What is best Casting

Signed-In Members Don't See This Ad
Signed-In Members Don't See This Ad

BeeAMaker

Member
Joined
Jan 30, 2017
Messages
695
Location
Elkhart IN, USA
Depends on what your doing but here is my 2cents.

I prefer Alumilite, but can be cloudy if not mixed right or sits on the shelf too long. Turn nice with little to no chipping. Requires a pressure pot to get a bubble free cast.

I am still testing/playing with a new kid on the block, Liquid Diamonds. Not sure I like it yet and it takes 24hours to de-mold and 48 hours to fully cure. It is still quite soft and flexible after 24 hours. However it does not require a pressure pot and it seems to be a bit more clear than Alumilite.

I have not tried polyesters yet, but from turning experience, the "esters" are very brittle and are pron to chipping, especially for the inexperienced turner. I've had my hard knocks more than once ;) However it can give a better polish and you can achieve some spectacular color patterns.
 
Last edited:
Joined
Mar 11, 2012
Messages
797
Location
Fuquay Varina, NC
I'm pretty new to casting, maybe 35 blanks or so under my belt now. I tried the polyester resin they sell at Penn State and it worked OK for my tube in casting trials with some carbon fiber blanks I made up. However, it took quite some time to get fully hard and as mentioned, it's very very brittle.

So, I dropped some cash on a pressure pot and picked up some Alumilite. Clear casting is silly easy with the 1 to 1 ratio and it turns like butter. Doing the fancy mixed colors is a bit of a learning process so plan on tossing some money into resin to experiment with.

I am now fully in the love/hate relationship with Alumilite when it comes to turning. The good thing is that is turns smoooooth with a skew or carbide tool. The bad thing is it turns so smooth. You get LONG ribbons of material that love to wrap around the mandrel. Drives me a little crazy but I'll take that over the brittle nature of some other products.
 

Tim'sTurnings

Member
Joined
Aug 19, 2008
Messages
420
Location
Central Michigan
I'll give my .02 cents worth of comment. I have read comments in regards to using Aluminite and Polyester Resin. I have also heard about more problems with Alumilite than I have heard with using Polyester Resin. I also have heard that Alumilite may turn better with fresh materials and in the right mixture. But I have also heard that PR turns good as well. I use Polyester Resin for making pen blanks and worthless wood, I like it and have no problems with it if I mix it correctly. It can be brittle but, adjusting the amount of catalyst you use can correct that problem. You can also mix PR with a bigger selection of coloring agents than you can with Alumilite and you do not need to use a pressure pot every time you use it. I use a pressure pot sometimes and with some blanks I do not. Personal preference I guess with PR. I think PR is available from more suppliers and I believe it costs less. So in my opinion, which I said is only worth 2 cents, maybe. But I would recommend the use of PR because of my experience with it and what I have read in turning forums. Good luck with whatever you choose to use.
Tim.
 

mecompco

Member
Joined
Apr 24, 2015
Messages
1,607
Location
Fairfield, Maine
All I've used is PR. It is cheap to get started--all you need is the PR and a mold. Takes a day or so to harden, if it's warm, longer if it's cold. My blanks have all turned well, and I've never encountered a bubble. Oh, PR takes a really nice shine--I think better than many of the alumilite blanks I've turned.

Regards,
Michael
 

JohnU

Member
Joined
Jan 31, 2008
Messages
4,924
Location
Ottawa, Illinois
Both PR and Alumilite have pro's and con's. I usually select my resin to fit the type of casting and material I'm casting.... block, vertical, tube on, clear, color, object, etc. This topic has been discussed many times so there is a lot of knowledge in the library and in past posts. You could spend a couple days reading it all but the best way to see what works for you is to give it a try. I've been casting for years and use both PR and Alumilite and I'm still learning. Lol. Just remember to keep a notebook when you cast. Nothing worse than getting something cool and then struggling to repeat it. Also, too much heat and any moisture are not your friend. Oh, and yes- PR finishes to a much better shine and is more affordable, but a nice CA finish on Alumilite fixes that problem and it's more durable. Good luck! And looking forward to seeing your creations.
 
