Sprue Extender?? (noob Here)

[jrock22]

Kinda embarrassed to say I don't entirely understand the virtue of using the sprue extender...in what ways will it help the outcome of my molds/plastics?

[ctom]

Most all of the molds you'll find yourself using will not call for an extender. Once in a great while a mold will make baits that have dents from irregular cooling. Its thought that the extender might offer more hot plastic at the injection port for the bait to draw on while in the process of cooling. The 6" Ripper requires a lot of plastic and I have yet to make on that dented. I wouldn't worry about an extender until you run into a mold that is dealing you fits. For everyday, plain jane, injection you won't need one and using one will only add another something to have to deal with that's totally un-necessary.

[jrock22]

thx! might the extender be a solution to the occasional dents I'm experiencing making senkos?

[Fishermanbt]

Who’s mold is it?  There are a number of variables that come into play with baits denting. Sometimes it’s one thing while other times it’s a combination of factors. One that stands out I believe is plastic temps. I have the same issue with my unknown brand CNC stick mold. Once I get the temp just right though things come together. Until then it’s very frustrating.
I don’t know that I’m fully certified to give you a complete answer. I would however point you to the search bar for a full breakdown from those that are certified.

[ctom]

Plastic temp. Mold temp. Injection speed. How long of a hold with pressure on the injector at the end of an injection....they all are relevant. Topping off the sprue is another.

As Fisherman has alluded to, you need to try different things to work thru denting issues. It start with plastic temp and hold time.

[jrock22]

thx fellas. The mold itself is the do-it mold yamamoto senko. And yes, I hear you on the multiple factors...I just started using a thermometer to test, and it's clear I don't yet have enough experience to "know" that I've reached 350 without seeing the reading myself.

Been having a blast and appreciate this forum.

[andrewlamberson]

I have been making baits for over 10 years...and I use a digital thermometer (not an IR) every time! Read up on all the posts regarding temperature and how it matters in regards to shrinkage, sticky baits and baits turning cloudy.

You can't bake a cake without knowing the temperature of the oven and you can't make good baits without knowing the temperature!

Have fun and good luck!