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Forming Polycarbonate "Lexan"
18 replies to this topic
Posted 25 May 2007 - 04:13 AM
I think I have finally got it, so simple, as usual we think of all the high tech ways to do things and don't see the obvious. I'm Excited! !
I have been trying to "concave" circular "lexan" bibs for ages, as I think they get a bit more grip on the water and can really make a lure shake. Always had trouble with the heat and could never get it spot on, so you finish up with either blisters, melted or bloom all over them.
Made six tonight and all bar one are crystal clear, and I am pretty sure I know why (see pics). Heres a site with heaps of info on working Poly.
Just checked out the Pictures and the lighting is crap, I will take some more tomorrow in the daylight (16 hrs time) and post them with a bit more "how to" info. Stand by-sorry about that .pete
Posted 25 May 2007 - 06:36 PM
O.K , I have got some pics, but first let me try and explain how it can be done. I read somewhere that Poly immersed in boiling water will allow you to bend it, This is probably right, but to form poly you need higher temperatures and it does not matter how much you boil water it is allways going to be about 100 C. I then started thinking "liquid and higher temps", thought deep frying and here we are "cooking oil". As I have a chelestrol problem (who doesnt) I used olive oil, but I think any cooking oil would do.
Get a small can, I used a SMALL discarded, chopped tomato can, anyway something you can heat on the stove and is narrow and tall. Put about 2" of cooking oil in it, I used olive oil, but any cooking oil should do. Place the oil on a very low heat gas or electric burner
and SLOWLY heat to 100 C or 212 F. If you have a thermometer all the better, but if not , put a drop of water in the oil and when it hits 100 C the oil will crackle as this water boils. 100 C is not hot enough to form poly so keep SLOWLY heating for a few minutes to get it around 120 C to 130C (not sure what F is).
Get 2 spoons of exactly the same shape, the lips I use are about 3/4", I used 2 teaspoons, but if yours are bigger use dessert spoons or plough discs, whatever your size-whatever your former is, make sure they fit neatly togeather!! Place the poly blank on the spoon (A little cold oil on the spoon helps keep it in place) and then place the other spoon on top (see PICS) and then clamp them togeather, as you can see I used a paper clamp.
Stand the spoons in the hot oil, making sure the actual spoon ends and poly are immersed in the oil, leave for about 30 sec to 1 min and remove.
Place the spoons on a damp wash cloth and wrap the cloth over the top, then press the spoons togeather (another spoon is handy). Hold in position for about 30 sec's so the damp cloth can cool things a bit, remove the paper clamp, seperate the spoons and flick the new lip into a glass of water/detergent mix to cool and clean, then do another one - sometimes the poly is formed so well it sticks to the spoon (suction) so you may need to slide it off the spoon into the water, be carefull as the poly is still hot and you may push it out of shape.
This sound pretty labourious but once you get the oil to the right temp, you could probably do 10 in 10 mins, get a few sets of spoons and god knows how many you can do. You may see one lip in the photo is a bit cloudy looking, this one was placed in the oil when the temp was too low and bought up to temp, it did not form properly. Allow the oil to get up to temp before you place the poly/spoons in it and they will come out crystal clear as in photos. These lips have not been sanded etc, they went streight from the die punch to the oil, the poly is 1 mm thick (or 0.040" I think!!). I ahve not tried it, but 1/8" should bend just as easily, maybe have to heat the poly for a few more seconds though.
Beware of over heating the oil and effects of water, hot oil and flame. Dry spoons before immercing again in the hot oil.
Hope this is of some use to some one. Have fun >Pete
Posted 25 May 2007 - 07:00 PM
Sorry -ran out of space- Here's 2 more Pics
Posted 25 May 2007 - 07:50 PM
Pete, that's one of the coolest ideas I have seen here in a while. This sounds a little tricky, but I'm sure with practice it becomes fairly easy. Good work and special thanks for sharing.
Posted 26 May 2007 - 06:27 AM
Thanks Doomart- hope you can get something out of it. I can't believe it's so easy, all the blistered poly laying around the place- once even tried my daughters electric hair streightner- now that has some promice for bending poly, but have not got to that yet. Pete
Posted 26 May 2007 - 09:59 PM
One question has nagged me since reading this....would the curved surface not present difficulties when it comes to lip slot? Are you using those in molded baits, or carved ones? I suppose you could cut the slot wider than normal, then use a product to fill the "air space".....but you would only have three contact points between the curved lip surface and the lip groove. I still think it would be possible to get a lip secure in that manner, but it seems like it would not be very easy. But nobody said this stuff is supposed to be easy.
