POP molds questions

[Die Hard Custom Baits]

Ok, I'm a newbie to mold making and to the TU. I've read a bit abou the pop mold making process and attempted a couple molds last night, but cracked both of them trying to get the mold out of the pan. The first one I just made too thin and the second I used a very unflexible pan. I have since bought some disposable baking pans to try tonight or tomorrow. My biggest questions are: How much plaster/water to use for the best results. I first did what the instructions on the plaster said(2 parts plaster to one part water) and it was really thick and got hard way too fast. Then I ended up using more water than plaster. I just guessed and winged it. Maybe that is why the molds cracked easier....I don't know. Then I noticed that at least one cavity on each mold(top half) had bubble holes in it. How can I avoid this on my next try? I thought I mixed it well enough, but still got the bubble holes. Last, how long should you let the bottom mold dry before pouring the top? and how long before removing both top and bottom from the pan? I waited about 45 minutes for both. Oh, I just thought of another...do you guys think it would help to grease the pan before pouring the bottom half? Thanks for all the help and hope to learn more from this great forum.

[Travis]

I use a bread pan for my molds typically and don't use any release agent. I shoot for molds to be 1 inch. As far as thickness I like mine to be the consitency of pancake batter or cake batter depending upon the complexity of the bait to be molded. I have never had any problems with the molds setting up too quick this way. I let my molds set for around 12 to 16 hours typically. To demold I just grab the pan and pull outward on the side and then the ends. What I look for is the plaster to "break" away from the sides of the pan. I then place the bread pan upside down over a piece of carpet and depress in the center and the mold falls right out. I have never had a mold break doing it in this fashion.

To avoid bubbles you have a couple options. It is important the bait is flat against the pan if not you often get bubbles. To avoid bubbles "paint" the plaster onto the bait to be molded by just rubbing the plaster on with your finger. If the baits are firmly adheared to the pan I typically just give it a few knocks against the table top to knock any bubbles to the surface. The thinner the mix the easier this is to do but too thin and it can run under the masters. Sometimes just some vasoline smeared over the face of the bait is sufficient to adhear the bait to the pan. You can go back and fill bubbes after the fact, just mix the plaster up thick like toothpaste and overfill the cavity after ten minutes go back with a dull prob, rounded toothpick, chopstick, etc... and smooth it down to the surface.

[bassn1]

I agree with Travis,

The only thing I do different is use vaselene on all sides of the mold so it slides out easier.

[Die Hard Custom Baits]

Thanks for the tips guys. I forgot to mention, I was trying to make a 2 piece mold. Great tip to get the bubbles out though, thanks. I think I just need to let it set for longer before taking it out of the pan. Any tips on the plaster to water ratio?

[nova]

I do mine by feel/eye. I use cold water to mix the plaster( if you use warm water the reaction will start too soon). You don't want the plaster to be too liquid but you don't want it too stiff either(as you already found out).

I don't use vasiline because I find it too thick. I use cooking oil. it soaks right into the plaster so you don't loose any detail. the plaster still separates very nicely.

"Painting" the bait with pop as it sets in the first part of your mold will help with the bubbles; just don't put any oil on the bait itself. A lot of what we call bubble impressions are actually water drops formed in the plaster by too much release agent. We only see the resulting hole once the water is soaked into the plaster. (Remember, water and oil don't mix).

Also, when you pour the pop into the mold, make sure you do it slowly from one corner and let the plaster flow over the rest of the mold.

www.novalures.com

[bojon]

I have used liquid soap in the past.A thin film was all that was needed.It's been awhile,but I don't remember having any problems.This is what we used in high school art class.Long time ago.The last mold I made was about 15 years ago,and was for a special lead sinker for fast water.It worked:),and the sinker worked as planed.The mold was very dry,lead and moisture don't get along.Has anyone tried this soap?

[Kajan]

I do mine by feel/eye.

Ma' Nova, You know not everyone has the talent to do things by feel/eye, Not everyone originated from Nova Scotia

[Die Hard Custom Baits]

Once again, thanks for the tips. I think I was using too much vaseline. I also found it hard not to get it on the bait which is now what I believe caused the "bubbles". I'm gonna try it again today. Maybe, I'll take some pictures and report how it goes. Thanks guys for all the help!

[Die Hard Custom Baits]

I finally got my 1st successful mold out of the pan without breaking it. It's in the drying stage right now. How long should I let it cure if I don't bake it? If I did bake it, do I have to worry about the wood sticks in it? I'll post more pics when it's ready to pour and after the 1st pouring. Thanks for all the help.

Edited November 14, 2008 by dinsane

[bear21211]

Dinsane

Glad you got one out without breaking it. I personally do nt bake mine but rather I let mine cure overnight then I put my sealer on them. I know of those that do bake them for a little while with the oven door open at a very low temp. If I remember correctly it was like 150 degrees for a couple of hours. That temp should not hurt the sticks in the mold. I Think Vodkaman mentioned something about baking them but monitoring the progress by weight of molds.Do a search for baking pop molds and see if you can find the post by Vodkaman

Good Luck

Those Look Great Dinsane!!

Edited November 14, 2008 by bear21211

[nova]

I always bake mine. Never had a problem. Just don't set the temp too high. (150/200)

Molds look good to me.

www.novalures.com

[Travis]

I usually don't bake mine and usually am not too worried about cure time to be honest. I have been using some of my molds for over 5 years now with no ill effects. When I don't let them cure before use I essentially let them cure later if not, mold generally occurs. The backside of the mold will sweat if not cured but can be placed on newspaper or paper towels to take up the moisture. Overall curing is probably the best to avoid mold but still doesn't keep me from using a fresh mold.

