Vodkaman

Pete, because of the time lag, he probably won't read this until yesturday!

From my electronics days, I remember radio shack as being VERY expensive. In the UK, every city has a couple of electronics components stores. They tend to be back street places, as they do not work the passing trade. Also, UK has Maplin, a good mail order shop and RS components, again very expensive but quality. Your best bet is to find the back street leky shop. Good hunting!

Excellent points Sagacious. I did not know about the porosity thing going on, so warming it on a radiator is not going to help much!

If you are really concerned, heat the ball from cold or heat it up with a gas torch or keep it behind a radiator for a few days. The water problem only exists if the water comes into contact with the molten lead. Other than a few cracks and the attachment hole, the water has nowhere to hide on a ball.

Same here Pete, except it's 5am! That's one thing I do not miss about England, the weather!

I think Pete's circular tank is the way to go. I don't know about TC, but when I was considering my options, it was to be able to video the action. It all happens so fast, it would be nice to slow it all down to study.

Great project. I have a simple spread sheet that calculates the flow rates required for various sizes of half pipe and square sections at various speeds. Metric and imperial! This information will help you choose a pump for the job, removing some of the trial and error. A lipped lure has a minimum speed before the action starts. This is about 0.5m/s or 1.5 ft/s. Whether a straight inlet and outlet system will work, you will have to build one to find out. My thoughts when I was planning the same thing, was laminar flow is the ideal test conditions. The inlet and outlets are going disturb the flow dramatically, probably a high speed jet up the middle and static water at the sides. To counter this effect, a series of baffles at each end, to even out the flow would be required. This would mean a longer tank length to accomodate the baffles. The best plan would be to decide on the length and width you want to work with. Using this information and the data sheet, select a pump that is capable of exceeding the figures in the data sheet and see if such a beast is available at the right price. As for the baffle design, I have no idea, but I'm sure we could work it out. PM me with your e-mail address and I will send you the spread sheet.

I think it would be best if you post some pics of the master and the mould, even if broken. I do two piece moulds. The masters are also made in two halves. I stick the half master down, build a box around it and pour the plaster in top. With this method I am guaranteed the correct split line. I generally remove the master about 30 minutes after hardening. Post the pics for a good answer.

Update. I attacked the mould and cut two new vents, as per my previous post. The pictures are the result. The first pic shows how the pour went. The second, the result trimmed and the mould face.

Having split one, you know all the internal structure layout. Maybe going in the side with a bit of dremel 'keyhole surgery' is the answer.

If you normally run this procedure and it worked fine before, then you must have done something different this time. Maybe a new paint, different bottle of windex a different amount. Something different, otherwise you are snookered! After cleaning off the lure, lay a couple of paint strokes down just to test. Use the hair dryer and it should be dry in a couple of minutes. If not, leave out the windex, the concensus is that it is not necessary. Please post your findings, good luck.

I through wire balsa, so I shouldn't get involved! My thought is that the glue is stronger than the wood. So why not drill oversize so that the screw just pushes in. Thoroughly fill the hole and coat the threads with epoxy and push in. My argument is that the extra void space gives more space for the adhesive to do its job. By screwing into a tight hole, all the adhesive does is prevent the screw from backing out. You need only apply a drip to the last few threads to achieve this. Controversial? Probably, but I'm ready and braced for the good thrashing that you are all about to deliver. I'm sure that many of you musky guys are cringing, but until someone does a comparative pull test, we will never know the truth.