Posted 27 May 2007 - 01:02 AM
Yep, I think you are right, but the poly I am using is only 1mm thick and with that hole punched in it , bends into the slot pretty easily- would not like to try it with balsa though. All my baits are wood, some balsa and cedar but mainly I like a local timber "Hoop Pine", it seems to be a better weight, hard and less grainy then cedar. To be honest I have more trouble with the sealer/paint etc filling up the slot, they're a pain to clean out.I'm thinking you could, after forming them, hold the lip in a pair of tweezers (or something) and re-dip the side you want flat - when its up to temperature pull it out and squeeze it flat with a pair of pliers or 2 pieces of wood etc!!! Sounds like a lot of stuffing around, but for me, flat bibs are "common" and the more parts I can make on a lure, the more I can say they mine, only need to work out how to make hooks and eyes now!!.Let me know how you get on wit it. Pete
Posted 27 May 2007 - 02:44 AM
"Doomart"-Just tried the tweezers and pliers thing- works pretty good and leaves maks from the jaws so the glue should grip better. If you don't want marks, maybe use two small blocks of wood or smooth jawed vice grips etc.Pete
Posted 31 May 2007 - 03:17 AM
I looking at all these buitifuo lures and I'm wordering if anyone has a painting booth for painting houy crankbaitts. I no good yet, there we come a day '''''''''''''''''''''''''''''''''''cranks by thomas will be the items
with in the next 6 monthsl;)
Posted 31 May 2007 - 03:22 AM
reading my thread it appears I may have one to many. Truth is I do not drink any form a alcoha or take drugs. I'm so tired that I will straightout I mead to say tomorrow.
Posted 04 June 2007 - 01:02 AM
One thing to add, for safety, make sure if you use a couple drops of water to gauge the temp of the oil, put the water in BEFORE it gets hot. Water dropped into hot oil will splatter and can hurt.
Posted 07 June 2007 - 10:36 AM
That is a great and easy way to form polycarbonate! So easy!...Larry
Posted 17 June 2007 - 12:46 AM
"Actionbaits" -Just tried bending "Stamina" pre cut Polycarbonate lip (32mm x 21mm x 1.5 mm) may be a bit simpler than trying to cast resins- see picture. Pete
Posted 14 March 2008 - 08:14 PM
You can get rid of any discoloration in poly using two simple methods. If you have a blurred effect on the poly, just put it in a small container with one drop of cyanoacrolate (crazy glue) Do not put the glue on the part, just next to it. Leave it somewhere warm for a while and it should do the trick. Warm does not mean in the oven! 70 or 80 degrees f. is fine. The vapor reacts with the polycarbonate. Also, if you have a smoked surface (usually matted or whitish in color) it can be treated by buffing with scotchbrite. If you dont have scotchbrite, just get a new sponge from your kitchen. The type that has the rough plastic scouring material on one side. That stuff is esentially "scotch brite". If the poly was turned on a lathe, and is heavily smoked, just put a little baking soda or even white toothe paste on the scotch brite for the first bit of polishing.
Hope this is helpfull..............
Posted 21 March 2008 - 06:28 AM
Thanks Sonny, theres some good info here - this stuff scratches so easily, these tips will be real handy. Maybe you should repost this in the "Quick Tips" post. pete
Posted 25 March 2008 - 12:04 PM
Pete, goofy question here, but some has to ask and guess it has to be me. Does the cup to the lip really help bait dive deeper? and can you give some reference data as how much diff. it makes? Yeah, I know that's two questions, but I can't count either (don't have my shoes off).
Posted 27 March 2008 - 06:47 AM
Sully - I have never used a flat lip on this shape. I once used to make the same lure with a shorter lip (12mm) which went to about 8' it was an aluminum lip which had a very slight concave, the 16mm concave poly now dives to around 15'. But beside the depth, I think the action is much more 'vigorous', or if you want to change things, reverse it (concave down, see gallery) and the same lure will go to about 6-8' with a more lazy action. I have just made a new former ( Mk5 - larger lips,that anyone can make), and am assembling a tute, which should be ready for posting after I get back from the T.U meet in Clinton - lots of photos, as opposed to the post at the top of this thread. pete
Posted 27 March 2008 - 09:32 AM
Pete, thanks. Recon I'm going to have to try this on some of my crankbaits. Always like something interesting, and this certainly classifies.
Neat thread, and looking forward to tute.