[GB GONE]

Looking good!!! I would get rid of the popsicle sticks for alignment on the next set as you will quickly find they are a pain when you start using the mold alot. Use something like marbles in oppsosite corners of the mold for alignment.

Seal them and show us some senkos!!!! Good job!!!!!!

Jim

[Vodkaman]

If you have the patience to cure without baking, then that is best. I don't have the patience, sorry about that. Curing PoP has a temperature limit, google for information. Also, if the molds get too dehydrated, they get brittle. Air drying is always best.

Ghost mentioned the marble idea. Much superior to sticks. You have to consider the purpose of the locators and how they function. I usually just add a couple of blobs of modelling clay, similar result to marbles.

Listen to the experts, I am not one of them, I just post my experiences, as you should do.

Looking good.

Dave

[GB GONE]

PS Never bake mine. Save your gas or electricity and put your molds in your car on a towel or something absorbent. Leave them in the sun on the dash while at work and you will have cured molds when you are heading to the house!!!

Jim

[Die Hard Custom Baits]

Thanks guys. Yeah, I can already tell the popsicle sticks are gonna be a pain in the a$$. The marble idea sounds like the way to go. One more question about the sealer. I used Mod Podge and it looks like I don't really need more than 1 coat. Anyone use this on their molds? And if I use it on the whole mold will it prevent it from drying properly? (assuming I use it before it's completely cured. Oh, is there a good plastic for senkos? The lurecraft plastic that I got floats, so I don't think that would be good for senkos. Any thoughts on that?

I'm not gonna pour any baits yet until I get some more colors and glitter. I don't want to waste plastic on colors I don't like.

[HJS]

dinsane - Others have already discussed most of the tricks of the trade. That won't stop me from babbling on. Here's my tricks. Just today I finished pouring two new 2-piece molds for 4" paddletail Bass Assassins to replace identical PoP molds that are slowly chipping away crumb by crumb. Still needs work to finish it up. Some thoughts:

- I switched entirely to Durham Water Putty (DWP). 3X longer curing time, and I need that bigtime. Gets a little harder than PoP. I add a teaspoon of vinegar (slows setting) and ~3 tablespoons of Elmers glue (extra strength) to 1/2 cup water before adding the DWP one heaping tablespoon at a time between stirring.

- Finished mix should be like runny pancake batter, I stress RUNNY batter. Too thick and tiny bubbles won't rise to the surface and pop.

- Mold cracking: Sounds like you made the same mistake that all newbies make, including me... impatience!!! After pouring the first layer wait 24 hours before pouring the second layer. Then wait 24 hours before separating the two halves. I heat my house with a wood stove. And wood stoves are custom made for quickly drying DWP (under the stove)... same place where the #$% cats stay warm!!! Probably any house heating system should help shorten drying time, just don't try to dry them too hot or too fast.

- After the first layer is dry (24 hours) I'll drill 2 or 3 shallow holes using a 3/8" drill in the flat surface... I stress shallow, just deep enough to serve as alignment markers (see pic). Then pour the second layer... alignment markers are made.

- If you're using a rigid pouring surface then try stretching a piece of kitchen plastic wrap tightly to the pouring surface, no wrinkles, then pour. That'll make removing the hard DWP a lot easier. Probably won't need this if you use a greased bread pan, or something similar. For a base I use a square of 1/8 inch thick, semi-rigid hard plastic used for making signs (see pic). Hard to find a source I guess, but thats what I use. Hard DWP easy releases from lightly greased plastic.

- I use to brush on vasoline using only a course shop brush (10 for $1 type). But that left heavy brush marks of vasoline that was picked up by the DWP. I still use the shop brush but now I smooth out the brush marks in the vasoline using a soft, fine bristled art brush (also 10 for $1).

- I built a little box (see pic) held together by screws to pour the liquid DWP into. The box shown is 1" deep and cut from 100% plastic boards sold at any Lowes. I got mine as scraps from a construction site. A box makes molds that are nicely squared. Unscrew the box and the mold comes right out.

Bubbles - are a royal pain but manageable. With DWP I can mix it runny in a small bowl then let it sit for 5 minutes for bubbles to rise to the top. DWP will give you the extra time before setting up. Tap the sides of the bowl a bunch to quicken the bubble rise. I then use a standard, hand held propane torch, flame set real low, to burn off the bubbles on the surface. Make extremely quick passes with the torch, bubbles instantly gone.

- Once molds are dry, couple of days, I paint the inside of each cavity with a light coat of 30 minute epoxy cut with a little rubbing alcohol to make it a little runnier. Epoxy will fill in tiny bubble holes nicely. I'll generally do another light coat just to be sure its sealed. I go to great length NOT to get any epoxy on either of the flat surfaces of the mold so as not to compromise a completely flush fit.

Tooth pick in master lure is to help in handling an oiled master. The little stubby tooth pick shoved in the nose is to mark the path that will be drilled out for a pour hole. You can see the mark the tooth pick left in the mold (see pic).

The mold pictured still needs to have a pour hole drilled. It also needs a tiny vent slot at the end of the tail. Sealing is the finally step. I use a small hack saw to cut the vent slot. I use the same clamps in the pic to hold the mold halves together for pouring.

And last, spend an extra ordinary amount of time making a mold. Its time well spent. A mold will make a 1000 lures, so make the mold right. My first 3 or 4 molds were a disaster and thrown away. Learn as you go. Most of what I described here I learned from fellow TUers.