Vodkaman

Paragraphs like the above quote just invite comment. If I am wrong or out of line, please accept my apology. But their is little left to interpretation when you read such a damning paragraph. You are all very gifted lure makers. I just wish you could apply yourselves more to design. I do understand the problems. Your business is customer driven. As such, they want proven lures and are reluctant to try anything that is not. I get enough of that just on this site, when members of a progressive site like TU are reluctant to even try new ideas. If you are going to copy lures then go for it, just don't brag or advertise the fact here. This site is about helping and innovation, to produce a better, original lure. No malice from me, just respect for your skills.

Their has been a spate of posts concerned with supply shortages and various problems with eyes. Over the last year I have read a lot of articles about making eyes. The most promising being white base, black dot with a blob of epoxy for the lens. Without having made one myself, I can imagine a problem attaching them to the lure because of the complex curvature. So I decided to explore the subject for a solution myself and this is what I came up with. In order to fit to a compound curvature, the eye needs to be manufactured from a soft, flexible material. I decided on silicone, with the pupil made of black card and a hole punch, simple and very quick. But the flexible material is not enough as it is always trying to return to the flat, leading to the edges pealing. The solution is to make the back of the eye concave. This means that although the back face does not necessarily match the mounting face, it is a lot closer, but in addition, the flexible eye, trying to return to its original shape, is flexing into the mounting face rather than pulling away. A mould would be required for the eye, consisting of a convex lens and a concave back. To achieve this mould shape, I chose glass marbles. Generally available in toy stores in two sizes, which suit our application perfectly. Should a deeper or smaller diameter eye be required, ball bearings are available in just about every size imaginable. Next, the mould material was considered. RTV would probably not work well, due to the adhesion of the silicone, being a similar material. Also, RTV is expensive. As the mould would be fairly simple, it seemed overkill to use RTV, so I explored PoP (plaster of Paris), sealed and coated with epoxy or polyester resin for a smooth finish for the lens. Next, I did some adhesion tests. This proved to be a big problem. The silicone stuck firm to everything. Clearly the smooth finish of the mould surface was not going to be good enough, even smooth plexiglass material was adhering so hard, it was impractical. I then performed a few tests on wax. This was the best solution. Not perfect, as the mould surface would have a very limited life due to erosion, but with a master pattern, the moulds could be re-melted an re-cast. Unfortunately, I have been unable so far to obtain the marbles, to complete the test. But have decided to publish these findings, should any of you care to try the method. Method Roll a lump of soft clay or plasticine into a sheet about 5mm thick. With a small marble coated with pam oil or similar, make depressions in the clay. Space them such that a large marble can sit in each dish with clearance from each other. Form a retaining box and pour PoP. This gives a positive mould. When fully cured, repair any faults, bubbles etc. This should be sealed and coated with epoxy or resin for a smooth finish. This is now the master mould, from which all the working wax moulds will be formed. several wax castings can be poured in an hour, with the use of a freezer. Place a blob of clear silicone in each dish. With a piece of plastic (plastic bag material) covering your index finger, dipped in pam oil, spread the silicone to cover the area of the dish shape. Excess is not a problem, in fact, desirable. With the tiniest touch of silicone on the handle of a brush, pick up a black card pupil and place it onto the silicone, centre or off centre as required. Next, add a blob of white silicone to the pupil. Place a large size marble, previously dipped in wax onto the silicone. Excess will be squeezed out. This is OK and does not need to be cleaned away. The silicone eye will dry in a few hours, as the thickness is not too great. But leaving over night is a good idea. Once dry, the eyes will peel very easily from the mould. Wash in soapy water to remove any wax deposits. To cut the eyes out, a suitably sized round metal tube is required. Using a file or dremel, sharpen the end to a cutting edge. Using a rubber mat as a backing, the eyes can be quickly and simply trimmed from the waste, giving perfectly formed eyes, ready for use. The eyes may stack inside the tube, but this is not a problem, as they can be pushed out with a pencil or suitable rod. Rather than using hundreds of marbles for the back, they could be half cast in wax. As I said, not tested to conclusion, but I am confident that the method will work. After a short learning curve, I estimate 300 - 500 per hour is a possibility. I suggest that you lay some wax down and test the silicone materials out for finish etc.

I am sitting here, reading your post, with a big grin on my face. I've been there so many times! I'm half way through writing a thread on volumetric analysis. It was supposed to be very useful for lure design, but it has got out of hand. So I have decided not to post it. I will re-visit it in a few months time and see if I can get a more useful perspective on the subject. In its current form, it will just annoy everyone (as usual). Think too much? I don't think so. I don't think I think thoughts through thoroughly enough. This thinking thread has thunked me out. I think I need some of Bruces medicine!

