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Husky

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

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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

Water is a catalyst that makes it cure in its' entirety. If you mix it well, it will cure despite its' thickness. Keep us posted on your experiences.

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The Hammer Mechanic's plan was put to good use. I ran out of RTV and made a clam shell type mold in two layers. The last layer was DAP clear RTV silicon sealer, I put some into a cut off disposable plastic cup, ran water over it, poured the water off, gave it one shake, mixed it the used it.

While developing an RTV system, new way to put old tricks together to make soft plastic, (I promise a tutorial) I stumbled into an idea for making the mold form, possibly an unexpected conclusion and at the least side effect discovery of my experiment.

This is it, an end result is a pyramid shape clam shell in the round mold. By suspending the lure to be copied on pins only enough RTV to cover it, even if only partially, is necessary. Then the bulk can be water RTV. Both my two part RTV and the DAP silicone were translucent Clear.

Lures from pyramids; I think I will make my RTV molds in a three sided molds, the point is at top. I use glossy cardboard from boxed retail items. I cut pieces and put the joints together from the back with duct tape, sometimes locking joints with hot glue if I am going to pour POP or DWP. A swabbing of the glossy cardboard with Vasoline releases it.

I had some extra RTV. I suspended a minnow bait on strait pins but had not enough RTV to cover the minnow, the tail stuck up and I could only get a skin on it. After it set up I cut a slit to the minnow and to the hook slot and then inserted the hook slot plate. The RTV barely covered the belly. I should have done that at first but forgot. I bent taps opposing each other accross the aluminum plate. Silicone doesn't stick to much of anything so the tabs lock it in.

The watered DAP silicon was worked onto the bottom of the mold by a small piece of the glossy cardboard was used as a trowl, it was swabbed with Vasoline. The RTV was smoothed out and pressed down. At this point a hard bottom like aluminum plated or fiber board could be used as a base and pressed onto the water cured RTV. This mold is stiff enough with out it. The two part RTV is shore 27A,. (shore is a measurement of stiffness and resiliancy)

After setting, it took under and hour, I cut a slit accross the minnow from behind the head to the tail paddle on the top peak of the pyramid. A "T" cut was made at the paddle. At the highest point of the minnow a cross cut was made to pour in, the sprue about a half inch long. In the photo you cannot see the slit very well, only the sprue because it closes so tight.

The mold is kept closed with a rubber band rapping before and after the sprue two crossed bands going end to end to make sure the T stays closed.

The pour is into the tail first, I tip the mold, once filled then filled flat, tip to the nose and a couple squeezes burps it for a final drop or two. After hardening it pops right out. This piece gets a dip in molten clear for top coat. Pouring the tail first, then the belly then the head can make bicolor or tricolor laminate baits with this type of mold.

What you see is an experiment with remelted baits, hard, soft, burned and all goofed up plastic but good enough to test a mold. The mold works. It is a clam shell type and makes a bait in the round, the sprue in this style is in the middle of the back and is clipped off.

PLEASE CLICK THIS THUMBNAIL PICTURE FOR A BETTER ENLARGEMENT, can' see anything in the thumb!

mold2.th.jpg

I am a hobbyiest, so my methods are for convenience, not production efficincy, yet this seems to me an efficient design.

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I found yet another use of the water catalyzed RTV! Husky, you started an epidemic.

I make a lot of POP and DWP molds and throw a lot away, I experiment with ideas on baits and mold making, buy POP in 25# sacks.

Both POP and DWP molds I shake down the liquid as best as possible, still get pocks in the mold. Air bubbles are terrible. Some too big to seal, or too many in a cluster for Elmer's. I use Elmer's yellow wood glue, it gets a shiny surface. Also I have drilled holde in molds I regreted drilling afterwards.

I mix some clear silicone with water and using a cotton swab massage the RTV into the pits, pocks and holes. As it sets you can smooth it with a little saliva on a cotton tip, better than plain water. One mold I made from a defective model and did not notice the divet in the model until after the mold was complete. I filled the divet this way too.

It easily an smoothly repairs these damages on the molds.

OK, someone, tally up the different ways we have applied this fast set RTV too, how many are there?