Last edited:
Joined
Aug 13, 2016
Messages
1,460
Location
Surprise, Arizona
I use both, but prefer PR, and Silmar 41 in particular, mostly because PR polishes better.

Alumilite Pros: Easy to mix, turns more easily than PR, doesn't stink to high heaven like PR does - but wear a respirator anyway.

PR/S41 Pros: Quite a bit cheaper (just under $120/2 gal delivered vs just under $170/2gal delivered for Alumilite), can pour a single blank in multiple stages, polishes to a better shine.

Chipping with PR isn't that bad IME, especially if you cast round blanks in pvc molds. You need to dial in the least amount of catalyst to use to get the best results. Alumilite is a no brainer, 1:1 by weight. PR is also more tolerant of moisture/high humidity than Alumilite, but that's only a problem during monsoon season here in the desert. Alumilite is better if casting in temps below 70F, I don't even bother with PR below 60 degrees and rarely below 70 (only if I'm out of Alumilite). I demold PR blanks in 4 hours during the hot season, at 80-90 degrees I go 6 hours, and below that I wait for at least 12 hours, a full 24hrs if it's below 70. Alumilite can come out in 2-4 hours regardless of the temp. You don't need vacuum or pressure with PR, but you will get consistent bubble free results with pressure, occasional air bubbles with vacuum, and unless the resin is warm, you always take your chances without either. Even if you do warm the resin in a bucket of water you may still get spotty results unless you're making thin casts, which doesn't include pen blanks. Alumilite has to cure under pressure, there's no way around it. PR is better for embedding objects in clear resin, Alumilite is better for worthless wood or other organic material like pine cones. PR works, it's just not quite as good. It helps if the resin is warm so it can flow better into all those tiny pockets. You can get a smoother fade from one color to the next with Alumilite, but for some effects PR is better.

This is based solely on my experience for the last two years and is my opinion, not fact. Except for PR polishing to a better shine, that's no contest. :wink:

EDIT: If you go with Alumilite and plan on using more than 1 or 2 colors per blank, do yourself a favor and get the slow (12 minute) cure. I've run into problems with the regular setting too fast when making multiple color pours.
 
Last edited:

tkbarron

Member
Joined
Nov 8, 2011
Messages
385
Location
Rowlett, Texas
Personally, I hate PR but it's cheap and a bit more tolerant of moisture. If you are adding mica pigment or dye then Alumilite is hard to beat. Just make sure anything that goes into it is dry dry dry. Also, you have to pressure cast with Alumilite and should with PR.

There's a new casting resin called Liquid Diamonds that a lot of guys are giving a try. It works wonderfully for most any applications. Great for clear or pigment casts. It bonds to most anything and shines better than PR or Alumilite imo. I've tested it with WW and gator jawbone with great results. The only downside is the cure time. You have to give it 24 hours. It turns like butter, very similar to Alumilite.

Best of luck casting!
 

BKelley

Member
Joined
Jan 31, 2010
Messages
891
Location
Tucker, Georgia, 30084
I cast labels using PR. I do not use a pressure pot. I use the procedure prescribed by Barry Goss. I get about a 20% rejection rate because of bubbles, but figure this as part of the game. If I count the cost and risk of adding a pressure pot to my shop I can put up with the 20% rejection. PR is a little brittle, but does not cause me problems. I have read about Liquid Diamonds and probably will test it in the near future.
 

crunch

Member
Joined
Sep 27, 2018
Messages
22
Location
Western MA.
I am a little surprised that there are not more replies here. This is something that, IMO, should be expanded on and possibly made a Sticky. Beginners and pros could use the input from others experience in this.

I have been casting about 5 years. Not every day but once a week or so. I have almost always used Casting Craft clear resin. It's a little pricey but I am allowed to add catalyst drops instead of 1:1. I also mainly use Jacquard Pearl-Ex pigments.

My reasoning: I usually do two color pours. My mold is 3" X 5" x 7/8" (saw cuts and end wastes.) I use a digital scale for the total volume of the mold by weight. 2/3 of the volume is the primary and 1/3 the secondary color. I mix and pour the primary 1st, then over-catalyze the secondary so it "flashes" (gets thicker faster) When pouring the 2nd into the 1st they do not mix when lightly stirred. I mean in a Blue/Yellow pour, the whole pour does not turn Green. The colors basically stay separate.

