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Weights And Measurements

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I was looking at the Solarez thread and wanted to get a 'feel' for how much product you get for the $$. I figured that it was best to do a comparison with the topcoat known by all lure builders, Devcon two ton.

 

The next job was to sort out the units and do some conversions. Man, you guys over there in the USA are really messed up.

 

Some packaging quoted US as well as metric measurements, this worked well for me, as I knew exactly what I was dealing with. The problem for YOU, is that all the packets quote in ounces. Now, is that an ounce weight or a fluid ounce, which you may not realize, is a measurement of volume. Some packets quote ounces, some actually mean ounce weight, but most actually mean fluid ounces and the difference is significant.

 

History – When America was stolen from the native Indians (discovered), the weights and measurements used in England were adopted. At that time, a fluid ounce was the volume occupied by one ounce of wine.

 

In 1824, realizing how stupid this measurement was, England changed the definition of a gallon to the volume occupied by ten pounds of water. This provided a much better link between volume and weight. The pint was 1/8th of a gallon and there were 20 fluid ounces in a pint.

 

America decided not to keep up with the technology and stayed with the old units. But the pound weight was still the same, so the American fluid ounce was rounded off and established as 1/16th of a US pint. The numbers did not round off well and so there is a difference between the US fluid ounce and the rest of the world.

 

As far as weights are concerned, the US decided to keep up with the rest of the world’s definition, and so 1 kilogram = 2.2046226 pounds, usually rounded up for convenience to 1Kg=2.2Lb.

 

So why does the rest of the world like the metric system so much:

 

Weight

 

the Kilogram is broken down into grams were 1Kg = 1000 grams.

The gram is further broken down into milligrams, 1 gram = 1000 milligrams.

 

Volume – this is the really clever part that blows away all other measurement systems:

1 litre = 1000 cubic centimeters (cc)

And, because the density of water is 1 gram per centimetre cube;

1 liter of water weighs 1 Kg. This is how the kilogram weight and the liter volume were defined, by weight and volume of water.

 

So why do I think that the metric system works so well for lure builders:

 

Lures are all about density compared to water.

A floater will have a density less than 1gm/cm³.

A sinker will have a density greater than 1gm/cm³.

A suspender will have a density exactly 1gm/cm³.

 

There is one more decimal unit which refers to density.

 

Specific gravity (SG), this is a unitless number that represents density as a decimal were the SG of water = 1. This ties in perfectly with the decimal system, as the density of water = 1gm/cm³. The numbers are the same and you do not have to write ‘gm/cm³’.

 

So why is this good?

 

Example – you have a wood that has a quoted density of 31Lb/cuft. The same wood is quoted as SG=0.5

 

I know, looking at the SG number that this wood is half the density of water and when floating, half the body will be sticking out of the water.

 

Give me any SG number and I immediately know how much it floats. As a lure designer, I aim for a final SG of between 0.9 and 0.95, so that between 10% and 5% of the body is above the water.

 

The American units tell me nothing, except that a cubic foot of the wood weighs 31Lb and what use is that knowledge to a lure designer. Even worse, some densities are quoted in ounces per cubic inch oz/cu in; density = 0.287 oz/cu in – useless information.

 

With the US units, I would have to develop a ‘feel’ for the numbers, I think of it as groping in the dark. With metric units I do not have to ‘feel’ anything, I can SEE and HEAR. The numbers speak to me and tell me everything that I need to know.

 

Do I feel sorry for you guys – No. There is nothing to stop you adopting metric units. If you choose not to, then either you don’t mess with densities or you are very good at mental arithmetic.

 

What is my point/ - no point, just that the thread that I was going to write on topcoat prices was abandoned as too tedious, so I decided to have a rant instead.

 

Dave

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Dave , ...I'd just like to be a smartass today :lol:  , .........water reaches it's highest density or concentration at a temperature of 3,98° Celsius(approx 39° Fahrenheit) , above or below it becomes a tad lighter again per given volume .

 

Sorry , I couldn't help it :P   , ....greetz , Dieter :yay:

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I've never tried to achieve neutral buoyancy , since I do not really like such lures , so it's not a problem to me  ,.......but now I have a possible explanation , why the sink rate of some of my glidebaits turned out to be a little different in the outdoors fishing cold autumn water , ...but water temperature is just one factor out of a few others ,.....not a problem , that one can't easily solve by switching splitrings , hooks or wire leaders .

 

Hopefully your thread might really convince some folks to go metric , as it is just easier and logical to use ,......for a single person it's just the habit and maybe traditon standing against it , but for a nation it means a really big and costly venture , but which would surely pay off after some time .

 

Dave , as a seasoned Englishman you grew up with the old imperial measurements , I suppose , .....so you're surely able to make a first hand comparison .

 

 

Greetz , Dieter :yay:

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Dieter - indeed; I was brought up on pounds, shillings and pence before we went decimal. hundredweights, Stones, pounds and ounces, miles, furlongs, chains, yards, feet and inches. My first 20 years in design was all aircraft and that industry is all inches.

 

It wasn't until I went to work for SAAB in Sweden that I came across metric, and then I chose to change over completely, it just made sense to me. It is just a personal decision and a small commitment, after that it takes very little effort. Hell, you can even do both sets of units. I can think in both, even to this day, except for lure design.

 

Measuring lure lengths in big, clumsy units like inches is just wrong. Enough said about densities above.Grams or cubic centimeters are perfect for weighing out epoxy rather than lumpy fractions of an ounce.

 

Metric is precise and gives an immediate understanding of a measurement, an immediate visualization of what you are dealing with.

 

Example - a 27/64" drill is precise, but to get a feel for the size, you have to do some mental arithmetic to find the nearest size in 1/16" units: 13/32" 6.5/16", so it is just less than 7/16" which is just less than 1/2". The equivalent in metric is 10.7mm.

