I'm going to make a second mould for one of my sma

[benniejordaan]

I'm going to make a second mould for one of my small lures so I have a finished lure that I'll be making a mould of. My main reason for this is simply to improve on my old mould design.

This tutorial follows onto the How to make your own Tin / white metal spoons thread. If you have not read that one, please do so as some key points may not be repeated here.

http://sealine.co.za/view_topic.php?id=86739&forum_id=78

This is the lure I am making a mould of.

After testing, it has proven very successful and worthy of refinement. Perhaps later we will discuss lure action and what exactly effects lure action. For now, it's moulds...

 

[benniejordaan]

The mould box.
What you need.
As previously, I am using the same technique to build the box so very similar materials. The photos should be self explanatory.
Wood: Ideally you want a soft wood like Jelutong or Balsa.

1pc 135X50X20mm
2pcs 135X50X5mm
2 pcs 60X50X5mm
Some elastic bands
Petroleum jelly
Paint brush
Pencil

Some tools we will discuss next.

 

[benniejordaan]

Although a vice isn't absolutely necessary, it will help a lot to steady the work piece.

First, lay the lure in the center of the 20mm thick plank and mark it out.

 

[benniejordaan]

Now you need to remove the material to suit the lure. Rather go under size initially, then work at it till the lure fits in snug. The reason for this is you want the wire form loops to be support in it's entirety and not just balanced.

You also want to make this a bit deeper than just half the lure. The will give you a bit of body in the clay when pressing the lure into the cavity. You will see this later on.

I use a dremel to remove the bulk of the material. If you do not have a dremel, cut it out with a jigsaw and simply glue the plank onto a second one. Or carve it by hand. It is worth puting the effort into the mould as time now is time saved later.



Constantly check the lure fitment.



Fine tune it with wood carving tools or a knife.



Until it fits perfectly.

 

[benniejordaan]

Place a small amount of clay in the cavity, then press the lure into it so it will hold the lure in position.



Now very lightly press the lure wire form loops in the vice. Very gently, just enough to make a light indentation in the wood so you can see the marks.



Using a utility knife, cut along the markings. This will allow the wood to "give" when pressing further. This is just to cut the fibres of the wood making it move "giving".



Now you can remove the clay and press each ring a little at a time to avaid bending anything untill the wires are approximately 50% into the wood.

 

[benniejordaan]

Now we can again, put a little putty into the cavity and re-fit the lure making sure the wire forms are in their respective cavity and flush with no gaps.



Then fill around the lure with more clay.



Using a squared off tong depressor, scrape the sides clean.




To avoid messing this up, place the lot in the freezer for 15min. It will make the clay hard and the lure wont budge.

 

[benniejordaan]

Next we need to design the sprew. Consider how the material will flow in and how air will escape. Again, with this lure, I will pour at a slight angle. I do this purely to save on material.



We can now do the keys.

Later, I will show you guys some alternative ways of making keys without a dremel.



As per our spoon mould, now we lay a very thin film of Petroleum jelly with a brush. My lure is smooth so I wont put anything on it. I am basically only sealing the wood grain. If you don't do this step, nothing will happen, it will still work fine but you will have the wood grain imprinted on the silicone.

 

[benniejordaan]

Greased and ready do build up the box...



Build up the box, like we've done before.



Seal all the joints with petroleum jelly.

 

[benniejordaan]

For this application (no heat) we want the mould flexible and durable. We are going to use Mould Max 30. The mix ratio is 100:10 (10% activator).

Before we start the mould, this is what you will need.
 - Mouldmax 30 (available from AMT Composites) It will come with it's catalist. If you have MM 60 it works perfect for this application too but it isn't as durable. MM 60 is 60 shore harness while MM30 is 30. Do not let them sell you Silsmooth or any other product. They do not degass.

- Silicone thinners (available from AMT)

- A kitchen scale

- Something to mix in, make sure this is a container wider in size rather than deep. It will help to expel the air.
- Mixing utensil, I use tong depressors.

