is a two part acrylic resin. This is basically the ingredients to make acrylic. I is recommended to use this when welding acrylic thicker then 1/2" or can be used to fill holes, etc. My experience in using this is it is very hard to use. You must mix it and wait just until it sets(it gets very hot) then use it otherwise you must use clamps and hold them for a very long time.

The secret to getting clean bubble free joints using weldon #4 is the finish on the edge. When you cut acrylic on a saw even though it may look very clean, it has an uneven surface. The best and easiest way to fix this is with a jointer, our a router using it like a jointer to finish the edge.

what kind of uv r u using?

very nice build!!!

I am not sure what brand it is. I purchased it new on ebay and it came in unmarked packaging. It seems to be pretty good quality.

 

[JustLooking]

Awsome build,look forward to seeing it progress.

Like the Y3 on the wall also.