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

[Piscivorous Pike]

The modified rtv sealant material from my experience is flexible enough that to use it in a two piece mold you need to back it with a board of some kind.

It would be best in a one piece mold because it is very flexible not prone to good support and seals.

I always keep my master model, or first casts to use to rebuild my mold. I learned from Longhorn (a mentor to me) a method to make a master cast. On single or multi cavity molds he over fills them so that the cavities are connected to a sheet of plastisol. This sheet and casts he saves and can be put into a container and a new mold easily poured over them.

While waiting out the testing of this RTV longevity it would be smart to keep a master like these examples, I do :

Easy POP Production Mold how he makes the masters up.

Quick and easy mold box

Finished product

[Husky]

The modified rtv sealant material from my experience is flexible enough that to use it in a two piece mold you need to back it with a board of some kind.

It would be best in a one piece mold because it is very flexible not prone to good support and seals.

I always keep my master model, or first casts to use to rebuild my mold. I learned from Longhorn (a mentor to me) a method to make a master cast. On single or multi cavity molds he over fills them so that the cavities are connected to a sheet of plastisol. This sheet and casts he saves and can be put into a container and a new mold easily poured over them.

While waiting out the testing of this RTV longevity it would be smart to keep a master like these examples, I do :

Easy POP Production Mold how he makes the masters up.

Quick and easy mold box

Finished product

This thread got a tad longer than I anticipated. So, at the risk of repeating myself, this is how I make a Mother Mold, so I can make quick and easy back ups.

When I get a well performing RTV mold, I box the mold in, cavity up, and pour a well mixed, lump free POP mixture over it. When it sets, work the RTV mold out. Let the POP totally cure and seal it. I use D2T mixed with alcohol as a sealer. When that is cured, you can fill the POP mother mold with the RTV of your choice and when that cures, you'll have a clone of your original RTV mold.

I had a project where a fellow was making custom chocolates and needed appx 10000 pieces so I made two MM's and many subsequent RTV molds from them to speed up the process.

In the picture bellow, you'll see the orange Master and the white clones cast from the MM's (They're the POP squares@ the upper left)

The point is that once you have a good RTV mold, you can have as many clones of it as you desire, with a minimum of work.

Edited October 30, 2009 by Husky

[dtrs5kprs]

Mothers are definitely the way to go for RTV reproduction. Try one of the 2 part liquid plastic (Smooth-On, etc) vs the POP. Price is a little higher but they are nearly unbreakable = easier to store. Need to hit them with some lacquer after curing.

[Husky]

Mothers are definitely the way to go for RTV reproduction. Try one of the 2 part liquid plastic (Smooth-On, etc) vs the POP. Price is a little higher but they are nearly unbreakable = easier to store. Need to hit them with some lacquer after curing.

Absolutely true, but not in keeping with the "we throw nickles around like they're manhole covers" theme of this thread.

Making a MM will aleviate any anxiety of "losing" a great producing mold, and is something DIY mold builders should embrace, If just for the sake of increasing production rates by adding the amounts of pours in any given time.

[Piscivorous Pike]

Hybrid MOLD-(sounds like a dangerous fungus...) Actually a new way to use this Poorman's RTV.

Using this RTV I modified a POP top pour one piece three cavity mold into a two piece mold; ready for injection in just minutes!

I can't top pour tail flukes because I shake and slop it all over and have to cut off flashing to use the finished product. I wanted to enclose this mold. By making a top I can make a two piecec mold using POP but that means after pouring the plaster seperating it, sanding off protrusions and bad spots, drying it and then coating with white glue. This could take days. RTV could be ready in minutes.

I carefully filled the three cavities with plastisol in two steps, laminate sorta, so I could get them as full as I could and left them in there as masters so as to be able to modify this into a two piece mold. They are flat top 9" flukes with long tail shanks. These are a 7" Fin S with a 2 inch section of a Mr. Twister sluggo grafted into it moving the flukes back. The image shows the 7' Fin S, 5" Creek Town Fluke I want to enlarge, the slug bait, a new slug wearing a Fin S fluke tail and the bottom the new version Fluke.(click to enlarge) The top pour fluke mold was wrapped with 4 boards around it using a little hot glue to hold them in place. Using a drill 4 sets of index holes were drilled by cutting the tip of the 5/16 drill into the POP between the cavities along the mold. I then used a utility brush and coated it all with Vaseline, rubbed the brush marks out with my finger. I mixed the white Mainstay silicone 10-12 oz. with two tablespoons of water, 36 drops of LC red colorant. I pressed the RTV down with a plastic putty knife and put a piece of masonite, smooth side out, on top and pressed it down until some squirted out. It set it 20-30 minutes about 3/4 to about 1 inch thick. I seperated the boards and used a scissor to remove flashing. In the POP side sprue holes were drilled on an angle into the front of the 9" fluke, vents notched with a blade from the tips of the flukes to the outside edge. The two sides are held together with a couple ratchet clamps and it is ready for injection.

