Mold Making-- Help!

[RiverSmallieGuy]

I have a project in mind, a fully carved 8" rainbow trout swimbait. Scales, gills, fins... Everything will be carved out of poplar, and I decided that if I am going to put weeks, or even months of carving into a bait, I might as well just make a silicone mold of it. Then I looked at the mold making products and their costs, and being 15 years old without a job... It would be hard to find 50+ dollars to pay for silicone, clay, mold release, and various other mold making supplies. So, I sat back in my chair and thought for a while, "how could I make a good mold for this trout, and not burn my wallet at the same time." I came to the decision to ask the TU community about good ways to make molds affordably. I hope to stay under, say, 30 or 40 bucks... (if possible, I know, very very ambitious). I would even be willing to arrange an exchange to have somebody who is far more experienced with making molds make one for me. What I would give in return is... uhh, probably wooden baits or money. Thanks fellas for any advice!

 

Braden

[Bentrod425]

You could make a mold out of plaster of Paris (super cheap!), then use that mold to make an epoxy master.

[Hillbilly voodoo]

I have never used this method and only seen it on the internet so can’t say how effective it is

There is videos showing people making silicone molds with a dish soap and silicone from the hardware store mix.

Google it because I suck at posting links 

As long as you don’t loose your carved master you can always take your time saving a few $ at the worst 

outside of that you might need to start doing yard work for your neighbors to earn extra lure making funds 

[Travis]

If the bait is designed properly you can mold it from plaster of paris.   I have made 100's of these molds over the years, mainly for soft plastics but many for crankbaits and top waters.  I am sure you will be able to mold the bait yourself with a little instruction.

 

[RiverSmallieGuy]

2 hours ago, Travis said:

If the bait is designed properly you can mold it from plaster of paris.   I have made 100's of these molds over the years, mainly for soft plastics but many for crankbaits and top waters.  I am sure you will be able to mold the bait yourself with a little instruction.

 

Thanks guys! Definitely going to look into this!

7 hours ago, Bentrod425 said:

You could make a mold out of plaster of Paris (super cheap!), then use that mold to make an epoxy master.

 

[RiverSmallieGuy]

Never heard of that method. Gonna look into it though. Sounds like it may work.

6 hours ago, Hillbilly voodoo said:

I have never used this method and only seen it on the internet so can’t say how effective it is

There is videos showing people making silicone molds with a dish soap and silicone from the hardware store mix.

Google it because I suck at posting links 

As long as you don’t loose your carved master you can always take your time saving a few $ at the worst 

outside of that you might need to start doing yard work for your neighbors to earn extra lure making funds 

 

[JD_mudbug]

I also have made molds out of Plaster or Paris. My first mold was using sections of threaded rod to make a senko-type mold. I melted old soft plastic baits in a microwave to use in that mold. Cheap and easy.

You may also want to try a casting resin like Alumalite High Strength 3 Casting resin. You can get a 1 lb. kit for $30.

https://www.amazon.com/Amazing-Casting-Products-Liquid-Rubber/dp/B07Q331JYR

You can make your masters out of Sculpey if you want to cut down on carving time.

https://www.amazon.com/Sculpey-Super-Sculpturing-Compound-Beige/dp/B0026C1T8C

Mike Lopez's video shows a quick way to make big baits.

https://www.youtube.com/watch?v=LVXeSBG-2-8

 

[Vodkaman]

Plaster of Paris (POP) is certainly the cheapest method of casting, and the experience carries over to other materials later. Quality is very good too.

But beware! If you are pouring a hard cast like resin then you run the risk of trapping your cast in the mold. This is called 'die locking'. You must be able to lift out the cast perpendicular to the split face of the mold.

Dave

[RiverSmallieGuy]

2 minutes ago, Vodkaman said:

Plaster of Paris (POP) is certainly the cheapest method of casting, and the experience carries over to other materials later. Quality is very good too.

But beware! If you are pouring a hard cast like resin then you run the risk of trapping your cast in the mold. This is called 'die locking'. You must be able to lift out the cast perpendicular to the split face of the mold.

Dave

 

1 hour ago, JD_mudbug said:

I also have made molds out of Plaster or Paris. My first mold was using sections of threaded rod to make a senko-type mold. I melted old soft plastic baits in a microwave to use in that mold. Cheap and easy.