Before we start. You need to add 8% by weight (not more than 10% max) of the thinners into the Mould Max 30 and let it stand for 24 hours before use.. This is very important, especially if you do not have a vacuum chamber. This will make the silicone flow better and assist in expelling air.



Try to mix it with strokes and try not to be too vigorous. You have time, dont rush it must be mixed properly with no streaks. The pot life is 45 min.



Method for calculating the volume of silicone required.

Before smearing the the box with Petrolium Jelly (Vaseline)

Mock up the mould box.
Then place some rice or dried beans or anything similar but clean in the box spreading it out evenly at the level you require it, which should be minimum 10mm above the plug.
Then place this in a measuring beaker/jug.
If it comes to 100ml add 18% and this will be the volume of silicone required by weight.

N.B. Water has an SG of 1 and Mould Max 30 has an SG of 1.18

Pour into the mould with a light but steady stream from one corner. then you can follow the flow staying just behind the edge of the flow.



Now you can sit and pop bubbles to kill the bordem or you can go have a cold beer!

Allow 24 hours to set.

 

[benniejordaan]

After it has set, deconstruct the box.



TIP: Remove the clay sprew carefully and place it in the freezer while you continue to the next step. When you replace the lure in the mould half, you can soften some clay to fill the sprew cavity then get the cold (not frozen) half and lay it over that to give you a perfect mirror image.



Now you can paint the mould half with Petroleum jelly before replacing the lure or clay sprew.



Re-fit the lure and clay sprew.



Then re-assemble the box around it.



Seal the joints with Petroleum jelly.



Repeat silicon mixture and pour the second half

 

[benniejordaan]

After curing for 24 hours, deconstruct the box.



As for the different shades of pink, the lighter half is old material and the darker half is new material. Not sure if they changed something in the activator??

Then you can reproduce your lure.

 

[GOJ]

Thank you Bennie, much neater and far more efficient than my last build.
I will be employing all your tips in my next build

Thanks again for the WM90, i have already poured 1/3, far nicer stuff to work with than lead.

 

[benniejordaan]

GOJ wrote:

Thank you Bennie, much neater and far more efficient than my last build.
I will be employing all your tips in my next build

Thanks again for the WM90, i have already poured 1/3, far nicer stuff to work with than lead.

You are welcome. Was good meeting you.

 

[benniejordaan]

updated post no. 11

 

[GOJ]

benniejordaan wrote:

GOJ wrote:

Thank you Bennie, much neater and far more efficient than my last build.
I will be employing all your tips in my next build

Thanks again for the WM90, i have already poured 1/3, far nicer stuff to work with than lead.

You are welcome. Was good meeting you.

Good meeting you to Bennie.

 

[GT Mayhem]

brilliant tuts Bennie, very neatly done,
gives us some hope in producing something for ourselves for a change!
def gonna give it a try!

what material is the actual lure made of?

 

[benniejordaan]

GT Mayhem wrote:

brilliant tuts Bennie, very neatly done,
gives us some hope in producing something for ourselves for a change!
def gonna give it a try!

what material is the actual lure made of?

Epoxy resin. Very durable. Very long pot life and curing is dependent on thickness of cast. These lures take 2-3 days to cure properly but they aren't brittle like Polyester and much stronger than PU resin.

 

[GT Mayhem]

great, keen to see how you make the keys without a dremmel.

 

[chokka 123]

Great tut Bennie ! I'm aspiring to make molds when i get the courage and cash to buy the molding materials . This tut makes me realize that it isn't as hard as i thought it to be ,so thanks for your effort once again

 

[benniejordaan]

chokka 123 wrote:

Great tut Bennie ! I'm aspiring to make molds when i get the courage and cash to buy the molding materials . This tut makes me realize that it isn't as hard as i thought it to be ,so thanks for your effort once again

Excellent, that is exactly the point! Then I have achieved something.

I look forward to seeing your stuff.