 

Threads, Whitworth, UNF, UNC, Wire gauges 18SWG, 20SWG what a nightmare. Threads are M6 (6mm diameter) M8, M10, wire thicknesses are 1.2mm, 1.0mm, 0.9mm, everything is just simple.

 

ENOUGH! I hear you say.

 

DAve

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How would a guy ever build a bait that catches fish if they didn't.....never mind.

 

:lolhuh:

 

In regards to metric I use it at work always and of course everyone is taught it as a kid.   Outside of work it is looses it value.

 

Looses it value only because it isn't the default.  I wished they would change but don't see it happening any time soon.  

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@ Travis

 

I work in the metal industriy grinding cutting tools of steel and carbide into tolerances of only a few microns(1/1000 of a millimetre) , ...off course some of my CNC controls have the option to chose from metric and imperial measurement , ........but I did ask myself several times , how one could have the brains to program neccessary subtle adjustments of a few microns converted into imperial measurements , especially when having to operate several machines , .......guess , the only things , that would get reliably programmed , are devastating and costly errors ?

 

Otherwise I do agree , ...it's a real big effort for a nation to go through such major change of measurements system ,...the industry would certainly get on the rampage .

 

Greetz , Dieter :yay:

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Dieter, I really wished we would change but figure we will hold onto it as long as possible.

 

 I worked in the metal industry for a short stint.  I was in the lab and just reported stuff to them in percent composition for the most part.   I would see shipping reports and laugh as at times metric ton was used, short ton, long ton, and sometimes pounds.  :censored:

 

The chemical plant I worked at prior was switching over but that was speed by acquisition from European companies.  Now I work in pharmaceutical research and outside of some very rare instances all SI.

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The metric system of weights is something you either grow up with so it becomes second nature and inherent in your thought and evaluation mental processes - or it doesn't. I know what a gallon looks like, what it weghs, etc but the same is not true for a liter. So I think in gallons, in ounces, inches, etc and not in their metric analogs. It's how I make sense of the world. I know centimeters, liters, etc make math a lot easier but that really doesn't matter. As long as American adults are raised on our outdated system, I suspect it will persevere. I keep a metric to U.S. measurement calculator beside my workbench. But this old dog will never be taught to think in metric

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I work in a huge tool and die shop "6 acres under roof" and we are all metric, measuring in inch gets a little long in the decimal points when saying 3 micron tolerance, but I agree with Travis outside work it looses its value.  

 

wouldn't that be  "2.42811 hectares under roof"

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Bob - From all the replies above, the general consensus is; metric units is a good idea and they work well, but the job of changing over is just too immense.

 

I do understand the reluctance to change, after all, the current system of miles, yards, feet and inches work perfectly well. The inconvenient numbers;

 

1 mile = 5280 Feet = 1760 yards

1 foot = 12 inches

1 ton = 160 stones = 2240Lbs

1 stone = 14Lbs

1 pound = 16 ounces

 

Well they are just not a problem because we only work in one unit at a time. Each unit physically means something. You pick up a stick and you know how long it is in feet, a man walks by and you can estimate his weight in pounds and so on. Everyone has a feel for the units.

 

The fear of change is losing that ‘feel’ for the units. But, attaining a new ‘feel’ for a new system of units takes a surprisingly short time when you have no other choice. But why change when the current system is adequate, not to mention the billions of $$$ that it would cost the nation.

 

I have personally witnessed such a change; 15th February 1971, the UK changed its monetary system from pounds, shillings and pence to a decimal currency like the US$. For many people it was a very painful period. People had to learn a new ‘feel’ and there was no escape. Ultimately it was a good decision. Was it the right decision is debatable.

 

The physical cost of the changeover was horrendous. The cost to the individual was not small either. Retailers were very quick to take advantage, as all conversions seemed to require rounding up. The pound went from 240 pennies to 100 pence, therefore a standard raising of price of 1 penny increased by 240%. Thus the cost of living was raised massively over the next few years. This followed a 100% devaluation of the pound only five years earlier, were all imported products doubled in price over night.

 

Although metrication makes sense, it is not going to happen overnight, nor does it need to. Dual product labelling, as is starting to happen now, is the answer. Let the next generation handle the big change. Schools should drive the change. Give the next generation the ‘feel’ for both sets of units and slowly phase out the old units over a period of 30 years or more.

 

Dave

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Metric makes sense... Its a better system... But no matter what changes take place, some things will always be the same on this end of the pond

A 2 by 4 will always be 1 1/2" x 3 1/2"

A sub sandwich will always be a foot long

A football field will always be 100 yards long

Drag racing will always be on a 1/4 mile strip

And we'll always drive in the right lane

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One interesting thing here  in Germany is , that even after having gone officially metric in 1871(dozens of small kingdoms , earlhoods , counties and cities all using different measurements and currencies became united to one nation) , people are still using "pounds" as a weight measure(our pound counts for 500 grams , not to confuse with the English  lbs. pound holding 454 grams , so roughly 10% less).

 

Anglers talking fish weights face to face ,..it's always "pounds" , ............. buying butter in the supermarket or potatoes at the weekly market , ......it's always pounds talk(the usual butter pack over here is at a half pound=250grams contents) , ......larger amounts of potatoes are also talked about in "Zentner"(1 Zentner equals 50 kilograms) , .......baking recipes are passed on by mouth using quarter pounds and half pounds of ingredients amounts .

 

But as soon as things get written down, they jump to full grams and kilograms units again , ...it's kinda funny , ........but still quite easy , though , as the "Pound" and "Zentner" are exact parts or multiples of grams and kilograms .

 

Greetz , Dieter :yay:

Edited by diemai
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