3.5 Swim Shad Help Please

[Muskygary]

Great video!! That explanes a lot. Thanks jason

[BassDetective]

Just watched the Video.  Awesome.  I am going to try and hold the injector tip up and purge a little and then hit the mold without topping off and see if that gets it.  I will post back tomorrow.

[Jason]

Just watched the Video.  Awesome.  I am going to try and hold the injector tip up and purge a little and then hit the mold without topping off and see if that gets it.  I will post back tomorrow.

Make sure the spru is full...

[Denny Welch]

What a great thread this is...problem solving at it's best.  I think the video was a brillant way to illustrate, in pictures, the cause, the effect and the solution of  Steve's issues.  Kudo's to all of you who contributed to this thread and special recognition to Jason who brought all together.

Unfortunately, there was one issue that was left hanging and I was reminded of it in the video.  I don't mean to beat a dead horse, but did you notice the big box of Pampers on the shelf in the backround?  I couldn't help but wonder if the heartbreak of onyonlyx  didn't also invade the confines of CCM. For those of you not using exhasust fans or respirators, I want you to know that Pampers also come in adult sizes.

And that's all I have to say on the matter.

[Jason]

Lol..  Be careful about making fun of one mans diapers.  You never know what's in store for you in the future!

The Pampers are actually Baby Wipes.  I've been meaning to start a thread about this.  We use those vs. shop towels as they are significantly cheaper and work great.  Diane usually gets the Kirkland brand, but she had a coupon for the "brand name" this time.

I'll start a money savings thread and post this in there.  Maybe others have some cool tips as well.

Jason

[BassDetective]

   Back to Business   

I watched video and followed the instruction intently.  Success!

Here was my set up:

1.  Clear plastic heated to around 350 - 370 - it did have some microbubbles but that will be for another thread

2.  I poured the plastic into the injector using the unofficial Caney Creek Method and placed the nozzle on the injector. 

3.  I purged the injector holding it tip up over the cup until a little plastic leaked out

4.  I immediately inserted in the injector into the first swim shad mold.  I slowly depressed the plunger until I felt back pressure and waited for a 2 count

5.  I removed the injector and allowed some plastic to fill the sprue back up

6.  I moved on to the second mold and injector the same way.

7.  I pulled the injector after I felt back pressure and waited for a 2 count.  I allowed some plastic to drip out and re-fill the sprue

8.  I waited a 2 minute and de-molded the baits.  No air in the heads, gate or runner

I did have some very small bubbles in various sections but there were bubbles in the plastic to start.

Here are some take-a-ways:

1.  When you have a multi-cavity mold small deficiencies in your method get magnified which would explain why I was not having an issue with the single cavity molds

2.  Purging the injector is critical to keep air out of the injection process

3.  Holding your injector tip up while purging seems to work better (I was purging with the injector tip down prior)

4.  Multi-Cavity molds are more likely to require a little re-fill of the sprue due to shrinkage

Thanks to all that helped and hopefully this will help many others in the future.  It has been an excellent learning experience for me.

[ghostbaits]

Glad you had success!!

I have to question the safety of purging upright. Plus bubbles (air) will go up. If you purge up, the air bubbles you do have will be moving towards the injector tip.

In addition, I never have purge mu injector prior to injecting. You should not have to. Thus just adds time and heat to your process that an hour later you wish you didn't have.

I didn't watch the video yet so maybe I am responding to something Jason said not to do.

Jim

[pjmcla]

Hurray!  Sorry I took so much of your time and effort.  I knew once "The Master" came on the scene,  the bubble monster was doomed.  Maybe I helped some by "going through the process of elimination."  
There is joke here between Denny, Jason, and the diapers but for the good of the forum I will leave it alone  .

[BassDetective]

Nobody took my time - I took your time and effort and I thank you.  It was a great learning experience.

Interesting safety note - Jim?  I will have to give that some thought.  Jason did have a plenty of disclaimers in the video.  Its purpose was to eliminate some variables and isolate the problem.  To be clear, purging was required because he hand poured the plastic to the barrel of the injector and then placed the nozzle (not recommended for obvious reasons).  This leaves air in the injector at the tip which required purging.

I plan on buying a CC injector and see if that makes a difference could have something to do with the challenges that are unique to me.

[ghostbaits]

Gotcha Paul. I just don't think anyone should have to purge before shooting. Check out you tube. Tons of videos and while I have not watched all, I have never seen anyone purge prior to shooting molds after drawing up plastic out of a cup.

I have 4 injectors from various places and 2 twinjectors. Never have purged my injectors prior to shooting. Maybe I am missing something on this.

Jim

[BassDetective]

I have done some more testing over the last few days and I am pretty sure that the injector is a little quirky.  I did change out the O-rings which I purchased from Napa and it seems a little better - definitely a lot smoother when injecting.  However, unless I purge the injector I am still getting air.  When I purge I am good - when I don't purge I get air in the baits (by air I mean the larger pockets) usually at the head or in the runner.  I have been wanting to order another injector anyway so I will get to compare.

I did notice that when I place the injector in the plastic large air bubbles come up in the plastic within a few seconds.  I am guessing this is the air that is in the tip?  I would assume this is normal.  Does anyone do anything about this?

[kipbass]

I removed the oring on my injector and wrapped teflon tape around the plunger were the oring sits. I just went around once and put the oring back in place. It's a lot tighter, but works really well once the injector is heated up. I don't know if the teflon tape is holding up, I ran out when I tried this. It still has a tighter seal though, and the NAPA oring is still holding strong and not breaking down. 

[ghostbaits]

I did notice that when I place the injector in the plastic large air bubbles come up in the plastic within a few seconds.  I am guessing this is the air that is in the tip?  I would assume this is normal.  Does anyone do anything about this?

Never seen that either. No bubbles come up prior to sucking up plastic.

This whole purging thing has got me thinking. Whay are all the injectors made the same virtually? The all, including the CCM version, have that area in the tip where air can hold. I am sure it could be eliminated easily.

My guess is that all the mold makers realize that this tiny amount of air should be expelled via the mold venting.

So why all this purging talk? I know this is what Steve is doing to be able to get acceptable baits but I just doubt this was what was intended when the hand injection process started.

Jim

[Jason]

Venting is intended to allow air from the mold cavity to escape.

No amount of venting is going to separate air from within plastic.

There are only 2 ways I know you could do this in a mold (that was designed for it). One would be to keep the plastic liquid long enough for the air to rise out of it. The second would be to pull a vacuum on it.

Neither of these are as practical or cost effective as not injecting plastic with air in it into the mold.

[ghostbaits]

I am not an engineer or a deep thinker but it seems common sense that the small amount of air in the tip of the injector would stay near the plunger and move away from the tip as you pull back. Air is much lighter than liquid plastic. With that, the "air" from the injector tip would not be in play. If a small amount was trapped and injected, it would be pushed out of the mold vents with all the air already in the mold cavity(ies).

I guess my overall point and belief still is, something is wrong with the injector, not the technique. Properly functioning injectors should not have to be purged prior to mold injection.

There are 100's of You Tube videos showing hand injection and I have not seen one that purges the air/plastic prior to injecting the mold. Watch Frank's laminate videos on the post here, no purging. In fact, if you watch closely, most injectors have plastic running out of the tip slightly so there would be no reason to purge these as plastic has already displaced most of the tiny amount of air in the tip.

Say No to Purging!!!! LOL!!! Sounded like a campaign slogan!!!   

Jim