Vodkaman

Here is a possible alternative method of drying PoP. I posted it in homebrew tools, as it is applicable to hardbaits also. http://www.tackleunderground.com/forum/showthread.php?p=76054#post76054

The general rule is soft pattern, hard mould. Hard pattern, soft mould. I tried several times to use PoP for hard foam castings, it was a disaster! The best mould material for alumilite is probably RTV. But you are concerned about the expense. I suggest you try the PoP, but don't use your valuable, irreplacable master for the test. Make a temporary master, but prepare it as you would your regular master. It must be sealed and finished smooth. It must be none porous, so the PoP has nothing to grip on to, maybe a coat of epoxy or something similar. Do several tests, removing the master at different time periods. Try after 30min, 2 hours and over night. Removing the master early is the easiest, but you run the risk of damaging the surfaces of the casting as the plaster is still very soft. If you are casting hard in hard, it is vital that the master is not die locked, in other words, you must be able to pull the master straight out of the mould with no twisting. For the same reason, deep flat sides should be avoided, too much surface friction, stopping the master withdrawal. Search for information on sealing your PoP moulds, there is a ton of it, also search release agents. Without a release agent, you might as well save yourself some time and throw the PoP powder straight into the bin. Best advice? Stick with the RTV.

Everyone agrees that using the household oven is not a good idea. Commercial plaster operators use drying ovens. There is no reason why the small production/hobbyist cannot do the same. So I have introduced this thread so that we can brainstorm the problem and arrive at a workable solution. I see the solution as a box, deep enough to mount a household bulb with sufficient air space around it. At the bulb end, a 2 inch dia hole. This is the air inlet. At the other end, a small 12v cooling fan (battery operated), as used for cooling computers. These fans move about 4

http://www.tackleunderground.com/forum/showthread.php?t=11049&highlight=photobucket This is a link with instructions of how I do it (post photo's of course!).

Thanks Dutchman, Finally found it! Just a pity they didn't explain why the oven is at risk. I understand the risk to the casting and accept that. Personally, I will continue, lowest heat and door ajar.

Why not, the same rules apply. Some of the lures on this site are bigger than the fish that I catch! When you post your pic, put something along side to demonstrate the size.

Welcome and enjoy.

definately volume. Micro balloons are extremely light. If your final volume is 100ml, then 25ml part A plus 25ml part B plus 50ml micro balloons. This is how I see it anyway. I would hang on a little longer, because if I have it wrong, someone will jump in and rescue us both.

I have not tried to turn cork grips, but I have tried to turn other wood in a drill, similar to your suggestion. What I found was that they did not turn evenly until they where absolutely central, with no high spots. I would spin the wood (not too fast) and touch the surface with a pencil. This would mark the high points. I would then remove the high points manually. Repeat until the mark is continuous. Then the cork can be sanded (lightly) while rotating. You would expect the cork to be concentric already, but the above will serve as a good check. You would think that rotation sanding would 'pull' the cork back to concentric, but it doesn't, in fact, it gets worse! When I was involved with rod building, the corks were small half inch sections, a bit like assembling a pack of polo mints. It was inevitable that they got mis-aligned. Not sure what you are dealing with.

Can't see anything from the link, just a sign in page. I did see a photo about thirty minutes ago. Looked like you were getting the boat ready for next years bass masters!

I put mine on photobucket.

Maybe, it's certainly totally out of character. Normally one of the most helpful and supportive members on the site. But I read it the same way as Mr Bester. Just a simple leg up into the mystical world painting is all that was asked for. Secret recipes? Just keep them secret!

I've never used 'paint'. If it can draw circles and lines, then it can draw any body shape that you desire and your set to go. I will add, build your lure, seal the wood, then take it out for a swim test BEFORE spending hours painting. It will probably need a lot of adjustments to lip, eye location and ballast location to find the movement that you are looking for.

Mr Bester, welcome to TU. I'm getting a touch of the de-ja-voux here (excuse my french, I don't have any). Question, what makes the lure wiggle? Answer, make some firewood and find out yourself?!!! Obviously paint recipes are a touchy no-go area of lure design, you only have to read the 'hard bait cookbook' to understand that, 2 pages and some chitchat in three and a half years! I think it is time to un-stick this sticky and let it slip away into obscurity, either that or start adding to it. I hope this thread slips away too. This is not the message we should be giving out. Merry Christmas to you all.

I would look through the gallery and get a feel for the various shapes. Choose a general shape that you like. Close the computer and sketch the shape on a piece of paper. Adjust it, adjust it some more, until it looks right. If it looks right then it probably is. Doing it this way, you can be satisfied that the shape is yours, there is no pleasure to be had from directly copying someone elses. Make a master and photocopy it. Use the copies and keep the master safe. If you want a computer drawn master, digitize your master and e-mail it to me, I would be glad to draw it out for you, or anyone else for that matter. It only takes a couple of minutes, same goes for lip sheets. I just read your post again, that is not what you asked, the offer stands anyway. Fish are shaped the way they are for a reason. If the tail end is too deep, there will be more resistance to side movement and you will end up with a log with no movement. Depth is OK around the ballast location and taper back to the nose. It's a force times distance thing. Start off with fish shapes, you can't go far wrong.

