danderson

casting resin

14 posts in this topic

I was just wondering if anyone uses a clear casting resin for crankbaits. I know there is some available, but I didn't know if I put microbubbles in clear alumilite if it would make the bill look cloudy. I have not made any lures that I cast myself yet so I don't know all the details of what to do. I read the slip mold tutorial and it was great. I would just like to make a bait that is one piece with a clear bill. That way I could put the wire in and just mold. It would defeat the purpose though if the bill was cloudy. Just wondered which direction to go. Thanks, Dan

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I was just thinking of asking the same question. I was looking at casting from plaster, alumilite, 2-part foam, etc. So I thought I would bump this back up to the top.

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Theres a few suppliers offering a clear urethane resin.

My research has shown that the max recommended thickness is @ 1/4"

Fine for lips but not a whole crankbait.

I'm almost sure any additives will cloud the resin. Most require a pressure cast to collapse air bubbles.

The ones Ive seen are recommended for industrial use only due to the chemicals involved & require a post cure around 200 degrees for a few hours to achieve maximum hardness.

All bad news for your particular application, however if you were looking to use a 3 or 4 part mold you could easily get below the 1/4" threshold.

My recommendation, make your mold with the lip attached, then cast with featherlite or urethane foam with the lip inserted into the mold.

There are clear hobby acrylic resins available but they are polyester based & not a high impact plastic IMO.

I'd love to try exactly what you're trying to do so if someone can can enlighten, please do.

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You need to find out which resin material you are dealing with. I am using polyester resin with micro spheres. The spheres turn the resin pure white, just like plaster. Also, the resin I use has a density of 1.2gm/cm3, which is heavier than water. After adding the spheres, I get a density of around 0.75gm/cm3. This is the equivalent of a heavy wood and if you are looking for anything other than a tight action, you may be disappointed.

The polyester resin/sphere combo is brittle, as stated by Redg8r, so if you are scraping the rocks on the lake bottom, you may be disappointed with the chipping that will probably occur. But if you are fishing mid or top, it will make no difference. I use polyester, because it is readily available where I am located.

I managed to get the resin on the back of my hand, in addition, I wiped an itch on my chin. It took three weeks for the rash to disappear, so wear throw away gloves. The fumes are fairly noxious, so if you are going to do a few hundred, I would recommend a respirator. A paper mask is not going to help much, but it is better than nothing.

I am currently working on an idea for making a mold for resin, were a square lip is fitted to the master. Part of the lip top surface will be blanked with clay (temporary) and the RTV poured. The idea is that the mold is closed with the ballast and hangers etc. Then the lip is inserted into the slot in the mold wall, maybe a little tape to hold it in place. The advantage of this method is that the lip should be as square as your master and different sizes and shaped lips can be fitted without having to make a new mold. I will post more on this after I have tried it (soon).

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The advantage of this method is that the lip should be as square as your master and different sizes and shaped lips can be fitted without having to make a new mold. I will post more on this after I have tried it (soon).

That interests me V-man, I havnt figured out how to use a variety of lips in the same mold.

Also, does your experiments allow for a variety of lip angles?

Good luck my friends.

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Between Vman and his polyester resin testing and hazmail and his various efforts with bending Lexan, I think the trip to Clinton, MO the last weekend in April is going to be a real eye opener.

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Lip angle is a problem I haven't addressed yet. But, I can see a solution by molding a third part around the lip. As long as you do not totally enclose the lip, then the insert can be one piece and the lip will be inserted after the mold is closed.

Hopefully, this weekend I will get down to some mold making.

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Just a question. I don't make lipped cranks.

Couldn't you paint a small prey item on the opaque bill, so it looks like the lure is chasing something? I know you'd have to clear over the bill then, but that might make it a plus instead of a minus. Especially for suspended fish.

I've caught a lot of fish on cranks with colored bills, but, admittedly, it's usually in stained or off colored water.

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My research has shown that the max recommended thickness is @ 1/4"

Fine for lips but not a whole crankbait.

When I was a kid, my mother use to make casts of dogs and cats using a resin. They were often 5-6 inches thick, but I don't remember what type of resin it was. She would add pigments from translucent to completely opaque. Any idea what that was?

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Thanks for all the replies guys. I feel kinda stupid not thinking of putting the bill in the mold and then casting like you would wire through hook hangers. The only question I have then is what makes the resin adhere to the lip, or do you remove it and glue it after you paint. It would still serve its purpose for keeping the lip square. I have not cast anything before so I apologize if that is a dumb question. Maybe the lip adheres to the casting chemically. As far as painting a bait fish or something on the bill if it isn't a bad idea, but most baitfish feed on plankton and I'm just not that detailed of a painter.:lol: Just kidding I couldn't resist. I love painting and repainting old baits so the next step is to mold my own. Can't wait to try it. Thanks again guys.

Dan

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When I was a kid, my mother use to make casts of dogs and cats using a resin. They were often 5-6 inches thick, but I don't remember what type of resin it was. She would add pigments from translucent to completely opaque. Any idea what that was?

If it was transparent, it was likely polyester resin. Its very similar to the material used to make clear paperweights & corporate award type items.

I feel kinda stupid not thinking of putting the bill in the mold and then casting like you would wire through hook hangers. The only question I have then is what makes the resin adhere to the lip, or do you remove it and glue it after you paint.

Hagens produces foam blanks with clear lips, one of the problems with urethane foam (a plus, in your case) is that it is extremely adhesive. if you cant clean it up with solvents before it cures, the only other way is to mechanically remove it (scraping/sanding/etc;) Ever hear of "Gorilla Glue" ?

Its a foaming urethane resin

Filled urethane resins (feather-lite & others) should be adhesive enough, one tip might be to add ridges, back cuts or even holes drilled in the embedded (hidden) section of your lips. Stringing the thru-wire back into the bait would help too.

I'm starting to see opaque white (injection molded) blanks with clear lips being offered too, but they are likely made to mate with each other in a way that seats them securely & assembled in 2 parts after curing.

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(scraping/sanding/etc;) Ever hear of "Gorilla Glue" ?

Do you think mixing saw dust or foam balls with the gorilla glue and a little water would make a good bait? It would expand in the mold.

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(scraping/sanding/etc;) Ever hear of "Gorilla Glue" ?

Do you think mixing saw dust or foam balls with the gorilla glue and a little water would make a good bait? It would expand in the mold.

I'm a cabinetmaker by trade & we use sawdust & various glues to make "Rue" for special applications (filler, thick glues, etc.) I would say yes, but if you are willing to take the trouble to do that I would recommend using any of the available 2-part urethane foams on the market, I'll venture to say it will be cheaper, more consistent & the learning curve will cut be drastically.

4 pound & 8 pound densities are often compared to wood in strength & density (flotation) some of the musky guys are using 16lb foam which seems bullet proof in my opinion.

Cool thing is you dont need a pour hole, just a small vent somewhere in the mold. Lay one of the halves flat, fill it, close the mold securely & let the foam do it's thing.

Staying on topic, simply place your diving lip in the accommodated slot in the mold & preferably a thru wire harness with the ballast anchored to it for easy production.

Stiff RTV molds shine in this application.

I've heard that priming the mold cavities before pouring will infuse the primer on the outer skin, again, saving an extra step.

If you try it, document it & report back.

I've made many foamies with barebones, vanilla techniques, but I'm a couple weeks behind you on trying the same scenario.

All the best.

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