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wilderbssmstr

Plaster Of Paris Lead Molds?

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Hello all,

 

I want to pour my own jig heads using a 2-part pop mold?  Has anyone ever done this?  My mold is completely dry.  I have seen videos on Youtube showing lead being poured into wood molds and I have read on here about silicone and possibly bondo, but nothing about Plaster.  I use 2-part pop molds for pouring plastics and have no issues with flashing.

 

Basically, on Christmas day I am going to try this, but I would like to know if any of you have tried this or know about this and what help/info you can provide me.  There is enough safety info on this website that you can't miss it.  So, the only question I would like to have answered is simply "can you use POP molds to pour lead jigs?"

 

Thanks in advance for any help/info you can offer up and Happy Holidays!

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I spoke with some guys who use pop for pouring molten glass. They said to add silica to make it more heat resistant. Bought the silica but best for that far. You might also try spraying it. with franks dropout mold release or who to home depot and get the drylube silicone spray they sell. One had good success with 2 part bondo molds.

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i have used POP molds for pouring saltwater jigs,  they dont last as long if you just use POP by itself.  Try adding 75% POP and 25% portland cement.  that will make the mold almost bulletproof.  but i use only Bondo for my 2 part lead molds.  it is alot lighter, easier to work with and you dont have to buy 25lb bags of it and dust out the garage while making the mold itself.  

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You can use the pop no real problems if you cure it . Let it air dry in a warm room a couple days .Then put it in the oven for 2 hrs at 200 degrees . let it cool to touch ,put it back crank up the heat all the way leave that puppy 4 hrs .You can add graphite , cement , titanium powder other stuff . But it will work fine as is till you get your method down pat .

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i have used POP molds for pouring saltwater jigs,  they dont last as long if you just use POP by itself.  Try adding 75% POP and 25% portland cement.  that will make the mold almost bulletproof.  but i use only Bondo for my 2 part lead molds.  it is alot lighter, easier to work with and you dont have to buy 25lb bags of it and dust out the garage while making the mold itself.  

 

How in the world do you mix enough bondo to make a mold half without it setting before you're ready?

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How in the world do you mix enough bondo to make a mold half without it setting before you're ready?

I first pour som plaster of Paris in my mold box then as it's drying I push my sculpture half into it. I like this better than the clay method. Then I coat with vasoline and pour the top half with Bondo and a little fiberglass resin. Flip it, discard the pop, coat the first half with vasoline and pour the second half. The big thing for me is taking my time.

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Well, it finally warmed up enough to open the garage door today to try and pour.  And I can confirm this - POP molds "can" work for pouring lead jigs, but my mold only lasted for one pour.  After that, the lead poured straight through the mold.  I did not try adding any cement hardener, spraying with anything, etc.  I just used straight Plaster of Paris.

 

I am now going to try this bondo mold.  However, I did not buy fiberglass resin, just plain old bondo.  So, we'll see.  I truly appreciate all the feedback. I will respond with my results as soon as I have them.

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Well.....Still having a tough time.

Because of some of the detail of the jig, straight Bondo does not seem to set well around the jig collar area and weed guard. I tried using Acetone to thin out the Bondo before adding hardener. This worked, but it did not seem to fully harden. I mean did become hard enough to pour, but after a pour or two the Bondo actually started to break apart.

So, I switched over to wood. Using modified Dremmel Tool bits I was able to make the mold I needed thanks to my friends steady hand. However, after one pour in wood, it seems to burn the wood around the cavity to the point it allows flashing on the next pour. I have tried Pine and Oak.

Either I do not have the experience necessary to work with Bondo properly yet or I need to still try mixing in Fiberglass Resin. Somebody on Facebook suggested I use straight Fiberglass Resin. Has anyone done this or have any suggestions on how I could improve upon what I am already doing?

Thanks again in advance.

Edited by wilderbssmstr
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When I made a mold for crank ballast weights, I used a 50/50 filler and resin combination, using the resin liquid hardener. This thinner mixture allows all the cavities to be filled.

It worked well enough for the job I was doing. The mold does soften with the heat, so the mold clamping has to be even. I suggest G-clamp between two wooden plates to spread the load. Allow the mold to cool after 2 or 3 pours. It is best to have a lot of molds for rotation if you plan on pouring hundreds.

Keep the first half master (bondo or PoP), this will facilitate making more molds.

Dave

Edited by Vodkaman
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