Bruce, a good response, I can live with that opinion, even agree. What I have a problem with is being told, "can't, it's too hard". Any solution is going to be an approximation or even statistically based. maybe using real feedback from testing prototypes and interpolating between cases. It will be a while before I consider tackling that one again, but I will, one day. I too studied the fishies from a dock. My problem was I very rarely caught anything. One day I asked a guy fishing next to me, with a net full, what was I doing wrong. He took a time out and came over to my swim, took one look at my gear and told me the line was too thick, the fish can see it. There was a pier there. So I dropped a handful of maggots in. They never reached the bottom. I then lowered my loaded hook with another handful. Same happened again, except my hook maggot was not touched. Life changing experience. From that day on I slayed them, using 2lb line max. Some days, when the fish were difficult, I would go down to 3/4lb line with No24 spade hook. So, when I joined TU and found that you used 10lb line I was horrified! But, fishing lures is a very different game to bait fishing. I now enjoy both. Glad I got to exercise your mind. Happy holidays to you all. Dave

Thanks Minuteman, yes, I read that doc, but could not find the oven reference. I think I'm just tired.

I could not find the part were it says ovens were bad, I am not doubting you, I only read it quickly. The article was interesting and informative. The recommended temperature was 120 deg F, in air fan driers. It also states that if the plaster is over dried, calcination occurs and the surface becomes powdery. I found that one out! If the drying process is too fast, cracking can occur, as the casting dries from the outside, in. As far as I can establish, apart from evaporating moisture, nothing else is going on. Everyone who uses PoP will probably agree that using an oven to dry the castings is not the ideal solution, but the alternative of waiting days for the thing to air dry does not fit in with my plans, I'm 51 and time is running out! So, I am going to accept the risks and continue with the oven. I am going to heed the new information and reduce the drying temperature by keeping the oven door ajar. Each oven is going to behave differently and a learning curve exists, a 'feel' for the drying times required comes with practise and experience. If you acquire a new oven, you've got to start over. But I could have a dozen attempts to get the result I want in the time it would take to air dry my mould. As long as you have a master, I really don't see the problem.

I get it now, the battery is a 7Ah (amp hours) rating. In that case the camera will not be drawing any where near 7 amps. A 0.5 or 1 amp fuse might be more appropriate. Usual disclaimer contract applies (kidding), good luck with it. Why not post some pics when you've had a chance to try it out.

Just to be sure, I would go along with Marks suggestion, but as long as the voltages match their should be no problem. The current is drawn by the circuit or device, not pushed in, so as long as the battery is capable of giving up 7 amps, you are OK. That is a lot of amps for a camera, has it got an electric outboard motor attached?

Basseducer, not sure, but I think they are hand made. I would PM directly to the owner of the stands that you like.

I hope you have all found this thread as interesting as I have. The results are surprisingly accurate and pretty much as expected, centre to right sided. Lure design is a very creative and artistically demanding process. The question remains, what the hell am I doing here? I hope more of you will take the test and publish your results.

Goldenshiner. That was one of the great threads, at least in my lowly opinion, but I would say that, I am left brained! I am in total agreement with you on all your points above. If people are not interested in the technical discussion, they should step aside and let those that are get on with it, everyone has a choice. I firmly believe that if you have nothing positive to say then say nothing. Yes, there are a lot of variables to take into consideration. But, as we are not trying to nail the solution to the milligram, I believe many of them can be side stepped and we should concentrte on the biggies, namely: lip geometry, eye location, ballast location and body shape. It is a daunting task to deal with even just these four at once, but it is possible to nail three and vary the fourth, in fact this is the standard procedure for prototype testing. You only change one thing at a time, otherwise you don't know which adjustment worked and you have to go back twice more to find out. Patience is the name of the game. When I joined TU, it was my intention to create a spreadsheet to do exactly as you stated. Enter your lures parameters and it will tell you the result. I tried for a while and will probably return to it some time in the future, but I am more of the opinion that it is sufficient to just understand how everything works, to design a new lure from scratch. Yes, the calculations are complex and require a fast computer, days to run a simulation. But I believe that an approximation is possible, like we said, we are only looking for a rough guide. But, before I could calculate anything, I had to find out exactly how everything works. This too has been a real trial. I feel that I am close to understanding the major principals, but not absolutely confident. Unfortunately, the learning curve has now kicked in. All the testing that I have done has given me an instinct for a lure, I can usually tell how it is going to behave in the water. But the whole point of this exercise was to help the newcommer to the addiction and try to minimise the learning curve. This is the part that dissjointed a few noses, "why should anyone get my hard earned knowledge on a plate"? Well, if anyone has that selfish opinion, then tough, because that is my intention, to put it on a plate, for new members and hopefully enough to enhance the knowledge of a few of the more experienced builders. As I work out little parts of the puzzle, I will continue to post them for debate. This process is a good way to test the theories, as all the theories should work together for every case, for all baits, hard, soft, lipped, lipless etc. Well enough soapbox. As for your reference to the size and speed. Very simple calculations are available for this one. Do a web search on Strouhal number. Top of the page will be wikapedia. This pretty much covers it in a nutshell. While you are there, look up vortex shedding and Karman vortex street. This covers all the lip theory. Having read these subjects, designing new lures is just a matter of interpretation and application of these principles. Anyone else have any ideas or theories? Publish or be damned I say, bring it on!

Bruce, You're right. Maybe it could receive temporary sticky status. I'm making the trip, wouldn't want to miss out on the opportunity to meet a few fellow TUists.

In addition to Bruces answer, to get down deep, you need a shovel on the front. If you put the tow eye behind, the lure will just roll over. By placing the eye just to the rear of the centre of the lip, a balance can be reached between the lip in front of the eye and the lip/body combo behind the eye. All this lip gives you action and, if the right position is found (by trial and testing) and all the other variables are set correctly, the lure will dive deep.