problem with laminates

[Bwfisher]

i just got into the hobby of hand pouring baits and its honestly a blast but laminates have so far kicked my butt.

I'm using deadon's jerk bait formula, following the instructions of heating past 350 on initial heat and then pouring my colors between 300-350f into silicon molds

the laminate looks pretty good to me through the length of the body however the nose and tail aren't fusing very well, it seems like all the lures that i have laminated to an abrupt stop (nose and tail) i can pull them all apart and they aren't totally filling in like they do when its a single color. if i stop half way down the body they seem to fuse pretty well.

i am pouring the first color into 3-4 molds then pouring the second so they aren't still 300 in the molds but they aren't cold.

my molds are left outside in a garage so they are getting kind of cold, its about 50ish here so they are probably colder

if its important i have a twin tail grub, 4''ish jerk bait and swim bait, 6'' segmented worm, and a beaver tail

thanks in advance and i apologize if this has been discussed in another thread however i did not see anything

[Apdriver]

If they aren’t fusing, you’re pouring too cold. Maybe try working with one mold at a time instead of four. Make sure your second color is hot because it’s the one that bonds the two halves together. It’s a balance, but try hotter.

[mark poulson]

I hand pour laminates in open silicone molds.  I pour the first color, and then go back over that with the second, heated to 340+ degrees so it bonds with the first color.  I still get some not too well bonded heads sometimes, but they don't come apart when I fish them.

 

[Bwfisher]

I dont think heat is really the problem because I will heat up the second color to usually around 350 before I pour, I didnt try fishing them just pulled them apart and I feel like they came apart too easily. 

I will try closer to 400 and see if that helps. Thanks for the input guys

[SlowFISH]

400 is gonna scorch the plastic.... best bet is to do 2 things...

1. Pour the second color as fast (shortly after) as possible after the first.... the more heat you keep in that first pour while it's in the mold the better the stick yo'll have with the second pour.  The bond is a relation of how much the second pour "remelts the first" and fuses together.... since you can't really raise your second pour temp up too much more.... try to keep that first pour warm/hot in the mold.  The reason your ends aren't fusing are there is more mold surface area at the ends... which cools the plastic more/faster.

2. To help the first pour not chill so fast - warm that mold up.... usually silicone holds heat pretty well so you don't have to bake it or anything like that - but even pouring a couple single color worms first should get its temp up a little - notably if the mold is as cold as the ambient air (40-50 degrees) as you mentioned.  I use resin molds and they always work better after a shoot/pour or two.

 J.

[bryanmc]

There's a fine balance between pouring the second color too soon and too late.  Too soon and you won't get that sharp delineation between colors that some folks want.  Too late and you get cold cracks that allow the baits to separate at the laminate line.  When I'm doing laminates in open pour silicone molds, I never do more than 2 cavities at a time. 

[mark poulson]

I do 10 5" swimbait open pour silicone mold cavities at a time, and my baits don't delaminate.  Just plan ahead, and be efficient, and you'll get a good routine down.

[CNC Molds N Stuff]

On 4/2/2019 at 5:42 PM, Bwfisher said:

i just got into the hobby of hand pouring baits and its honestly a blast but laminates have so far kicked my butt.

I'm using deadon's jerk bait formula, following the instructions of heating past 350 on initial heat and then pouring my colors between 300-350f into silicon molds

the laminate looks pretty good to me through the length of the body however the nose and tail aren't fusing very well, it seems like all the lures that i have laminated to an abrupt stop (nose and tail) i can pull them all apart and they aren't totally filling in like they do when its a single color. if i stop half way down the body they seem to fuse pretty well.

i am pouring the first color into 3-4 molds then pouring the second so they aren't still 300 in the molds but they aren't cold.

my molds are left outside in a garage so they are getting kind of cold, its about 50ish here so they are probably colder

if its important i have a twin tail grub, 4''ish jerk bait and swim bait, 6'' segmented worm, and a beaver tail

thanks in advance and i apologize if this has been discussed in another thread however i did not see anything

Are you pouring into silicone or aluminum?  For open hand pour silicone works better because it doesn't remove heat from the plastic as fast as aluminum does.  If you think your mold are to cold you can preheat them in a toaster oven.  A good grade of silicone doesn't start to break down until it hits around 390F.  So you could easily warm your molds to 200-250F without issue.  Just remember that 200 will be painful to handle so wear some gloves.  If you are using hardware store silicone caulk I have no idea if it can take it.  I pretty much only work with food grade bake-able silicone.  

I have a toaster oven on my pouring and test bench for powder coating so warming a problem mold on a cold day (or pre warming a mold when casting resin) is pretty handy.