Jump to content
BuckeyeFishing

Issues with a Do- it 3" K-Chub Mold

Recommended Posts

Whats up?

I am having some issues with a Do-It 3" K-Chub mold. When I pour at 330 degrees and lower, I am getting incomplete pours (one of the tails isn't filling in) but no denting. When I pour at a higher temp than that, I am getting denting on most of the grubs (I am keeping the sprue topped off) but they are all pouring completely. I am preheating my mold slightly because its cold in my garage but they are only warm to the touch. Is this a venting issue, design issue, or something I am doing? Or is this just something I need to live with and pour at a cooler temp and just deal with one never pouring correctly? 

Thanks for any advice.

Share this post


Link to post
Share on other sites

I bet opening the gate just a bit would help you. Easily done with a dremel and tapered stone. Denting happens when the runner is closed off from the cavity as the mold cools. I wrestled with a doit mold for a long time trying this and that but this was the final solution. 

  • Like 1

Share this post


Link to post
Share on other sites

Had the same problem with the 4" twin tail. I had a local machine shop open up gate all the way down. The original gate decreases in size by about half and freezes off. It won't matter how much pressure you hold or how long you hold it if hot plastic can't get to the cavities. I believe it is a design flaw with those molds.

Share this post


Link to post
Share on other sites
14 hours ago, Roger Linnell said:

Is the grub identical to a Kalin?

Its pretty close. I use 3" Kalin grubs all the time, thats why I bought this mold. Been kind of a hassle though with the denting and incomplete tails. 

Share this post


Link to post
Share on other sites

This is the exact mold I was having the problems with. Same issues too, denting and incomplete tails. I took to the custombaits forum and was told this.

Try moving the clamp closest to the hinge more toward the center of the bait/mold so its not directly over the tail portion and don't bear down as hard on the clamp. Try using a small soft paintbrush dipped in worm oil to coat the tail cavities on both sides of the mold. If you have a small, fine flat file, try opening the vent runner up just a hair using the very edge of the file....you may have a slight tail after opening up the vent but that will come off with a tug. 

ended up all I need was to lighten up on the clamp, and now I get about 90% of my pours with complete tails. Same with denting. About 90%, but that comes with monitoring my temps better. Just cant bear down on the injector or else it blows out in the mold. Just normal light pressure and hold for 5-10 sec. if all this still fails I was also told to contact Kyle himself at do-it explain the problem. I’ve heard they go a long ways to make things right with their products. But to do that before any mold modifications.

  • Like 1

Share this post


Link to post
Share on other sites

I tried all the usual stuff with negative results. Do-It sent me an extension tube to try and it didn't work. It wasn't until I opened up the gate that I got good results. I don't worry about pressure or clamping and I don't get incomplete baits.

First picture is how the molds come from Do-It. Second pictures is mold after mod.

 

thumbnail.jpg

IMG_2843.JPG

Share this post


Link to post
Share on other sites
21 hours ago, Thembonez said:

This is the exact mold I was having the problems with. Same issues too, denting and incomplete tails. I took to the custombaits forum and was told this.

Try moving the clamp closest to the hinge more toward the center of the bait/mold so its not directly over the tail portion and don't bear down as hard on the clamp. Try using a small soft paintbrush dipped in worm oil to coat the tail cavities on both sides of the mold. If you have a small, fine flat file, try opening the vent runner up just a hair using the very edge of the file....you may have a slight tail after opening up the vent but that will come off with a tug. 

ended up all I need was to lighten up on the clamp, and now I get about 90% of my pours with complete tails. Same with denting. About 90%, but that comes with monitoring my temps better. Just cant bear down on the injector or else it blows out in the mold. Just normal light pressure and hold for 5-10 sec. if all this still fails I was also told to contact Kyle himself at do-it explain the problem. I’ve heard they go a long ways to make things right with their products. But to do that before any mold modifications.

 What temp are you pouring at? I will try lightening up on the clamp near the hinge.

The gate seems ridiculously small for the size of the grub body. I pour a 2" paddle tail that has a bigger gate and the body is half the size. I really don't want to modify it but I will if it eliminates my frustration. I have a few rat-tail files and a Dremel. Anyone have a suggestion on a bit for the Dremel if I have to open the gate?

