Is mono buoyant enough to float jig heads used in tubes? If I cast a weightless 5" senko into 30' of water will it hit the bottom or will the 6lb mono eventually stop it from sinking?

A bare hook will sink monofilament line. 

55 minutes ago, Shaggie said:

Is mono buoyant enough to float jig heads used in tubes? If I cast a weightless 5" senko into 30' of water will it hit the bottom or will the 6lb mono eventually stop it from sinking?

the bait will hit bottom but you will have a bow in your line , reducing sensitivity and when you do get bit that bow you have in your line will make it difficult to get a good hook set since you have to swing through all that slack before you can move the hook in the fishes mouth , that's why mono is mostly used for moving baits and flouro for dropping baits like a stick bait and flouro for jigsand shakey heads  where you want the sinking of the flouro making a straighter line to your bait , increasing sensiyivity and quicker hooksets on light bites .

 

1 hour ago, Shaggie said:

Is mono buoyant enough to float jig heads used in tubes?

No

1 hour ago, Shaggie said:

If I cast a weightless 5" senko into 30' of water will it hit the bottom or will the 6lb mono eventually stop it from sinking?

No 

Mono works just fine its been used for fishing for as long as any current fishing line produced. Yes copoly, braid, and fluro all have some better qualities for certain particular situations but there is no reason you cant fish with mono on jig heads or senko baits.  

Mono and braid have a specific gravity of about 1.0, same as water.  Braid with the Gore thread is a little higher.  FC has a specific gravity of about 1.5.   A sinking line, like FC , will screw up the action of most surface lures, causing a jerk to pull them under, not pop on the surface.  I use braid with a FC leader for soft jerks in fairly shallow water, and it works fine.  For 30 feet, I'm not patient enough to wait for anything unweighted to get to the bottom.  Keep in mind too that the resistance of the line to water will act like buoyancy if you move the lure.  It may get to the bottom, but most likely will not stay there when you move it.  Unless it's weighted.

Nylon monofilament fishing line is neutral buoyant in 70 degree fresh water and absorbs water. Super braid is lighter than water and the fibers tend to trap air reducing it's weight, increasing buoyancy, if Teflon coated slightly increases the weight. FC is heavier than water and doesn't absorb water.

What affects a surface lures action with FC is the slack line tending sink creating a underwater belly in the line with the at rest.

When fishing with mono line using underwater lures like jigs or T-rigs all the slack line belly is tightened to move the weight unless there is current. Using mono for crank baits the lures resistance to move or dive keeps the belly out of the line.

So many myths and miss understanding about fishing lines, mostly due to advertising claims.

Tom

Nylon "floats", yeah right, like a cork, yeah right.

No one said nylon floats like a cork. Since its specific gravity is the same as water it has neutral buoyancy.  That is nothing like a cork.

Hello everyone, I do educational videos about technical specificities, I am looking for a completely neutrally buoyant string of the density of 0.99-1.02g/cm3 like a fishing line, which remain one position below water surface, to mechanically show earth curvature over at least 3300 yards. What did you say about Nylon floating neutral? Do you mean with a bait? I wont attach a bait, I pull on one side, but I need good accuracy, I havent found any line with the specific density et, but I found those materials:

COC - Cyclic Olefin Copolymer 1.010-1.030 g/cm3
PP, 10-40% Talc Filled 0.970-1.250
PP, 10-40% Mineral Filled 0.970-1.250
PP - Polypropylene 10-20% Glass Fiber 0.970-1.050
PPE, Impact Modified 1.000 1.100
XLPE - Crosslinked Polyethylene 0.915 1.400
PE/TPS Blend - Polyethylene/Thermoplastic Starch 1.000 - 1.050
PPE, Impact Modified 1.000 1.100

What fishing line can you recommend me, that floats completely neutrally buoyant please?

thanks Kevin

Hmmmm....have you considered braid?  That's probably your best bet.

I used to fish for King Salmon using salmon roe under a bobber with mono line, before modern spectra fiber braid was available.  The mono would slowly sink, causing a large belly in the line, making setting the hook difficult and mending the line nearly impossible.  I found applying dry fly floatant or wax on the mono line helped it float, and float made bobber fishing for kings less difficult.  When braided line came out I quickly discovered it floated, solving the large belly in the line problem, and as a bonus it also had very little stretch making it a perfect line for setting the hook while bobber fishing.  At the time I started using braid for all of my fishing, but soon learned that it's advantages over mono were few, and now I only use it for specific applications, where ability to float, low stretch, or strength per diameter are the most important requirements of my line.