Woods Used: English walnut slab with paduk base, cherry figurines, walnut mountains
Fountain System: Aquarium pump with copper pipe (soldered), ballpeen textured funnel with patina finish
Slab Size: Approx. 22x26.5in
Finish: 220grit followed by hardwax oil (Rubio Monocoat) and ceramic top coat (Black Forrest), figurines painted with chalk paint

Project Challenges and Lessons Learned:
This has been my most "artsy" project to date I would say. There was very little planning upfront, I kind of just jumped right in. I started with the figurines. I was running out of time before Christmas and and knew there needed to be a home for them. I started brainstorming but struggled imagining what that would look like. I kept making compromises because Christmas was right around the corner. I had some visions (not involving rivers yet) and not enough time to execute. I did not want to compromise the end result so I turned the project into a 2 part gift. I am glad I did this.

To be perfectly honest, I did not set out on a quest to find a slab that could be made into a river as is. I was really just looking for a high quality slab in the right size. When I found this one with a natural cutout I said to myself, "Hey, that looks like it could become a river!" Again going back to the artsy theme, this was not planned. I saw the slab, a lightbulb turned on, and I went for it. Like my other slab work I think there is real value in bringing out the natural features of wood. This was no exception. It was perfect for the project so I grabbed it and the challenge was on. All of this to say...take your time, do it right.

In terms of the slab cleanup and shaping I think things generally went pretty well. I've had 50/50 success getting slabs flattened by others so I figured I would give it a shot myself. This was the first time I flattened a slab, and it went surprisingly perfect first try. I made up a gantry system out of linear rail and threw on a Dewalt router with a 3in flattening bit (scary!) to a custom router base I made. MDF is very flat (relative to wood working tolerances) and provided a good reference base. I needed to do a little shim work on the garage floor but it wasn't too bad. I gave the slab a few passes on both faces and it was good to go. I will be using this technique on all of my smaller slab projects moving forward.

I did a really thorough job sanding this slab. I researched sandpaper, got some proper 3M Cubitron and really took my time with this one. Consistency is really important. Use a light pencil marking on your sanding surface to ensure everything is being sanded down evenly. Take multiple passes at the same grit if necessary to remove blemishes and scratch marks. Do not skip a grit number. There are plenty of articles and YouTube videos on this stuff, I am not reinventing the wheel. But this project was proof that good sanding technique pays off. This was my best finish yet.

Lastly, the river. We all know that water + wood = bad. You can get swelling, warping, and other movement. This was really scary for me because after all that work I would hate to see this thing turn into a potato chip. I must confess, this was the one time I have used epoxy resin. I just could not come up with another way to protect the wood. There was some iteration to this design though. My first attempt was to only apply the resin in the river bed area and the rest of the slab was oil finished. I also directly fed the copper pipe up through the slab without a proper seal. After a few weeks I started to see some slab movement. It wasn't catastrophic but it gave me some anxiety. I drained everything and let it dry. After about a week the slab returned to its neutral position. I kept a close eye on things and found that the movement was only a few millimeters and then it would stop so not really a big deal. Overtime this became worse though and I decided to stop, let it dry out and come up with some ideas on how to improve the design. I had 2 theories.

The first was simply water ingress. There were a few points along the river bed where the epoxy seal could have been improved. The biggest issue was right around the copper pipe going into the slab. There was also a chance of water coming in from the bottom after it flows into the copper funnel. The second theory was humidity/water vapor coming in from the bottom of the slab since the tub of water was below.

For theory 1 I improved the epoxy sealing on the river bed with a second layer, paying close attention to any holes I may have missed the first time. I also applied a thin layer of epoxy just underneath the funnel on the bottom side. I could have applied it to a larger area underneath (or even the entire area) but again, trying to minimize epoxy usage. For theory 2 I purchased an "ultra quiet" 12V gaming computer fan and positioned it close to the water tub right at the funnel point. This would extract any water vapor in the air before it has a change to absorb into the slab keeping it nice and dry. It's a little more noisy then the aquarium pump but still completely reasonable.

I am happy to report that so far the testing for this is looking really promising. Absolutely no movement after a week of usage. Before there was obvious movement after 24 hours.

Technical Details