Clamboni, I do agree with you. If the lures shell does not change shape then no matter how much pressure on the outside, the pressure of the air inside does not change. In this case, the lure will obey the changes to the water due to temperature, namely the lure will be more buoyant in the cold water. But consider a balsa body with a standard epoxy top coat. This coat is not strong enough to resist the pressure difference and will distort. Hardly noticable, but the distortion would be more significant then the difference in the water due to temperature. Under these circumstances, IN THEORY, it could be explained why the lure might become less buoyant as the temperature dropped instead of more buoyant. As the body compresses, the volume decreases, the weight stays the same. Therefore the average density of the lure increases and the lure sinks. Archimede's must have been a lure designer.

Yes, that would introduce a vacuum by using venturi theory. Not sure it would be strong enough though. Everything has to be tested, this is all new. I would like to get more information from weighinalimit as he has worked on this problem with success. Can you show any pics of your setup, moulds and pours?

Yes, that would work. The important thing is that it has to be operated with one hand. A cake icing syringe would do it. Totally hands free would be an added bonus though. Stability is one of the most important aspects of the process. The mould should be fixed in such a way that it cannot accidently be pulled over by the pipe. Pushing is out of the question, as has been demonstrated on more than one recent thread. This would involve the hot plastic in the syringe. The beauty of the vac-venting system is that the hot plastic is poured in the normal way, except into an oversized sprue or funnel. It then disappears inside the mould and is not seen again until the mould is opened.

Yes, it seems that we have got copying successful commercial baits down to a TEE!

Of the above, the Tacoma is my favourite, purely as the collapse was all about vortices, my favourite subject! Come to think of it, I haven't mentioned vortices for quite a while. Nice to get the first one of the year out of the way. Vortex vortex VORTEX!!!

With the mould sealed correctly, the volume of the drawn air is the volume of the lure being cast. For the stuff that I have cast so far, this amounts to about 30cc. Weigh out an ounce of water in cup to get a feel for the amount of air involved. It is not possible to breath it in. It is more like blowing a kiss at your wrinkly grandma. Cured RTV is inert and cannot be any more of a problem than keeping it in the same room all day. The whole issue can be avoided with the use of a vacuum pump. I am estimating that a fish tank pump would be strong enough to do the job. It is more important to make the suction pipe a long one and made of clear plastic. So far, I have never managed to draw the plastic out of the mould, but why take the chance. Another safeguard for both the above hazards, would be to introduce a DRY reservoir half way up the pipe. This could be a hard plastic bottle, with one pipe in and a separate pipe out. Thanks for your concern Bruce and I am looking for a pump For testing, also I am only doing a few test pours for TU, once the pour works, I move on to the next project, which is probably back to hardbait lips.

Bruce is right. If it is your first, I would not paint this one, but use it for testing. If you have invested a huge amount of time, you might want to put this one in the draw for now and make another one for testing. Only needs to be roughly finished. You will need to experiment with eye location, in addition to Bruces suggestion of ballast location. Test it out, write information down about what you try, any measurement changes etc. Any problems or queries, come back and post them. You have chosen a difficult lure to start with as its best swimming setup is very close to instability. But ask the right questions, the members can help you get it working.

Many years ago, I used to home brew from the basic ingredients. I tried kits, but like lures, more satisfaction was to be had from building it myself. Tedious labour, mashing at 150 deg for four hours and then simmering for another 90 minutes. I wish you good luck and prosperity with your venture. Don't forget, 'drinking on the rocks can seriously damage your health!'

You would think that with todays mathematical and engineering knowledge, computer stress analysis and simulations, that designing bridges would be childs play. Not so. Just a few years ago, a new bridge over the Thames, in London, had to be closed very shortly after the ceremonial opening. The bridge had a very slight sway. This caused the people to walk in step with the movement, also it is a natural instinct for humans to walk in step with each other. It just happened to be that the frequency of this step pace matched the resonent frequency of the bridge and the sway was dangerously magnified. How embarrassing for the designers!!!!

Re-visiting this thread after so long, does put a fresh perspective on things. Upon re-reading fishnfool's post, it struck me immediately, the same as Hughesy, that the changes in the lure are causing the contradiction. In my mind I was keeping the lure constant and only considering the water density. Respect to Fishnfool, no fool it seems!

