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Husky

DIY An Instant 1/2 Rd RTV Silicone Mold For Under A Buck.

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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.

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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.

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

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

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5. Fill the cavity with the mixed silicone.

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

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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.

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

Husky

Edited by Husky

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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

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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.

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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

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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!:whistle: It should hang in there.

AND, yes, it's from the Wally World paint section!:)

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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

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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?

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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.

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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?

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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!:twocents:

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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.

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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.

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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.

DSCF0001-13.jpg

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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

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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.

DSCF0001-13.jpg

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

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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.

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husky

i am going shopping as soon as you tell me the brand of Silicone you are getting from walmart! my master is dune i"m hope mine look as good as yours

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husky

i am going shopping as soon as you tell me the brand of Silicone you are getting from walmart! my master is dune i"m hope mine look as good as yours

Mainstays Project ALL PURPOSE SILICONE SEALANT, WHITE. It's in the paint department under where the D2T used to be!:pissed:

Just follow the instructions, being sure to mix the water in well, fully fill the cavity, press the model in centered and flush. You can spray your WELL AFFIXED model with Pam or WD40 for a smoother finish.

If you have a scale, Here's a guide; For every cubic inch of cavity, weigh out 18 -20 grams (appx 3/4 of an oz.) of Silicone. That will be exactly as much as you'll need to get a complete fill w/o too much waste.

FWIW, I save any silicone that is excess after the Squish and use it as filler when I pour RTV silicone molds for my hard baits, and two sided molds. It cuts costs, dramatically. That's another lesson I learned @ HAMMER MECHANICS SCHOOL.

Keep us posted.

Mike P

Edited by Husky

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It just got Easier! A modification in making the mold box. (the original method is still an alternative, of course.)

To make a mold box quickly and flawlessly:

1. Layout your model onto a 1/2" piece of Pink Styrofoam Insulation Board. Allow for necessary clearance, and cut that area out with a razor. (Models thicker than 3/8" will need thicker Insulation board.)

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2. After affixing your model to a flat surface, slightly larger than the cavity hole you cut, DSCF0002-30.jpg position it so it is centered in the cavity and then trace the lines of the edges of the model supporting board onto the cut out Insulation Board. Run a bead of Silicone around the cavity opening and place it on a flat surface. Fill the cavity as shown previously, plunge the model into it, using the lines you drew as a positioning guide. After the silicone sets, break away the board and remove your mold. The results will be a perfectly sized and positioned mold that will take minutes.

DSCF0002-29.jpg

DSCF0001-37.jpg

And that's what I learned at Hammer Mechanics School, today!

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This is awesome Husky. I actually molded a lipless crankbait like this. I did mix a dab of paint in with the water drops before mixing with the silicone. It is a good indicator of how well the water gets mixed in. Thanks for the info, I think this with some pop molds might get me going on some resin baits.

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