DIY PVC and Acrylic Sump

allen00se · Feb 19, 2022

Rjramos said:
Looks like the leak is pvc to pvc. Nothing around the acrylic windows? That’s where my concern would be. Disimular plastics don’t bond well together. Hope the silicone works especially with that rabbet cut into the pvc. Flexing, due to water pressure might cause separation with time. I am following because I make acrylic sumps. Another thing, don’t know if you looked into a 1/2” white acrylic sheet and cost as compared to PVC sheet.
This would solve your bonding issue.
I believe the PVC flexes more although it is easier to cut.

ya the PVC to PVC was my only issue, I think I just needed to be more liberal with the Weld-On, also It was my first sump glue up and I didnt have anyone helping me hold and clamp. What I ended up doing to fix the leak was just run a fillet of Weld-On on the inside seam.
I am actually not concerned at all about the acrylic viewing panes, I know that Silicone isn't great at attaching to either PVC or Acrylic, but the silicone was on the cut edges of both where there should be plenty of grip, combined with the rabbit and the fact that the water is pressing the acrylic into the pocket.

allen00se · Feb 19, 2022

Rjramos said:
I looked it up on eplastics. Black or white acrylic is crazy expensive comparatively! 3/8” and 1/2”.

Yes, exactly why I chose PVC. Assuming it holds up for the next 10 plus years it seems like a no brainer, although I would use a lot more cement were I to build it again.

allen00se · Feb 19, 2022

flagg37 said:
Do you have any idea why it leaked? Like do you recall not putting as much Weldon on in that area or something? Did you do the silicone in the corners? Would you do anything differently looking back?

I'm certain I just didn't use enough cement, I fixed the leak by just running a filet of cement on the inside corners of all the seams. Looking back I would just use twice as much cement and then do the filet on top to make it double sealed.

Tenecor Aquariums · Mar 5, 2022

Nice CNC I work. You are going to have a real problem bonding PVC to acrylic as in there will be no "bonding". The best you can hope for is a "glueing" with silicone. With the minimal water pressure you should be fine. As for eplastics dot com... They are crazy expensive.

Tenecor Aquariums · Mar 5, 2022

I don't want to jump on your build thread so I will ask once and leave it. Is there a demand for pre cut acrylics out there in the DIY world? We could have sold you that 3/8 black for about 60% less.

Duncan62 · Mar 5, 2022

allen00se said:
Weld-On 16
I’ve used it many times in the past on this sheet pvc, but this is the first time I’m doing anything water tight, so I hope it works. I’m planning to do a filet on the inside corners with silicone or something of that nature to make double sure it doesn’t leak.

Good luck. The 40 might be worth the wait. It look awesome

allen00se · Mar 6, 2022

Tenecor Aquariums said:
Nice CNC I work. You are going to have a real problem bonding PVC to acrylic as in there will be no "bonding". The best you can hope for is a "glueing" with silicone. With the minimal water pressure you should be fine. As for eplastics dot com... They are crazy expensive.

Yes I am aware, thats why I "attached" the face of the acrylic to the face of the pocked, then used silicone between the edges of the acrylic and the edges of the pocket. The water pressures should keep the acrylic pressed into the pocked, and the silicone should just be the seal.

allen00se · Mar 15, 2022

Finally getting around to posting an update and good news, everything is working out great so far. Once I got the last pinhole leak sealed up I was able to fill the display and run the whole system for testing. After about a week I felt comfortable to fill with salt and officially start my tank.

Finally finished making modifications to my DIY filter roller and it is installed and working. The lines you see across the front of the filter roller viewing pane are actually from a separate compartment that the filter roller sits in which is inside the sump if that makes sense. I had to chop the compartment and the filter roller base into 3 sections so that I can remove it from the sump while the sump is under the stand.

Also cut all of the lids for the different compartments to keep it all nice and clean, got the Chaeto growing in the fuge.

Overall I am pretty satisfied with the results, I really cant think of anything I would change as of right now. Just hope it holds up for 10 or so years.