Repairing an Acrylic Sump with Epoxy

Cashlaw · Jun 30, 2009

A repair project!

I got one of these with a busted corner:

http://www.preferredpetproducts.com/bio-fil-1-wet-dry-filter-box.aspx

Bio-Fil wet/dry, 24" x 12.5" x 16", for up to 125 gallon aquariums - they're so expensive new! $215 on discount? That's crazy! My regular sump is a 29 gallon plastic tub that I got for $7 on sale.

If I end up not using this sump, it will be up for sale in the classifieds at a very good price, once it's ready.

I thought about using Weld-On for the repair. Problem, if the joints aren't perfect when you apply the Weld-On, the repair will look good to the eye, but it could be really weak. I think I'm pretty handy with small home projects, but I don't have the tools or expertise to machine perfect acrylic joints.

I decided to use LocTite Marine epoxy. I've used this before to repair acrylic. It's sturdy, water-proof, and non-toxic to fish, once it cures. Cosmetically, it cures to a pale gray color, so it's not as nice looking as Weld-On, but this is a sump! And it's very cheap at Home Depot and stores like that.

The corner was mangled with a web of curving cracks and some holes in the vertical joint. I decided it was cleanest to take the chewed up material out.

I thought about putting in a new square corner, versus patching with a triangular piece. I decided to go with a triangular patch, because that's less area to join. Just the three sides, instead of three sides plus another three joints to build a new corner.

Here's the corner cleaned up, and the corner with the patch and first line of epoxy. More pics to follow soon!

Cashlaw · Jun 30, 2009

Second line of epoxy, outer tape removed:

Cashlaw · Jul 1, 2009

Inside line of epoxy applied, tape removed. View from outside and inside.

Now to let it finish curing (24 hours), then water test!

After it passes the water test, it will get a thorough cleaning to take off some of the smudges and water marks.

chesterthehero · Jul 1, 2009

Cashlaw · Jul 2, 2009

. . . and the patch is good. It has been holding water all day!

Next, a cleaning, cutting some egg crate for the bio-ball area, and re-assembling everything.

I was thinking about cutting a hole inside the triangular patch, to fit a bulkhead or a length of 3/4" PVC, that could be used as a drain spigot or for pump attachments. Holding off on that, need to get a better hole cutting attachment for my Dremel.

It will probably be for sale, too, I don't think I'll use this on my new 90G . . . the 90G has a built-in overflow tower that I'm turning into an internal filter.

These sumps sell for over $250 retail, about $215 on discount. They are good for up to 125 gallon tanks. If anyone is interested, PM me with an offer. No fair offer refused! It's probably worth getting just for the acrylic. It can be used as a sump, and then chopped up for acrylic pieces when you're done using it as a sump. Removing my patch wouldn't be too hard . . . the epoxy can be sanded away, then the seams "popped" by scoring down the seam with a blade. So if someone eventually wanted to re-patch with Weld-On, that's still very doable.