Has anyone ever used alumilite products for casting?

[Darthsideous]

Hi,

First, I am new to casting and really need help in learning how to cast. Can anyone point me to any good online or offline resources regarding casting?

Second, I am interested casting simple shapes and small 1/25 scale figures for some of my models. Has anyone used Alumilite products for casting? Are they any good? Easy to use etc?

Third, I am alsdo looking at using materials that are safe, and not toxic as well.

Any help would be appreciated.

Thanks,

DS

[modelnutz]

You really can't go wrong with Smooth-On's SC-300 or SC-305.
Very user friendly.

It's my experiance that the Alumilite materials are "hot" and can shorten the life of a mold.

[tsenecal]

I have been casting simple shapes for about 4 years now using nothing but Alumilite resins and Silicones Inc GI-1000 Silicone.

the only issue I have is that alumilite generally sets off too quickly for larger shapes. for smaller figures/shapes it might be ok.

[TazMan2000]

The only casting resin hobby stores around here sell is Alumilite. It works well and have been using it for a couple of years. But I agree with tsenecal, it sets up much too quickly (and not quickly enough, when you want it to). I would prefer something that I could add a chemical to in different amounts in order to adjust the set time. Perhaps there is a product out there like that?

TazMan2000

[NNYGamer]

I used it a long time ago. I probably wasn't doing it right I guess since some of the things I ended up with were very bubbly. Of course if I had some good scales to measure with it might have worked better. It does give off heat as I remember I got a slight burn from it. Most of what I had ended up separating and is useless now.

[Darthsideous]

Hi,

modelnutz, thanks for mentioning Smooth on. I had never heard of it before. Also, I had not considered that the resin would give off heat.

tsenecal, thanks for your feedback, I am trying to cast some cones and domes in clear. When you say it sets off too quickly, in your experience how much working time do you generally have?

TazMan2000, All my hobby shops stock nothing but Alumilite as well. Thanks your the second person who has mentioned the fast set up time. Is there a different product that you'd recommend?

NNYGamer thanks for your comment on the heat/burn issue I hadn't considered that. From what Modelnuts has said it looks like smooth on elliminats that problem.

[tsenecal]

darthsideous,

setup times for the alumilite vary by volume, humidity and ambient temp... the more resin, the faster it sets up. the more humidity, the faster. the higher the temp, the faster it sets up. I mix it in the tiny 1oz mixing cups, and that can slow it down to the 5 or 10 minute range. on a humid spring day in large quantities, it would setup in the mixing cup while i mixed.

remember, to me a humid day is anything over 20% humidity. i live in arvada colorado, where summer humidity can be as low as 10%.

and now that you mention it, it does get pretty hot when used in larger quantities.

to give you an idea of what I have molded, check out this build photo:

http://www.rcgroups.com/forums/attachme ... id=2153120

all the little detail pieces in the front basket that are white are molded in alumalite, as well as the lamps at the top of the sail.

the largest pieces i have cast out of alumalite are the endcaps, 3" diameter and 4" diameter. the 4" weighs several ounces.
http://www.rcgroups.com/forums/attachme ... id=2156244


finally,
several of my friends swear by the smooth-on stuff... including my friend Hugh Letterly...

http://home.earthlink.net/~loosecannonproductions/

[TazMan2000]

TazMan2000, All my hobby shops stock nothing but Alumilite as well. Thanks your the second person who has mentioned the fast set up time. Is there a different product that you'd recommend?

Don't know. Alumilite is the only product that I tried. Search scratchbuilding forums for user's rating for different products.

Good Luck

TazMan2000

[Joseph Osborn]

Besides the previously mentioned very short pot life, another reason I don't use Alumilite's standard resin is that is stinks to high heaven, both before and after it has been mixed and cured. When you cut or sand a casting, it stinks. Smooth-On's resins don't smell quite so bad.

[Darthsideous]

Joseph Osborn Posted: Tue Apr 06, 2010 10:08 pm Post subject:

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Besides the previously mentioned very short pot life, another reason I don't use Alumilite's standard resin is that is stinks to high heaven, both before and after it has been mixed and cured. When you cut or sand a casting, it stinks. Smooth-On's resins don't smell quite so bad.

Thanks I hadn't heard that before. I have purchased smelly resin products in the past and I can't stand it. I've purchased a small amount of alumilie and I"ll try using it. If it is as bad smelling as you suggest I may have to toss it out and chalk it up to learning.

[Darthsideous]

Thanks to everyone who took the time to respond. I went to smooth on's web site and they have some good tutorials there. It looks like I'll try their products once I'm done with the alumilite.

[Kylwell]

You can often find Smooth-on's products @ well stocked art supply stores.

[Darthsideous]

You can often find Smooth-on's products @ well stocked art supply stores.

Thanks I hadn't thought of looking in art stores

[bambamproductions]

I use mpk resins and rubber he is a greta ghuy and great prices.The Alumininte has had its problem very expensive and sets off way too quick and the rubber is brittle.They do make a lot of "starter kits" Many places has stopped carrying the products due to this complaint so if it is a small project I guess ok but largeer or more then a few pours do not use it.Sil pak and smooth on are good but more expensive

[novahobbies]

Hey Bambam, where do you get your MPK rubber from? I found them on http://www.hobbysilicone.com , but the rubber seems pretty soft and the prices aren't any better ( and sometimes a little worse) than smooth-on. For instance, the 10 lb MPK standard tin cure extra firm only has a hardness of shore 36 max, and is $105, versus Smooth-On's 11 lb Mold-Max 40 kit for $91.94, and it's a shore 40A rubber.

I've used Silicones Inc GI 1000, GI 1040, their P-45, Smooth-On's Mold-Max 40, and Oomoo. I'd have to say that the Silicones Inc platinum cure P-45 is the best rubber for long life and worry-free non distorted castings. Platinum cure rubbers resist the heating from resins much longer than tin cure, but you have to make sure that there isn't the slightest thing that might inhibit the rubber from curing (or it will never cure), and you must, without any question, degas the rubber - preferably before it has been poured, then again when it's on the part. More finicky and time consuming, but worth it in the end.
GI 1000 and 1040 are very similar. GI 1000 is softer. Both of these are tin cure rubbers, and will cure against practically anything. For $hits and giggles I once poured a little on a piece of cooked pasta. It cured against a wet noodle. Of the two products, I'd use GI-1040 again, if only for its slightly firmer properties. Again, degassing is a necessity, but you really only have to degas once - since its a little softer rubber, its easier to degas.
Mold-Max 40 is a nice all-around rubber, very similar to GI-1040. I use this because it's easier for me to get than GI 1040.
Oomoo is a nice, inexpensive prototyping rubber. It's VERY soft - shores 25 and 30A hardness - but has the advantage of being easy to mix, does not need degassing under most circumstances, and cures quickly. You can have a complete 2-part mold in less than 6 hours with this product. However, you will only get 1 to 2 dozen or so castings with this product, and the shelf life of the unused mold is very short - it reacts to humid conditions and the rubber warps badly.
Anyway, that's my experience with the rubbers I've used before. Clear as mud?