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I'd just like to say thanks for the info on this. After reading this thread, water cure RTV was the 1st molds I made. Here are a few tidbits that might help others:

- No Mainstay white 100% silicone at my local Walmarts.

- Used the DAP equivelent. Works fine, but runs $4-$5 a tube in local area.

- I used soft plastics as models, with some success.

- Plastics that were on the hard side, originaly made from pour type molds, came out OK.

- Plastics with soft details, like zipper worms, get twisted and pushed away by the compressed silicone.

- Putting a skim layer of pure silicone on model, did not fully cure for me. Using water cured, dye added, silicone did.

- Closed cell foam insulation worked fine for mold framing.

- Also was able to gouge out and use for permiment frame for small models. (see below)

- Be patient, and expect a few scrap molds in the learning process.

Plastics4.jpg

Thanks again for the great info, and hope a couple of my tidbits helps some other newbies.

John

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Husky great thread!, it deserves a bump up. I finally got a chance to try it. I talked to a few others that have did this as well and have gotten some great tips.

I have a question and need a oppinion from anyone that does this stuff.

So, first mold made, and I need to improve it. I did it as a whole one piece and I don't like the flat top to the bait, it is a full round bait

the bait im wanting to reproduce for me and my son is 5/8 round and 3.5 inches long, very simple. Its a walk the dog style and is all plastic. it has a hook relief in it on the bottom. it also set up for eyes and its a dipped over.

I used the bait product as a copy, and it twisted on me when i pushed it in, or when i compressed the silicone down.

my question is should i stick with a whole one piece mold or consider a two piece mold?

if its a two piece consideration should i simply mold it in whole form and then after cure time just cut it in half straight down the middle, is it that simple?

or make a side at a time, if so how would you go by this so it can be a perfect match, this bait is round with eyes and a hook slot.

I'll stop there for now.

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Husky great thread!, it deserves a bump up. I finally got a chance to try it. I talked to a few others that have did this as well and have gotten some great tips.

I have a question and need a oppinion from anyone that does this stuff.

So, first mold made, and I need to improve it. I did it as a whole one piece and I don't like the flat top to the bait, it is a full round bait

the bait im wanting to reproduce for me and my son is 5/8 round and 3.5 inches long, very simple. Its a walk the dog style and is all plastic. it has a hook relief in it on the bottom. it also set up for eyes and its a dipped over.

I used the bait product as a copy, and it twisted on me when i pushed it in, or when i compressed the silicone down.

my question is should i stick with a whole one piece mold or consider a two piece mold?

if its a two piece consideration should i simply mold it in whole form and then after cure time just cut it in half straight down the middle, is it that simple?

or make a side at a time, if so how would you go by this so it can be a perfect match, this bait is round with eyes and a hook slot.

I'll stop there for now.

If you're dealing with a complex soft model, I would say, the very best way to make a 2 part mold using conventional molding RTV...BUT for the sake of frugality, you can greatly reduce costs by using less expensive Sealer RTV in conjuction with the molding RTV.. RTV uses appx 20 gms per sq in. Knowing that, you can mix just enough to cover the model. When that sets, fill the rest of the mold box with the caulking/water mix. It will extend your RTV by 2 to 3 times, or more! Plus, molding RTV will yield terrific rendition and results. MicoMark sells a real easy to mix, 1 to 1 molding silicone.

Piscivorous Pike has a few posts about making 2 Pt molds making in this thread, I believe.

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Ok I guess I am a plum idiot :) I decided to make a rtv mold today I made 2 attempts and failed out about $15 on silicone but wasted a lot more on other thing that did not work out. I went to wally word bought several tubes of rtv mainstay branded silicone in white. Here is what I did I added 1/2tsp of water to 20 oz of rtv mixed and placed in a pyrex rectangular shallow dish i did this really fast before I could pour my baits I was wanting to clone the rtv was already setting up too fast. Next tried to pour the rtv over the baits while positioned laying in the pyrex dish and rtv would not flow egnough around the bait I am at a loss I read a lot here and apparently I am missing something is POP easier to pour over plastic worms. I wanted to duplicate a popular swim worm for personal use...

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It hasn't flowed easy for me CR, I used a putty knife for this but i believe if its a one piece mold you should be filling up the box first with silicone and then plunge the bait in.

Mine went great except im convinced that the bait twisted on me when i compressed the silicone.

