Making weights with plaster molds????
24 replies to this topic
Posted 04 January 2009 - 07:01 AM
Hi all, how goes?
Not sure if I am in the right section for this question but here goes.
I have just discovered Buzz-bombs and am not able to get hold of any in the UK and wondered if anyone had a go at making molds made of plaster for lead?
I'm pretty sure this can be done although the plaster will not last that long but perhaps long enought to make a few.
I have made a few plaster molds so have some experience and I have also poured melted lead but never together.
Not sure whether I need to seal the plaster before pouring lead etc.
Anyone have any experience in this field?
Absolutely any input very much appreciated.
Posted 04 January 2009 - 07:49 AM
The materials available for home constructed, short life molds are: Hi temp RTV, Plaster of Paris, Durhams water putty and Bondo.
Plaster of Paris and Durhams, the consensus of opinion seems to be that they are only good for about 30 pours and you have to take care to make sure the molds are completely cured, as they contain water. At least a week air drying, couple of days in a warm airing cupboard or behind the fridge against the heat exchanger. Could not find any information on sealing for lead.
Hi temp RTV, room temperature vulcanising rubber, much more expensive, but should give more casts as it is flexible and thus less wear on the mold cavity. A few members have mentioned it in the past.
Bondo. This is a polyester resin based filler. It is a thick paste usually supplied with a hardener in a tube. It is used for automotive body repairs, sometimes impregnated with glass fibres. It can be mixed with polyester resin (fibreglass resin), this will thin it out enough to enable pouring. Not sure of the ratio, about 70:30 filler/resin, add more resin if too thick to pour. Use the hardener provided with the resin. This will not require a sealer, but does tend to warp under heat, so allow plenty of time between pours and make the molds thick, to minimise the warp. This mold should be good for 100+ casts.
You can search the individual items. Here are a few links to get you started:
TU reference http://www.tackleunderground.com/forum/wire-baits/14941-how-make-spinnerbait-mold.html
This leads to Triton Mike's tutorial http://www.wmi.org/bassfish/bassboard/fishing_tactics/message.html?message_id=131571
Yankee Jigger made a Plaster of Paris mold, but no information or feed back. Could be worth a PM. http://www.tackleunderground.com/forum/wire-baits/14941-how-make-spinnerbait-mold.html
Likewise, PAVABill did something similar, still no information or feedback, again a PM might gey you some information, http://www.tackleunderground.com/forum/wire-baits/14137-spinnerbait-heads.html
Here is another discussion close to the subject, http://www.tackleunderground.com/forum/wire-baits/12331-custom-mold.html This refers to another tutorial by Senkosam, although intended for plastics, still good information, http://www.tackleunderground.com/forum/soft-plastics-how/5393-kb-mold-making-1-2-3-4-5-6-7-etc.html
Posted 04 January 2009 - 10:17 AM
As Dave said; be absolutly sure that your Plaster of Paris molds are "bone" dry. If not you could be off to the ER for repairs.
What I did was apply several coats of oil to the cavities and allow it to soak in. You may have to re-apply the oil after a couple of pours.
Warning:- it will get smokey, so do it in a garage with door open.
Use motor oil as it will take the heat better than kitchen oil.
Let us kow how you make out.
Posted 04 January 2009 - 12:36 PM
Many thanks indeed guys for those replies.
I'll see how I get on with it and let you know if I decide to give it a go.
Posted 04 January 2009 - 12:55 PM
Is a buzz bomb the same as a buzz bait? If so, you can get a mold from Do-It molds to pour them with, JIM
Posted 04 January 2009 - 01:29 PM
Hi, no these are buzz bombs:
BuzzBomb Zzinger Lures Inc makers of Buzzbomb, Zzinger, Spinnow, Halibut Spinnow and Zelda Jig Lures
I'm not sure whether the lead will be too heavy to make these though and whether I can successfully drill a hole right through?
Posted 04 January 2009 - 01:40 PM
You don't need to drill a hole through the lead. Just install a steel rod in one side of the 2 piece mold. Make sure the rod is secured with a 90 degee bend and anchored in the Plaster of Paris with epoxy. After the lead cools it should pull right off the rod forming a nice "smooth" hole. Drilling will leave burrs which can cut your line.
Posted 04 January 2009 - 02:42 PM
That is a great idea! Thank you nova!
I'm just rying to get my head around the best way of doing this.
Should I Get myself a steel rod that fits through the original "weight" then bend one end as you suggest and keep this rod in while making the plaster mold?
Crumbs, no I'm not sure about this?
Do I need to attach the rod to the plaster mold or could I simply lay the rod in the cavity if I do the mold side on?
Either way am I better making the pouring cavity somewhere away from the rod?
