collar not pouring

[muddler]

i have a new do it bullett sb mold and am having trouble getting a complete pour.when i pour the mold without a wireform it,s fine,but after the wire is added and poured the collar on three of the four sizes is not pouring.after researching this forum,i gathered that it probably is getting an air pocket in the collar & needs to be vented.i etched a line out the side of the collar,and got a little bit of the collar to pour,but it,s still not right.question i have is how big of a vent do i need,do i vent both halves of the mold?or should i have vented the collar at the bottom,parralell to the wireform? could someone maybe post a pic of there vented mold & it,s

location and depth. i just cant believe i have to alter a brand new mold to work.

thanks in advance for any help.

ed c.

[sagacious]

Yes, unfortunately some new molds do need to be tweaked a bit to work right. Your problem could be due to inadequate venting, but my humble guess is that probably, it's not. To a degree, the collar is vented at the bottom, where the hook channel is. Usually there's a couple thousandth's gap that allows air to escape. Even if the hook channel is a tight fit with a hook in it, usually there's enough tolerance to let trapped air out.

Venting should be done directly from the area that doesn't fill out, to the edge of the mold. Be sure the vent groove actually connects with the cavity. The vent groove only need to be about 1/64" deep, or so. However, venting usually solves the problem immediatly. If it didn't, look elsewhere for the problem. Plus, if you're having problems with more than one cavity, the cause is unlikely to be inadequate venting, and likely due to more fundamental pouring problems.

The collar is a very thin area of the spinnerbait mold cavity, and lead will only flow into it if the mold is hot enough. As well, that narrow area has the hook acting as a fairly substantial heat sink. A heat sink in a narrow area of the cavity is extremely prone to causing incomplete pours. This is very common. The solution is to:

#1 Make sure your mold is hot enough before pouring with hooks. If not hot enough, the mold will 'steal' heat from the lead, and prevent lead from flowing into the narrow area of the collar.

#2 Make sure your lead is adequately hot. Whatever temp you're pouring at now, crank up the heat a bit.

#3 Warm up your hooks! If the hooks aren't warm (but not burning hot) enough, they'll rob heat from the molten lead, and cause it to solidify before entering the collar. Place the hooks somewhere near your furnace where they can warm up a bit. If you pour in cold weather, this is especially important-- but it's good practice in any weather, especially with a stubborn mold.

If you're using wheel weight lead, you can also try pouring with soft lead and see if that helps. However, you should generally be able to use ww lead, as long as you're doing everything else right.

Hope this helps, good luck!

[MDC]

Sagacious lined everything out pretty well.. The only other thing you might try is smoking your mold. This will allow lead to flow better in your mold. Some of mine had to be smoked before they worked right, some not.

[Big-D]

I also pour 4-5 "blanks" (without hook and wire) in rapid succession to heat the mold and that seems to help with collars filling out.

Big-D

[muddler]

i,ve been pouring all the cavities,getting the mold real hot,and i,ve tried

pouring at the highest setting and working at each heat level.but what

makes the most sense is that my hooks could be too low of a temperature.

my lead has come off a scuba weight belt,but i think it,s soft enough,

because of the flawless pours without a wire.if the hooks get heated ,

and there,s no change should i be adding some wax or some other flux?

thanks for the quick responses.

ed c.

[Jig Man]

Not all molds are equal or even good.

I have an old spinnerbait mold that has made thousands of spinnerbaits as it was originally from a spinnerbait company. It has to be so hot that I have to have gloves on to get a collar pour. Sometimes I even have to take a propane torch and heat up the hook and wire just before pouring and that is with plumbers lead which has been fluxed and is as hot as I can get it in my Lead pot.

[sagacious]

... should i be adding some wax or some other flux?

...

ed c.

Fluxing the lead before beginning a pouring session is never a bad idea. Do this outside. Add a small (corn krnel sized) piece of paraffin or beeswax to the molten lead. Be ready to stir it in as soon as it melts, and be aware that it will smoke and may flame up. Keep stirring until you have a bunch of powdery black gunk on top of the lead, and then skim that off. Then you're ready to pour.

As MDC noted above, smoking the mold is also a good idea. Sometimes a mold needs to be 'broken in' and is stubborn at first, but will pour fine later. Sometimes a certain mold just needs to be treated and handled a little differently, and it takes a couple pouring sessions to figure it out.

I suspect that the source of your specific problem is cold hooks. Try heating the hooks, and use good pouring technique, and see if that fixes the problem.

Good luck!

[Unagi]

Complete pours and sharp barbs were a constant frustration. Hours of research and ensuing alloy manipulation still yielded inconsistent results. Venting was also tried with varied success. In the end a $5 auto-ignite butane torch remedied all problems. As described, the heat capacity of the wire form and hook shank are the culprits which are causing your problems. After laying in your wire forms and hooks, a quick shot of the butane flame over the cavity and especially the collar will ensure complete pours every time. A quick shot is exactly that, don't try to weld anything!!! You will destroy the temper and have the lead exploding out of the pour hole. Wave the flame a couple of times over the described areas. The delay caused by this step will soon become insignificant as you find your rhythm. Furthermore 1 re-pour more than compensates for the time spent preheating your hooks.

Hope this helps,

-Paul

[sagacious]

... After laying in your wire forms and hooks, a quick shot of the butane flame over the cavity and especially the collar will ensure complete pours every time. A quick shot is exactly that, don't try to weld anything!!! You will destroy the temper and have the lead exploding out of the pour hole. ...

-Paul

Good advice, this does indeed work.

However, never ever use a propane/butane torch to initaially warm up the mold cavity! Never heat up hooks in a cold mold! The products of combustion include water vapor, and if the mold isn't hot, that water vapor will condense in the mold. When you pour in molten lead, the water will cause a steam/lead explosion, or you may hear spitting and popping. Not good.

There is no risk of steam explosion if the mold is thoroughly hot. Be sure to use standard pouring techniques and heat-up the mold by repeated pours without hooks or wire forms. When the mold is hot, you're safe to proceed.

Hope this helps, good luck and be safe!