POP Molds

[Bountiful Waters]

I have searched and maybe have not looked hard enough, but I have one question here. I have a clay prototype lure complete ( I have not baked it yet) If I use POP, how do I get the prototype out of the plaster? Should I leave the origional lure unbaked so that I can get it out of the POP? I feel stupid asking this question, but I have always bought my molds, never made any.

[Joe S.]

Coat your prototype with vaseline before pouring your pop onto it, you should be able to pull it right out after the pop dries, if your making a two peice mold you are going to have to make two separate halves.

[Bountiful Waters]

I guess I was invisioning pushing the bait a little deeper into the POP so that I may get more roundness on it. If I did that and I allowed the POP to fully dry, the bait would break apart upon pulling it out, I think. Are you telling me I can't push the bait in that far, only flush?

[Joe S.]

You can push the bait in, it depends on your material if your going to get it back out in one piece, if it was plastic it wouldn't be a problem because it would be flexible, if you say it is clay, then you could push it in as long as it's not completely hardened, you should be able to get it back out, but you will take the chance of it coming back out in pieces.

I think if your your going to make your master solid and if you crown to much over it, (push it to far in) you'll take the chance of breaking the mold when trying to remove it.

[sagacious]

I have a clay prototype lure complete ( I have not baked it yet) If I use POP, how do I get the prototype out of the plaster? Should I leave the origional lure unbaked so that I can get it out of the POP? I feel stupid asking this question, but I have always bought my molds, never made any.

You're talking about Sculpey polymer clay, right?

The answer is to bake the prototype lure master-- it won't be tough enough for mold making unless it's baked, and you'll likely damage it during demolding. If you're new to mold making, your first concern should probably be to ensure the safety of the master. If your plaster mold breaks, for whatever reason, or just wears out, you'll want to have the same master available to make another mold. If the master gets damaged during mold making, you'll have to start over and make a new master. Bake your clay prototype, and also be sure to wait until the plaster fully hardens before attempting to remove the master. Take your time with this. Let the mold set a few days at least, especially if you're not sure the master will pull out easily. I set 'em aside and just forget about it for a week.

Pushing the prototype bait deeper into the plastic to get "more roundness" won't likely work. You risk damaging both the master and the mold. Trying to remove the bait before the plaster fully hardens won't work either-- it'll just ruin the mold. Any overhangs on a plaster mold will almost invariably result in much frustration and a broken mold-- unless you use a master made from plastisol (worm plastic). The solution for "more roundness" is a two-piece mold.

Sculpey clay will retain plenty of flexibility after baking. Bondo works extremely well for mold making using a Sculpey lure master. It's a lot tougher than plaster, cures faster, and will tolerate some slight overhang using a Sculpey master.

Hope this helps. Good luck!

[thryb]

Is this the clay you are talking about Sag?

http://www.sculpey.com/Products/products_poly_superflex.htm

[sagacious]

Is this the clay you are talking about Sag?

http://www.sculpey.com/Products/products_poly_superflex.htm

Correct. The link you provided is to the super-flex Sculpey, and the regular stuff works well too. You can usually find it at art stores, and sometimes at hardware stores in the 'crafts' section, and it's not expensive. It's like most any other modeling clay, but made from a heat-setting plastic. You form it into whatever shape you want, bake it in the oven (follow the simple directions on the packet), and you've got your master for making a mold. It can be sanded or carved after baking. It firms up and hardens during baking so you can handle it without damage, but it retains some flex and 'plasticity', so it's easy to remove from a mold half. Plaster and Bondo won't stick to it, but it's best to still use a mold release, like vaseline.

I've used it for making prototypes for small finesse baits up to large reaper-style baits, and also for jigs up to 9oz (for ocean fishing here on the West Coast). Very easy to work with, and doesn't dry out, so you can take your time when making up a new bait.