Glueing plastics to glass

[HJS]

After a couple of abysmal failures, I thought I would try again to make a 2-part POP mold using six 3" Bass Assassins as masters. ( I got the making of one-piece molds down pat) Knocked together a 4"x7" box, 1' high, and taped it to a pane of glass as a base. Greased up all components with Vaseline to include the glass base. Mixed up the POP like extra heavy cream using ice cold water. Poured 1/2 into the box then quickly started setting in the greased masters. Even though I was working as quickly as possible, the POP had set up too hard by the 4th lure. Man was I p*ssed. Stomped around the house for 15 minutes searching in vain for something good to kick.

After an hour of thinking it over I decided to try again. I disassembled the mold box to remove the ruined, now-hard plaster. I had one HECK of a time trying to remove the plaster from the surface of the glass. Ended up having to break up the plaster with a putty knife. SOOOOO... I'm guessing that glass is NOT a good material for the base, even if its well greased... am I right??? I'm guessing the base material needs to be at least a little bit flexible so that it can be peeled from the hard plaster.

If I try again to make a 2-piece mold I guess I'll need to limit myself to setting in only 3 masters.

Anyone know of a way to slow down the setting time of POP???

[Troul Hawk]

I know you say POP, but are you using Durhams water putty? Or the real Plaster of paris, white stuff.

Durhams has a much more workable setting time, IMO.

[COBRA]

real plaster of paris watered down should flow really easy, dont worry bout to much water make it soupy, it will set up after about 10 minutes and excess h20 will float up and you can towel out.

[HJS]

Trout Hawk - I'm using standard plaster of paris (POP) I bought in a hardware store. Looks like flour. Give me more details on this Durham water puddy. Does it come dry and is mixed with water like POP? Is it available in hardware stores or craft shops? Might give it a try.

COBRA - I mix the POP fairly runny. When I pour it in its almost self leveling. Just 2-3 taps on the side and its flat as a pancake with no excess water on top. I'd think water collecting on top would interfer with the laying in of the masters when attempting a 2-piece mold.

Also, I read in other threads about using a base called lexan? (not sure I have the spelling right) available in hobby stores. Whats that stuff like? Is it flexible?

As a side note. I'm fairly new to this board and it only took me an hour of reading thru the many threads to find out what the heck POP was... and I had been using plaster of paris all along:lolhuh:... how embarrassing was that!!!

Edited June 5, 2008 by HJS

[nova]

I use a marble cutting board (I stole from the kitchen..shhhh) to make my pop molds. I have no trouble getting it off after it sets up. It doesn't come up; like picking up a book from the table; I do have to grab it with both hands and twist it while it's still in the frame, carefully.

I haven't tried spraying the board with Pam before; but I must try that the next time I make one.

www.novalures.com

[HJS]

Troul Hawk - Just found Durham Water Putty at my local hardware store. Directions say to mix with water until its like putty. Question: Can more water be added to make it as pourable as POP?... or doesn't that stuff work that way?

[COBRA]

same as nova, i do also use marble or granite pieces to lay up on. lexan is a type of plexiglass, or clear plastic. i also have used pyrex dishes either inside or on the bottom if flipped over. almost any plastic container works also. i have some pics i should post of a 2 part swimbait mold i just did, i use blue painters tape instead of mold release when i pour the second half.

[HJS]

COBRA - Do you use some sort of release agent on the top of the marble/granite before pouring the POP?

Also, I'd think if the marble was chilled in the freezer 10-15 minutes that the setting time of the POP would be extended... big plus in my book.

Thanks for the info.

Edited June 5, 2008 by HJS

[Troul Hawk]

Yeah, I water it down to thin pancake batter consistency, then bake the water out after it has set up. seal it and your good to go.

[COBRA]

you could use release agent but i find POP to usually not really stick to much because its dry on the surfaces, as long as they are smooth and not porous. i molded my swimbait from a piece of balsa wood untreated and it came right out.

[King Bait Co.]

I use sheetmetal trays I made to pour my POP in. I do spray them down with WD-40 first. I haven't had one stick yet.