dramone

Rock Puddy / Foam mold release

17 posts in this topic

Hola

i wanted to make some new baits with rock puddy molds instead of rtv-silicone which should be used with polyurethan foam.

the puddy mold was "seald" with epoxy, a silicone based mold release was applied, but the 2 parts of the mold where "glued" togehther and the "bait" was unusable :pissed:

before wasting any other puddy molds which i allready made, what do you use as mold release??

what about WD-40 or vaseline?

your help is much appreciated

RTV vs. putty1.jpg

RTV vs. putty1.jpg

RTV vs. putty1.jpg

RTV vs. putty1.jpg

RTV vs. putty1.jpg

RTV vs. putty1.jpg

RTV vs. putty1.jpg

RTV vs. putty1.jpg

1957_thumb.attach

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I use Johnson's Paste Wax with excellent results on my Bondo Molds, casting Foam. Lay on a couple of coats, inside the cavities and out, wiping the dried wax with a clean cotton cloth and you'll be good to go.

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What is that Husky? Where might I find some?

Generally speaking Dramone you will have better luck using a soft flexible material like silicone while molding something rigid like foam. Soft materials on the other hand like soft plastic lures can be easily molded with rigid molds like those you built with the putty.

RM

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What is that Husky? Where might I find some?

Generally speaking Dramone you will have better luck using a soft flexible material like silicone while molding something rigid like foam. Soft materials on the other hand like soft plastic lures can be easily molded with rigid molds like those you built with the putty.

RM

Most hardware stores carry it, as well as Walmart. It's a wax used for wood and floors. It used to be a house hold standby. It comes in a can.

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@ HUSKY

THX for your help! the jonson wax, is it a syntethic or bee wax?

any way, i'l give it a try!

@ RiverMan

rtv-silicone is kind of expensive over here (1 liter = 38 swiss franks excl. shippment = 31u$ per 0.264 us gallon). so for bigger baits, I wanted to use puddy to "substitiut" the silicone. better cost efficiency...

But thank you anyway...my be i'll switch over to urethan rubber...

let's see how the puddy will perform

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@ HUSKY

THX for your help! the jonson wax, is it a syntethic or bee wax?

any way, i'l give it a try!

It's been around for 100 years. Look at the ingredients of the waxes that the mold supply companies sell. Any pure Canuba based wax should work. FYI, cover the whole mold with it.

@ RiverMan

rtv-silicone is kind of expensive over here (1 liter = 38 swiss franks excl. shippment = 31u$ per 0.264 us gallon). so for bigger baits, I wanted to use puddy to "substitiut" the silicone. better cost efficiency...

But thank you anyway...my be i'll switch over to urethan rubber...

You can stretch out the silicone by applying a thin layer over the model and then using Commercial 100% Silicone Caulk , mixed with water to fill the remainder of the mold. Mold Making Silicone costs as much here in the US as it does for you. The Silicone in the tube costs $5 for 10.5 oz. It comes in Clear, Whire and Black. Black is inferior to the other two. See this.

let's see how the puddy will perform

IT must be 100% Silicone. BTW, Silicone is by far the best way to go when casting Urethane, etc. No MR is necessary and you can spray the cavity with paint. Once it dries, cast your model and it will come out of the mold with a base coat!

Mike P

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Dear Husky

thank you verry verry much for your help! :worship:

btw what kind of paint do you appley to the rtv mold as base coat for the foam lure? (acrylic ?)...

do you have the "original" tutorial with pic's?

http://www.tackleunderground.com/forum/showthread.php?t=5205

No, but the instructions are pretty straight forward. The Silicone Caulking will only hold so much water so you can't make it too thin.

Michi

Any spray paint. I use rattle cans from Walmart. Technically, the foam is sticking to the paint so the adhesion is remarkable.

BTW, the method I describe to stretch out the Silicone and make it more affordable may require you to cover your model more than once if you're not totally covering it. You want the "Good Stuff" to encapsulate the lure, totally. The thinnest of coating will suffice.

Another thing you can do is make "Filler" pieces, pebble sized from the cheaper silicone and put them in the mold box after you make your initial coat and it cures. Put some good stuff in so the pebbles will have something to grab on to, add the "pebbles", and then use the good stuff to cement it all together. You may only use an ounce where you would have used 4. Once it sets up, it'll be a pure silicone block.

Try a test piece to assure compatibility. Usually, the cheaper stuff will stick well to anything so I'd be more concerned with the Molding Silicone if you're going to use the filler method. Good Luck.

Mike P

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I have Husky's original tutorial, with picures, saved in WORD form. With his permission, I would be happy to email it later tonight.

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I have Husky's original tutorial, with picures, saved in WORD form. With his permission, I would be happy to email it later tonight.

Any of you guys can use whatever I posted here, here. The tutorial he was referring to is one for a clam mold that Redg8tr posted.

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I was thinking it was the bondo mold. My bad. I do have the pics of that one.

I have learned a lot since then.;) I still use Bondo for my metal castings. I should do another tutorial. Truth be told, Silicone is the way to go with urethanes and foams. It's so much more forgiving and it needs no Release agent which means a neater and cleaner casting which is much simpler to finish.

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Dear Husky

outstanding help! :yay: thank you so much!!

i'll try your "filler method" to "stretch" the rtv with Silicone Caulk...

ps: i sent a pm to Redg8tr to see if he still has his fine tutorial with pic's...

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Dear Husky

outstanding help! :yay: thank you so much!!

i'll try your "filler method" to "stretch" the rtv with Silicone Caulk...

ps: i sent a pm to Redg8tr to see if he still has his fine tutorial with pic's...

Remember, the silicone caulk must be 100% silicone. I bought 10.5 oz, locally, today for $2.37 US at Walmart. That's $.23 per oz as opposed to $1.05. That equates to 5 molds for the price of 2.

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Dear Mike

first: THANK YOU

i also went to the store after "walking the dog" and bought 100% silicon caulk...

the first test run is allready curing, with some rtv left overs on top, to see if all is sticking together. i also kept the caulk left overs to use them as "filler" for further molds. thinking about the whole siliconeing process; broken molds "shreded" can be used as "filler" (i'm sure, no news for you)

as soon as the mold is ready, i'll give it a try with paint in the cavity to attach a basecoat directly to the pu-foam (smart hint from you!!)

after comming back from holliday i'll try your mentioned method with a thinn rtv coat first, and filling it up with caulk...

once again, many thanks for sharing your remarkable knowledge with me!

Michi

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Dear Mike

first: THANK YOU

i also went to the store after "walking the dog" and bought 100% silicon caulk...

the first test run is allready curing, with some rtv left overs on top, to see if all is sticking together. i also kept the caulk left overs to use them as "filler" for further molds. thinking about the whole siliconeing process; broken molds "shreded" can be used as "filler" (i'm sure, no news for you)

as soon as the mold is ready, i'll give it a try with paint in the cavity to attach a basecoat directly to the pu-foam (smart hint from you!!)

after comming back from holliday i'll try your mentioned method with a thinn rtv coat first, and filling it up with caulk...

once again, many thanks for sharing your remarkable knowledge with me!

Michi

You're very welcome. I hope the results are everything you hoped for.

I Thank Jerry for giving us such a great place to exchange Ideas, from all over the world!

Mike P

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thank you 1000 Husky

the results are far more then i hoped for!

excellent tips and hints?

i also want to thank TU for the outstanding board :worship:

Michi

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