The sprue was drilled first with a small drill from the inside out then from the outside with the larger drill down to a reasaonable proximity to the edge. Therefore the hole is easily plugged with silicon if I want to convert back to a one piece mold.

I will report more when I use this modified mold with a hand injector; likely start a thread about the injectors, converting molds and the fast way to do it.

Edited November 4, 2009 by Piscivorous Pike

[Husky]

Hybrid MOLD-(sounds like a dangerous fungus...) Actually a new way to use this Poorman's RTV.

Using this RTV I modified a POP top pour one piece three cavity mold into a two piece mold; ready for injection in just minutes!

I can't top pour tail flukes because I shake and slop it all over and have to cut off flashing to use the finished product. I wanted to enclose this mold. By making a top I can make a two piecec mold using POP but that means after pouring the plaster seperating it, sanding off protrusions and bad spots, drying it and then coating with white glue. This could take days. RTV could be ready in minutes.

I carefully filled the three cavities with plastisol in two steps, laminate sorta, so I could get them as full as I could and left them in there as masters so as to be able to modify this into a two piece mold. They are flat top 9" flukes with long tail shanks. These are a 7" Fin S with a 2 inch section of a Mr. Twister sluggo grafted into it moving the flukes back. The image shows the 7' Fin S, 5" Creek Town Fluke I want to enlarge, the slug bait, a new slug wearing a Fin S fluke tail and the bottom the new version Fluke.(click to enlarge) The top pour fluke mold was wrapped with 4 boards around it using a little hot glue to hold them in place. Using a drill 4 sets of index holes were drilled by cutting the tip of the 5/16 drill into the POP between the cavities along the mold. I then used a utility brush and coated it all with Vaseline, rubbed the brush marks out with my finger. I mixed the white Mainstay silicone 10-12 oz. with two tablespoons of water, 36 drops of LC red colorant. I pressed the RTV down with a plastic putty knife and put a piece of masonite, smooth side out, on top and pressed it down until some squirted out. It set it 20-30 minutes about 3/4 to about 1 inch thick. I seperated the boards and used a scissor to remove flashing. In the POP side sprue holes were drilled on an angle into the front of the 9" fluke, vents notched with a blade from the tips of the flukes to the outside edge. The two sides are held together with a couple ratchet clamps and it is ready for injection.

The sprue was drilled first with a small drill from the inside out then from the outside with the larger drill down to a reasaonable proximity to the edge. Therefore the hole is easily plugged with silicon if I want to convert back to a one piece mold.

I will report more when I use this modified mold with a hand injector; likely start a thread about the injectors, converting molds and the fast way to do it.

That's pretty inovative. I hope it does exactly what you want it to do, and am anxiously awaiting seeing the end results! One modification I might want to consider adding is to put a rigid backing on the silicone half for stability. Just use straight sealant to glue on a sized piece of wood or other hard substance to it.

Edited November 4, 2009 by Husky

[Gator44]

. I use D2T mixed with alcohol as a sealer.

What is D2T?

Thanks

[Husky]

What is D2T?

Thanks

Devcon 2 Ton Epoxy.

[Piscivorous Pike]

That's pretty inovative. I hope it does exactly what you want it to do, and am anxiously awaiting seeing the end results! One modification I might want to consider adding is to put a rigid backing on the silicone half for stability. Just use straight sealant to glue on a sized piece of wood or other hard substance to it.

The masonite it the rigid backing, it was cut to fit exactly into the "mold box" and when I pressed down on it some excess flashed out the space between it and the box wall. I put is texture side down, slick side out. I used it just for what you said, rigidity. I use two ratchet clamps. Today is the 5th, I should get an injector by UPS today, if I do I test it tonight.

Am pressed for time though and that could hamper the "git 'er done", leaving on my Pike Hunt on Saturday, got 3000 miles round trip to drive, 25 hours one way. Hope to catch up to Shane in Montana. Seems he is "just down the road form my plot up there"! got another member near me down here, Delw!

Husky, you are so enriched with ideas and tinkering I would love to meet up with you some time and swap stories. TU has been a wonderful place of like minds for me.