You can see from the legs, that some are longer than others, so the limit is being approached. RTV is a very good insulator and maybe the plastic gets to flow a tad further because of that fact. Pre-heating the aluminum would help, but I'm sure you tried that. Another feature of my mould is the size of the venting. This greatly increases the force on the plastic. The third important point is the sealing of the mould. If you block the sprue with your finger, you should not be able to draw any air through the suction pipe. Any leakage would reduce the drawing force on the plastic. Try a coating of pam oil on the contact surfaces. Personally, anything but the very simplest of pours, will be vacu-vented in my pouring studio.

Sorry Bruce, English humour.

Clemmy, I think we are missing the point here. Could you post a pic.

Semidry - adjective - wet behind the ears!

How to mould 3D legs with a 2 part mould This thread is in response to the thread linked below. Hopefully, it will open up the possibilities for new designs, such as octopus, squid etc or even abstract designs that were not within the realms of feasibility before without expensive equipment. this is the lure posted by DelW in the ‘IKA like pours’ thread. http://www.tackleunderground.com/forum/showthread.php?t=11261 this shows the legs emerging from the body radially. The only way to mould these in a conventional mould would be parallel to each other in the plane of the mould joint face. This would be aesthetically unacceptable. Materials ¾ inch dia dowel. Packet of sate sticks Body master RTV RTV is used as the mould manufacture includes under cuts. However, the design can be adapted to carry the undercuts on the slug. This is more work intensive, so for this experiment I chose to cast the legs into the mould. To create the leg master, the dowel and satay sticks are cut to the length of leg required. Glue the satay sticks around the outside of the dowel. I managed 14 legs with a smaller diameter, but I did lose some definition between the legs, resulting in some trimming. The lesson is, don’t put the legs too close together, I would say minimum 1/8th, 3/16th would be better. The plan was to grind flats onto the satay sticks, but this was found to be very tedious and subsequently not necessary. I used instant super glue for this operation. The leg master must be sealed, epoxy or resin will do the job. A good coating of Pam oil or something similar will be required to stop the RTV from binding. Set the master up against the leg pattern and create your 2 part mould in the usual way. Personally, I use a split master technique, but each to his own. The slug insert is another length of the same dowel, cut a few millimeters shorter than the leg master and seal. The plain slug cylinder is inserted into the mould. Make sure a gap is left at the top for the plastic to reach the legs. The mould is now ready for the pour. Whether you can get that many legs to pour using the regular gravity method, I don’t know. I did not try, I went straight in with the vacu-venting method. This is my layout ready for pouring the RTV. If PoP is to be used as the mould material, then the undercut of the satay sticks has to be eliminated. This is done by casting the plain dowel cylinder into the mould and cutting the legs into the slug. This method would be the solution should the mould be made in aluminum. However, the long thin legs would not lend themselves readily to the heat transfer characteristics of the aluminum and an injection or vacuum method would probably have to be employed. Del would be the man to advise on this possibility. Below is a photo of the resulting lure. Scruffy? Yes, that is down to my lowly position on the learning curve, but proof enough that the technique works. By choosing more accurate and stable materials, such as a turned master, plastic rod or tube to replace the satay sticks, decent RTV, attention to detail and precise workmanship, it will be possible to produce a quality casting with zero flash. This test pour also demonstrates further the effectiveness of the vacu-venting process. http://www.tackleunderground.com/forum/showthread.php?t=11056&page=2&highlight=vacu-venting I would appreciate some feedback on this thread and the vacu-venting thread, questions, reservations, like it, hate it etc.

Silence is golden.

The concave back and deeply convex belly will act together to rotate the body downwards. The result being that the lure will swim shallower than the same bait with a regular configuration. Similar to an aerofoil section up-side-down.

Liquid latex. I was thinking about that application. While deciding whether to post it or not, I saw zman's post. It sounds like the same stuff.

The Falkirk wheel. Yes, I posted it, an awesome piece of modern engineering. But you have to respect the guys that built the old masters a hundred, even two hundred years ago. Their work looked good too. This is where I fished every night after work when I was in Sweden. Alvsborg bridge, Goteborg. Just look at that geometry!

To dampen some of the action, try adding some weight to the rear. Temporarily tape it on first and test it out. A photo or two would help.

This is a project that has been in my book of 'things to do one day', for quite a while. 3D legs from a 2 piece mould. I brought it forward because the subject was touched on a few days ago in a thread called, 'IKA like pours'. I have posted it separately because it has much wider applications than just copying IKA's.

Their have been a few good posts on cutters, you might want to try a search if you have not already.