The Vman-Dano vacu-venting process for manual pours KcDano and I discussed this process about ten months ago, sorry it has taken so long to test it out and present it to the forum. Object: To achieve fine detail with manual plastic pours. Solution. The vacu-venting process involves a network of vents to each ‘difficult’ part of the pattern, not much different to regular practice. The difference is that all the vents are connected to a large vent or canal. At some position on the canal is the venting port were a suction pipe is fitted. Finally, a large sprue or funnel to accommodate enough plastic for the entire pour. Fill the sprue and very gently suck. The sprue may need topping up during the operation, as it is important not to let air in via the sprue. Providing the two halves of the mould are a good fit, the volume of air to be removed will be the volume of the bait. In most cases, less than a mouth full. It is definitely not necessary to inhale the air. By closing your throat and drawing air in with the tongue, sufficient air is moved to complete the casting. If the mould leaks a little, repeat the above action a few times in quick succession. Spray the surfaces of the mould with Pam or apply petroleum jelly, this will help achieve an airtight seal. The plastic is drawn into the body but is not initially drawn into the legs, as like any other fluid in nature, it takes the path of least resistance. Once all the vents are blocked, only then do the legs fill simultaneously. The whole pouring process takes only a few of seconds. In the case of the spider, the vents blocked before the abdomen filled. The legs formed, but a pocket of air remained above the vents. It is therefore very important to include two extra vents adjacent to the sprue, to remove the last of the air pockets. Pattern materials. The patterns are made as normal, but the sprue funnel, canals and mould locations can be formed from any soft material. I used plasticine. Some transfer to the mould surface occurred, but this is minimized by coating with Pam oil or petroleum jelly. Other materials will do the job just as well or better, soft clay for example. Suction pipe. A short length of the pipe to be used is held in place by the canal plasticine or clay. A light coat of Pam oil will enable easy removal. The pipe can be soft plastic, 2 –3 feet of ¼” internal diameter should do the job. The pipe is gripped between the teeth, giving hands free operation. Mould material. The system will work with any mould material to different degrees of success. But the ideal material, as Delw mentioned in a related thread (“what if” August 07) is RTV. As a good insulator, it does not suck the heat prematurely from the plastic. Regardless of the material, Pam spray or similar oil should be used to promote a good seal and prevent air leaks. An additional advantage of RTV is that the mould halves are drawn together by the vacuum. My test castings exhibited no flash. RTV is good for low flash anyway, but I would expect a significant improvement in flash reduction even with PoP moulds providing leaks are avoided. This would be enhanced by increasing the distance from the pattern to the vent canal, resulting in more contact surface area for the sealing oil to do its job. Multiple pours (untested). There will be a limit of how many castings could be made in one operation. But I can imagine ten worms, linked together by the canal network, being poured from one sprue, in less than ten seconds. Multi color pours (untested). Obviously, multi-color pours would not work with multi pours. A multi-color pour could be achieved with a complex single casting by having a split sprue. In the case of the hairy worm, one set of legs red, the other blue. Hollow worm pours (untested). By venting at the bottom only and only using a small sprue reservoir. The plastic will stick to the sides of the mould and draw air into the cavity. Stop the pour and keep drawing the air for a few seconds more. Timed perfectly, the bottom will seal. Add a dribble of extra plastic to seal the top. The air bubble will contract with cooling, but can be injected with a hypodermic needle to achieve a floater, suspended or slow sinker. I achieved this by accident as part of the learning process but it is not fully tested. Health and Safety issues. The mould should be clamped firmly to stop the weight of the pipe from tipping the mould. The hands free operation is a big plus. If you are concerned about the pipe venting into your mouth, several solutions can be found. The obvious one is the use of a vacuum pump. The required vacuum for the process is very low. Alternatively, an air reservoir in the form of a rigid plastic bottle could be introduced ‘in-line’. This would dramatically reduce the concentration of any plastic vapors. Conclusions. Advantages: intricate castings, speed, low cost, cooler plastic temperatures, cold moulds (except aluminum). Disadvantages: more complex moulds, larger moulds, much larger sprue (recycle). I’m sure many more ideas will come to light for the application of this vacu-venting process and I hope one or two of you will at least try it out.

Nick. Nice try but no cigar. The mould was cast vertically from one point. Although it is a two piece mould, for this test, I closed the mould with 3mm thick plastic. The spider was poured from the end of the abdomen. This means that the plastic in the rear four legs flows upwards. The plastic was just beyond melting point and the mould at room temperature.

Thankyou gents. Other than here on the pages of TU, I have never even seen a plastic bait let alone fished one. So these are unlikely to be used. I did these experiments for TU members. The large vents and huge sprue are only half the story, can anyone work out how it was done before I write the tutorial?

Thanks Longhorn and Senkosam. Obviously, the worm was not that impressive, so I tried to push the boundaries with the next one. I had a few problems, did not mix enough mould material and it was a bit leaky. The body did not form, but that is just a small modification in the learning curve. The photo is not my best ever, but I wanted to get this out to you now, not tomorrow.

Open a photobucket account or similar, it's free. Upload your photo's. Once done, display the photo you want to use. Right click in the photo, copy and paste into your TU post. This is how I do it anyway, good luck with it.

Please don't judge the worm, it was modeled, along with the rest of the pattern, in plasticine, in five minutes. It's all about getting all the legs to fill. It is cast from a two piece mould. The second half was a slab of plastic, just for this exercise. The legs fill every time and the pour takes 5 seconds or less.

Senkosam, my interpretation of the foil application, is to reduce the contact area of the plaster. As long as you do not get too close to the mould cavity, otherwise a 'flash' gap would be introduced. I now bake the first half and seal it. I pour the second half the next day. No foil, just petroleum jelly or pam spray.

Please don't judge the worm, it was modelled, along with the rest of the pattern, in plastacine, in five minutes. It's all about getting all the legs to fill. Almost forgot, it's a two piece mould. The second half was a slab of plastic, just for this exercise. Redg8r, sorry, I posted on the wrong forum. could you possibly move it? Ta.

Nice wheel idea. Nice lab too. Looks like you dipped your toe to test the water and fell in!

Looks great! Don't rush the sealing process, if you can, give it over might. You don't want to spoil it now.

My tips would be to look after the background. Try to make it mildly interesting but not distracting. Try to include something that will give the viewer scale or you will be asked, "so how big is it then?".

It is probably just condensation as you guessed. a cooler object will cause condensation if the humidity is up. My guess is that it occurs at sun up. Because plastic is a good insulator, it takes longer to warm up than the surrounding air. Subsequently, the condensation occurs on the plastic surface. I could be off track with this, but take a glass out of the fridge and observe.

I've read a lot of posts on this subject and always the power or torque is questioned. I am not convinced that this is an issue. Check this article out, about the Falkirk wheel. http://www.falkirk-wheel.com/faq-s-on-the-falkirk-wheel/how-much-power-is-required-to-turn-the-w.html An eight storey high boat lift, driven by 22.5Kw!!!! Also, it may be worth testing the wheel out at 1rpm before going to the trouble and expence of modification. I know at least one other member with the same speed and he said that it worked fine. I don't think anyone has really tested this rotation speed thing objectively. Many have said that a particular speed works, but no one has ever said that another speed definately does not work. If anyone has tried speeds and proved that it is too slow or too fast, now is the time to speak up.