Re: PR and the cold

[Marko50]

No doubt, this kind of question has been answered before, but I can't find it in the library:

I use Alumilite extensively, but have a need to do some PR work. With the cold temps, can I just bring my pressure pot in the house, let it get to room temperature and run the air-hose to it from my shop?

I know it's pretty stinky stuff but I only have a small pour to do. I store the PR in a utility closet inside my home and it will already be to room temp. Will it work to mix it quickly inside, pressure pot it inside for 12-24 hours?

Thanks in advance for any help folks.,

Mark

 

[robutacion]

No doubt, this kind of question has been answered before, but I can't find it in the library:

I use Alumilite extensively, but have a need to do some PR work. With the cold temps, can I just bring my pressure pot in the house, let it get to room temperature and run the air-hose to it from my shop?

I know it's pretty stinky stuff but I only have a small pour to do. I store the PR in a utility closet inside my home and it will already be to room temp. Will it work to mix it quickly inside, pressure pot it inside for 12-24 hours?

Thanks in advance for any help folks.,

Mark

Mark, I don't know that temperatures you are experiencing and particularly, the temperature where you normally do your casting but, using PR, you can work it it temp not exceeding 35°Celsius (I done it many times in Summer) so, I doubt that inside the house you will have such high temps so, the only thing that you have to consider is the normal amount of time you have to work with it and the slightly reduced amount of time when above you normal working temps.

I see no problems, if you get you mixes done, poured and in the pot within 20 minutes or so, after that, the pot slightly higher temp, will accelerate the resin setting time and I don't think that you will need more than a overnight waiting time, to get your mold(s) out to solidify/dry the top sticky surface, this when most of the smell, will come from...!

Best of luck...!

Cheers
George

 

[79spitfire]

Well, here is my experience....

I tried casting some with the temps in the shed in the 40F range (4C or so) using the same hardener ratio I was used to when it was more like 90F (32C) It took several days to cure, but it did cure. The next time I ran the heater in the shed and got it up to 70F (barely). Much better, but still several hours. The next time I tried placing the poured blanks near a heat source. It didn't work out... Next time it went to 70F out I poured again, but this time I did a test with a higher amount of catalyst. The blanks set with no drama.

I did it again today, with a new heater in the shed where it got up so 80F (27C) and experimented with a couple of different catalyst ratios. All went well and the blanks set up enough to demold in 2 hours. I was having problems with some of the blanks cured this summer in warmer weather, changing shape after turning. I'm hoping the higher amounts of catalyst will make them more stable, but not to the point of being 'chippy' when turning.

Are you embedding something in the PR or just doing 'clear' casting? With PR pressure isn't usually needed unless your needing something exceedingly clear or are trying to make a 'waste wood' blank. PR sets slow enough that it self de-gasses very well (in my experience...)

By the way, the smell of PR hangs about for a while. I brought in some de-molded blanks that still had an odor to show off, and took them back out. I could smell them a couple of hours latter... ):

 

[Marko50]

Thank your for the tips

No doubt, this kind of question has been answered before, but I can't find it in the library:

I use Alumilite extensively, but have a need to do some PR work. With the cold temps, can I just bring my pressure pot in the house, let it get to room temperature and run the air-hose to it from my shop?

I know it's pretty stinky stuff but I only have a small pour to do. I store the PR in a utility closet inside my home and it will already be to room temp. Will it work to mix it quickly inside, pressure pot it inside for 12-24 hours?

Thanks in advance for any help folks.,

Mark

Mark, I don't know that temperatures you are experiencing and particularly, the temperature where you normally do your casting but, using PR, you can work it it temp not exceeding 35°Celsius (I done it many times in Summer) so, I doubt that inside the house you will have such high temps so, the only thing that you have to consider is the normal amount of time you have to work with it and the slightly reduced amount of time when above you normal working temps.

I see no problems, if you get you mixes done, poured and in the pot within 20 minutes or so, after that, the pot slightly higher temp, will accelerate the resin setting time and I don't think that you will need more than a overnight waiting time, to get your mold(s) out to solidify/dry the top sticky surface, this when most of the smell, will come from...!

Best of luck...!

Cheers
George

Thank you for the tips George! It's much appreciated!

 

[Marko50]

Well, here is my experience....

I tried casting some with the temps in the shed in the 40F range (4C or so) using the same hardener ratio I was used to when it was more like 90F (32C) It took several days to cure, but it did cure. The next time I ran the heater in the shed and got it up to 70F (barely). Much better, but still several hours. The next time I tried placing the poured blanks near a heat source. It didn't work out... Next time it went to 70F out I poured again, but this time I did a test with a higher amount of catalyst. The blanks set with no drama.

I did it again today, with a new heater in the shed where it got up so 80F (27C) and experimented with a couple of different catalyst ratios. All went well and the blanks set up enough to demold in 2 hours. I was having problems with some of the blanks cured this summer in warmer weather, changing shape after turning. I'm hoping the higher amounts of catalyst will make them more stable, but not to the point of being 'chippy' when turning.

Are you embedding something in the PR or just doing 'clear' casting? With PR pressure isn't usually needed unless your needing something exceedingly clear or are trying to make a 'waste wood' blank. PR sets slow enough that it self de-gasses very well (in my experience...)

By the way, the smell of PR hangs about for a while. I brought in some de-molded blanks that still had an odor to show off, and took them back out. I could smell them a couple of hours latter... ):

Thanks for the tips George! It's much appreciated. To answer your question, yes, I'm embedding items and the pour needs to be clear. I've done one PR pour last summer, and I concur with the stinky molds!

 

[FidemScit]

I cast all of my resin in my outdoor shed. I have a small portable Mr. Buddy heater that I run for at least an hour before I start and let it run for at least 5 hours after I cast. Personally I don't know if it can be done, but I have never attempted casting PR in a dry environment that isn't at least 65 degrees with a max of 90 degrees.