First Molds

[Pinson Custom Knives]

Getting ready to make some Open pour swim bait molds with smooth-on. I have the wooden masters sanded and smooth, but was wondering what I needed to seal them with to keep the silicone from sticking to them. I apologize if this has been answered, just couldn’t find it when I searched

[Hillbilly voodoo]

I make molds with smooth on mold max with wood masters no real issue sticking to wood. I do spray with mold release but that is because I make two piece molds

[Pinson Custom Knives]

Do you put a finish on the wood or just sand smooth? Using bass wood if it matters. 

[Hillbilly voodoo]

I have used just sanded cedar no issues. With my hard bait molds I do find is your master has been clear coated with epoxy you get a really nice smooth mold 

[Pinson Custom Knives]

Got my first couple of baits poured and curing, I’m having some air bubble problems...is there a way to remove them without a vacuum chamber? Because I don’t have one. 

[Anglinarcher]

You need to mix slower, pour in one corner and let the mold material flow from one corner to fill the mold box.

I use Alumilite products now, but they concept is the same for both.  But, yes, in the end, for production quality you may just need to pony up and get a vacuum chamber.  

Still, I have one and almost never use it.

[Pinson Custom Knives]

12 minutes ago, Anglinarcher said:

You need to mix slower, pour in one corner and let the mold material flow from one corner to fill the mold box.

I use Alumilite products now, but they concept is the same for both.  But, yes, in the end, for production quality you may just need to pony up and get a vacuum chamber.  

Still, I have one and almost never use it.

Yah, I was having lots of bubbles in the cup before I ever poured. I’ll get one eventually, when I can afford it lol. I tried to pour as slow as I could, still learning the technique. Tested them in the tub and loved the action I got on them though, so that’s a plus lol

[Anglinarcher]

You will find that the fish often care less about bubbles and color than we do.  LOL

[Hillbilly voodoo]

If you are talking about bubbles in the silicon mold there is one thing that definitely helps. When pourIng your mold only cover your master with a thin layer of silicone and stop. You will be able to actually see the bubbles form an pop. This only takes a few minutes to pass then you will be able to continue pouring. 
 

it makes a big difference and I kick myself every time I rush and forget this step. When I do this with a master that was clear coated master I get an extremely smooth mold cavity. You will still have bubbles in the rest of the mold 

[Pinson Custom Knives]

7 minutes ago, Hillbilly voodoo said:

If you are talking about bubbles in the silicon mold there is one thing that definitely helps. When pourIng your mold only cover your master with a thin layer of silicone and stop. You will be able to actually see the bubbles form an pop. This only takes a few minutes to pass then you will be able to continue pouring. 
 

it makes a big difference and I kick myself every time I rush and forget this step. When I do this with a master that was clear coated master I get an extremely smooth mold cavity. You will still have bubbles in the rest of the mold 

Mold is beautiful, just bubbles in the plastisol

[Hillbilly voodoo]

4 minutes ago, Pinson Custom Knives said:

Mold is beautiful, just bubbles in the plastisol

I think both of us were thinking you mold had bubbles 

with the plastisol aspect I am will have to bow out and lay someone more knowledgeable help you there

[Apdriver]

3 hours ago, Pinson Custom Knives said:

Got my first couple of baits poured and curing, I’m having some air bubble problems...is there a way to remove them without a vacuum chamber? Because I don’t have one. 

I’ve never heard of anyone vacuum chambering their plastisol. What you can do is wait a minute or two to let the bubbles rise to the top. Some of the bubbles will pop and disappear on their own. When most of the bubbles are at the top, you can take a propane torch or a heat gun and run that over the top of the plastic and it will pop the bubbles that rise to the top. Breaks the surface tension. Be careful not to scorch your plastisol. The heat trick works on epoxy also.

[Anglinarcher]

Ya, thought it was the mold you were talking about.

I still mix the plastisol slow to not mix in air, only enough to mix in the color.  Apdriver is also correct.

[Apdriver]

I’ll have to correct myself. I thought you meant vacuum chambering hot plastic. I know it’s common Vac chambering cold plastisol and L. Smith used to run five vac chambers when he was selling Calhoun’s. 

[mark poulson]

2 hours ago, Apdriver said:

I’ll have to correct myself. I thought you meant vacuum chambering hot plastic. I know it’s common Vac chambering cold plastisol and L. Smith used to run five vac chambers when he was selling Calhoun’s. 

Bait Junky used to sell degassed plastic.  That was all I used.  

[Les Young]

On 4/4/2020 at 11:30 AM, mark poulson said:

Bait Junky used to sell degassed plastic.  That was all I used.  

Yep me too Mark.

[eastman03]

Marling baits uses a vacuum chamber to degas his hot plastisol.  I just recently poured my first two plastic paddle tails and noticed lots of bubbles too. I think it was mostly stirring a lot, i'll take better care to stir slowly and try not to whip it into the plastic, then let it sit a bit to release some of the bubbles at least.  

[mark poulson]

I use a doubled coat hanger wire, with a 1/2" flat at the bend, to stir my plastics, and that makes very few bubbles.  I am currently using Bait Plastics' PM262-00 Med/Hard Plastisol, and it doesn't seem to bubble as much.

[Les Young]

6 hours ago, mark poulson said:

I use a doubled coat hanger wire, with a 1/2" flat at the bend, to stir my plastics, and that makes very few bubbles.  I am currently using Bait Plastics' PM262-00 Med/Hard Plastisol, and it doesn't seem to bubble as much.

Mark i've  been looking for info on the medium/hard. How do you like it? I'd be using it for most everything & hadn't found anybody that was using it.  Thanks

[mark poulson]

1 hour ago, Les Young said:

Mark i've  been looking for info on the medium/hard. How do you like it? I'd be using it for most everything & hadn't found anybody that was using it.  Thanks

This is what I posted in your message to me:

I went to the med/hard because their med was too soft for me.  I bought the med/hard last summer, but just started using it around New Years, when I finished the med.  I was adding some hardener to the med to get it firm enough for me,  but the med/hard has been fine without it.  I use it straight, with a little heat stabilizer and some scent, for my craws, creatures, and small swimbaits, up to the 3 1/2" ripper.  I haven't poured anything bigger than that with it yet.

I haven't noticed any oil leaching so far, and I've poured probably 6 dozen baits with it.

For me, it's the perfect all around blend, like the old bj medium degassed.  

I haven't had any problems with bubbles either.

When this gallon is done, I'll order another.

I hope this helps.

 

[Pinson Custom Knives]

progress so far. Less bubbles this time around, figured out I can get rid of any bubbles on the surface of the bait with my heat gun once they set up a bit. Still playing with the colors

 

[Apdriver]

Those look nice. I don’t see any bubbles.