Vodkaman Posted December 13, 2007 Report Share Posted December 13, 2007 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. Quote Link to comment Share on other sites More sharing options...
longhorn Posted December 13, 2007 Report Share Posted December 13, 2007 Good idea on getting the legs to fill...I'm sure that will get some wheels turning. Thanks for sharing. Quote Link to comment Share on other sites More sharing options...
Senkosam Posted December 13, 2007 Report Share Posted December 13, 2007 Reminds me of the Arkie centipede. I'll bet yours works as well! Quote Link to comment Share on other sites More sharing options...
Vodkaman Posted December 13, 2007 Author Report Share Posted December 13, 2007 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. Quote Link to comment Share on other sites More sharing options...
GB GONE Posted December 13, 2007 Report Share Posted December 13, 2007 Now that is what I call venting on a mold!!! My mind is running right now!! Good one Vodkaman!!! jim Quote Link to comment Share on other sites More sharing options...
Tubeman Posted December 13, 2007 Report Share Posted December 13, 2007 The creative minds of TU at work, very nice ! I like the venting idea, larger runners for better plastisol flow. Quote Link to comment Share on other sites More sharing options...
GB GONE Posted December 13, 2007 Report Share Posted December 13, 2007 Question.... With the added venting, how much more do you have to add into the sprue area as the bait cools? At first I thought it may be a lot but then I thought the air pressure may keep the excess at a minumum. Just curious... Jim Quote Link to comment Share on other sites More sharing options...
Gloomisman Posted December 13, 2007 Report Share Posted December 13, 2007 should have made that spidy red and blue. LOL Very very nice Vodkaman Quote Link to comment Share on other sites More sharing options...
Vodkaman Posted December 14, 2007 Author Report Share Posted December 14, 2007 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? Quote Link to comment Share on other sites More sharing options...
nickcalderone Posted December 14, 2007 Report Share Posted December 14, 2007 Awesome idea, Vodka! Very clever to shape the mold cavity that way...I would have never thought of that! Quote Link to comment Share on other sites More sharing options...
nickcalderone Posted December 14, 2007 Report Share Posted December 14, 2007 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? Just from looking at it, you set the master on the slab, and molded the plasticine around it...and from looking at the right side of the pic, it looks like some additional vertical vent on the opposing end from the gate...perhaps an additional fill hole? If it is poured horizontally, this would make sense...but it is hard to tell just from one picture...I would LOVE to see the backside of the mold. EXCELLENT JOB, no matter how it was done!!!!! Nick:yay: Quote Link to comment Share on other sites More sharing options...
Vodkaman Posted December 14, 2007 Author Report Share Posted December 14, 2007 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. Quote Link to comment Share on other sites More sharing options...
Vodkaman Posted December 14, 2007 Author Report Share Posted December 14, 2007 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. Quote Link to comment Share on other sites More sharing options...
hazmail Posted December 14, 2007 Report Share Posted December 14, 2007 Dave. It looks just like the 'Huntsman' spider I squashed last night. Great work, I can see these hanging out of the trees shortly. pete Quote Link to comment Share on other sites More sharing options...
Vodkaman Posted December 14, 2007 Author Report Share Posted December 14, 2007 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. Quote Link to comment Share on other sites More sharing options...
weighinalimit Posted December 14, 2007 Report Share Posted December 14, 2007 Another solution well done! I've done about the same thing with many of mine, except I built a rubber lipped box which has a hose attachment so I can use my shopvac to create the suction to get full pours in complex molds that otherwise would require an injection machine. Now I have a presto pot above the vac. box so I can pour a crapload in a relatively short time, you can make a multi-cavity mold & join the vents, I found it best to make a 3 layer mold, the 3rd (bottom) layer is just a series of channels to get vacuum to all the cavities(sort of like an intake manifold from a carbed car engine) only upside down so the runners go to the cavities and vac. is applied at what would be the carburetor mounting flange. Hope ya'll can understand what I'm trying to describe. LOL Quote Link to comment Share on other sites More sharing options...
Vodkaman Posted May 16, 2015 Author Report Share Posted May 16, 2015 (edited) All the pics for this project got deleted, so I am adding them all here. Remember, these are from many years ago and early experiments. Dave Edited May 16, 2015 by Vodkaman Quote Link to comment Share on other sites More sharing options...
Vodkaman Posted May 16, 2015 Author Report Share Posted May 16, 2015 More pics, not so sure these were ever posted. But, they show the possibilities of the method. Dave Quote Link to comment Share on other sites More sharing options...
JRammit Posted May 16, 2015 Report Share Posted May 16, 2015 This is wondrous!... The old pics must have been deleted by someone who sells injectors Quote Link to comment Share on other sites More sharing options...
Vodkaman Posted May 16, 2015 Author Report Share Posted May 16, 2015 Obviously I have had a lot of time to think about this project since the original work. The way I see it working now, is a combination of injection and vacuum. The vacuum to be driven by a simple foot pump, leaving the hands free to look after the injector side of the operation. The actual vacuum required to be effective is not all that powerful, as in the initial experiments I used mouth suction. Ultra fine appendages like that discussed in the prawn life casting thread will require more power, but I still think that a foot pump would do the job. I haven't designed the foot pump as yet, but it is on the list, as is re-visiting this project for a thorough update. The idea never really took off, despite my optimism. One or two members did try it out and raved at the success of the method. Many, rightly so, were put off by the mouth suction side of the procedure, which is why I am going to design a pump for the job. The plan is to present a lure that could not possibly be made by any other method and do it with plaster molds. I will consider suggestions for what I should mold. At the moment I am thinking of a millipede with 2" legs. Another idea is a radial collar with super fine hairs. Any more ideas? Dave Quote Link to comment Share on other sites More sharing options...
JRammit Posted May 16, 2015 Report Share Posted May 16, 2015 Dave, you know how i am with my ideas (ha ha!).... But if by "radial collar" you mean "bass worm", then that is one that i had filed under "impossible"... I've read of many guys having problems injecting the deep ribbed worms, so i abbandoned the idea of a worm surrounded by tiny spikes.. Like a koosh ball or a new tire... When i come up with something better ill pm you Quote Link to comment Share on other sites More sharing options...
Vodkaman Posted May 16, 2015 Author Report Share Posted May 16, 2015 You will have to post a pic of what you had in mind. Dave Quote Link to comment Share on other sites More sharing options...
JRammit Posted May 16, 2015 Report Share Posted May 16, 2015 Since i dont belive one exists, i took the liberty of sketching a detailed artist's rendition (ha ha!)..... Likely the body would be thinner, the bulk of the bait would be in its spikes... Obviously many challenges associated with this one, 3 dimentional appendages and possibly hundreds of tiny passages.. ... Way out of my league!!... You are welcome to it if you like Quote Link to comment Share on other sites More sharing options...
Vodkaman Posted May 17, 2015 Author Report Share Posted May 17, 2015 Yes, it is possible - as an 8-piece mold! I am looking for mold-able but not cast-able, but thanks for trying. Dave Quote Link to comment Share on other sites More sharing options...
JRammit Posted May 17, 2015 Report Share Posted May 17, 2015 I was thinking a 2 piece mold inside a 2 piece "vacuum chamber", connected at top and bottom to remain centered... If the spikes are made short enough they will pull easily out of the mold even though they are not in the seam.... The challenge will be creating a master that can be removed from the mold...... Ive been known to make multiple molds for one bait, only so different pieces are symetrical.. But all of the sudden im connecting the dots in my head of how this can/could be done.......... I may attempt it after all...? Quote Link to comment Share on other sites More sharing options...
