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Achieving neutral buoyancy
61 replies to this topic
Posted 18 June 2008 - 01:34 PM
Shortlite, thanks for the PM and for the comments above. PM your e-mail and I'll send a copy.
The spreadsheet is not finished completely yet and is not of any real use. When finished, it will take into account the lip, all the hardware, paint and epoxy. I believe even paint will make a difference.
The epoxy is the tough one, as it will be down to the builder to be consistent in the application.
The aim is to be able to determine the ballast and fit it with confidence early in the build, with no further testing required. Well, you have to give yourself a challenge.
Appologies to Carpoleo for all the tech talk, but you just might end up with something that helps.
Posted 18 June 2008 - 01:49 PM
Awesome mate! Paint and epoxy up to the builder though. Lip and hardware assume total uniformity, or very little variance. Great if you have laser cut bibs, etc. Split rings and hooks shouldn't have enough variability to greatly affect that. I suppose you'd have to build up a components database in addition to that, wouldn't you?
Definitely a great idea. Will PM you, cheers.
Posted 18 June 2008 - 02:15 PM
Just an idea for calculating the paint/topcoat in the spreadsheet. I know you are doing it for you, but you also may change (develop?) your paint/clearcoating process... Why not have a function built in to allow for paint/clearcoat. My thinking is that if you weighed a few baits before and after painting/clearcoating, it should give you a ratio of before and after. This ratio could then be used as a function to apply to the spreadsheet calculation adjusting to your way of painting/clearcoating, i.e. brand, application thickness, # of coats, etc.
Of course you may also need a seperate one for foiled baits, or for "toothy" fish neccessitating more epoxy coats, but hopefully you see the idea....
Also given that densities are normally published at, I believe 20 degrees celcius, you should be able to input a desired fishing temperature constant.....
One further complication (lol) is that monofilament line will act as a buoyant force, fluorocarbon a ballast....
Hope this helps???
Posted 18 June 2008 - 03:31 PM
Vodkaman, Thanks for super video. Definitely not an engineering mind here, I mostly rely on trial and error. The video is quite inspiring and just watching has helped me a lot.
Posted 18 June 2008 - 06:33 PM
Do we need a different spreadsheet and lure for each 3 or 4 degrees difference in water temperature we might be fishing? And will we need a different set of lures for each water column we will be fishing in?
About 6 of each deep, medium, and shallow divers (to cover the temperature variations) in about 5 different colors should cover the days fishing for suspending lures. 6X3X5=90 lures. Might be a few more for extreme conditions.
Or if we know the water temp prior to departure we could just swap out the box with the lures for that temperature of water.
Then I will still need to pack the cranks that rise and the ones that back up on the rise and the Rattle Traps Jerkbaits and the jointed swimbaits.(I have got to be leaving something out)
I just realized that I will need 3 different sizes of the suspending baits so that takes my total to 270 suspending baits + all the others. Will 5 colors be enough?
This is all just in fun.
The cool thing is that most lure builders that read this thread will get something out of it that will help them in some way or another.
Edited by Palmetto Balsa, 18 June 2008 - 06:35 PM.
Posted 18 June 2008 - 07:16 PM
Clemmy, you are on the same wavelength. Yes, the epoxy and paint will be a before and after estimation. So the builder will have to finish one first, to extract this infomation. Extra entries will be built in for foil and fins. If not used, just enter zero.
Shortlite, I am thinking of a components database too. But, the builder will weigh a number of hooks, type in the weight and the number that he weighed. The spreadsheet will work out the volume of the hook etc. The same for split rings, quick releases etc. This would take care of variations between hook types. This would only have to be done once for each item. I will add extra lines that can be defined by the builder.
Lips will be dealt with by material type. The builder will enter the weight of the lip against the material used, also the thickness and a rough estimate of percentage glued in the body (10 -20%), this should get us close.
I am planning on including water density, for the salties. It will also allow those that are concerned enough about water density to still play. I'm sure I could do something with temperature too.
The spreadsheet is not just about suspenders, it is designed for all types of lure and will help to achieve repeatability between lures. The builder enters a percentage that represents its buoyancy. The builder enters 100% for a neutral buoyancy, or 95% for a slow rise, 105 for a slow sinker, and so on...
I am accepting any suggestions, but the danger is making the thing too complicated, seeing as it was developed to make the job simpler.
Edited by Vodkaman, 18 June 2008 - 07:18 PM.
Posted 18 June 2008 - 07:44 PM
It's already getting there by the sounds of it. Calculating the volume of a hook? Bloody hell..... Well, if you want one set of lures for specific conditions and another set for others, then you will end up with 90 crankbaits in a box.
Water temperature and salinity plays a bit part as well. Varying salinity occurs depending on where you fish, and even conditions. Playing with you lures and adapting is one of the keys to success, but keeping down the amount of gear you are slinging is also important. Sticky putty, SuspenDots and SuspenStrips work for those times when you have to weight the bait down to get it to act right. So I just go for a slow float in fresh water, then tweak it when I fish brackish or fresh. You can swap for a thicker wired treble, go up a size, heavier split ring, drop down a size, etc. No need to get all bent out of shape and overcomplicated with calculations and computer programs. Repeatability is fine if you want to be stuck there forever, but need to guarantee the same performance for each bait you produce, ie. ones for sale.
