Introduction: Loon Nesting Platform (Work in Progress Updated 03/15/20)
The inspiration for this project is simple. We have a place on a lake in Northern Minnesota and frequently see loons trying to find safe nesting locations. It is harder than you might think given that the Eagles that live on our lake are not shy about robbing the loon nests.
This is going to be a work in progress so there will be updates to the steps, and addition of pictures as the project progresses. For right now the instructions are based on illustrations.
Note: Loons in Northern Minnesota begin searching for suitable nesting sites as soon as they arrive in the spring, and they use the nest until the chicks can safely navigate the waters. Figure between April 1, and mid-to late August. So the safest way to "Place" a nest is to drag it out onto the ice in February or early March and have it positioned to drop into the water when the ice melts. You will want to pull the nest off the lake in August to do repair and cleanup before any muskrats start to pile their own building materials onto the platform for a winter retreat. They have been known to sink nesting platforms.
Step 1: Supplies
The basic materials are PVC Sewer pipe for floatation. Treated 2x4s for structural support of the nest with a hardware cloth platform support. The tubing over the top supports any form of screening to prevent aerial predators from descending on the nest. Lastly some form of anchoring to keep the nest in place on the lake.
You can use various size PVC tubing, but I chose 4" DWV Schedule 40 cellular core pipe for its strength. I'm hoping this nest will see many years of service. NDS or Sewer drain grade pipe can also be used, just be aware that you must use the same grade of pipe for the elbows as you do for the long runs. They are different outside diameters so not interchangeable.
- 4 x 4" x ~4' PVC pipe NDS or DWV Sch-40 - Floatation sides
- 4 x 4" PVC 90-Degree Hub x Hub Elbow NDS or DWV Sch-40 PVC
- Solvent Primer & PVC Solvent Cement. Small packs like the Oatey-handy-pack are available with 2 4oz containers.
- 3 treated 2x4"x~4'6" - Fitted into the curve between the openings of the platform.
- Tyvek strips ~16in x 4' stabled between bottom 2x4s to keep water from splashing up to the nest.
- 3 treated 2x4"x~5' - mounted on top of the lower platform support and providing anchoring for holding the wooden frame to the PVC floatation support.
- 3 1" irrigation tubing 8' (24') - Attached to the ends of the top 2x4s creating the arch of the protective cover.
- 6 22" Metal strapping (12') - Strapping to wrap under the PVS tubes and bind them to the top 2x4s.
- 3x4'6" either 1/2" or 1/4" Hardware cloth to cover the 2x4s and support nesting materials.
- 13' - 4' Wire fencing/Plastic Safety Fence/reed mat - several options exist for the protective cover material details will be in the instructions.
- Wide head wood screws 3", 2", 1 to 1 1/2"
- 24 5"-6" Zip ties
- 4 reflectors
- 1/4" Polypropylene Hollow braid or 5/16 Nylon Rope
- 2 Cinder Blocks or cement filled bottles.
Step 2: Planning for Differences in Materials (Before You Cut)
My goal was to have the space between tubes be 4'x4', with a finished dimension of roughly 5'x5' and about 3' tall.
Pipe configurations make exact dimensions a little challenging to specify. For the tubing I'm using, there is about 1" of space between where the end of the tube pushes into the elbow, and where the curve of the elbow finishes it's 90 degree turn. Some fittings make a sharper turn, some more gradual, so your finished dimensions will either be slightly different, or you will have to calculate the offset to adjust the length of your side tubes. I will share what my situation was, but your mileage may vary. If you don't make any adjustments to the tubing lengths, be aware that the length of your 2x4s and platform materials may have to be adjusted to accommodate the change in the tubing's dimensions. Measure twice, cut once.
My 4" Sch 40 Tight bend elbows extend the length of the side by 1 3/4". See image. I nested a pipe into an elbow and marked the depth with a pencil. I then pulled it apart and with another pipe set into the elbow I aligned my marked line with the end of the elbow's opening and measured the offset. This 1 3/4 inch needs to be subtracted from the overall length for both ends, since there are two elbows, so my final tube length was 44 1/2" (48-3 1/2"). Cut all 4 tubes to this length.
Step 3: Floatation Base Construction
Lay out your tubing. You will need a fine tooth a hack saw, or Sawzall to trim your tubing to length. A file or sandpaper would be useful to clean up the resulting course edge making insertion into the elbows easier. This size pipe is difficult to get off once it has been nested, but it is worthwhile to seat a pipe into an elbow, mark the lip of the elbow where it meets the tube and then pull the elbow back off. Measure this distance and mark both ends of all the tubes with that line for the depth that will need priming, and glue.
Gluing PVC pipe is a two-step process. The First step is not time dependent. Apply the primer to both the inside of the elbow, and the outside of the tube. Most primers are colored so you can see that you covered everywhere.
The Second step must be done fairly quickly. It only takes about 10 seconds for the cement to start to set up. Lay everything out on a flat surface so your final platform will lie flat. Follow the directions on the solvent for proper application. Apply the Primer and Solvent and then push the tube into the elbow with a twist. You may need to use a rubber mallet to seat the tube in fully. Ideally you will see a small amount of cement pushed out along the joint.
Do the sides in pairs.
