2020-09-06

Improved plant marker

I decided to make some markers for Debbie and followed the great instructions found at:

https://lakestewardsofmaine.org/wp-content/uploads/2013/11/IPP-Buoy-and-Anchor-Assembly.pdf

While I was making them I saw an opportunity for an improvement. When placing a marker one often needs to shorten the length of the cord, by tying off part of it in a knot. I realized that by making a notched holder in the PVC tube, and tying knots in intervals along the cord, the length of the cord could easily be adjusted when placing the marker.

I cut 6" lengths of pipe and 5" lengths of noodle. About 1/2" from the end of the pipes, I drilled 3/16" holes big enough to take the nylon cord.

Holes drilled in one side near end of each pipe

I then cut a notch from the end of the tube to the hole so that the cord can be pulled into the drilled hole.

Cord length adjusted by pulling cord into the notch

I threaded the cord up through the pipe and through a washer, then tied an overhand knot at the very end. I also made overhand knots at approximately 1 foot distances along the cord.
 
Each knot represents a different effective length

The washer prevents the last knot on the cord from separating from the float. All the other knots can be used to set the length of the cord simply by pulling the cord into the notch on the pipe.

Cord at maximum length...
A washer prevents last overhand knot from going through the tube.

I had some bits of plastic I could use as the end washer, and they have the advantage of not rusting.

When making the cement weights, I decided to simply drill a hole in the bottom of the plastic tubs and thread the cords through before adding the cement. It dispenses with the need for an additional loop to be set in the cement but does dedicate the tub to the marker.

Cement weights with cord running right through.

This approach of leaving the tub on the weight, also means that any chance of invasive plant seeds and fragments clinging to the cement is vastly reduced.

Update #1: 5" of noodle tube is too long. It has enough buoyancy to hold the cement weight off the bottom!

Update #2: I found I can use the drill press to make the notch in the pipe by drilling a few holes in a row.

Update #3: We went to the transfer station (dump) and collected some brick that have holes in them. These make instant weights. These weights should be cleaned well (and dried) before being reused.

Update #4: I now write the length of the marker on it to enable making accurate depth estimates. 

If the weight ages so long that the yogurt tub becomes brittle, break the tub off so it does not present any sharp edges.