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Bassbme

Mold making questions

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Hi peoples, I'm brand new to the site. I've been reading it for a while, but just now joined, and I am just getting my feet wet in making soft plastic baits. I've made a couple of open pour molds using fiberglass resin, and other than a few little learning curve kind of problems, they turned out pretty good. I just started trying to make some injection molds using DWP, and have some questions concerning those, and some of the products I saw on Makelure.com.

First, concerning the injection molds I'm making using DWP. As the first mold isn't dry yet, I haven't tried to do any baits as of yet. I coated the bottom half with Vaseline (per a mold making video on Youtube) so my top cap wouldn't stick to the bottom. It worked great, but now the flat surfaces on both halves, have Vaseline on them. And a little got down into the mold cavities themselves. How do I clean that off, or do I even need to? I am thinking I have to get it out of the actual cavities of the mold, or my sealer isn't going to stick. Any suggestions on how to go about cleaning it would be great!

On to the videos I've seen on using the Makelure.com products. I watched a video Larry Dahlberg made showing the use of Vac 50 for making a mold. It's what I think is a great way to make a mold. In it he makes masters out of modeling clay that you bake to make hard. He then uses those masters for making the mold. The bait I made the mold for out of DWP, is a craw tube bait. I am thinking it would be difficult making a master out of clay, so I am wondering if I could use a casting resin, or perhaps some of Makelure.coms expanding foam, and inject it into the DWP mold, and use that as a master?

I hope that makes sense. Sorry for the long post. Any ideas or thoughts on my questions would be greatly appreciated. This hobby is already addicting as heck, and I can see it getting expensive. lol

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Bryanmc, thanks for the reply. I kind of figured a washing with Dawn dish washing liquid would be the way to go, just wasn't sure it wouldn't mess up the mold, being that it's made with DWP.

Another question concerning making molds with DWP that you, or others may be able to answer. I mixed the DWP so that it would be a little thick so I wouldn't have to worry about the bait sinking into the mixture, before it could set up. The bait itself isn't heavy enough to cause that, but since it's a tube bait mold, I need to have a piece of 1/4" aluminum rod in the baits, that I also need to account for. Just didn't want to take any chances. 

Anyhow, since it's a bait that will be oriented a certain way (bottom down) when rigged, I'm not too concerned with having a detail bottom on the bait, but I want the top to be as detailed as I can get it. When I made the top cap for aforementioned mold, I mixed the DWP to the same thickness as the bottom half. It filled in nicely around the bait I was molding, but I'm wondering if I mixed it a little thinner, if it would pick up more detail?

I don't want to make it too wet, as I assume that could lessen the strength of the finished product. Just how thin can you go with DWP and not have it affect the strength of the finished product?

I would be thankful for any thoughts you, are anyone else could offer.

Edited by Bassbme
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4 minutes ago, Bassbme said:

OIR? I'm guessing you mean just flush it with boiling water? I just figured something like that would damage the mold?

 

And Mark, DWP is  Durham's Water Putty. It's like plaster, but harder and with a creamy kind of color.

Thanks.  Back in the 60's and 70's, when we used it on construction jobs we called it Durham's Rock Hard Putty.

Good stuff.

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33 minutes ago, Bassbme said:

OIR? I'm guessing you mean just flush it with boiling water? I just figured something like that would damage the mold?

 

And Mark, DWP is  Durham's Water Putty. It's like plaster, but harder and with a creamy kind of color.

How long is the working time before it begins to set?

Can you add something to extend the working time?

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Mark, yep that's the stuff. It still says rock hard on the can. And it is good stuff.

As far as working time goes, I'm new to it as far as using it to make a mold goes. IMO it sets pretty fast. Working time before it starts to set, I don't know? 10 minutes? As I said in my initial longggggggggg post. I mixed it pretty thick, pretty much the same as if I were patching sheet rock with it. You might be able to extend working time if you mixed it a little thinner. I'm not sure though.

 

And OIR ..... I did your suggestion of boiling water. It cleaned it right up with only the expected softening of the outer layer of the mold. And it was only a slight softening. So thank you for that suggestion. Just need to let it thoroughly dry for a couple more days and then I can seal it and try and shoot some baits. Or at least shoot some baits when my order from Lurepartsonline.com get's here.

Gonna place the order tomorrow. Hopefully be shooting baits this weekend.

While I'm here.... if anyone has used the hand injector that Lurepartsonline sells, what are your thoughts on it? It says the nozzle isn't secured with a locking pin. Does that present a problem other than I'll need to be a little careful while using it?

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I always wiped it off but find Johnson's paste wax or Mann's Ez Release easier to deal with.  I mix thinner typically more like cake or pancake batter.  I wan't it to run as it fills in detail better.

I don't use and injector very often but mine doesn't lock, just take care and all good.

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Travis, thanks for the response. I really appreciate it. I'm glad you mentioned about having the DWP a little more runny. I'm definitely going to do that with the top half of the mold for this bait.

 

And thanks for the response about the injector. Kind of what I was expecting to hear, just nice to get verification.

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