Leaderboard

I found this technique here on http://www.tackleund...h__1#entry33351 In theory, the technique is used to find the volume of a lure, but in our application, it also tell us what the final weight of the lure needs to be for neutral buoyancy in fresh water. The down side for you guys, is that you have to work in grams, NOT ounces. The Archimedes dunk test: 1 - Fill a beaker with enough water to completely submerge your lure, without touching sides or bottom. 2 - Place beaker of water on scales. 3 - Set the scales to measure grams and zero. 4 - Hold the nose eye with long nose pliers and submerge in the water, upto the eye. Leave the hooks on for this. 5 - Read off the scale and write the number down. Because one gram of water has a volume of one centimeter cube, the number written down represents the volume of the lure in centimeter cubes. The number also represents what the final lure should weigh (in grams) if you are going for neutral buoyancy. If you want a floater, just add less ballast. This test can be done as early as the first seal of the body, to get an early indication of the final weight of the lure, or right at the end of the build process. If you want to tweak the final lure to get neutral, fit all the hooks etc and test. This will indicate the size of the slug you need to add. Another application is, if you want to copy a lure and get the same amount of float. Weigh the original (with hooks) and divide by the dunk test weight. This will give you a ratio. When you build your copy, ballast to achieve the same ratio. I have been using this technique for a few months now and it is quick, very accurate and simple. I recommend that you at least give it a try out. Dave

A LOT of time is involved. BUT, if you construct the model right, it will be possible to make changes very quickly and easily. Also, I can change the length of the lure, keeping the relative proportions. All the major dimensions are stored as variables, so simply by changing the variable value, I can control the model dimensions. A short stubby 2.5" lure will be no good as a 6" lure, but by changing the thickness variable I can make it useful again in seconds. Dave

It's just the opposite for me. I spent a lot of time trying to get my jointed wooden baits sealed. Finally, another TU member, John Hopkins, suggested I try AZEK PVC decking and trimboard, and now the only wooden baits I make are small cranks from balsa. If I had started with PVC I would have saved a lot of headaches.

Thanks Dave. You've just made my lure building life a lot easier. I've been hanging different size weights from the hooks to try and determine how much ballast was needed. This will be so much easier and quicker. I've copied your text and printed it out so it can be hung at my work area until this tired, old brain can remember it. thanks again, Ben