Raft Building and Liner Installation
Rafts in Deep Water Raft “Box”
This article was written in response to several peoples questions to me (Neal Thomas was the most recent). Both had purchased the Friendly Aquaponic’s Micro System 64 plans and needed help with details. Apparently there is still not a Step-by-step how to build the rafts good enough for the non technical user to confidently build the rafts. I also assume the current version of the plans does not include links to Tim’s fine videos. What follows is some info I thought would be helpful.
Reference the Micro System 64 Instructions, you purchased, for dimensions and main details.
It is 20-mil thick Dura Skrim R20WW, made from Low Density Poly Ethylene (LDPE) available from Raven Industries, Sales Rep Courtney Mendelson, National Market Account Specialist, Raven Industries – Engineered Films Division,Phone: 800-635-3456. It comes in 6-foot and 11-foot 6-inch wide rolls. Aloha, Tim
Reference this Article.
Introduction to Friendly Aquaponics mission, video
Q&AQ1: How do you build the troughs? I need Step-by-step Instructions.
Too much detail needed to answer it all here but perhaps this overview will help:
This info will extend the info in the Friendly Aquaponics Micro 64 System instructions.
Raft “boxes” for the Micro 64 system are made from non treated 1/4″ plywood. This takes 4 pieces per 4×8 raft. Paint all sides with 2 coats and all edges with 3 coats.
Next cut and paint all sides of the 4 each top edge 2″x4″s. These are nailed on the top edge of the plywood and from a thicker width for the raft “box” on the top. Nailing is after all lumber is painted and well dried.
Cut the 4 top edge trim pieces from 1″x2″ lumber. I recommend high quality white wood or smooth sanded cedar.
This design does not use any physical (wood) bottom, just the liner. Make sure the surface you use it on does not have any bumps or sharp edges or thick weeds that might poke through your liner. I raked the grass, removed the sprinkler head, and lay a thin coat of sand to fill the ground lever. My raft beds sank into the ground on one corner because I added soft dirt and did not tamp it firmly.
Optional: I installed 2 each 2″x4″s on each end to hold the bottom of the 1/4″ plywood together. If you add this, measure, cut, and paint these. (Later screw the long sides together to from a right angle. Then screw through the 1/4″ plywood edges, at the corner of the raft, into the 2″x4″s to hold the plywood corner / edges together.) This addition also acts as legs to provide more support to the raft “boxes”
Use an good quality outdoor paint that has UV protection but no additives. Some paints have anti-mildew and anti insecticides in them!
Paint all edges and sides of all lumber. Make sure it dries well between coats. Using a thinner coat, brushing paint so it is an even thickness, helps it all dry at the same consistency. Use a good brush. Store in a large seal top plastic bag when not in use. I put in the refrigerator. Paint on 2 coats to everything and 3 coats on all edges of the plywood.
Screw the plywood to the 2″x4″, from the inside, as per the instructions. I think I used 1″ sheet rock self tapping screws but you should use galvanized or stainless steel (expensive). Be sure you use the flat head so the head of the screw will not catch or damage the liner.
Assemble the raft “box” by connecting the ends of the 2″x4″s, as per the instructions. I pre-drilled 3 holes near the ends of the side 2″x4″, and drilled a chamfer so each screw head would be flush when installed. These 3 screws go through the long side 2″x4″s and into the end of the shorter (end) 2″x4″s.
Purchase and cut as per the FA instructions. Install the liner as per the videos.
Click the here for access to the Liner installation videos #1 – #6by Tim Mann.
End first, side next, corner forms a triangle that you overlap over the end. You can also put the triangle on the side, or fold it under either, to leave a nice straight line up the corner. Easier to do the last step if you fold and crease it as and outside fold and then refold into the inside position.
Note: I used pond liner because I couldn’t find the DuraSkrim easily. It has worked for 22 months and it is OK to start with but it will need to be replaced after 2-3 years, or if I have an accident. Don’t walk on the pond liner (when it is wet or dry) as that will be inviting a hole.
Make sure you get your staples straight and pretty like I did (not!).
Rent or buy a hammer stapler as it makes the job MUCH easier than a hand stapler. Ask your friends. Likely you know a friend that knows a friend with one to loan. I saw them from $20 to $40 dollars at Home Depot. You could try Harbor Freight for lower cost that could still do the small job well enough.
Install the 1″x2″ trim on the top edge of the raft box. This will cover the edge of the 2″x4″ and the edge of the 1/4″ plywood. Note that this surface now has the liner stapled to it. I used flat head screws spaces about a foot apart. My holes were pre-drilled through the 1″x2″ and chamfered, so the screw heads would not poke me when I sit on the edges. 🙁
Notice the 1″x2″ trim installed on the top edge, in the picture.
As you can tell from the pictures, I also added 2 short 2″x4″s to each corner so I could keep the edges of the 1/4″ plywood together. If you add these, screw the long sides together to from a right angle. Then screw through the 1/4″ plywood near the ends, at the corner of the raft “box”, into the 2″x4″s to hold the plywood corner / edges together. This addition also acts as legs to provide more support to the raft “boxes”
Custom corner “legs”.
Picture of the freshly assembled raft “box”. It is a good idea to lay your liner out in the sun for a few hours so the creases will go away. Just make sure it is not hot when you install it as you don’t want it to stretch. I should have done that. See the creases, they make it more challenging to install.
From here on I have a general sequence of info. Reference the instructions you purchases and perhaps these pictures will help clarify some of it.
Raft material, Corning Blue board insulation; painted.
This is how I laid out my raft holes. I used 1/4″ plywood to make a spacer / drill template with 1/4″ holes in it spaced 6″ apart.Use a dry erase marker to make the holes on your foam and also mark where you want to cut the foam into smaller rafts, like 2’x4′ or 2’x2′. Make sure you are happy with this arrangement. I cut all my hole spacings the same on both 4’x8′ rafts.
You could build the raft with holes 5″ apart if you like. Here is a sample of that hole lay out. This works well if you plan on growing small to medium size greens. Bigger plants get a little crowded but still do well. You might try pieces of the raft with both 5″ and 6″ spacing.
I used 2″ net pots and 2″ holes. Make sure you buy the net pots with the lip on the top else they will fall through the 2′ hole.
I cut my raft into 2’x4′ pieces after I drilled the holes, using a skill saw.
Then I turned the foam over and located the 1/4″ hole the center drill bit of the hole saw made, and drilled from the back side to complete drilling all the way through the insulation. Your hole “plugs” should pop out like this.
Save the plugs to keep sunlight out of the water so Algae does not grow, if you don’t have the holes filled with plants.
Deep water raft “box” with rafts:
Alternative mount for Air Pump. I use this near my fish tank for my other system. It is a fill-and-drain system.
Example routing of air lines from Air Pump to the other end of the deep water raft. This is 3/4″ PVC electrical conduit that I buried. The tubing can be pushed through it (or pulled with a sting that has been blown thru it) for easy replacement or servicing.
Example Air Stone on end of air hose. This is in my fill-and-drain system but all are the same setup.
This is how I mounted my water pump. I have added a “water faucet” that I would highly recommend. It makes getting water for seedlings, etc. very easy.
The PVC pipe to the faucet located on the side of the raft box, is in the middle of the picture. The faucet is to the left. The line to the fish tank is to the right and has a faucet on it so I can isolate the water inlet line to the fish tank. When I do this I turn off the pump or open the faucet to release pump pressure and preserve the pump.