[rustyman]

If you mix in glycerin, which you can find at the pharmacy instead of straight water your product will mix better. I use five drops of glycerin and one drop black acrylic paint to one ounce of silicone caulk. For big muskie baits I stipple the first layer then spatulat the next. After that I build a box and set the piece inside and pour POP on it. Flip it over and you have your level mold. I love cheap molds.

[Husky]

If you mix in glycerin, which you can find at the pharmacy instead of straight water your product will mix better. I use five drops of glycerin and one drop black acrylic paint to one ounce of silicone caulk. For big muskie baits I stipple the first layer then spatulat the next. After that I build a box and set the piece inside and pour POP on it. Flip it over and you have your level mold. I love cheap molds.

Welcome to the "We Throw Nickles Around Like They're Manhole Covers Club"! Do you use water at all? Got Pictures of the molds and Finished products?

Edited November 6, 2009 by Husky

[Husky]

The masonite it the rigid backing, it was cut to fit exactly into the "mold box" and when I pressed down on it some excess flashed out the space between it and the box wall. I put is texture side down, slick side out. I used it just for what you said, rigidity. I use two ratchet clamps. Today is the 5th, I should get an injector by UPS today, if I do I test it tonight.

Am pressed for time though and that could hamper the "git 'er done", leaving on my Pike Hunt on Saturday, got 3000 miles round trip to drive, 25 hours one way. Hope to catch up to Shane in Montana. Seems he is "just down the road form my plot up there"! got another member near me down here, Delw!

Husky, you are so enriched with ideas and tinkering I would love to meet up with you some time and swap stories. TU has been a wonderful place of like minds for me.

Have a fun and safe trip! I'd love to hook up with you. I'm overdue to visit an Old friend in your neck of the woods. When I do, I'll touch base with you.

Do you ever head south and fish Baha? I hear they have some good fishing there, too.

Edited November 6, 2009 by Husky
Added more stuff.

[Piscivorous Pike]

That's pretty inovative. I hope it does exactly what you want it to do, and am anxiously awaiting seeing the end results! One modification I might want to consider adding is to put a rigid backing on the silicone half for stability. Just use straight sealant to glue on a sized piece of wood or other hard substance to it.

Does it work? Yes and no. I had an injector made for me, it just arrived. Have to say it is not much different from my DIY. The turkey injector would work for me! Delw and Bear injectors will work for me too. Next is what I found out in a short experiment with the Hybrid Mold.

DIY molds have generalized sprues in 2 piece molds and they do not fit straight injector nozzles with a tight seal. Some of my sprue holes are divided between the two pieces of the mold, others lie entirely in one side as with the hybrid. DIY molds do not seal against pressure and it is too easy to over fill and pressurize the cavities. The RTV side flexes when over pressued and over filled and you get flashing. You need more than two clamps on a long mold, the creature in this case is 9". There is a lot of flex in the RTV side.

I ran out of time to experiment. The injector came with the wrong dimension on the nozzle and I had to cut the diameter down, not difficult but I have no more time to touch it.

I believe the fix is to notch in a vent in the POP side, or cut the vent in the other molds of different media this same way, at or near the junction area of the sprue hole and lure cavity. Have the mold set securely so you cannot knock it over. Use two gloved hands on the injector and fill until you see the new sprue area vent spurt. This is the projects way of saying WHOA, STOP, HOLD IT! It is full.

The poorman's RTV hybrid mold and all RTV molds had a lot of flashing because of the flex of the RTV under pressure. I assume that occures after they reach full capacity. If they flex and allow flashing before over filling this system is not going to work. From what little I did see I think if I stop over filling the molds it would be ok, I did not see flashing on underfilled cavities.

For the moment, since it is the most time efficient way, I will convert all my remaining one piece molds to two piece molds using the RTV in the hybrid because they can be ready to pour in minutes as the modified silicone sets so fast. If I make two piece molds from now on I will make them with POP as I can make both top and bottom in a 24 hour period and dry them out at the same time . Two piece molds made with this modified silicon have a lot of flex and you must fiddle with two or more clamps and get even pressure to close them up.

There you have it. I will continue to use this RTV conversion, it works. I will also use it for top pour one piece molds.

[rockylinx]

Hello Everyone,

I found the original guide that was posted by redg8r. He was the guy that originally posted a how-to guide for 100% silicone molds. I noticed redg8r is no longer a member, I hope he doesn't mind.