You may also want to try a casting resin like Alumalite High Strength 3 Casting resin. You can get a 1 lb. kit for $30.

https://www.amazon.com/Amazing-Casting-Products-Liquid-Rubber/dp/B07Q331JYR

You can make your masters out of Sculpey if you want to cut down on carving time.

https://www.amazon.com/Sculpey-Super-Sculpturing-Compound-Beige/dp/B0026C1T8C

Mike Lopez's video shows a quick way to make big baits.

https://www.youtube.com/watch?v=LVXeSBG-2-8

 

Is Plaster of Paris a mold making material or is it a lure casting material? Is it good for resin swimbaits?

[Hillbilly voodoo]

If you are going to look at actual mold silicone Smooth on is cheaper then Alumilite and I actually prefer the smooth on silicone. But for casting resin Alumilite makes a better product 

I have made lots of silicone molds and resin lures with the above products. Not the cheapest but good products. They are cheaper for you being in the USA then I pay in Canada though 

[RiverSmallieGuy]

1 minute ago, Hillbilly voodoo said:

If you are going to look at actual mold silicone Smooth on is cheaper then Alumilite and I actually prefer the smooth on silicone. But for casting resin Alumilite makes a better product 

I have made lots of silicone molds and resin lures with the above products. Not the cheapest but good products. They are cheaper for you being in the USA then I pay in Canada though 

Alright. Thanks guys! Ima have to look at those products soon. I tore up the bass in a lake near me today, so I am tired lol.

[Vodkaman]

20 minutes ago, RiverSmallieGuy said:

 

Is Plaster of Paris a mold making material or is it a lure casting material? Is it good for resin swimbaits?

POP can be both, but in out application it is a mold making material.

POP for casting resin is risky. If you die-lock your master, you will need a hammer to retrieve it.

Dave

[Hillbilly voodoo]

2 minutes ago, RiverSmallieGuy said:

Alright. Thanks guys! Ima have to look at those products soon. I tore up the bass in a lake near me today, so I am tired lol.

Luck bugger still 2ft+ of ice on the lakes here. I won’t be fishing any lakes till May 

 

[Travis]

Plaster of paris is dirt cheap.  As I mentioned just design the lure properly.  If you screw up no big deal.. a careful blow with a hammer and screw driver and you can get the master back.  That said just make sure none of the detail has undercuts and not many issues.  Just have to visualize the removal of the bait from the mold.. if the tail curls no go, if a gill is undercut no go, etc....

 You can also use Bondo body filler and can demold a little earlier and you get some play as it will flex when warm.  Can heat in an oven also.  Once again just easier to design the master properly.

When it comes down to it all the detail stuff isn't needed but where is the fun in that.

I used two part urethane to cast most of my lures when messing with it on a consistent basis.  Cheap enough.

 RTV silicone is better way to go and Smooth on Mold Max 30 is what I routinely use.  The lure below would easily cast in plaster of paris.  The eye socket has no undercuts and the simple detail around the eye is smooth and round.  The molded in lip slot would cause issues and eventually break in plaster of paris.  

Now if you get too much detail will have to go RTV.  The trout below has several issues (wasn't going to mold it) just goofing around carving.  The undercut on some of gill rackers on the underside would lock the bait in a POP mold and of course the mouth. 

Edited March 20, 2022 by Travis

[RiverSmallieGuy]

1 hour ago, Travis said:

Plaster of paris is dirt cheap.  As I mentioned just design the lure properly.  If you screw up no big deal.. a careful blow with a hammer and screw driver and you can get the master back.  That said just make sure none of the detail has undercuts and not many issues.  Just have to visualize the removal of the bait from the mold.. if the tail curls no go, if a gill is undercut no go, etc....

 You can also use Bondo body filler and can demold a little earlier and you get some play as it will flex when warm.  Can heat in an oven also.  Once again just easier to design the master properly.

When it comes down to it all the detail stuff isn't needed but where is the fun in that.

I used two part urethane to cast most of my lures when messing with it on a consistent basis.  Cheap enough.

 RTV silicone is better way to go and Smooth on Mold Max 30 is what I routinely use.  The lure below would easily cast in plaster of paris.  The eye socket has no undercuts and the simple detail around the eye is smooth and round.  The molded in lip slot would cause issues and eventually break in plaster of paris.  

Now if you get too much detail will have to go RTV.  The trout below has several issues (wasn't going to mold it) just goofing around carving.  The undercut on some of gill rackers on the underside would lock the bait in a POP mold and of course the mouth. 

Other words, if I carve the trout I was planning to carve with the fully carved scales and such, I wouldn't be able to de-mold the master without breaking it. What would you guys do for a lure with a lot of undercuts?

 

[RiverSmallieGuy]

1 hour ago, Vodkaman said:

POP can be both, but in out application it is a mold making material.

POP for casting resin is risky. If you die-lock your master, you will need a hammer to retrieve it.

