181 replies to this topic

[Husky]

Actually this 5.75" mold cost $.60
Time to build was under 15 minutes, ready for pouring. Ingredients; 100% Silicone and water.
Cost Silicone, $2.97 for a tube, 280 gms. Water, nearly free.

Interested? Read on...

1. I started out with a wood model and crazy glued it onto a piece a wool 1/2" longer than the Model. I'm sure you could do the same with a well affixed soft bait.


2. Box in an area slightly wider than the model and as long as the wood it's affixed to;
Usually I screw the wood together to make a box but I used a clamp instead, for this project. Place it on a flat surface, preferably not your dinning room table.


3. Squeeze out enough 100% Silicone to fill the cavity, onto a flat non porous surface. Here I used some insulation board.


4. Add in a few drops of water and mix thoroughly. (I got this technique from the Clam Shell tutorial posted by RedG8r)


5. Fill the cavity with the mixed silicone.


6. Position the model so it enters the silicone, face down, centered, and press it in until it is flush with the side runners


7. When the silicone is cured (appx. 5 to 10 minutes. The silicone displaced by the model will be your guide)the model is ready to be removed. Trim any flash and pour.


And that's what I learned at Hammer Mechanic School, today.

Husky

Edited by Husky, 09 October 2010 - 08:37 PM.

[ronald rig1]

Husky
1) what type of Silicone did you use!
2) do you think its possible to make a 7 inch swimbait with this method
3) how durable is this mold

[Husky]

ronald rig1 said:

Husky
1) what type of Silicone did you use!
WalMart Silicone Sealant
2) do you think its possible to make a 7 inch swimbait with this method
Yes. You'll have to play around bit, but it should be quite doable. In any event, it's so very inexpensive and available.
3) how durable is this mold

Sturdy enough to withstand the elements for 35 years, according to the packaging.

[rinht2]

i am slow on the up take whats the water for? thanks for the info rick the barber

[rinht2]

never mind i need better reading skills thanks again rick

[ronald rig1]

Husky said:

Sturdy enough to withstand the elements for 35 years, according to the packaging.

what i meant was does it warp? do you have to store it on a flat surface? is this the stuff you got at walmart

[Husky]

ronald rig1 said:

what i meant was does it warp? do you have to store it on a flat surface? is this the stuff you got at walmart

Warp? Just silicone it to a rigid surface for stability.
I've only had it for 6 hrs so I can't speak to storage! It should hang in there.
AND, yes, it's from the Wally World paint section!

[ronald rig1]

how thick can i go before i have to be worried about the silicone not curing? i noticed your mold was thin. i was thinking 1 to 1.5 inches on both sides

[Husky]

ronald rig1 said:

how thick can i go before i have to be worried about the silicone not curing? i noticed your mold was thin. i was thinking 1 to 1.5 inches on both sides

That mold was 3/4 X 3/4. Fully cured in 5 min.
The water is the curing factor so it's not like waiting for it to air cure. FWIW, I've had 2" pieces fully cure in under 10 min. So What are you building?

[COBRA]

cool. i have seen some other silicone molds made like that. i suck at math but looks about $40 to buy a gallons worth of silicone.

[ronald rig1]

Husky said:

That mold was 3/4 X 3/4. Fully cured in 5 min.
The water is the curing factor so it's not like waiting for it to air cure. FWIW, I've had 2" pieces fully cure in under 10 min. So What are you building?

thanks for answering all of my pesky questions i'm making a 4" bluegill and a 7" bass. 10 min. that's fast! your making 2 part molds how are you clamping them or holding them together?

[Husky]

ronald rig1 said:

thanks for answering all of my pesky questions i'm making a 4" bluegill and a 7" bass. 10 min. that's fast! your making 2 part molds how are you clamping them or holding them together?

1/2 round generally means 1 part. BUT you can make a 2 pt mold using this technique. I'll need a day to explain it!
Truth be told I believe I know how to do it, Get some half round beads and I'll spill what I know!

[ROWINGADUBAY]

I am not sure but for thicker molds you could probably layer the silicone on the original.
Nice job
George

[Husky]

Dimension Correction,
The mold is 6.75" x .75" x .75" and completed, weighed 54 gms.

That should help you calculate the amount of Silicone needed to fill a cavity.

[COBRA]

if silicone is clean you can apply another layer and it will bond perfectly with no problems. alumilite corp. makes a good brush on release agent for silicone mold making that you can coat the wholefirst half with, then pour the new silicone on top of. if you look you probally use flowable silicone which i am pretty sure is still 100% but it is used in sealing and window applications where the silicone actually flows and will not need to have a part pressed into it. i have some flowable silicone here i will have to do a small mold and see how it works. you wouldnt need to add any water just squeeze and go.

[Husky]

COBRA said:

if silicone is clean you can apply another layer and it will bond perfectly with no problems. alumilite corp. makes a good brush on release agent for silicone mold making that you can coat the wholefirst half with, then pour the new silicone on top of. if you look you probally use flowable silicone which i am pretty sure is still 100% but it is used in sealing and window applications where the silicone actually flows and will not need to have a part pressed into it. i have some flowable silicone here i will have to do a small mold and see how it works. you wouldnt need to add any water just squeeze and go.

Here's the deal. For a 2 Part mold, you'll need registers to align both halves. You can easily do that with "half rounds" (see Photo below) placed on side 1. With a release agent and pourable silicone, you could cast side 2. You could also use water cured as in Part 1 to make Part 2, but you'd have to take care that you've completely covered the model. IOW's you'd need to pack side 2 onto side 1, with diligence.
As for release agents between the parts, WD40 works well, as does warmed petroleum jelly.
As for not using water to accelerate the cure, be advised that if the silicone is more than .25" it will cure, painfully slowly and in some spots, may not cure at all.

[ronald rig1]

COBRA said:

if silicone is clean you can apply another layer and it will bond perfectly with no problems. alumilite corp. makes a good brush on release agent for silicone mold making that you can coat the wholefirst half with, then pour the new silicone on top of. if you look you probally use flowable silicone which i am pretty sure is still 100% but it is used in sealing and window applications where the silicone actually flows and will not need to have a part pressed into it. i have some flowable silicone here i will have to do a small mold and see how it works. you wouldnt need to add any water just squeeze and go.

cobra you better add water! i tried to make a mold of a crawdad an did not ad water and it never cured. lesson learned! i"m trying to figure out how to clamp a two part mold befor i dive in this time. i figured i save my self some money by planing ahead

[ronald rig1]

Husky said:

Here's the deal. For a 2 Part mold, you'll need registers to align both halves. You can easily do that with "half rounds" (see Photo below) placed on side 1. With a release agent and pourable silicone, you could cast side 2. You could also use water cured as in Part 1 to make Part 2, but you'd have to take care that you've completely covered the model. IOW's you'd need to pack side 2 onto side 1, with diligence.
As for release agents between the parts, WD40 works well, as does warmed petroleum jelly.
As for not using water to accelerate the cure, be advised that if the silicone is more than .25" it will cure, painfully slowly and in some spots, may not cure at all.

nice real nice! what is the reason behind the die? or is it die

[COBRA]

husky is right with the registers and yes vaseline and wd40 work well also. rtv is for room temperature vulconizing, yes water will speed cure but i wouldnt see an issue without water except for a prolonged curing time. i have made silicone molds and not completely mixed enough activator and the mold took a week to cure. as for the craw mold not curing was it mixed silicone or out of a tube? i have used silicone in some pretty thick applications and havent seen a tube type never cure, just take a longer time.

[ronald rig1]

it was a tub of dap i think