Don't waste fishing time!!! We all know tuning is a part of the game. Get close, and do the rest on the water with whatever is at your disposal.
Posted 18 June 2008 - 08:41 PM
Personally, I don't fish, so hopefully I can save everyone else some fishing time. Everything you have said is true and because of all the inputs and variables, we can only expect to get reasonably close. Every measurement has errors and these will accumulate, so don't be expecting majic, just close. Adjustment on the bank would still be necessary.
Posted 18 June 2008 - 08:43 PM
Shortlite, you gotta excuse the guy for trying to help, he thought someone asked for it.
If you want to get into the ballpark, pay attention to the video he so generously provided & there you go, no density factors, salinity factors, temperature factors, pressure factors, or added components.
Take some lead wire with you & adjust on the water, ignorance is bliss.
To each his own, if the class is too hard, drop out & go fishing
Edited by redg8r, 18 June 2008 - 08:44 PM.
Posted 18 June 2008 - 09:55 PM
I have exchanged PM's with VodkaMan, and have watched the video. I offered the same help: we are now in a discussion about the spreadsheet. No ribbing/screaming/anything. I used quick reply, so no emoticons either, so my bad I guess for not saying that comments like "put the damn thing in the water!" are said in jest, with the best intentions.
I am totally in for the spreadsheet by the way. Something to try and iron out inconsistencies is definitely a plus. I know it would definitely help me when it comes to actually molding some of these wooden masters I have laying around and making some resin or foam bodies.
Take a chill pill mate
Posted 18 June 2008 - 10:49 PM
Daily..... maybe running low
I'm sorry if I took your post the wrong way. To be honest you personally came off Bi-Polar to me (no disrespect). Your earlier post was patting him on the back, giving recommendations on what to include in the spreadsheet, then later suggesting it's being over complicated, & he should just get on the water. (I just happened to remember that Vman don't often fish)
Overly complicated, Possibly so, because yes, there is a considerable array of factors to calculate & after that, like Vman said the resulting data would have a decent margin for error.
Lets be honest, "TRUE" (perpetual) neutral buoyancy isn't possible IMO (divers have been trying for decades) & its not a necessity unless you plan on casting the bait, propping your pole on a forked stick & waiting for a bite . I also need to apologize to Fish Devil, because his method will get you there, generally speaking. & those of you who don't want to absorb all the technical jargon laid out here, by all means, take his advise & watch Vman's video, it'll get you close.
The amount of rise the lure shown in Vmans video would be acceptable enough for Pradco, or Pure fishing Inc. or any other mass producer, however it did rise slowly which isn't "truely" neutral, but like said earlier, live bait usually dont make it a habit to sit still for too long.
The info derived from the continued experimentation could be helpful in many other ways, such as investigating topcoat density, material density, effects of various hardware, etc. You are right, one will never come to an exact formula, but a general formula can be derived using averages to help a future luremaker straighten that learning curve.
You may argue that nothing can beat on-the-water testing, which is good ole' trial & error at its finest, but I find it easier to spend more time refining in the shop instead, than on the bank or in the boat when the bite is on.
Anglers are accustomed to "tuning" a new bait fresh out of the box, but many here pride themselves on making quality product that runs true, fresh out of the package. It's a great marketing tool......Given that they likely tuned each one beforehand.
No harm no foul, again I'm sorry. I have many friends here who agree to disagree. I like to say, "this is what I'd do, your mileage may vary"
Posted 18 June 2008 - 11:18 PM
It's all good gator. We are all on the same page here. No harm, no foul. And your little insight is well received also. Yes, craftsmen take more pride in their work, so getting it right straight out of the box is what they aim for. And that's why they work so hard and come up with stuff like this. Striving for perfection. And agreeing to disagree is one of the healthiest things.
Neutral buoyancy unachievable.....maybe. I am never out of the testing stage with my lures. Always keen to fish them and get some action. I've even fished them unpainted! Plus yeah, baitfish don't sit around waiting to be eaten! The diving lips that get the lure down will still contribute to getting it deeper when worked. Slow float counteracts diving action, helping keep the bait at the desired depth. Throw in a whole lot more variables, and the real fishing world quickly shows itself to be nothing like a test tank. Ultimately we get as close as we can, and let the fish be the final judge.
Tight lines fellas,
Posted 19 June 2008 - 12:49 AM
Hey Vodka & company, in regards to your thought of including hardware weights (ok, MASS!) in your spreadsheet I have a question. When tackle manufacturers produce then ship components do they actually count every single split ring, screw eye, hook, etc., or do they calculate large quantities by weight? If by weight it would be fairly easy to gather this info on every item they produce no? I would think their weight calculations would have to be pretty accurate or they would be either ripping everyone off or giving away lots of free merchandise:?
Just as a footnote, I personally believe that crankbaits are far more effective when they tend to be on the rising side of neutral as I have caught most of my larger walleye on cranks which had stopped forward motion & were on their way back up:yay:
Edited by pikester, 19 June 2008 - 12:51 AM.
