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Slip Molds for Hard Baits Tutorial
29 replies to this topic
Posted 13 May 2006 - 09:07 AM
Here ya go and thanks to Coley for inspiring me to do this. What you're seeing is the rebirth of an old wood bait I made some years ago, the "WooderDog". It's a walking lure with a soft tail designed to mimick a Tiger Salamander or Waterdog swimming. The procedure is the same for all hard baits so I hope this gives some ideas to you for making your own slip molds.
Start out by selecting a section of PVC pipe long enough to make two molds. You want each mold to be about 1/2 inch longer than the lure you plan to mold. Mark the center and drill a 1/2 inch or larger diameter hole all the way through both sides of the pipe.
Now cut through at the exact center of the hole with a good saw. I like a miter power saw as it gives clean cuts.
Next position the piece lengthways to the cut and cut through one side of the piece. I held this piece in place with a long block of wood for the cut. A table saw with a rip fence would be safer. You want this cut to be straight in exactly in the center of the piece.
Sand the inside edge of the piece with some fine sandpaper to a rounded edge. This end with the half holes will be the top of the mold and sanding here will result in a tear resistant cap.
Posted 13 May 2006 - 09:16 AM
Insert a piece of folded sandpaper into the cut, apply some pressure to squeeze the gap together and sand the cut to get a good fit when held so the gap is closed.
A small section of paintbrush can serve as a sprue to glue on the tail or wherever you plan to pour from and safety pins cut will serve for the screw hole inserts.
Insert the pins into the places you want screw and/or weight holes to be in the bait.
The pins should align straight as possible!
Posted 13 May 2006 - 09:26 AM
Position the bait into the pipe so that you have at least 1/4 inch all around.
The sprue should stick out of the top a bit.
Now with the piece clamped, heat the pins evenly with a lighter or candle gradually until you see the gap in the pipe close up around the pins.
Tightly wrap some tape around the piece on both ends paying special attention to the top...make it neat! You want enough tape, about four or five rounds to cause the top to fit snug into a PVC cap for the pipe size diameter. Depending on your insert placement you may need to cut a groove in the cap to accomadate the insert.
Posted 13 May 2006 - 09:44 AM
Insert the cap onto the piece just till you contact the end of the sprue. If you planned ahead, the angle of the sprue end will fit flat against the inside top of the cap.
Mix your RTV Silicone and pour into the mold, filling it to the top but not overflow or rounded. You want the bottom to be flat.
After the proper cure time, the PVC cap will come off with a little effort and the tape and pins are removed. A razor blade is used to clear away a little bit around the sprue opening.
A new sharp razor is pushed into the RTV where the cut in the pipe is to the sprue. An insert has been placed back into the mold to help with aligning the razor to cut to the center of the bait.
The places where the pipe melted to close the gap around the pins may stick together slightly. Before making the initial cut with the razor into the RTV, make sure these places are unattached. A little pressure with a razor blade corner going up the seam will seperate them. For the cutting of the RTV though you want to apply pressure to reclose the seam so the cut goes exactly through the center of the insert pin holes at least to the one you plan to use for a weight insert. You need to cut enough to remove the bait you are molding but no more than necessary. Only some experience will tell you how far to cut.
Posted 13 May 2006 - 09:57 AM
The blade going in at exactly the angle of the insert.
Once the initial razor cut is made, s-l-o-w-l-y follow the countour of the bait as you cut down the seam. A clamp is applied to the sides to keep the seam together while cutting. Positioning the clamp backside a bit will apply enough pressure to keep the seam together but not squeeze it so tight you can't make the cut. You want a continuous clean cut if at all possible, the corner of the blade contacting the lure master inside. Sharpness is a must!!!
Now if you pry the seam open a bit with thumbnails and apply pressure to the bottom with a finger, the RTV will slide out pretty easily.
If you did a bad job sanding the piece of pipe this flash can be cut off with scissors!
Posted 13 May 2006 - 10:06 AM
If you make a good cut, the bait can be removed pretty easy by spreading out the mold a bit and pulling it out. Should be mentioned a smooth surface will result in a smooth mold and wood lures should be finished prior to molding or bare wood coated with paste wax and buffed.
To insert a weight, squeeze the desired size weight onto a pin and insert it into the desired hole. Aligning the weight to the circle of the insert wire will assure it is straight in the mold.
