2-piece,DWP,Sculpy Mandril,pic

[HJS]

Just finished another 2-piece mold using Durham Water Putty (DWP), with pic. No store bought masters available so I made one from Sculpy clay that bakes semi-rigid. Sculpy is great stuff if you lack a soft plastic original to copy, in this case I didn't.

- Make Sculpy mandrel to suit and bake.

- Drill shallow hole in hard sculpy mandrel at balancing point and insert screw a few turns. The screw makes handling the greased-up mandrel a LOT easier. Coat with very lite layer of Vaseline, more like a sheen.

- Pour first layer of DWP and CAREFULY insert mandrel half way in, being very careful not to go past the center or widest point of mandrel, or you'll never get it out.

- Insert aligning marbles. Let harden completely. (In my case I don't use marbles. After the first layer is hard I drill a few shallow holes with a 3/8" countersink drill... see pic)

- Do not remove mandrel from mold yet... heck, barely even touch it... you don't want to even knock it loose... that might compromise the second layer of DWP.

- Remove screw from mandrel and fill little screw hole with Vaseline

- Lightly Vaseline surface of 1st layer of hard DWP and mandrel.

- Pour second layer of DWP. Let dry for a day or two in a very warm place, like the dashboard of my closed up car while in full sun.

- Separate mold, and hope to Gawd almighty that you can remove mandrel, do it very carefully.

- Reassemble mold tightly with heavy rubberbands.

- Drill pencil-sized pour hole,~5/16th, then a reservoir hole, 1/2". Both are just barely visible in pic.

- Use hacksaw to saw in tiny vent slot to let out trapped air as you pour, see pic.

- Coat cavities ONLY with your choice of sealants. I use 2-part. 30 min, epoxy.

- Spray warm mold with PAM, bind halves together and pour several lures. THESE WILL BE USED AS NEW, SOFT-PLASTIC, MASTERS TO MAKE YET ANOTHER 2-PIECE MOLD, 4-5 or more CAVITIES, SO YOU CAN POUR MULTIPLY LURES AT ONE TIME.

Additional notes:

You will need to plan ahead concerning the front and back spacing of the mandrel in the mold box so there is room for a big enough reservoir hole.

Also, my original mold suffered minor chipping at the edge of the cavity when I extracted the rigid mandrel. No big deal, the small defects in the lures from the clipped mold line were carefully trimmed with scissors. These will be my new masters for a second mold.

Note on applying Vaseline to surfaces: I use one of those little cheap shop brushes with the metal handle to spread out the Vaseline. Works OK for starters, but this type of heavy bristled brush will leave brush/streak marks that will be picked up in every detail by the DWP. So before pouring I will brush out the streaks with a fine, weaker bristled brush. Be absolutely sure there is no globs of Vaseline ANYWHERE in the mold, especially in preperation for pouring the top layer of DWP. Especially check for excessive accummutations of Vaseline where the master meets the mold.

OK folks, this is as far as I have gotten so far. Next step is to make the multi-cavity production mold using the plastic lures I made from the original mold. Yeah... there's more intricate steps to this entire process than there is in ballroom dancing. I'm about wore out, but I'll eventually finish this project.

BTW, these lures will be used on stripers using a 3/4oz bullet nosed, flat-backed jighead... thus the flat nose on the lure... makes it hug the jighead flush. Little dap of superglue on the jig shaft and that lure will last for 10-20-30 fish before getting wrecked.

[Pop]

Nice job and thanks for the tutorial. I still can't figure how you did the tail being it was so thin. The mold looks like the tail woul be thicker. Pop

[MDC]

Good job

You can also use a heat gun to remove the brush marks in the vaseline

[Mags]

Nice work!!!!

Steve

http://www.amistadtackle.com' rel="external nofollow">

Edited August 7, 2008 by Spike-A-Pike

[HJS]

Finally got around to finishing my 2-piece mold for an 8.5" soft plastic similar in appearance to a Bass Assassin, but with tail. First I made a single cavity mold using a mandrel I made from Sculpy (pictured at the beginning of this thread). Using this mold I poured 3 soft plastic lures. Then used these lures as new masters to make a 3 cavity, 2-piece mold. Worked out pretty good.

Toothpicks were stuck in the 3 plastic masters to facilitate handling.

White cones at the nose end of each lure were made from baked Sculpy and act as pour funnels and reservoir for excess molten plastic (solves problems associated with shrinkage during cooling. They too have toothpicks for handling.

So far I've poured a dozen lures from this mold and it seems to work very well.

QUESTION: How do you guys bind your large 2-piece PoP or DWP molds together prior to pouring??? All my previous 2-piece molds, prior to this jumbo mold, have been for 4" plastics and were relatively small. I bound the halves together using heavy rubber bands... quick & easy. But the jumbo 3 cavity mold pictured above seems to need more pressure that can be gotten from rubber bands alone. I used 2 big C-clamps with 1/2" plywood on each side of the mold. This worked but is a royal PITA to assemble and must be reassembled with each pouring. I'd appreciate any ideas.

[Richard Prager]

QUESTION: How do you guys bind your large 2-piece PoP or DWP molds together prior to pouring??? All my previous 2-piece molds, prior to this jumbo mold, have been for 4" plastics and were relatively small. I bound the halves together using heavy rubber bands... quick & easy. But the jumbo 3 cavity mold pictured above seems to need more pressure that can be gotten from rubber bands alone. I used 2 big C-clamps with 1/2" plywood on each side of the mold. This worked but is a royal PITA to assemble and must be reassembled with each pouring. I'd appreciate any ideas.

You might try large hand spring clamps.