The Hunt For Big Fish with Larry Dahlberg

Hi Larry,
Thanks for providing an outstanding resource. I want to create a bait loosely based off of an old hollow plastic bait I have. The bait appears to have been originally made in two halves, which I have cut apart on the centerline where I could see the halves had been fused together. I planned to make a two piece silicone prototype mold for each half that will also incorporate the changes I want to make. So I will have two molds when done, one for each side. Is this the only way to properly make a hollow hard plastic lure or is there another way to do it with one mold? Lastly, I will be using Alumilite products for the bait and I would like to know what you would recommend using to fuse the two halves of the bait together? I have not been able to find a tutorial for a two piece hard plastic bait, non-jointed that is. Help is much appreciated, Jeremy

Hi J
I'd suggest doing a slush casting with a thin surface of alumilite and fill it 320 foam.
best,
L

Great! I am not sure what all that means....but I am sure it's nothing Google and a tutorial somewhere can't teach me. Thanks for showing me the path of least resistance. Jeremy

go to the makelure site and watch the whopper plopper tutorial.
L

Hey again,
I watched the tutorial on the slush mold and as presented, I do not believe it would work for the bait I am making. Is it possible/recommended to use this same technique for a flat(ish) sided bait? It doesn't seem so to the inexperienced eye, or is the amount and consistency of the RVT the key? The bait I have designed is not round and it needs to retain it's hollow form as it is key to it's functionality, so the foam fill is also a deal breaker. The application and presentation itself is 100% unique. I have an existing prototype I made via deconstruction of an old bait then modified and reconstructed it resulting in a completely fishable bait. The significant modifications, I believe, make it a completely different bait than the old one from an intellectual property standpoint. To be safe I just need to make my own molds and I want to change the shape of the original and have more shapes anyway. I hope I will be able to make the deadline for this years lure build off. If not I will have plenty ready for next year! Thanks in advance. Jeremy

Very good question. Couple ways to go about this ... one slush casting or hollow casting as the rock star suggested which is probably the easiest (fewest amount of touches). When slush casting or hollow casting I like to add some amount of microballoons to increase the viscosity. This allows a thicker and more consistant coating to be achieved. The unfilled resin is so thin it slushes around too fast in the mold. Adding some filler to it thickens the resin up and allows you to rotate it slower and coat the mold thicker.

The other option is to tongue and groove the mating surfaces and make 2 - two piece molds as you describing. Tongue and grooving the lead edges will give you more surface area to bond them as well as line them up much cleaner will less sanding in the finished product.

Once you've poured the two halves of your lure, simply use some thin CA (Cyanoacrylate - super glue) to bond the two together and wipe off or sand any excess.

Creating the masters to mold with a very clean edge is the toughest part. Spend the time here and use the QuickSet silicone which is more stiff to make your two piece molds. The stiffer mold will give you better dimensional stability because the two halves of the molds line up very well with good locators. If you are doing the slush or hollow cast, I'd recommend the High Strength 2 or 3 and try to get away with a one piece mold or split mold to eliminate seam lines all together. Pour from the tail area.

Hope this helps.
Mike
Alumilite

All ideas have been extremely helpful. Thanks again Larry and Mike! I will give the slush mold a try and see what pans out. Otherwise the tongue in groove idea for consistent alignment is excellent and something I can incorporate into my original plan. Although I hope I can figure out the proper mix and technique for the slushing to produce a highly durable one piece bait with half the work. Perhaps I will remove the tail and incorporate a different material after the fact in order to make the slush molding easier. This forum is awesome and the support you guys provide to DIY'ers is extremely valuable. Jeremy