Great Stuff 99112849 Smart Dispenser Pond & Stone, 12 oz, Black

Building or maintaining a rock waterfall means constantly battling water loss. If water slips into the gaps under your flagstones, your waterfall loses its visual impact and drains your reservoir. I used this Great Stuff Pond & Stone Insulating Foam Sealant to bridge the voids between my landscape boulders.Historically, single-use spray foam cans are notorious for clogging permanently after one use. This "Smart Dispenser" version completely changes the game for multi-day DIY builds. Here is my field test of how it performs under direct water exposure.1. The Smart Dispenser (Is it actually reusable?)Standard red-straw spray foam cans seal themselves shut within two hours of your first spray.The Performance: The spring-loaded mechanism on this new clear-trigger assembly stops the flow instantly when you let go of the trigger, eliminating annoying, messy post-drip strings.Reusability Test: I deliberately left a half-empty can sitting on my workbench for 12 days mid-project. When I picked it up again, I simply scraped a tiny bit of cured foam off the very tip of the tip, tipped it over, and it immediately dispensed a smooth, uniform bead without sputtering or locking up. The 30-day reusability claim is completely accurate.2. Hydrodynamics and Placement StrategyWater Diversion: It is critical to note that expanding polyurethane foam is a water diverter, not a 100% waterproof rubber membrane. It expands beautifully into deep crevices (up to 1 inch thick) to form a dense, closed-cell barrier. By filling the voids beneath my spillway rocks, it forces 100% of the stream to flow visually over the top face.Color Blending: The foam cures to a dark charcoal/black hue. Against slate, granite, or river rock, it melts away seamlessly into the natural shadows of the structure.3. Material Bonding & Curing RealitiesIt clings aggressively to both porous concrete pavers and rough, natural stone.Application Prep: While the label states it can be applied to damp surfaces, I achieved far better adhesion by wire-brushing loose dirt and mud off the rocks first.The Cure: It expands with minimal force (so it won't push your heavy stones out of alignment) and cures to a touchable state within an hour, reaching full structural cure in about 8 hours. Once cured, it is completely inert and 100% safe for koi, goldfish, and aquatic plants.Pros & ConsPros: True 30-day reusability saves money on small touch-ups, black color blends perfectly into rock shadows, fish and plant safe.Cons: Like all polyurethane foams, it degrades under intense, direct sunlight over time; you must tuck it deep into shadows or paint/coat exposed edges to protect it from UV damage.Final VerdictIf you are tired of throwing away half-used cans of messy building foam, the upgraded Smart Dispenser makes this product worth every penny. It provides a fast, sturdy bond without the mess of mixing traditional mortar, drastically increasing waterfall flow performance. No odor easy to use. Wear gloves

I have been using aquarium cement for putting rocks together for my reef aquarium but it was always a pain and it didn't really hold well together. This foam is completely different beast. It holds the rocks to get us so well you can grab it by one of the rocks and everything else stays securely attached to it. The strength is much better than the usual insulation foam in the spray can you can buy at Lowe's. The yellow kind. A strong word of warning though, this black foam is really nothing like the usual yellow one. When you work with it, absolutely use disposable gloves because this thing sticks to your skin so well that it's took me more than a week to get it rid off my skin. And it's more that my old skin just peel off after a week, not that the foam would peel off the skin. On the other hand it's the testament how well this thing sticks. Which also means you don't have to use too much of it on the rock. It will expand quite a bit and if you put too much it will just get out everywhere. EDIT: I have the structures in my tank for almost a year and everything holds still like the first day. Moreover, Even tho the nozzle dried, I removed it and put there another one from normal foam can and it still worked almost a year later! I glued 5 towers (4-6 stones, 16-20" tall) and about 10 smaller structures and there is still some left in the can.

I was hesitant the spray patterns would make it look weird so I used a glove to mess it up so it was even while spraying. Came out strong at first and then fizzled out and was kinda hard to spray. Can get messy if you aren't careful. I used one and a half cans for the back of my 20gal tank. Pretty easy to do if you are patient- I let mine cure for a week because snakes are sensitive to glasses and fumes. Afterwards I took a sharp little knife and carved some peices in the back so they looked a little more rock like. Looks amazing ( I'm getting a charcoal pool soon so it will match the back wall haha). Super happy with the turn out!

This stuff is fabulous and if you don’t use up the entire, can you can still get the rest of it out hours if not a day or so later. It here’s the rocks to the pond structure really well and fills in any potential gaps. But but but but but this thing needs to come with a warning label. If you get it on your hands, it is almost impossible to get the black off your hands I had to purchase a professional orange hand wash and even then it took me over an hour to get most of the BLACK off my hands so wear gloves big must wear gloves and follow the instructions about wearing eyeglasses. I can only imagine if this stuff got in your eyes.

worked wonders, easy to use, no smell!

Great for bioactive terrarium build.

Excellent product quick shipping

Not black foam. Can says black, but tan foam came out. I still used it because I was in the middle of building a backyard pond. It also does not cover very much. I have a 2’ x 3’ stone wall, with 10-11” stones. The one can didn’t even finish filling in the gaps.

Muy rendidor, fácil de aplicar

海外のビバリウム制作動画を見て購入。 類似商品と比べたら、高いけど、国内製の黒色発泡ウレタンを探すことができなかったため、満足して使いました。 ただ、ウレタンの出力が均等ではなく向きによったりする傾向が強い。

Works great but wear gloves lol it stains the hands and even gas doesn't take it off.

El funcionamiento es bastante raro para sacar la espuma veces se escapa mucho aire y no tira espuma no se infla tanto y aparte tiene poco contenido Cabe destacar que he usado muchas espumas no es la primera vez

Really good but horrendously overpriced