Thermoplastic Polymorph/Moldit/Polycaprolactone

[Norwegian]

Hi, has anyne used this for lure making? It is a plastic that gets moldable at relatively low temperature.
I am just experimenting but it would be interesting to hear others experienses.

 

[mark poulson]

I've never heard of it.  Do you have a link to a source or specs?

[Norwegian]

54 minutes ago, mark poulson said:

I've never heard of it.  Do you have a link to a source or specs?

Here is a good bit of information: https://poliplasticpellets.com/shop/polymorph-mouldable-plastic-pellets-62c-variant-friendly-plastic/

It is widely available on places like Amazon. 

[Big Epp]

I was a guy on YouTube who uses modeling clay to make masters for molds. I wonder if this would work similarly?  Seems like a neat product.

[Norwegian]

7 hours ago, Big Epp said:

I was a guy on YouTube who uses modeling clay to make masters for molds. I wonder if this would work similarly?  Seems like a neat product.

I have used oven curing modeling clay like Fimo for masters. This is noting like that, the plastic cures in minutes and everything I make free hand tend to look like it is made from play-doh by a 2 year old.

 I did however make molds from tin/pewter and pressed the warm plastic in there, and it seems to work out ok. No idea how well it will last thou, but time will show.

[Vodkaman]

This is interesting stuff, I am tempted to buy a kilo just to keep around for any future projects.

There are a few problems with our application:

1 - It is too thick to pour or inject, so that means weighing an exact amount and pressing into the mold halves and closing, avoiding any bubbles or voids.

2 - The density of 1.145g/ml makes it heavier than water, so a hollow center has to be included in the mold. This means molding two halves separately.

3 - Too slow for production, but fine for own use.

A 3D printed mold might work well, the flexibility will help assembling the two halves. My post reads a bit negative, but this could be fun to work with. Problems can be solved.

Dave

[Norwegian]

Hi Dave,
Thanks for useful input!

1 - Yes, it is too thick to pour. My solution so far has been to overfill both sides of the mold and clamp it together whilst hot. Some times emerged in hot water, if I am too slow. That way I don't get bubbles or voids. The metal mold holds heat well so it helps. I then cut away the excess plastic after cooling. (it can be re-melted, so hardly any loss)

 

2 -  I don't really need air pockets for this bait, a sinking bait is fine.  But if I was I was thinking about attaching floating, hard foam beads to the wire. 

3 - I agree, not a method suited for production, but that's not my goal. I guess you could mold 8-10 baits per hour with this method if you really tried. Possibly more. Not that I am going try 

[Vodkaman]

6 hours ago, Norwegian said:

1 - Yes, it is too thick to pour. My solution so far has been to overfill both sides of the mold and clamp it together whilst hot. Some times emerged in hot water, if I am too slow.

I was hoping the 'over-fill' method would work, so thanks for confirming that, as the weighing the correct amount would get very tedious in a hurry. I look forward to some pics of your methods.

Dave

[Norwegian]

I will try to make a rough guide based on my method. I made it up as I went along so probably massive room for improvement. I just use the pictures I already got. Also, English is not my native language, so things may come out wrong. Any questions, just ask. 

 

I made the molds out of tin/pewter as I melt old bowls and plates for some other lures. And I wanted the molds to be able to take some pressure without deforming. Also I left my silicone out in freezing conditions and fear it might not cure. 

 

Since the mold is made from metal at 230+ Celsius i made the masters from aluminium. Just hacksaw, files, sanding paper and patience. I also tried with a master of wood, it was very dry but it didnt work out at all.  It emitted steam and got all bubbly and made a hole through the mold. It could probably be dangerous too. 

 

 

To make the molds I used molding sand, built a frame of some copper sheet, buried the master half way and poured molten tin over it. 

 

Then I turned it over, removed the sand and sprinkled talc powder over to keep the metal from sticking. Not sure if it is needed. Then another layer poured from the other side. After cooling the layers was easily separated and the master was not very hard to get out.

In the first mold I did not make any bumps to make help aligning the two parts, but I did on the second:

 

I also drilled some holes and fit in some screws to help out fixating the wire. Heads was removed with hacksaw, and I drilled holes in the opposite part to make room for the screws. 

 

To make the bait I melt the plastic in warm water, I also throw in the molds. 

I first fill the one with the wire, the attach the wire and lead. Next I fill the other mold and put them together. I use a screw clamp to squeeze out the excess plastic. If the plastic gets too hard to squeeze the two molds properly together I just throw the whole thing back in the kettle and tighten some more. 

Cool the whole thing in cold water and remove the excess plastic with a sharp blade. It can be remelted several times. 

 

 

Edited January 18, 2023 by Norwegian

[Vodkaman]

Very interesting explanation and novel technique. Nothing wrong with the English.

Dave

[Flaswimbaiter]

I saw a woman Using that on YouTube to modify dolls. I thought it would be useful in making fins or tails, but was concerned about the hot temps we get here in Florida. 

[Norwegian]

13 hours ago, Flaswimbaiter said:

I saw a woman Using that on YouTube to modify dolls. I thought it would be useful in making fins or tails, but was concerned about the hot temps we get here in Florida. 

It melts/goes gooey at 58-60 degrees Celsius. Fins and tails sounds like a good idea, it's really tough even when the goods is thin. I need to try that too.