Posted 19 June 2008 - 10:07 AM
I repeated the experiment in the video, this time using balsa. The results matched the spreadsheet figures.
Inputs typed in:
Body weight – 3.1
External lead – 22.7
Internal ballast – 20.95
Final body weight – 23.8
Look at the difference between the internal and external ballast, 1.75 grams.
28 grams in an ounce, so the difference is 0.0625 ozs.
The number looks very small on ounces, considering I am trying to work to 0.1 gram accuracy, which is 0.0035 ozs.
I have sent out the spreadsheets. If you asked and did not get one, let me know.
Pikester, We would count by weight, but these factorys can be very modern and use optical systems. But I do not intend offering a library of parts, too much variation between manufacturers.
Posted 19 June 2008 - 12:34 PM
I've found that a sufficient amount of Bud Lite helps me achieve a neutrally buoyant state whenever I need to!
Not sure about the science, but the results are conclusive.
And I've found no variation between batches, no matter where they're made.
My borther-in-law and father-in-law are both aerospace engineers. They could never talk about what they did, because they work on secret stuff, but they've both embraced the computer challenge, and joyfully spend hours discussing and arguing the different things about computers, software, and all the other stuff that goes along with it. It seems like they finally have something they both do and can talk about, and they're makeing up for 15 years of silence!
My point is they love having problems to solve, and spend hours trying to come up with more and more elegant solutions.
More power to them.
But when they need a door hung, or windows fixed, or structural repairs to their houses, they call me, and I go over and do it. Not a lot of elegant solutions, just a bit of sweat.
I use the KISS method for weighting lures.
Just make the lure, install the hooks and bill, seal it, put it in some water, add enough weight until it just barely floats, and then install that weight, paint, and topcoat. The combination of the epoxy that holds the ballast, the paint, and the topcoat should be enough to make the bait neutrally buoyant. If it still floats, wrap a little fly tying lead around the front hook shank. But if you really fight to get it to just barely float before you finish it, it should work fine.
You'll never get it right the first time, unless it's dumb luck, but you'll learn a lot about what to do, and what not to do.
Seriously, read this next line carefully.
It can't be that difficult if I can do it, and it sure ain't rocket science.
Posted 19 June 2008 - 01:13 PM
After viewing your video, I noticed you used a beer glass for your testing.
Did you consider your lures might have a natural aversion to the bottom of the glass?
I know I have that fear, so I strive to keep my beer glass at least half full at all times.
Seriously, that looks like a great method, and a great spreadsheet!
And you can toast the lure when you're done with the beer glass! Brilliant!
Posted 19 June 2008 - 01:18 PM
I also will stick with my tried and true method.
Just make the crankbait, paint and seal it, put on the hardware, tie a short line to the belly hook, put on the swimming trunks, get in the pool, start putting weight on the line that is hanging from the belly hook,(I don't pull it through the water, just hold it under) when you get the slow rise or very very slow rise you are looking for get out of the pool and drill the hole and put in the weight and seal the damn thing and go fishing. As I said, works for me.
Edited by jim45498, 19 June 2008 - 01:20 PM.
Posted 19 June 2008 - 01:41 PM
@ mark poulson
"Bud Lite" achieves a neutrally buoyant state.....HAHAHA:lol: !
I do my weighting just the way , that you do , thought I have never tried to set a lure to be suspending , just barely floating and slow , -or fast sinking !
For musky , -and pike fishing a rigid leader of either stranded or solid wire is essential , the length(also in limits the diameter) of it can be varied to trim a lure to be suspending or sink at a more or less fast rate .
One might also fool around with different hooks(thin wired or XXX-strong) and even splitrings .
Off course only , if one can't expect the targeted species to straighten out the lighter gear:huh: , or such changes would affect the lure action too much !
For example , in fall 2006 I bought myself some of those relatively new "Rapala Super Shad Rap Sinking" and fished them slowly tossed along the bottom for Zander(very similar to walleye , but gets bigger) .
They sink at about a bit more than 1 foot per second , since I fished at between 35 and 45 feet , I attached a solid leader(!!!!!!)of welding wire , almost 2 feet long and 1 mm thick(sorry , don't get to calculate this into inches:huh:) !
This leader just not quite doubled the sink rate , so I did not always have to wait for too long for the lure to reach the deep bottom on those short times of daylight , and I still got some nice fish that way:wink: !
On the other hand I have some American bass lures(I suppose) , mailordered years ago from "Bas Pro" , that I was rather disappointed on .
In almost all German waters a steel leader is essential , pike are everywhere , and even the smallest ones of these leaders let the lures sink , even though they are meant to be deep divers , fore they have a long deep diving lip !
It later came to my mind , that these cranks are supposed to be fished without a leader:huh: !
Greetz , diemai
Posted 19 June 2008 - 06:50 PM
How about that soccer game! My older daughter was watching it as she did her homework, and talked on the phone to her sweetie, a member of their school's soccer team. According to her (all I know about soccer is my girls play it, love it, and I pay for it), it was a great game.