Cast net tutorial update

Started by Cone, March 19, 2014, 11:41:43 PM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

Cone

Well gents, I'm ordering some more mono filament netting tomorrow. I will try to take some video cutting out some new panels  and sewing them together. When I decided to order more netting, I went ahead and finished the seams and put the horn in the net I started. I will go ahead and start hanging the lead line and put in the braille lines. I need to get this one done before the spring mullet run here.
     This is how I figure the lead line. The formula for the circumference of a circle is 2piR. The measured radius is 12 feet. 2x12x3.14=75.36 feet. Multiplied by 12 is 904.32 inches. We multiply this figure by .92 because the net loses about 8 percent of its length when open. This gives us 832 inches lead line length. Each panel will take 83.2 inches of lead line.
     I counted the mesh at the bottom of each panel. There are 78 mesh including the one double selvage Sewn in at the seam for a total of 780 mesh.
    I'm using recycled leads from some old nets. I counted 200 leads weighed them. I wanted to have around 14 to 15 pounds of lead. I ended up with 270 leads being almost 15 lbs. I divided 780 by 3 and got 260. That's close enough for me. I will end up with 1 lead every 3 mesh.
    I measured a lead and it is 1.75 inches long. 1.75 x 260 is 455 inches. The lead line is 832inches. 832 - 455 = 377 inches. 780mesh -260 = 520 mesh. 377 / 520 = .725 inches.  There will be a little less than 3/4 inches between each knot between leads.
     I took the lead line I would be using and marked off 10 segments 83 inches long. I will now have to thread on the leads and start hanging it on the netting I will be posting pictures and explaining what I'm doing. I will also try to get some video of cutting out some panels when the netting comes in.
Bob
"Quemadmoeum gladuis neminem occidit, occidentis telum est." (A sword is never a killer, it is a tool in the killer's hands.)
   -    Lucius Annaeus Seneca, circa 4 BC – 65 AD

Makule

Bob,

Help me to understand how you calculate radius (net hanging from center to ground), versus number of eyes, versus spread of each eye.

You say the net will "shrink" about 8%.  Assuming the eye size is 2" (stretched), and each eye (at the lead line) is spread about 3/4", isn't the reduction in "height" of each eye actually about 20% (or the height of each opened eye about 1.6"?

I've been making my nets using that general average (depends on the exact spacing of each eye) so for a 12' net (handing radius) the spread is actually based on 10'.  For mullet nets, I will normally attach a 3' straight section (no eyes added after 12', but total comes out to 15').  The net walls sink straight down before the "roof" starts to sink.  Makes for a bulky net, but seems to work better for mullet.  Pancake nets don't seem to sink as fast and the mullet will swim out before the net hits the bottom.  Perhaps I can reduce the bulk and still maintain effectiveness net by using your calculations.
I used to be in a constant state of improvement.  Now I'm in a constant state of renovation.

Cone

Makule, I have built a few nets but I don't pretend to know it all. I have hung nets with the lead line calculated with the full radius of the netting. On a 12 foot net it would be around 75 feet of lead line. These nets will lay flat on the ground when opened. The lead line will however be a little long. The lead line will not form a perfect circle but will have waves in it of slack. To be honest they throw fine. I have a net that I still use made this way.
     I have tried to get more information from other people and resources. I have had people say anywhere from 90 to 95% of the circumference. The link I posted says 92%. I have built a few nets using this ratio and they lay flat on the ground when spread. they do not have the pucker in the top of the net. The pucker can be caused by too few mesh in a panel or not enough panels too.
     It seems to me that figuring a 12 foot net using a 10 foot radius would have it way under lead lined. I would prefer to have a net with a slightly longer lead line than one that is too short. The nets I make still have enough material for a good bell shape when falling in the water. I agree that a net that is too flat when sinking will cost you fish. There is a difference in a net laying flat on the ground when spread and how flat it is when sinking though.
      I do measure my netting. I have had the stated depth of the net vary by as much as six inches.  ???
     I am always open to input. It may well be that I am doing things wrong and by changing I may improve my nets. I fish for mullet quite a bit. In a lot of places they are trash fish. Here we have clean sand bottoms and they are one of my favorites.    Bob
     
















"Quemadmoeum gladuis neminem occidit, occidentis telum est." (A sword is never a killer, it is a tool in the killer's hands.)
   -    Lucius Annaeus Seneca, circa 4 BC – 65 AD

Derpherp