I'm curious about starting to make my own lures but I really want to make it 'all' namely I want to make my own moulds.

What I'm curious about is what material you would use to make the molds and what are the benefits between injection molds and poured molds? I am thinking that delrin plates carved with a dremel would do it as they have a much higher heat tolerance than the plastic used for the lures so they wouldn't warp but I'm not sure if the plastic would bond or stick to the delrin. Pretty sure it wouldn't but can't be positive unless I try it.

i have a place to get plenty of delrin at a decent price and lots of tools for carving and shaping I just need to know if you guys think delrin would be good or if you'd suggest another material. I don't have the tools to shape aluminum so that's sort of out. Any info at all would be great.

Got a little rambly so here's the summary of my questions.

What are the pros and cons of injection vs poured.
what materials would you use to make yoru own molds? would delrin work?

thanks in advance

Glue the plastic down solidly to a pyrex dish and then use automotive fiberglsss you can find at walmart in the auto section.its two parts that you mix and then it hardens in about 2hrs.makes a excellent mold. just use enough to cover your worm about 1"deep then let it dry.

wouldnt that leave a flat spot?

In lures are you talking plastics or cranks? I can only speak for making molds for plastic worms. Two piece resin or POP molds can be done to eliminate the flat spot but are a little more complicated. If you are going to have a bunch of thin parts like legs or antennae then an injection is the way to go. Simple molds are better suited for hand pour. Not familiar with delrin. Most use resin or POP as they are the cheapest way, RTV is more expensive but another alternative.

Thinkin worms/soft plastics for now. I'll get into the cranks and what not later but I'm thinkin I'm going to go the balsa route with them and hand carve.

I like the idea of not having flat spots. I want to take existing baits and cut bits off, glue bits on, etc and modify an existing shape into what I want it to be then make a mold. I assume if I want to make an injection mold I'd suspend my pattern bait in a container vertically then pour resin into it and cut it down the center to make two halves?

let's say you're doing a chigger craw looking lure, it's not symetrical so you can't really get equal 'halves'. How would the mold and injection process work? I assume making hte mold would be the same, you'd suspend and leave a hole (drinking straw?) leading to the pattern lure, pour, let harden, cut in half, remove pattern lure, put the two halves back together with screws or straps or whatever to hold em together and inject the plastic into it (not sure how that process works), let it cool, take it apart and bam new lure.

How does the injection process work? do you litterally just squirt a bunch of molten plastic into the mold? how do you make sure there are no bubbles or air pockets?

Thanks again in advance I appreciate the help. I doubt I'll ever sell anything but I would love to make my own shapes, colors, etc.

Well a two piece is not that easy. It is better to start with a one piece. For a two piece you pour one half then the other after it has cured. You would place objects partially into one mold like a marble or popsicle stick. This is so you line up the parts when you go to pour.

Drinking straw will not cut it for the pouring hole. In part it would work but you will need a sprue section at the entrance. A sprue is shaped like the top part of a golf tee. It allows extra plastic to be drawn into the mold as it cools off so the bait does not deform.

Bubbles and or air pockets will be take care of when you cut very shallow channels from the bait to the outside part of the mold. This allows the air to be forced out. The "molten" plastic is in the 325-350 degree area and for the injector you will need to either build one or buy one already made.

Maybe start out small and get a feel for pouring before you jump into the mold aspect. Get a feel for working with the whole process safely first before getting carried away.

I think that's good advice. I'm going to mess with pouring some flat sided stuff first before I go injection style. I'm also looking into making my own vacuum former so I can experiment with making lure bodies out of plastic instead of balsa though I still intend on playing with balsa as well

Here are a few I made from bondo like stated above. BTW the fish don't mind the flat side.

I agree with Dayne, I make somewhere around 55-60 diffrent lures and all but 2 fo the have flat sides and the BASS DO NOT care at all about the flat side, the biggest bass on mine is a little over 14lb, and this year it's 11 1/2lb.
Every year ther are a least 5 bass caught over 10lb on my flat side lures.

The link below has a detailed tutorial on how to make a plaster of paris (POP) mold. It's in two different parts with lots of pics.

POP mold making tutorials

Hey Longhorn - Looked at the link and some of the photos links appear to be broken. Any chance you could fix it?
Thanks.

I can't fix the links. They were submitted by others. That site has had some big "wars" and lots of folks stopped going there so that's my guess on the broken links. The only ones I did were the POP mold part I and II. They still have all the photos.

Thanks for tryin Longhorn. Got most of the ideas behind it. Pics do help but not necessary.

The bondo/fiberglass resin molds are very durable. I make them all the time. I have found that you can make double sided molds out of the stuff using wd-40, crisco, Vaseline, Pam cooking spray or good ol bearing grease as a release agent. The problem I ran into was the heat ruins the bait being molded on the first pour (the bottom half) and is too destorted for the top half. Replacing that bait with another will also have distortion as no 2 baits are exactly alike. I found using an old plaster mold coated in mod podge and sprayed with whatever release agent you choose, then filled to the top of the sprue with either plaster (very tricky and usually riddled with bubbles) or the fiberglass resin. This gives you a positive that is not temp sensitive and usually just as detailed as the negative it came from. Next lay all your stuff out to pour the bottom half of your mold. Using coat hangers or what have you for an overhead frame, suspend your resin or plaster bait (sprayed ir coated in release agent like wd-40) in the poured resin at the depth you want for that half. Don't submerge past halfway (horizontally of course) or you won't be able to remove the negative. Let the resin set fully and cool off. Remove your strings that suspended the worms. I usually attach the strings with a good masking tape. (I used the blue kind) Spray the entire resin mold and resin or plaster bait with your release agent. Pour the top half to the desired thickness. Let set fully. Remove entire mold from pan. The mold should stay stuck together. Hold it up to the light and locate the plaster or resin baits. Drill holes that WILL NOT HIT the plaster or resin baits. These holes are for future alignment of the mold. I use about 1/4 holes and a small bolt that fits the hole tight. Then after the holes are drilled, tap the mold around the edges and use a butter knife or putty knife to work it apart. Try not to chip the edges. If you cannot get in the seam between the 2 molds (next time use more release agent) you can go around the edges with a belt sander lightly until you see the hairline crack that separates the halves. Then remove the resin baits and save for future molds, if you used plaster baits, chip away, they are not salvageable. Use water and a brush to remove all the plaster from bait details. Now finally, take a dremel or small chisel or blade and scribe a small vent groove from cavity to cavity to the edge about halfway up the bait. This allows the gasses to escape and makes the molds pour better. With the same tool clean up the sprues (I usually sand that side to make sure they are all flush etc). You are now ready to pour. Please be careful when molding, pouring, SELLING these baits. Some are copyrighted. I would enclose pics of these molds but they are across the state on loan. I generally made stick type soft jerk bait style bait molds this way. It was a lot of trial and error, but the final product was as good as aluminum and future molds will be at a fraction of the aluminum price. You can make your own baits in your own secret colors or sink rates to do what you wished the factory ones did. Good luck, and don't tell my bass club, they been trying to figure out how I made molds for years.

Apologies for any typos or grammatical errors. This was typed on my phone.

I've heard from others you can try melting down delrin, but like you said, it's pretty heat resistant so I don't even know if it'd work. I'd say it's much less likely to burn when carving with a dremel but I've never tried it so I can't say for sure.