Plastic getting hard to fast

[Andyj]

Hello everyone. I just started making my own plastic lures and I keep running into a problem with the plastic getting hard before all of it is out of my injector. I heat it to 350 and suck it up with my metal injector and about 1/4 of it turns hard and forces the head of the injector to fly off. I then have to stick a small screw driver in the head to clean it out. I usally can get 1 mold filled but I just bought the senko mold and was going to try and fill a single craw mold and senko mold at the same time.

I usally do 2 Oz plastic heat for 1 min. Stir heat for 30 seconds stir then 20 more secs. It then is clear and I add my color and glitter. Heat for 20 more sec stir and suck and Immeditly shoot into the mold.

[Apdriver]

It's sort of a learning curve, Andy. Welcome to the forum and to soft plastics. When I first started, I had a problem just filling one mold so you're off to a good start! I would suggest heating your injector before you draw plastic into it. That cold injector will harden plastic in seconds. Several ways to do this. I like a propane torch with a piezo igniter and heat it while my plastic is in the micro. I put the flame right to the metal. Concentrate on the nozzle but heat the barrel also. It's fast and works very well. Others will give more advice as there are more ways to skin this cat.

[Andyj]

Thanks for the fast reply I'll give that a shot.

[Mike J]

If your injector is cold there can be an inch or so that cools before you can squeeze it all back out. You should have no problem shooting those two molds before it cools. You will always have some plastic left in the injector, it would need to be super hot to get it all out. I usually just let it cool enough to pull the part out inside the nozzle. As far as pushing the nozzle off that is just going to take time to get used to knowing when too stop pushing.  Stick with it and you will get the hang of it. And welcome to the forum.

[andrewlamberson]

I run a couple shots of plastic through my injector to warm it up. During the cold months I wrap  it in a towel to keep it warm.

I keep a cup of used plastic handy to  use  as my injector heating plastic.

[bassinfool]

I would also use more than 2 oz at a time. The more plastic you heat at one time the more mass you have to hold that heat.

[kevin]

I would also use more than 2 oz at a time. The more plastic you heat at one time the more mass you have to hold that heat.

try  doin 4-6oz and as said b4 try to cycle plastic through inj, or heat it up some with torch or hot plate. Just be careful on how much cause u can ruin inj, rings

[Dextraction]

While I am fairly new at this (gone through 1 gallon)...this is what I would try.

Heat 4-6oz up to temp
Shoot your Senko mold
Reheat your plastic to temp (~20-30 secs)
Pull the Senkos
(injector is now warm)
Stir plastic
Shoot the Senkos and quickly top off the sprue.
Shoot the Craw and hold pressure for a 10 count. (this ensures the little legs or tails don't shrink)
top off the sprue

[Justin9j]

Dex for a rookie you have it down.

[Fishfulthiking]

Heating up a larger amount of plastic will help tremendously.  2 ounces of plastic is just not enough to hold the heat necessary to overcome a cold or even cool injector.  4 ounces of plastic will allow you to fill your injector completely and even if you have a 1 inch section near the plunger that solidifies, you will still have enough liquid plastic to fill your mold completely. 

Another trick is to set your injector tip on the table and pour the heated plastic directly into the injector and then place your injector tip.  This technique requires gloves each and every time and is admittedly a bit dangerous.  But I have found this technique to conserve plastic a bit better and it is a good technique when the plastic that I want to inject is running a bit low.  Here's a video that demonstrates the technique I mentioned.  https://www.youtube.com/watch?v=E3-9hKyxLkQ