Dave

Yeah, looking at it online, it wouldn't really be suitable for a very detailed bait like I'm wanting.

[Hillbilly voodoo]

4 minutes ago, RiverSmallieGuy said:

Other words, if I carve the trout I was planning to carve with the fully carved scales and such, I wouldn't be able to de-mold the master without breaking it. What would you guys do for a lure with a lot of undercuts?

 

Silicone will keep the details and flex so you won’t have issues remolding 

[Travis]

7 minutes ago, RiverSmallieGuy said:

Other words, if I carve the trout I was planning to carve with the fully carved scales and such, I wouldn't be able to de-mold the master without breaking it. What would you guys do for a lure with a lot of undercuts?

 

RTV silicone only real way to go.  It will wear in time depending on the severity of the undercuts.

https://www.smooth-on.com/products/mold-max-30/

A 2.2 lb kit isn't too bad 34 bucks before shipping/taxes and will make several molds with no issues.  Doesn't have to be smooth on but hard to beat on price and known well performing product with customer support.

I don't see scales being an issue to be honest.  Typically ends  up being fins and gills and potential eye socket if not done correctly.

Edited March 21, 2022 by Travis

[RiverSmallieGuy]

1 minute ago, Hillbilly voodoo said:

Silicone will keep the details and flex so you won’t have issues remolding 

Ohhhhhh so POP is a solid, hard material. That helps.

[Travis]

You need to make some pop molds first and make some basic cranks.  Screw up and figure it out before moving on.

 

[RiverSmallieGuy]

1 minute ago, Travis said:

You need to make some pop molds first and make some basic cranks.  Screw up and figure it out before moving on.

 

I would guess that POP is just less user friendly than say a silicone. Ima probably have to try it all to find what I like.

[Travis]

It honestly isn't too hard to use just comes down to the user. 

Based on some of your questions and likely experience it is an easy product to start off with with no real money invested.   Over the years things some find easy and common sense are impossible for others to ever do. Just way it is.

Legos, molding clay, Vaseline, some worm weights, bb's, and few commonly found tools (popsickle stick, skewer, tooth picks, etc..) and plaster of paris and you are ready to make molds.   Then you need to decide on what product you want to pour your baits with.  I used US Composites 16 lb 2 part polyurethane foams and poured with a weight harness inside the bait.

 

Edited March 21, 2022 by Travis

[RiverSmallieGuy]

3 minutes ago, Travis said:

It honestly isn't too hard to use just comes down to the user. 

Based on some of your questions and likely experience it is an easy product to start off with with no real money invested.   Over the years things some find easy and common sense are impossible for others to ever do. Just way it is.

Legos, molding clay, Vaseline, some worm weights, bb's, and few commonly found tools (popsickle stick, skewer, tooth picks, etc..) and plaster of paris and you are ready to make molds.   Then you need to decide on what product you want to pour your baits with.  I used US Composites 16 lb 2 part polyurethane foams and poured with a weight harness inside the bait.

 

Are glass microspheres compatible with POP?

[JD_mudbug]

As Travis said, POP is just as easy to use as silicone. Measure properly, mix properly. It probably isn't the best product for your detailed swimbaits. POP is mostly used for ornamental ceiling, cornice and wall details like the rosettes around ceiling light fixtures.

POP works great for soft plastics because those baits are pliable and can be demolded from a hard POP mold.

Microspheres are compatible with POP. But, why would you want to do that? The mold would be made of POP and there is no need for the spheres in the mold. You don't want to make baits out of POP. POP is only durable in a static environment.

If you want to make a big sun dial on your ceiling and are concerned about the weight, POP can be lightened with the spheres. Plasterers use POP with spheres to make a lightweight fill material for delicate plaster repair work.

[RiverSmallieGuy]

22 minutes ago, JD_mudbug said:

As Travis said, POP is just as easy to use as silicone. Measure properly, mix properly. It probably isn't the best product for your detailed swimbaits. POP is mostly used for ornamental ceiling, cornice and wall details like the rosettes around ceiling light fixtures.

POP works great for soft plastics because those baits are pliable and can be demolded from a hard POP mold.

Microspheres are compatible with POP. But, why would you want to do that? The mold would be made of POP and there is no need for the spheres in the mold. You don't want to make baits out of POP. POP is only durable in a static environment.

If you want to make a big sun dial on your ceiling and are concerned about the weight, POP can be lightened with the spheres. Plasterers use POP with spheres to make a lightweight fill material for delicate plaster repair work.

Ohhhhh ok. I was kinda confused with something Vodkaman had said about it being suitable for both castings and molds, and I was curious if it would work with microspheres to make crankbaits float.