what is the average of hardener for casting.

[sumterdad]

Ok so I know this is a trial and error type question but I was wondering what the average drops was pen blank I have seen any where from 5-6 per ounce to 15per ounce. Please feel free to give your two cents
Thankz

 

[sumterdad]

Is there a base chart to go by or do you just add some and see if that is enough.

 

[Justturnin]

Are you using/talking about PR?

 

[animefan]

If you are casting an acrylic blank it is 3 drops per ounce. For casting worthless wood blanks I would use about 4 to 5 per ounce.

 

[mredburn]

depends on how large a pen blank your making in what kind of mold. If your pouring one of the molds that take 9 ounces and makes 3 pen blanks then each pen blank is apx 3 oz.

 

[dexter0606]

depends on how large a pen blank your making in what kind of mold. If your pouring one of the molds that take 9 ounces and makes 3 pen blanks then each pen blank is apx 3 oz.

Think he wants to know how much catalyst per ounce.

I use Castin' Craft with 3-4 drops of catalyst

 

[mredburn]

Possibly but his question was how many per pen blank. I use 4 per ounce or 12-per blank. Although I rarely pour 1 blank. Different colors will effect the setting time so you add more per ounce.

 

[DozerMite]

The biggest thing is the amount being poured. The larger the pour, the less catalyst you use. Too much catalyst and the blank will fracture while curing. Not enough catalyst, it will just take a while to cure.

 

[bitshird]

Mike is correct, the actual amount of MEKP depends on how thick the blank is, for instance if doing ribbons for using in casting I use about 20 drops per OZ. why? because the ribbons are only about .030 or so thick, where as a Pen Blank is or should be at least 3/4 inch. The thicker the PR the less MEKP needed, doing bottle stoppers, 2 drops per OZ will give me about 30 minutes working time 3 drops cuts my time down to about 15 minutes, Not a lot of time to de bubble.

 

[sumterdad]

Sorry for the confusion. I was talking about per ounce. Did not mean to put the pen blank thing in there I just have heard different methods and wanted to try and get a idea by the veterans out there

 

[Justturnin]

ok the first thing you want to do is find out how much resin your mold will hold. I use sand but you can use rice, sugar, flour or Water, I try to keep water away from my casting to eliminate any issues from it not drying. Fill you mold with the sand and dump it in a measuring cup and see how many fluid Oz you mold will hold. Once you have that add a little since the resin will shrink a bit and you blank will be short, DAMHIKT.

Now from the side of my Resin that I got from Artstuff.com for $12.50 per quart.
Thickness / Drop of MEKP per Oz of Resin
1/8" or less / 12-14 drops
1/8-1/4" / 10-12 drops
1/4-1/2" / 8-10 drops
1/2-1" / 6-8 drops
1-1.5" / 4-6 drops

This is just a starting point you can adjust to fit your needs.

I am still learning how to cast myself so I cant really give pointers beyond this. Good luck and cant wait to see your first cast.

 

[jason_r]

The biggest thing is the amount being poured. The larger the pour, the less catalyst you use. Too much catalyst and the blank will fracture while curing. Not enough catalyst, it will just take a while to cure.

Not 100% sure I agree here. I'd say the #1 thing is the temperature, with amount of resin being very close. As you get to a larger volume (or more importantly a larger volume/surface area ratio) then the pour size matters more.

When it's 110 even crystal clear alumilite will gel in under 3 min.

Otherwise- it varies with pigments and amount of resin being cast as others have said. Check out my Resin Color Library for a number of empirical examples.

 

[DozerMite]

Not 100% sure I agree here. I'd say the #1 thing is the temperature, with amount of resin being very close. As you get to a larger volume (or more importantly a larger volume/surface area ratio) then the pour size matters more.

When it's 110 even crystal clear alumilite will gel in under 3 min.

Otherwise- it varies with pigments and amount of resin being cast as others have said. Check out my Resin Color Library for a number of empirical examples.

He isn't asking about Alumilite. Alumilite doesn't get catalyzed.

Yes, temp. will effect PR, but the amount of the pour (ounces, gallons, whatever) has the biggest impact on the amount of catalyst to be used. Then the other factors come in, temp., humidity, colorants, the alignment of the stars, etc...