I mixed it like Husky said, what I did was layed out the amount of silicone on a tinfoil covered 1X4, sprayed a coat of water over it and I added two drops of bait color blue, mixed it well ntill there was no white color left except blue, then i sprayed over the silicone one more time. I will stick to this process cause it worked very well and friendly. my issue is making my mind up on a one pc mold or two?

The other thing is the bait i was copying i found out it is foam dipped in plastic, so im stumped on how i pour a plastic bait and make it super floater, I've got a idea i will challenge myself at tomorrow.

I myself will not walk away from this silicone stuff just yet ;)

Husky thanks on the reply and yes I have read all the threads in here, and actually talked to PPike. im just stuck on should it be a one pc or two pc, but now Im held back on figuring how to get plastic to float like foam, instead of buying expensive foam to practice with <_<

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Husky- P/P and others- I don't dabble in this stuff but this is an amazing thread, chock full of info and inniovation - great to see guys sharing small pieces of information, which will eventually result in the perfection of a cheap/ no rip off, silicone moulding process which could be used in all sorts of baits, I think!!!!!!!!!!! I hope.!!!!!!! Great read. Pete

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Husky- P/P and others- I don't dabble in this stuff but this is an amazing thread, chock full of info and inniovation - great to see guys sharing small pieces of information, which will eventually result in the perfection of a cheap/ no rip off, silicone moulding process which could be used in all sorts of baits, I think!!!!!!!!!!! I hope.!!!!!!! Great read. Pete

Thank you, but Husky should get all the credit, I just following in his steps. He sure has helped me get the most from my RTV.

I used the water mixed RTV as filler in a few of my RTV molds, I found that it floats in the two part RTV, a little innovation and caution though solves that problem.

A hint for the folks working with it now. When I skinned a big bait I was copying I allowed that to set up quite a while before I added the water mixed RTV, then I did not have a problem of that layer not setting up. When using it with two part RTV, make sure it is set before adding the two part or it might not set up as it will get sealed in. I had that problem, I had to cut into the un-set portion to expose it to the air.

On one piece molds I glued the models down and then I could press the water mix RTV into it without distorting the model.

On two piece molds I pushed the model into the top of the water mixed rtv. That became the inside of one half of the mold. After setting I painted it with Vaseline all over and then added the top layer. I have made a sprue piece and set it with the bait I was copying. I put a lump or two on top of the surface to make indexing points for the second half to mate up with.

It works, but RTV two part is much nicer to work with. I dont worry about the cost as it is a hobby and fun and entertainment sometime is not cheap. This is wholesome and mentally stimulating so I dont mind the cost.

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hey Pike, i worked out a hollow body rtv mold on that bait im wanting(it worked!!!), im redoing a better quality mold(hopefully) and when finish i'll post a pic of it with detail of what i used, thanks again Husky, Pike and all

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two piece silicone mold, made 2 of them.

as you can see i poured them and for now I'm using a alan wrench for the hollow filler.

media1-2.jpg

only thing i still have to work out is the air pockets at the top, i still get a few. I placed two vents, one on each end and it dramatically helped but still a few more tweaks

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

I wish you'd point out where in the posting you mentioned brand and product. What's up with you e-cons? I've read your post like five times

and I don't see it mentioned at all.

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Post #23 for sure, a few other places...maybe the 6th time...Its all there. Good luck it is a great way to use the silicone for other projects beside molds too.

Wal-mart in the Paint department. They usually have a rack of caulking. It is a full caulking tube full. It is in there with all the other brands, $2.97 a tube, Mainstay brand, Walmart's generic brand.

But only the white works worth a darn and even better with a few drops of Plastisol coloring added to it for some reason.

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[/size] I wish you'd point out where in the posting you mentioned brand and product. What's up with you e-cons? I've read your post like five times

and I don't see it mentioned at all.\

Here you go.

If that doesn't work search this topic for "mainstay"

What the heck is E-con?

Edited by Husky

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Blatz, it would probably help a lot if we knew where you are from. Pangea although mildly amusing (not), just does not cut it.

My guess would be that just about every DIY store in the USA sells silicone sealant. But not all silicone sealants are the same (page 2, post No26, Husky). The correct sealant will smell of vinegar. Of course, you cannot open the tube for a sniff, so read down the small print on the label and look for 'acetic acid'. You can then buy with confidence.

