Hi all. This is a heed of call to the chaps wh

johnrhodes wrote:
Hey all

I've been pouring for a couple of month’s now mainly re-melting old plastic. I managed to get some plastisol and have been using crayons to colour it with good success. I manly use a plastic syringe to inject, reason being baits has long curly tails etc. But have been struggling a bit with hollow heads. Anyone got any ideas?
Hollow heads? if you explain perhaps I can help, meaning you want them with hollow heads ro they have hollow heads which you don't want?
 

johnrhodes

New member
Sorry meant hollow heads I don't want. I tried making the pouring hole a bit bigger and this seems to have helped but I still get get one or two which are hollow. Some also have a dent in the side. I'm using dental plaster moulds. The bait cavities are coated with epoxy.
 
Kay, I know exactly what you're talking about, try pre-heating your mold, or inject let it cool a bit remove and immediately redo without the mold getting cold and see if that doesn't solve your problem, the thing is the plastisol cools too quick in the mold but more importantly it cools way quicker in the inlet of the mold thus creating a vacuum inside as it starts cooling there, which then contracts the lure out of shape and forms the hollow bubbles.
 

Andre Laas

Sealiner
Have any of you guys used these vacuum formed worm molds for making soft plastics, or better still, have any of you tried making your own vacuum formed plastic molds? I am playing around with some grub ideas that I cannot find locally, and I think a clear plastic mold will make it easier to see if the mold is filling out properly, especially on real small grubs.
 

sealady

New member
Little Green Fish wrote:
Kay, I know exactly what you're talking about, try pre-heating your mold, or inject let it cool a bit remove and immediately redo without the mold getting cold and see if that doesn't solve your problem, the thing is the plastisol cools too quick in the mold but more importantly it cools way quicker in the inlet of the mold thus creating a vacuum inside as it starts cooling there, which then contracts the lure out of shape and forms the hollow bubbles.
100% in agreement little green fish, however cant see how anyone can use a plastic syringe to inject hot plastic at 180 degrees C. I have tried and the syringe end melted away so I have now purchased a 6oz injector from Del Mart Molda
 
sealady wrote:
Little Green Fish wrote:
Kay, I know exactly what you're talking about, try pre-heating your mold, or inject let it cool a bit remove and immediately redo without the mold getting cold and see if that doesn't solve your problem, the thing is the plastisol cools too quick in the mold but more importantly it cools way quicker in the inlet of the mold thus creating a vacuum inside as it starts cooling there, which then contracts the lure out of shape and forms the hollow bubbles.
100% in agreement little green fish, however cant see how anyone can use a plastic syringe to inject hot plastic at 180 degrees C. I have tried and the syringe end melted away so I have now purchased a 6oz injector from Del Mart Molda

@ sealady :hyst: Yeah i too tried the plastic syringe thing and it happened as you described which then moved me on to using an empty silicone tube, tghen that started melting the tips after the second or third injection, so then I bought a cookie press (handheld) modified a funnel with the CO2 welder but it had rough edges inside, then I bought a serious silicone injector (industrial strength) so now the plastisol goes into it directly and gets injected into the moulds like nothing, also has quite a coarse thread on the caps and the aluminium cylinder which makes it much easier to refill and so forth, still has a plastic nozzle, thou but it's reaaly thick and hence doesn't get bend out of shape or melts that easy, works like a charm.

@ critter, not really, been using resin and RTV silicone for my molds, but if you really want seriously GREAT MOLDS give old Dog TAURUCK a PM, he's done some for me and well, ::respekt: is all I can say!!!
 

sealady

New member
then I bought a serious silicone injector (industrial strength) so now the plastisol goes into it directly and gets injected into the moulds like nothing, also has quite a coarse thread on the caps and the aluminium cylinder which makes it much easier to refill and so forth, still has a plastic nozzle, thou but it's reaaly thick and hence doesn't get bend out of shape or melts that easy, works like a charm.
LGF This sounds like a awesome idea considering we have to import all our stuff - Please advise where i could get one of these silicone injectors from as a backup should it come to that. Thanks a lot
 

sealady

New member
Guys check out making swirls and laminates http://www.del-mart.com/forum/showthread.php?t=7681
The way one achieves this is awesome.
 
sealady wrote:
then I bought a serious silicone injector (industrial strength) so now the plastisol goes into it directly and gets injected into the moulds like nothing, also has quite a coarse thread on the caps and the aluminium cylinder which makes it much easier to refill and so forth, still has a plastic nozzle, thou but it's reaaly thick and hence doesn't get bend out of shape or melts that easy, works like a charm.
LGF This sounds like a awesome idea considering we have to import all our stuff - Please advise where i could get one of these silicone injectors from as a backup should it come to that. Thanks a lot
The one I got was from DYKOR paints in Silverton Pretoria, the make is a DeJuca if I remember correctly, but this this is seriously geared towards the industrial sid eof things. will see if i can post a pic of the thing, i have seen another one somewhere but for the life of me cannot remember where. Oh and the answer on the next question is : "sorry I cannot remember what I paid for it!"
 
here's a pic on the same gun, mines just not blue but normal aluminium colour.

Caulking-Gun-ZR-200149-.jpg
 

johnrhodes

New member
@ Little Green Fish. Thanks for the advise on the the hollow heads.  Heating the mould did help.  Also found if the sprue is longer its helps tremendously..  I see you have been using RTV to make your moulds.  Do you make 1 or 2 part moulds?  If 2 part do you use clay for the initial bottom half or ??
 
No prbs Buddy, Yeah I make two part molds, I do use clay but not entirely or exclusively clay only, here's what I was taught by a real Master of mold making,

Take a flat sheet of wood, cut out the shape of the plug you wanna make the mold of, then stick some clay (childrens play clay) to the inner edge of the cut-out, press the plug into that and press tha clay from the back towards the front of the wooden base so that the clay is higher than the wooden base, then use a hobby knife or something similar and remove the excexx clay so that the clay virtually becomes a soft extention of the edge of the wooden base to the lure.

If my explanation doesn't make sense lemme know, and perhaps I can see if I can take a picture tutorial to make it easier.
 

nutt

New member
Hi Guys

I have a friend in Canada who owns a lure factory and produces baits on contract for a lot of the large manufacturers. He sends me stuff from time to time and I have got lure substrate from him in the past. Yes it is expensive to bring in but if we all consolidate our requirents and place a big order for like 200 litres we could probably get it for under R60 a litre. You can make a whole heap of worms with a litre.

nut.

 

 
 

Frikster

Senior Member
I know it is and old topic but sure is interesting,anyone maybe have a reason why some flukes makes thousand small bubbles when you leave it on your deck after fishing with it.All my old flukes got this " Disease"trowing them away anyway because they are shot ,but just wondering why they do it?
 

swarley81

New member
Little Green Fish wrote:
here's a pic on the same gun, mines just not blue but normal aluminium colour.

Caulking-Gun-ZR-200149-.jpg

Reviving a very old thread, but I have a question about this silicone injector. I also have one and I intend to use it for plastic lure injection.

Was the injector you guys used modified in any way?

When you dipped the tip into the plastisol, did you just pull back on the knob with the spring and was there enough suction to pull the warm plastisol into the tube or did you make changes to the internal parts?
 
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