- Side A with its two elbows 1 & 2,
- Side C with its two elbows 3 & 4.
- Insert side B into elbow 3
- Insert side D into elbow 4.
- Now you have A with its two elbows and B C and D as a large U.
I hope you got a lot of practice with the cement because these last two need to be done together and will be much easier if you have two people. Be generous with the cement, it will actually make it easier to tap these together, and it will make up for the fact you won't be able to apply any twist as you push it all together. I used a bungee to prop my big U against a sawhorse applied the primer and solvent and then with help pulling the tubes into line with the new elbows pulled the top tube unto the bottom big U and then tapped everything tight with a rubber mallet.
Check all the joints. This needs to be airtight, so you should see some amount of cement pushed out all the way around each joint. If you do not, then use the brush and apply a bit more solvent to the joint to fuse the PVC in that spot.
Step 4: Wood Frame Base
The Wooden frame portion of the base is made up of two layers of 2x4s The first layer needs to have its ends trimmed to allow the boards to nest into the profile of the PVC pipes. The easiest way to do this is to use a piece of scrap tubing as a template to mark your boards. Cut or chiseled a curve into each end of three boards cut to fit even with the top of the curve of the PVC pipe. Set these boards into the PVC base. They will be anchored by the next layer.
Cut some Tyvek sheeting to span the three base layer boards. This can be a single 3' wide sheet, or multiple 16" wide strips. Staple the Tyvek to the 2x4s.
Cut the upper 3 2x4s to fit a little wider than the outside of the PVC base. Lay these on the base. Find the center of the PVC pipe to place the center most upper 2x4. Attach the board to the 3 lower platform boards with 2 3" wide head screws at each junction. Measure 16" from the center of the secured board to either side and place a mark. For each of the two remaining upper deck boards, lay them centered on that mark and fasten them like you did with the center board. You now have the upper frame waiting to be secured down to the PVC pipe.
As show in the close up diagram of the strapping relative to the 2x4 and PVC pipe. Use the metal strapping and a 1" screw the end of the strap to the edge of the 2x4, centered over the PVC tube. Bring the strap across the 2x4 and wrap it under the PVC tube, bringing it up on the opposite side of the 2x4 where you can use a screw to fasten the strap back to the 2x4. Cut the strap past the screw. Now put in a second screw in the strap near the opposite side of the 2x4 as shown in the diagram.
Step 5: Nest Support Mesh & Ramp
So far you have been constructing the structural framework fo rthe nest. Now using the hardware cloth, cut it long enough to extend across the whole frame, and extend beyond the tube on one end where it will reach down into the water.
Adding a 1' section of plywood by stapeling it under the hardeware cloth should let it sag down into the water for aid in getting onto the platform. You can score or cross cut the plywood surface to privide improved traction beyond tthe hardeware cloth's reach.
Step 6: Cover Frame
The cover of the platform is supported by three sections of Irrigation tubing 8' long. Drill 2 holes through the irrigation tubing near the ends. Use two 2" screw with wide heads, or with washers and attach the ends of the tubing to the ends of the upper 2x4 frame with the arch perpendicular to the platform.
Cut 2 pieces of plywood approximately 30"x36". Hold each plywood piece up to the arc of the irrigation tubing and mark the curve on the plywood. Cut the line of the arch. Drill a 1/4" hole near each end, and at the center of the arch. Don't attach these yet, they will be attached with the zip ties used to attach the cover.
Step 7: Cover
You can cover the platform with many materials, wire fencing, plastic snow fencing, or a simple reed mat. I chose to use a reed mat for this plan. Trim the mat to match the length of the supporting tubing. Using plastic zip ties attach the mat to the Irrigation tubing.
When you near the top of the arch for the outer tubes thread the zip ties through the mat, around the tubing, and through the holes on the plywood arches. This will solidify the arch, as well as provide a mounting surface for two reflectors and the registration number.
As you bind the cover to the center arch, use a zip tie about half way up to secure a reflector on each side.
Step 8: Creating Anchors
The platform should be anchored by at least two points at depths preferably greater than 5'. You can use cinder block anchors, or my preference is to fill a 1 gallon bottle with quickcrete.
Attach the anchors with 1/4" Polypropylene Hollow braid or 5/16 Nylon Rope. Poly is very light and easy to create loops via splicing, but very hard to tie a knot that won't unravel. Nylon rope is a little heavier, and more expensive, but is easier to secure with a simple knot.
Step 9: Placing Your Platform on a Lake
Before you put your platform out on a lake, it is a requirement in the state of Minnesota they must be registered with the county police. They will give you a registration number that must be displayed on the platform somewhere visible from a passing watercraft. It is also required that these platforms have a reflector placed on all four sides to visible to boaters from all directions of approach.
The Minnesota DNR recommends that the platform be placed in an area outside any busy traffic lanes for motor boats or paddle traffic. Placing it near lake foliage provides cover for the comfort of the nesting family. It should be placed to provide shelter from storm winds.
Step 10: Floatation Options
The design of the floatation base in this plan uses 4" PVC pipe. This should be sufficient in reasonably calm waters. If the waters are prone to a lot of wave activity, you might consider trading up to 6" pipe, or this 4" variaiton with two T sections and an additional central tube.
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