I too am curious what an e-con is.

Dave

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I was using some clear DAP 100% silcone for a job, and tried adding some water to some extra silicone on the side.

Bingo!! Amazing. It set up in 5 minutes! And, to think, I've been waiting 24 hours for it to cure all this time!

I've been using GE silicone ever since it became available commercially, after GE developed it for NASA, and I never thought to use water as an accelerant.

I sprayed some water on the siicone I was using to attach aluminum screening to a sst frame, and it set up much faster, too.

What is it they say about an old dog and new tricks? :lol::lol::lol:

Edited by mark poulson

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Thanks to this post I was pouring within days as a first timer, all with materials I already had with the exception of the silicone. I re-melted old baits just to go through the process to see what I was getting myself into. I made a half dozen molds in one day, I'm officially addicted to this ALSO. Genius little idea. My very first mold is still the best one so far. I wasn't sure exactly how much water to put in, so I naturally over did it, so I had to put the silicone in the mold VERY quickly. I sprayed my jig cavity with Pam and after I dumped the silicone in the cavity I sprayed the plastic mud scrapper i used to mix it with pam also and nothing stuck to it making it very easy to smooth the silicone out and relatively evenly at that in the cavity. I chose to place my trick worms in by hand in the silicone to make sure they laid out straight and gently pressed them in the silicone by hand and then placed a wood block in the cavity that I pre cut on top of them and lightly pressed it in placed and put a fews weights on top while it dried. I still need to tweak the water, but this is great. My only question is does the strong silicone odor on the mold ever fade away? (particularly underneath the mold) I wear 3m masks etc but should I be wearing gloves when handling the dried silicone or just until it completely cures or something? Silly question I'm sure...

Thanks guys!

:)

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Thanks to this post I was pouring within days as a first timer, all with materials I already had with the exception of the silicone. I re-melted old baits just to go through the process to see what I was getting myself into. I made a half dozen molds in one day, I'm officially addicted to this ALSO. Genius little idea. My very first mold is still the best one so far. I wasn't sure exactly how much water to put in, so I naturally over did it, so I had to put the silicone in the mold VERY quickly. I sprayed my jig cavity with Pam and after I dumped the silicone in the cavity I sprayed the plastic mud scrapper i used to mix it with pam also and nothing stuck to it making it very easy to smooth the silicone out and relatively evenly at that in the cavity. I chose to place my trick worms in by hand in the silicone to make sure they laid out straight and gently pressed them in the silicone by hand and then placed a wood block in the cavity that I pre cut on top of them and lightly pressed it in placed and put a fews weights on top while it dried. I still need to tweak the water, but this is great. My only question is does the strong silicone odor on the mold ever fade away? (particularly underneath the mold) I wear 3m masks etc but should I be wearing gloves when handling the dried silicone or just until it completely cures or something? Silly question I'm sure...

Thanks guys!

:)

The silicone will only hold a small amt. of water and the excess will run off, so don't concern yourself about metering the water.

The odor is the acetic acid escaping as the silicone cures. The smell will most definitely disappear in a short time. ONE member here said he felt a burning sensation when he touched water that was standing on the mold for a while, but to date I've never experienced any issue with the acid that is built into the silicone. You are more than careful in regard to the precautions you've taken.

Once the silicone is cured, no gloves are needed but if you're pouring hot plastic, it may be wise to wear the gloves as protection from the hot plastisol.

Mike P

I'm heading back onto the roof for more chimney repairs so Good Luck and post some pics. TIA

Thanks to this post I was pouring within days as a first timer, all with materials I already had with the exception of the silicone. I re-melted old baits just to go through the process to see what I was getting myself into. I made a half dozen molds in one day, I'm officially addicted to this ALSO. Genius little idea. My very first mold is still the best one so far. I wasn't sure exactly how much water to put in, so I naturally over did it, so I had to put the silicone in the mold VERY quickly. I sprayed my jig cavity with Pam and after I dumped the silicone in the cavity I sprayed the plastic mud scrapper i used to mix it with pam also and nothing stuck to it making it very easy to smooth the silicone out and relatively evenly at that in the cavity. I chose to place my trick worms in by hand in the silicone to make sure they laid out straight and gently pressed them in the silicone by hand and then placed a wood block in the cavity that I pre cut on top of them and lightly pressed it in placed and put a fews weights on top while it dried. I still need to tweak the water, but this is great. My only question is does the strong silicone odor on the mold ever fade away? (particularly underneath the mold) I wear 3m masks etc but should I be wearing gloves when handling the dried silicone or just until it completely cures or something? Silly question I'm sure...