I am now going to try the Silmar 41. I've rarely had a bubble problem with the CC, no pressure pot either. These are straight casts, I've done the tube in pours but they don't allow much swirling. Single colors or multiple pours ( think the dregs from the cup you are working with) work good for that.

I am in no way an expert but I think the ability to add catalyst drops beats 1:1. Just my 2 cents. Also. I'll be post some pics or links to my pens soon..... well when I get a decent camera lol. Probably next month, then you can see some of my casts and woods.
 
Last edited:

acmaclaren

Angi the Maker
Joined
Oct 28, 2012
Messages
266
Location
Seattle WA
I've been using Liquid Diamonds, because I don't own a pressure pot. I switched the ratio to 1.7 oz Part A and 1 oz Part B. It's worked really well for me. I use molds made by PTownSubbie with Stoner Mold Release. I don't have too many issues with bubbles.
 

MRDucks2

Member
Joined
Jul 17, 2017
Messages
3,215
Location
Bristow, IN
My reasoning: I usually do two color pours. My mold is 3" X 5" x 7/8" (saw cuts and end wastes.) I use a digital scale for the total volume of the mold by weight. 2/3 of the volume is the primary and 1/3 the secondary color. I mix and pour the primary 1st, then over-catalyze the secondary so it "flashes" (gets thicker faster) When pouring the 2nd into the 1st they do not mix when lightly stirred. I mean in a Blue/Yellow pour, the whole pour does not turn Green. The colors basically stay separate.


What is the difference between your primary mix and the portion you "over catalyze". Do you add twice as many drops to half as much resin or some other amount?

Curious as a few weeks ago, we tinkered with the number of drops on the same amounts of resin to see the overall effect and it seemed minimal. - Thanks.



Sent from my iPhone using Penturners.org mobile app
 

crunch

Member
Joined
Sep 27, 2018
Messages
22
Location
Western MA.
It's close to 1.5 X.
The volume of the mold I mentioned is 9 ounces by weight of resin. CC recommends 5 drops/ounce. The 2/3 primary color gets the standard 30 drops (6 oz) whereas the 1/3 (3 oz) secondary gets ~ 24. Keep in mind the primary is already catalyzed and doing it's thing in the mold. Also, the colors are already pre-mxed and weighed in their respective cups. I just have to add the catalyst.
I also DON'T use accurate volume measures, weight...yes.. I have cheap clear cups with a magic marker line , transferred from a baseline set. But I weigh the resin as I pour it to the line. I use a battery drill and a modified tongue depressor to mix for about a minute. I then dip a stir stick in to gauge the viscosity and dip again, and again.... It's really a crap shoot. It is never a consistent science. It's a visual, syrupy, thing. Experience I guess. Sometimes it gels too fast and you have to pour this blob in, then separate/stretch it out with said sticks lol. Interesting results.
I am getting the Silmar 41 next week and some new pigments also. I'll update this when I have a few pours done. I hope this answered, though longish, your question.
 

crunch

Member
Joined
Sep 27, 2018
Messages
22
Location
Western MA.
Edit. Question/reply for acmaclaren
Are you pouring 2 colors? Or more? What ratios are for which color? Inquiring minds and such. I replied to another post below about how I do the drops.
 
Last edited:
Joined
Aug 13, 2016
Messages
1,460
Location
Surprise, Arizona
Thanks for bringing that up Crunch. Depending on the look I want I've added more catalyst to one of the colors as well, especially when using white or any of the very light pearl colors to keep them from mixing in with the darker color(s). It works quite well and helps give a sharp definition between colors rather than a blend or worse yet, a "muddy" appearance.
 

acmaclaren

Angi the Maker
Joined
Oct 28, 2012
Messages
266
Location
Seattle WA
Edit. Question/reply for acmaclaren
Are you pouring 2 colors? Or more? What ratios are for which color? Inquiring minds and such. I replied to another post below about how I do the drops.

I actually haven't tried colors yet. I've mostly been making my own blanks using postage stamps and stickers. I color the tube and apply the stamps or stickers. Then apply Mod Podge over everything.
 
Top Bottom