Man I'm so sorry about this aspect of things. I have no clue.
Posted 04 January 2009 - 02:49 PM
It may be easier to place the rod in the mold from the bottom and pull it out just after you pour the lead. Make sure you put a small wood handle on the rod or you will burn your fingers.
Just make a groove in the mold so that the rod passes from the bottom to outside the top of the mold; and make sure it is dead center or the balance of your lure will be off.
Posted 05 January 2009 - 04:02 AM
Ah ok that makes sense to me.
So the only other thing I'm not sure about is where to put the pouring funnel?
Should this be where I already have a hole for the rod or somewhere else?
Also do I need to make a vent hole or will it be ok as long as I make the pouring chamber/hole big enough?
Again, many,many thanks indeed for your support guys.
Posted 05 January 2009 - 05:22 AM
These lures are looking quite similar to "Tasmanian Devils" , but I guess , that they are way heavier , since the "Devils" only have a lead tubing insert , whereas wings and body are of transparent plastic .
The German mail order shop HAKUMA ihr Spezialist für Köder, Kunstköder, Meeresangeln, Raubfisch angeln, Pilker, Wobbler, Fischen, Bleiguss, Formen, Ruten, Rollen, Dorsch angeln, Leng angeln in Norwegen, Dänemark, Hitra sells a system based on silicone sheets , that are supposed to be used to duplicate lead lures to make clones of these .
In brief the original lure is clamped between the two silicone plates in a special frame and then placed in boiling water to cure the mold , said to be good for many casts , depending on size and weight of lures .
Haven't used it before , just wanted to mention this possibility .
On their start page go to "shop" , after on the left bar click on "Bleigussformen und Zubehör" and browse through , you should find pics of it there .
Sorry , no English site version available !
greetz , diemai
Edited by diemai, 05 January 2009 - 05:23 AM.
Posted 05 January 2009 - 06:23 AM
The first consideration for pour hole location is to achieve a complete pour. A close second is clean up of the sprue.
If the cavity is vertical and the pour hole positioned at or close to the top, the escaping air is going to be affected by the rod insert and the narrow cavity. This is going to increase bubble contact with surfaces and increase the chance of the bubble sticking or being trapped. Also, the sprue will be in an awkward place for clean up.
My suggestion is to orient the cavity horizontal, with the pour hole at the highest point, in the middle of the back. But because the top surface of the cavity will be approaching horizontal, there is still a chance of the bubble being trapped and unable to get around the corner to exit through the pour hole.
To solve the problem of this potential bubble trap, I would include a small vent (vent 1), exiting to the outer edge of the mold, both sides of the pour hole.
A potential for a bubble exists at the junction of the rod and ends of the body. Additional vents (vent 2) can be added to solve these problems.
I suggest you make the mold without vents and cut the vents only if required. The vents should be very small diameter where they intersect the cavity, maybe just a score with a sharp knife is sufficient, otherwise the lead will pour out. Once the vent is clear of the cavity, it can be widened, this makes keeping the vent clear much easier. The vents only need to be cut on one half of the mold.
This is only my opinion, I am not an expert but still fairly new to molds. If anyone disagrees, or has other ideas, I would like to read them.
Posted 05 January 2009 - 08:21 AM
Good diagram Dave.
This may not work as the bait in question has ribs on it and the sprue will take too much room causing a deformation of the ribs.
I suggest that you make the pouring hole on one end and pass the rod from the bottom to the top all the way out of the mold so that the rod does not get covered by the lead in the pouring hole, as in Dave's diagram.
Edited by nova, 05 January 2009 - 08:23 AM.
Posted 05 January 2009 - 08:43 AM
Thank you very much guys for taking the time to respond.
I've managed to find a couple of photos of a mold that may work.
As you can see on the attachment I have drawn up 2 simple ideas that I think could work.
Nova are you suggesting I go for the B idea with the pouring hole directly above the rod?
I thought that if I copied the molds in the photos Diagram A
The rod hole may allow for air to escape as I fill it with lead?
Posted 05 January 2009 - 08:51 AM
B would not require a vent. A would require a vent at the highest point, to release the innevitable trapped bubble. I think B would be much easier to manage the rod, being fixed at both ends.
Posted 05 January 2009 - 09:12 AM
Ok, thanks very much guys.
So If I go for B how will I secure the rod on the pouring end?
Also do you think I will need to turn the rod while pouring somehow or should the rod come out noi problem after pouring?
The thing that attracted me to diagram A is the fact that the rod will be secure at either end but I understand your point about the advantage of Diagram B. Obvioulsy if I am going to pour direct I need space around the rod to let the lead through.
Posted 05 January 2009 - 12:41 PM
Thank you ever so much guys for the sound advice.
Looking forward to having a go.