Thanks guys!

:)

The silicone will only hold a small amt. of water and the excess will run off, so don't concern yourself about metering the water.

The odor is the acetic acid escaping as the silicone cures. The smell will most definitely disappear in a short time. ONE member here said he felt a burning sensation when he touched water that was standing on the mold for a while, but to date I've never experienced any issue with the acid that is built into the silicone. You are more than careful in regard to the precautions you've taken.

Once the silicone is cured, no gloves are needed but if you're pouring hot plastic, it may be wise to wear the gloves as protection from the hot plastisol.

Mike P

I'm heading back onto the roof for more chimney repairs so Good Luck and post some pics. TIA

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Husky said, "I'm heading back onto the roof for more chimney repairs so Good Luck and post some pics. TIA"

Getting ready for Santa already, or making repairs from his last visit? :)

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First off thanks to all of the great ideas here, they have all helped a bunch. I plan on trying to use this to make worm molds for catfish worms. (Dip Bait Worms). I even thought about trying the silicone as the casting agent. But really wanted to say thanks for all the time and effort that everyone else has put into the forum so that it makes it a little easier for the rest of us.

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I even thought about trying the silicone as the casting agent.

I had one go at this idea, as I cannot get the plastics the soft plastics guys use in USA. I tried it in a PoP mold that I made very quickly. Maybe I did not seal it enough, but the silicone stuck so well to the surface of the mold, I could not remove it without destroying the mold.

I intend comming back to this idea, as I think that this silicone material has potential as a bait. Next time I will experiment with release agents and obviously seal the PoP better. Thinned D2T might be a better option, I used Elmers last time.

If you do try casting silicone, please post back what you try, success or failure, so we can learn. Thanks.

Dave

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I had one go at this idea, as I cannot get the plastics the soft plastics guys use in USA. I tried it in a PoP mold that I made very quickly. Maybe I did not seal it enough, but the silicone stuck so well to the surface of the mold, I could not remove it without destroying the mold.

I intend comming back to this idea, as I think that this silicone material has potential as a bait. Next time I will experiment with release agents and obviously seal the PoP better. Thinned D2T might be a better option, I used Elmers last time.

If you do try casting silicone, please post back what you try, success or failure, so we can learn. Thanks.

Dave

Dave,

Use a MR on the POP. Butcher Block Wax (paste wax)works great.

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New to this board and lure making in general. I have been playing around with silicon molds for the past couple of days and this is what I've found. First off, the Walmart where I live does not carry Mainstay Silicon but another brand called ColorPlace. I have been using the white version as recommended by Husky. As for it's ability to cast an object, this stuff is really amazing. It accepts and releases plastic very well and the quality of the mold is very high. One limitation I have encountered is the amount of bubbles or air pockets you experience. Another thing I have noticed is that the amount of water you add will impact the texture, smell and volume of silicone in your end product.

For example, the first mold I cast was, like I said, my first mold. I was very excited and couldn't wait to see the finished product. I layed out som silicon, added water( no specific amount) and started turning with a puddy knife. As soon as the water contacts the silicon, you will get a white vinegar smell. Less than a minute into stirring, you will notice the silicon getting fluffy and tighter. At that point I place it in my coffin, pushed in a lure and let it set. With the exception of air bubbles, the finished product was perfect. I have cast four dozen very acceptable baits.

However, if you add more water as the silicon begins to get fluffy and set, it will keep it in a pliable state for a little while longer. When it begins to harden again, just add more water and it will stay pliable. Two things I noticed after doing this three times is thatn the smell of vinegar is lessened and the silicon seems to shrink. The amount of silicon I had at the end of this experiment was considerably less than when I started. Also, it's texture seemed to change in that it had become more supple, like silly puddy and it does not cure as quickly.

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