fly Line Grain

[Shakeyfly]

Hello again everyone!! I have been reading and taking in a lot of things that are posted with enthusiasm.

I have a quick question that I decided to present to you all regarding fly line grain. I see alot of people referring to Grain in lines. What is the grain in lines? I know they say it is it the sample of the first 30 feet in line. Is it the weight of line? Does it impact the rate of sinking? How can a line be 500 grain and floating? while there is a 550 grain fast sink?

I have seen that chart posted in several places. it says a 12 weight is 380 grains? then how can you end up with a 500 grain 9 weight?? :?::?:

Any clarification would be greatly appreciated, as all my previous thoughts on the topic is gone.

[ol_blue]

First, there are 7000 grains in a pound. There should be a certain grain weight for the first 30 feet per the AFTMA standard.
I know you’ve seen it but here is the info: http://www.common-cents.info/aftma.pdf
or here:
http://www.rodbuildingforum.com/index.php?showtopic=6274&pid=55735&st=0&#entry55735

Weight isn’t the issue of floating/sinking. It is the density of the line and the displacement it has. If it is less dense than the water, it will float. More dense, it will sink.

If the first 30 feet of a flyline is 500 grains, it isn’t a 9 weight according to the AFTMA standard. They may be referring to another length or characteristic.

[Shakeyfly]

@ol_blue

First, there are 7000 grains in a pound. There should be a certain grain weight for the first 30 feet per the AFTMA standard.
I know you’ve seen it but here is the info: http://www.common-cents.info/aftma.pdf
or here:
http://www.rodbuildingforum.com/index.php?showtopic=6274&pid=55735&st=0&#entry55735

Weight isn’t the issue of floating/sinking. It is the density of the line and the displacement it has. If it is less dense than the water, it will float. More dense, it will sink.

If the first 30 feet of a flyline is 500 grains, it isn’t a 9 weight according to the AFTMA standard. They may be referring to another length or characteristic.

thank you… so as just a further clarification, you can have a 300 grain line in both sinking and floating? Just the diameters would be different to compensate for the displacement and density?

[nb_ken]

@Shakeyfly

thank you… so as just a further clarification, you can have a 300 grain line in both sinking and floating? Just the diameters would be different to compensate for the displacement and density?

Yes, you can have floating and sinking lines which weigh the same, and it’s not just a matter of diameter. Think density. Although a pound of lead and a pound of feathers weigh the same, one floats well, one not at all. That’s a little bit of an oversimplification, but line manufacturers know all about density and buoyancy. That’s why 30’ of one line will float while 30’ of another line, weighing the same and having a similar diameter, will sink like a rock.

It’s the weight that determines which line will load a particular rod. It’s the density which determines its characteristics in the water.

[Shakeyfly]

Well now this is starting to make sense now. Thank you. Basically I was having a hard time understanding why people would choose to refer to a line by it’s grain rather than weight. Not realizing they were just providing a more specific weight of the line.