Reptile & Amphibian Forums

I'm building my cage for my water dragons and I've come to a problem. the bottom is 48" x 36" and is modeled after a shower-type bottom. The plywood is sealed with polyurethane, then pvc shower liner was tacked on with finish nails, and concrete on top of that. I used concrete (mortar) because I needed a substance that would be easy to shape. Well, my problem is that the liner didn't tack on as quite as tight as I wanted and when the liner moved the concrete came out of place. This left a big gap between the side of the concrete and the liner. What type of sealant could I use that would be water-tight, and adhere to both pvc liner and concrete? Another problem that I'm having is that silicon doesn't adhere that well to pvc liner. I need something that will fill the gaps between the wood and liner. What could I use for that? Please help...and Chris Harper, if you read this...I'm sure you've got some ideas!

Could I use the foam that comes in a can and you just spray it to fill in the gaps...I can't remember what it's called, but can I use it?

I would use 3M 5200 sealant and adhesive. Or 3M 4200.
The 5200 takes a full week to completely cure, while the 4200 takes 24 hours.
Once cure, nothing except maybe laquer thinner will remove it, yet it can be scraped away is need be.
Home Depot sell the stuff,as do most boating centers, as the 5200 is made to be used underwater.
I'm confused as to why you used finish nails to attach the showerboard to the plywood.Especially when there are so many other great ways to attach it.

I would not use the expanding foam as it might push the concrete out even further.

I'm pretty sure I've used the 3M sealant suggested by Burmboy and it's pretty amazing stuff. It's a polyurethane based caulk, correct?

A similar product that I have used is Vulkem polyurethane caulk. Freaky strong stuff.

Only problem with those might be if the crack is very deep. It that case a self-leveling concrete caulk might be better to fill up the gap. Then the last 1/4" of the depth can be filled with a poly-based caulk.

I used finish nails because the people at Home Depot said that that is what I could use the tack down the liner. Maybe next time, I'll look at ALL of my options.

As far as to deep of a crack goes, use what is called backer rod. This is a round foam strip, it comes in various diameters 1/4" on up. All you do is push the backer rod into the gap w/ a putty knife. Make sure its a little below the finished edge of what you are caulking. Another thing, use a rod which is a little larger than the crack you are tring to fill, otherwise it will slide too far down. Any home improvement store carries this, either by the caulk or insulation products. Goodluck, Clint