Help With 2 Part Pop Mold

[omartinjordan]

I have a couple questions about the 2 part pop molds.  I think I can make the mold with no problem but I wanted to know what you guys use or how you cut out the channel for where to pour the plastic?  Is it cut by hand?  I haven't seen it mentioned in any of the tutorials.  Any help would be great.  Thanks.

[mark poulson]

My mold boxes are usually made with 3/4"X 3/4" pine sides, and 1/4" masonite bottoms, so when I clamp them together I have 1 1/2" for my POP. 

I usually mark the center of each cavity on the top of my wooden mold frame, clamp the two halves together, and use a drill press to make a 1/2" hole in my wooden frame, and then a 1/4" hole on down to the cavity through the POP.

After I've drilled the holes, I clean them out, sand the wood part smooth with a dremel, and seal them with D2T epoxy.

[Senkosam]

I just learned something new which makes sense where it concerns making the sprue (pouring channel). Use a cylinder of clay. If you use the kind that hardens, grease it up each time you need it,

 

I use half and half cartons, the bottom of milk cartons and at times, cheap aluminum disposable baking pans that come in different shapes and sizes.

Edited March 16, 2013 by Senkosam

[ipt]

i pour my first half and obviously leave room for a sprue/channel. after that is hardened and sealed, ill draw my channel with a sharpie, then once i like it. ill trace over the sharpie with an exacto knife to give it a small impression. after you pour your 2nd half, the sharpie and imprint will be on both sides of the mold, then ill take my pocket knife and a 5/8" drill bit to carve the channel out and drill the sprue.

 

works perfect, i have about 20 injection pop molds that work flawlessly

[tupong]

I'm not that great at describing how to do stuff so I'll just post a pic of one of the injection pop molds I make. I use things like old pen shafts and plastisine to make the channels for injection etc and marbles or ball bearings for the locating pins/holes. I lay them in place while the pop is still soft.

 

 

 

 

 

 

 

 

regards mick

[Senkosam]

Nice Mick!

[omartinjordan]

Thats a pretty good idea.  I also wondered if anyone had thought of maybe using a shoulder bolt of something.

 

Also, could you hand pour that bait in the mold shown?

[Senkosam]

Sure, if you wanted a flat side.

[omartinjordan]

I mean with putting it together. I am new to the plastics thing. I pour lead in a two part mold and wondered if you would do the same with a small mold like that one

[mark poulson]

I have made some two part POP molds that I can hand pour.They are both large, simple molds like my fat Ika mold, and my swimbait tail mold.

Most of my two piece molds pour better with my Cajun Injector that I bought from Cabela's.

Being able to get the hot plastic all the way down into the mold, so you are filling it up from the bottom to the top, is the key with hand pouring a two piece mold.  Most two piece molds have small details, or are long and thin, and need to be injected.

[Senkosam]

I mean with putting it together. I am new to the plastics thing. I pour lead in a two part mold and wondered if you would do the same with a small mold like that one

 Sure, but like Mark said and the further away from the sprue the thinnest part is, the less likely to be filled hand poured. Here is a 5.5" hand poured copy and laminate to boot!  :

Edited March 20, 2013 by Senkosam

[omartinjordan]

I would really like to be able to pour these skinny dipper baits.  Do you guys think you could pour a two part mold and be able to make these?

 

I would post a pic but can't seem to get it to work right.

 

[ipt]

you can make a 2 part pop mold out of almost any bait. and most of them you'll be able to hand pour if you set it up right. the key will be hot plastic. if your baits are heavily salted, it wont work well because the salt will settle with the hot plastic.

 

ill post some of my 2 part pop molds when i get a chance

[mark poulson]

 Sure, but like Mark said and the further away from the sprue the thinnest part is, the less likely to be filled hand poured. Here is a 5.5" hand poured copy and laminate to boot!  :

 

I am soooo jealous!  Those are really nice laminates!

[Senkosam]

Thanks. For those that don't know, those are top and bottom views of the same bait.

The key is plastic about 320 degrees and fine salt from Diamond.

As you can see on the blow up, the green pumpkin didn't go all the way to the bottom of the tail so I poured some hot plastic on top of the pearl half and used a razor to reshape the edges. The most important final step with any lam. is sealing all edges with a flame or soldering iron to prevent separation.

Maybe an injector might have saved me from doing the last step vs. hand pour in this 5" two-part. The extra few inches allows the plastic to cool too fast flowing downward, preventing the best melting together of the halves.

Didn't mean to digress from the topic.

Edited March 20, 2013 by Senkosam

[mark poulson]

Senkosam,

I never thought of using a heat gun to get the plastic to lay down better when I hand pour the first half of my molds.

Thanks for the idea.

Edited March 21, 2013 by mark poulson

[Senkosam]

Senkosam,

I never thought of using a heat gun to get the plastic to lay down better when I hand pour the first half of my molds.

Thanks for the idea.

This was your idea and a good one at that! Thanks. (Maybe my wife's 550 degree hair dryer? .....)

[Senkosam]

Because of the limited time to edit, I'm reposting the laminate mentioned in my previous reply. Sometimes I move images around on photobucket killing the link. Again, this is top and bottom of the same 5" lure.

 

Edited March 22, 2013 by Senkosam

[CrabbyBass]

When I make a multi-cavity injection mold, I use straws for my sprue channels.  The bendable straws work great.  I then use a knife to carve a channel from the straw to the lure.  Then I take my injector tip and trace it on the mold and carve out the injection port.  This works great for me.  I hope this helps!

 

Chuck