catalyzing theory with PR resin

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redfishsc

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I am really about to leap off into casting PR blanks, but I do have a question I'm hoping will save me some money.

How do I know--- or even guess--- at how much catalyst to add? I know it depends on the size of the mold and amount you are catalyzing.


My method will be to mix up two batches (say, one black and one white) for bi-color blanks. Add the colorants, mix well, add the catalyst, mix well.... pour the blanks.


If I am pouring the blanks into 3/4 X 2.5" or 4" PVC pipe molds, how much catalyst would I need to add?

If I were pouring the stuff into a square flat mold (like a sandwich tupperware container size) how much would I add?


Thanks for the suggestions!

Matt
 
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doddman70

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I just did my first round of casts some were round molds and some were in the square sndwich container molds i did the same amount in each one 3 to 4 drops per ounce the casts turned out great in each one. good luck and let us know what you did and how it turned out.

Shane
 

its_virgil

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You don't need to guess. The amount of catalyst to use is well published in several casting forums. In fact, here are two excellent articles on casting polyester resin in out own library.
Read this one first by Jay Pickens: http://content.penturners.org/articles/2005/pr_instructions.pdf
Then this one by Anthony Turchetta: http://content.penturners.org/articles/2005/casting_polyester_resin.pdf

There are other articles which I have not read but may offer information. Then, there are articles on casting ribbons to get various effects and embedding things in the resin glued to the brass tubes.

The amount of resin is not as difficult as some seem to think. I cast in a mold that holds 16 oz of resin and is about 1" thick and I use 3 drops per ounce. Works every time and the resin turns nicer than ANY OTHER I've turned and I'm trying to be unbiased here. You can use Alumilite...and go broke[}:)][;)]
Do a good turn daily!
Don




Originally posted by redfishsc
<br />I am really about to leap off into casting PR blanks, butI do have a question I'm hoping will save me some money.

How do I know--- or even guess--- at how much catalyst to add? I know it depends on the size of the mold and amount you are catalyzing.
 

cozee

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I have found the easiest way to begin is to first follow the directions of any given product. This way, error on your part can be moreso eliminated. From there, tailor to suit your needs.
 
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Originally posted by its_virgil
<br />You don't need to guess. The amount of catalyst to use is well published in several casting forums. In fact, here are two excellent articles on casting polyester resin in out own library.
Read this one first by Jay Pickens: http://content.penturners.org/articles/2005/pr_instructions.pdf
Then this one by Anthony Turchetta: http://content.penturners.org/articles/2005/casting_polyester_resin.pdf

There are other articles which I have not read but may offer information. Then, there are articles on casting ribbons to get various effects and embedding things in the resin glued to the brass tubes.

The amount of resin is not as difficult as some seem to think. I cast in a mold that holds 16 oz of resin and is about 1" thick and I use 3 drops per ounce. Works every time and the resin turns nicer than ANY OTHER I've turned and I'm trying to be unbiased here. You can use Alumilite...and go broke[}:)][;)]
Do a good turn daily!
Don


Originally posted by redfishsc
<br />I am really about to leap off into casting PR blanks, butI do have a question I'm hoping will save me some money.

How do I know--- or even guess--- at how much catalyst to add? I know it depends on the size of the mold and amount you are catalyzing.

Don,

How much longer does it take to cure with less hardener?
 

redfishsc

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Thanks guys. I guess I was being a bit overconcerned. I haven't lept into it yet but it is becoming more and more a temptation. I want to try to duplicate and even improve on the look of the Trustone Turqouise blanks. I have some ideas on getting the veins to run throughout the blank and also in varying the color. Now just to spend the cash and get started.....
 

its_virgil

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I'm not sure the exact time, but I leave it in the pressure/paint tank for 4 hours just to be sure it is cured. If the pressure is released before the resin has hardened, then the air squeezed into the tube and corks escapes as tiny bubbles and collect between the skin and the resin. Every once in awhile, the resin is not totally rigidly hard, but close and it is always ready to turn the next morning. I often do the actual casting late in the evening and just leave it all night.
Do a good turn daily!
Don


Don,

How much longer does it take to cure with less hardener?
 
M

Mudder

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Originally posted by MesquiteMan
<br />Use Alumilite and you will not need to worry about it![:D]

Pr Resin= Approx .25 per ounce
Alumilite= Approx .63 an ounce

You pays your price and take your chances.

I have used Alumilite and it is a sensational material however I am able to obtain very similar results with PR at less than half the price.
 

MesquiteMan

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If you buy in bulk you can get the price down quite a bit on Alumilite. Of course that means you have to buy 5 gallon kits (total of 10 gallons mixed resin). Buying in bulk will get it down to $55 per gallon. It is still more expensive than PR, though.
 

its_virgil

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I'm bitting my tongue! [}:)][;)][:D]
Do a good turn daily!
Don
Originally posted by MesquiteMan
<br />If you buy in bulk you can get the price down quite a bit on Alumilite. Of course that means you have to buy 5 gallon kits (total of 10 gallons mixed resin). Buying in bulk will get it down to $55 per gallon. It is still more expensive than PR, though.
 
M

Mudder

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Originally posted by MesquiteMan
<br />If you buy in bulk you can get the price down quite a bit on Alumilite. Of course that means you have to buy 5 gallon kits (total of 10 gallons mixed resin). Buying in bulk will get it down to $55 per gallon. It is still more expensive than PR, though.

hmmmmm...

You can also purchase PR in bulk so lets compare apples to apples.

$55.00 /128 oz = .429 per oz in bulk. (Alumilite)

10 gallons of PR resin would run about $18.50 a gallon......

$18.50 / 128 oz.= .144 per oz in bulk.

Still a pretty hefty difference, Wouldn't you say?

I'm not against Alumilite at all, I have used it and I think it's a great product. It's more expensive and when I'm fooling around and experimenting I want something less expensive.
 

gketell

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I've seen one thread where someone tried to cast flowers in PR and the setting PR cooked the flowers. 1) Would Alumilite do that? 2) is there a way to cast the PR so that it could be successful against flowers?

GK
 

MesquiteMan

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Greg,

I believe the problem that Roy had with the flowers was due to them not being COMPLETELY dry. In that case, Alumilite would not have been any better. I have made a number of flower pens with Alumilite and it worked great but I also dried the flowers in a dehydrater before casting. I don't believe his problem had anything to do with PR. Alumilite also gives off heat, probably just as much as PR.
 
M

Mudder

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Originally posted by Glass Scratcher
<br />Not that it would change the price of the PR significantly, but did you remember to add the cost of the MEKP in as well?

The place I got the quote from included the hardener in the quote so it does not change the price.[:)]
 
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as others have said, the amount of catalyst really has nothing to do with your molds- just how much you are pouring/mixing. And if in doubt of how much resin to pour in, just pour in enough water to measure for each blank, then pour that into a cup to measure.

We have found that it doesn't do as well in the winter for us (in the South)--it does cure (PR) finally-- just takes forever & is still a bit tacky.

And, our next batch will probably be ordered from a local fiberglass/plastics place here in B'ham... maybe we can save some on shipping!

Doing PR can be addictive-- i've several ideas going on in my head right now-- just need the time to cast it! Mike isn't sure about one idea....but I'll work on it until it does work-- or doesn't! hahaha You'd think I was from Missouri at times...

good luck on your first castings... be sure to show off whatever you do!
 

gketell

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Thanks for the info, Curtis!

I'm not sure if my idea will work now. Once the flowers are dry I can't shape them as I would need to. Maybe I could put the tube with flowers attached into the dehydrator. I'll just have to try it and find out.

GK
 
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