Slide the mold back into its box, clamp and insert the rest of the inserts.
Posted 13 May 2006 - 10:31 AM
Tape can be wrapped around the box tightly to hold the seam while pouring. Since the mold was made with the seam closed it needs to be held tightly to pour baits. Having a mold like this in its box assures you cannot overtighten it and disfigure the bait but not tight enough will result in excess seam flash.
The Alumilite RC-3 Black resin parts A and B and Microbaloons here are available from www.alumilite.com
I use dental syringes to get exact equal amounts in each and have some microbaloons already in a small cup, then shoot them into the cup together and mix with the end of a small paintbrush. Pot life is about three minutes so quickly mix and pour into the sprue opening a small steady stream. Alumilite expands a bit while curing and will come out the sprue as it does so you can figure to pour a bit shy to save material. A little practice will get you very little waste.
Cure time for RC-3 Black is 5-15 minutes and your bait can be removed from the mold after pulling the inserts. The sprue can be cut off with a sharp knife...a VERY sharp knife if Gene sharpens it for you at the gathering!!! A good mold tightly clamped shut will have very little or no flash and barely a seam on just one side of the bait. This ought to be a plus for finishers! This flash is so thin it scrapes off easily with just a fingernail.
Here is the master, a lizard poured in Alumilite white with a hard segmented tail on a string and the new black floating lizard with hardware attached...waiting for a soft tail...
Posted 13 May 2006 - 10:35 AM
And here's the tail mold...waiting for some black plastic.
This is the end of the tutorial. Hope ya'll get something you can use from it and the lizards will be where my siggy leads soon as I get the hardware in from Jann's. Thanks for such a great place to be a part of venting our creativity!
Posted 13 May 2006 - 11:25 AM
Absolutely, outstanding job.
I am glad you did it, I couldn't of done it as well.
Posted 13 May 2006 - 12:13 PM
Awesome tutorial. I heard good things about you from Coley at the Clinton get together. Thanks for the tutorial......you make it look easier than it is!!
Posted 13 May 2006 - 01:52 PM
Super Job Charlie! Between the indoctrination Coley gave me on mold making and your fine tutorial I might be able to pull it off!
Posted 13 May 2006 - 02:09 PM
Love the idea of the one piece mold, for all the reasons you've said. It looks as though it would lend itself to through wire by placing a strategically placed, mold release treated rod into the mold. One quick question, can a wire harness be cast in or are you only able to add hardware after casting?
Posted 13 May 2006 - 02:45 PM
Thanks fella's, it was fun! But taking one handed zoom pics is quite a challenge...
I suppose a wire harness could be placed somehow, somewhere. It might need a different sprue location and an end to end seam on one side to get the wire harness in. If I could see a lure and the harness it requires I would be better able to visualise the mold.
Posted 13 May 2006 - 09:11 PM
Excellent work Chuck! I've made this a sticky untill the KB reopens. Can you snap a shot of a float test? I'd like to see how the microballons float. That so kicks butt.
Posted 13 May 2006 - 09:43 PM
Here ya go...
The microbaloons part is taking some getting used to. By volume, if you add 100% gives a high floater fully loaded. The lizard body in the pic is about 50%-60% by volume. Loaded with hardware, I want them to sink slowly when stopped in case I want it to drop in on a bed but short easy twitches of the rod cause it to swim on top. A 50% by volume in a crankbait will make a suspender with the right hooks. Go over 100% and it gets hard to pour in a small opening.
Pic quality isn't that great. The tail end is just under the surface with the weight in the rear belly and the nose is level with the tip center.
Posted 19 May 2006 - 10:25 AM
Here's a little update on a couple of easy tricks. These clamps are around $4 for several of different sizes in a bag at Wal Mart and work great to hold the molds together. The little plastic cup is easy to form a small pourspout on by squeezing the cup together a little at the rim and holding a bic lighter close to the inside edge for just a second or two and the spout will form nicely for pouring. I use two cups when pouring, alternating them and find it works out just right witht the cure time so the stuff hardens in the cup for the next pour. Got some regular Alumilite Black in the mail today which is supposed to have a faster cure time than RC-3. Will post later on the results.
Posted 14 January 2007 - 09:52 AM
this inspires the tackle hos to take it to another level. Thanks a bunch!
Posted 16 January 2007 - 08:35 AM
I'm thinking yesterday how to make this, but you ahead of me