a couple of PR quesions

[bdonald]

Hey all

Well, I cast my first pr bottle stoppers <hope to post pics later> yesterday. Very basic colors done in pill bottles, figured I'd just get my feet wet before getting too fancy with it. This morning, after about 20 hours, it popped right out of the pill bottle <used pam for release agent>, so I just left it outside out of the bottle to cure. I'm not doing it inside because of the fumes, but as the weather is changing to 60's and 70's during the day, and 50's at night, I'd rather bring it in to finish out of natures elements. How long should I wait before bringing it in so it doesnt stink up the house? Also, how long of a wait before I can start turning it? I saw 24 hrs in the library file, but that's for a 3/4 pen blank, didnt know if the same logic applied. Thanks in advance for any advice

 

[stevers]

I have turned PR after just a few hours. If it is hard, it can be turned. If it's hard on the outside, it's almost certain to be hard on the inside. Providing the PR was mixed thoroughly.
As far as the smell, that could take a week or more. It can depend on the surroundings. It may also be oder free until you cut into it. That question is a little harder to nail down.

 

[JohnU]

It sounds like you have a good grasp on casting. The next step might be a pressure tank. I use mine for two reasons. First the obvious, it takes air bubbles out and the second, its air tight and allowed me to mix outside and place in the tank to bring inside (odor free) to set up. I let it sit overnight in the tank and then usually have to put in a conv. oven for a bit to get the sticky surface smooth. Ive turned blanks after about 4 hours in the summer when its real hot outside. Good Luck

 

[bdonald]

I have turned PR after just a few hours. If it is hard, it can be turned. If it's hard on the outside, it's almost certain to be hard on the inside. Providing the PR was mixed thoroughly.
As far as the smell, that could take a week or more. It can depend on the surroundings. It may also be oder free until you cut into it. That question is a little harder to nail down.

Thanks Steve

I think I'll toss one of them on the lathe tonight, and if it smells too bad, I just throw it back outside. I was just worried about whether the fumes were noxious or not, if there was some kind of mandatory wait period. Since the furnace nor the a/c is coming on now, if it does smell bad, it wont get pushed up from the basement so easily.

 

[bdonald]

It sounds like you have a good grasp on casting. The next step might be a pressure tank. I use mine for two reasons. First the obvious, it takes air bubbles out and the second, its air tight and allowed me to mix outside and place in the tank to bring inside (odor free) to set up. I let it sit overnight in the tank and then usually have to put in a conv. oven for a bit to get the sticky surface smooth. Ive turned blanks after about 4 hours in the summer when its real hot outside. Good Luck

Hi John

Well, I dont know how good my grasp is, but reading your folks posts has really been a big help in that direction! I do plan on a pressure tank as I have big plans for casting <dont we all >, just want to make sure that I have the basic principle down beforehand. I can see where the air bubbles will be a problem with some of the stuff I want to cast. Thanks for the advice

 

[td]

Bob,

You're going to get answers everywhere from 4 hrs to 48 hrs or more. Alumilite sets and cures faster than PR - and even after PR appears to be solid it will not be through its complete chemical-reaction cross-linking process until after a proper cool down period and then still may need a little baking in the sun... oven... whatever. There are so many variables that there isn't one answer that's correct for all environments. So in light of that I'll offer you my little "test"

I tap on it. :embarrassed: The closer I am to "cast time"... the softer the brick... the duller the sound.:music: If I wait 24 hours and tap on it I get a bright, clear, high "plink":musical-note::smile-big: (this is the only word that comes to mind for what I hear).:laugh:
Okay you guys..... go ahead and laugh:rotfl:.... I know it's funny but what the heck.... you asked!!:bananen_smilies035::bananen_smilies051:

 

[DozerMite]

It also depends on what brand PR is used. There is a huge difference between Castin' Craft and Silmar. They each react differently to the colorants, the catalyst reaction is also very different.
The best thing for you to do is take the opinions here and use that as a starting point then figure out a method that works for you. I have my blanks mixed, poured and ready to turn in less than 2 hrs.

 

[bdonald]

I know what you mean Terry, I use sound for alot of determining factors This batch was cast with castin' craft, but I also have a quart of silmar 41, which hopefully I'll get into that next week and see the difference. My pal at Woodcraft told me about a local supplier <and I've been buying wood from him for years without knowing they had silmar>, I guess it's a big item for guys who build boats and surfboards. I'll probably be sticking with that after the CC stuff is gone. Thanks for the info

 

[bdonald]

It also depends on what brand PR is used. There is a huge difference between Castin' Craft and Silmar. They each react differently to the colorants, the catalyst reaction is also very different.
The best thing for you to do is take the opinions here and use that as a starting point then figure out a method that works for you. I have my blanks mixed, poured and ready to turn in less than 2 hrs.

Heya James

Yeah, I am doing that, taking the opinions and working from there, hopefully I wont screw up too bad My main concern was toxicity and smelling up the house, but it sounds like if it spends the better part of the day outside, it should be ok. Thanks