Share this post


Link to post
Share on other sites

Just so we are on the same page when discussing the names of the different parts of the injection mold. I believe the machinist increased the size of the runner on Basseducers’ mold. The gate, from what I understand, is the necked down area just at the start of the cavity. Allows you to separate the finished bait from the sprue with a tug. Please correct me if this is wrong. This gate is where the cavity is closed off from the runner first and is the smallest restriction.

What I did to correct a denting problem was increase the size of the gate with a tapered stone in my dremel. It didn’t take much and minimal modification.

Use this type of stone. I picked mine up at Lowe’s.

https://www.mscdirect.com/browse/tnpla/09023375?cid=ppc-google-New+-+Abrasives+-+PLA_sDcSlgQhy___164110813569_t_S&mkwid=sDcSlgQhy|dt&pcrid=164110813569&rd=k&product_id=09023375&gclid=EAIaIQobChMIs6jt8LzF4AIVmh-tBh1XCQXjEAQYCSABEgKfqfD_BwE

Edited by Apdriver
Added content.
  • Like 1

Share this post


Link to post
Share on other sites
33 minutes ago, Apdriver said:

Just so we are on the same page when discussing the names of the different parts of the injection mold. I believe the machinist increased the size of the runner on Basseducers’ mold. The gate, from what I understand, is the necked down area just at the start of the cavity. Allows you to separate the finished bait from the sprue with a tug. Please correct me if this is wrong. This gate is where the cavity is closed off from the runner first and is the smallest restriction.

What I did to correct a denting problem was increase the size of the gate with a tapered stone in my dremel. It didn’t take much and minimal modification.

Use this type of stone. I picked mine up at Lowe’s.

https://www.mscdirect.com/browse/tnpla/09023375?cid=ppc-google-New+-+Abrasives+-+PLA_sDcSlgQhy___164110813569_t_S&mkwid=sDcSlgQhy|dt&pcrid=164110813569&rd=k&product_id=09023375&gclid=EAIaIQobChMIs6jt8LzF4AIVmh-tBh1XCQXjEAQYCSABEgKfqfD_BwE

I agree, the gate is the area where the plastic first enters the bait cavity. It has been my experience over the past 15 years of injecting that if it is a dent problem it is because the gates are too small, if it is a filling problem it is usually venting. I am not saying that temperature or clamp pressure can't play a part, but I feel if they do it is usually because of design to start with.

  • Like 1
  • Thanks 1

Share this post


Link to post
Share on other sites

I was always told that the gate is in the mold and the runner is that piece of plastic the baits are attached to once you pull then out of the mold. The gate used to be really short back when we were top pouring, but injection made it longer.

Share this post


Link to post
Share on other sites

 What temp are you pouring at? I will try lightening up on the clamp near the hinge.

 

335-345°

Share this post


Link to post
Share on other sites
11 hours ago, ute said:

I agree, the gate is the area where the plastic first enters the bait cavity. It has been my experience over the past 15 years of injecting that if it is a dent problem it is because the gates are too small, if it is a filling problem it is usually venting. I am not saying that temperature or clamp pressure can't play a part, but I feel if they do it is usually because of design to start with.

Ok cool, we are all talking about the same thing. I was hoping that I was using the right terminology. 

 

I tried reducing clamp pressure, I got it to inject completely but still got dents. I shot it 3 times today at 340, 330, and 320 and got dents at all those temps. 

 

Apdriver, thanks for linking the stone. I probably have that in my box full of Dremel bits. If not, Lowes is a mile away and I will go pick one up.

 

Thanks for the help everyone. I find it slightly annoying that I have to modify this mold to get it to pour correctly but its the only mold I have found that is a fat 3" grub like a Kalin grub.

Share this post


Link to post
Share on other sites

I made my own molds, the one on top is the 5" Kalin, they come out alright. I had to search through my collection of originals to find enuf factory grubs that weren't dented to make the mold

20180411_092024_zpscb7ojloe (1).JPG

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...

×
×
  • Create New...
Top