If you want it just email a request to

Powechko@msn.com

[Husky]

Hello Everyone,

I found the original guide that was posted by redg8r. He was the guy that originally posted a how-to guide for 100% silicone molds. I noticed redg8r is no longer a member, I hope he doesn't mind.

If you want it just email a request to

Powechko@msn.com

It's readily available in the Soft Bait tutorial section. http://www.tackleunderground.com/community/index.php?app=core&module=attach&section=attach&attach_id=2392

I think RedG8r is still on the board!!

Hello Everyone,

I found the original guide that was posted by redg8r. He was the guy that originally posted a how-to guide for 100% silicone molds. I noticed redg8r is no longer a member, I hope he doesn't mind.

If you want it just email a request to

Powechko@msn.com

It's readily available in the Soft Bait tutorial section. http://www.tackleunderground.com/community/index.php?app=core&module=attach&section=attach&attach_id=2392

I think RedG8r is still on the board!!

[orlando]

thanks a million man, excuse me for mi writing mistakes, i´m portuguese and mi english isn´t that good, but i just wanna say thanks for helping me saving 50 euros (more or less the same in dolars).

silicon to make molds is rather expensive and hard to find around here, in fact i´ve been looking for it just about two years now, and i onli found out how to guet it yesterdai, but the price ...

i´m goig to tri out your thecnique to make a lead jig head , i just hope it can take melted lead without melting itself.

[Husky]

Silicone sealant will not stand up to the heat of lead for very long. Make sure all the moisture has escaped the silicone! If it doesn't work for you, try making the jig mold from Auto Body Putty, brand name Bondo, here. I've had good success with that.

[orlando]

Silicone sealant will not stand up to the heat of lead for very long. Make sure all the moisture has escaped the silicone! If it doesn't work for you, try making the jig mold from Auto Body Putty, brand name Bondo, here. I've had good success with that.

it worked!!!

the final result has some problems , i didn´t mind with the air bubles, so it has a lot of imperfections, i used a lure to copy the head but , the details ,like the guils and eyes didn´t came out perfect.

now i think its a mather of practice to reach perfection.

thanks for the tips

[Husky]

it worked!!!

the final result has some problems , i didn´t mind with the air bubles, so it has a lot of imperfections, i used a lure to copy the head but , the details ,like the guils and eyes didn´t came out perfect.

now i think its a mather of practice to reach perfection.

thanks for the tips

Here's some Bondo jig molds.Check the details. Im keeping with the theme of the thread, these Bondo molds cost less than a buck, too.

Edited December 8, 2009 by Husky

[orlando]

thats a good idea to, and it seames the result as better details and less imperfections.

i wonder if i can make hard baits and soft lures with both of these tipes of molds (bondo or silicone)??

[Husky]

thats a good idea to, and it seames the result as better details and less imperfections.

i wonder if i can make hard baits and soft lures with both of these tipes of molds (bondo or silicone)??

Bondo molds need to be perfectly symetrical with no undercuts for jigs and hard baits, and will need a good MR, It works well with soft baits if you use soft masters,

Sealant silicone works best with squish 1/2 rd baits, molding silicone works be$t for both hard and soft baits but is expen$ive, Dow Corning 3120 red RTV will work with lead as well as hard and soft baits.(Appx. $25 an lb.) There are ways to extend it that were mentioned in this thread.

[orlando]

Bondo molds need to be perfectly symetrical with no undercuts for jigs and hard baits, and will need a good MR, It works well with soft baits if you use soft masters,

Sealant silicone works best with squish 1/2 rd baits, molding silicone works be$t for both hard and soft baits but is expen$ive, Dow Corning 3120 red RTV will work with lead as well as hard and soft baits.(Appx. $25 an lb.) There are ways to extend it that were mentioned in this thread.

since i´m new in this lure making and my inglish is a bit poor , can you tell .e what his MR and RTV?

[Husky]

since i´m new in this lure making and my inglish is a bit poor , can you tell .e what his MR and RTV?

MR = Mold Release and RTV = Room temp. Vulcanizing

since i´m new in this lure making and my inglish is a bit poor , can you tell .e what his MR and RTV?

MR = Mold Release and RTV = Room temp. Vulcanizing

[orlando]

THANKS

[TBaits]

Hi Newbie to bait making, but not new to silicone and making molds, etc. because of my former taxidermy career. I can tell you that we make a lot of molds and use a lot of silicone in the taxidermy profession. I can tell you that if tube silicone gets too thick it will not cure all the way through. Looks like with the molds for what I plan to make and others here have made that it will work fine. I was hoping that the use of silicone would be brought up.

Thanks for the tips in this thread!

Tom