Help with Alumilite

Signed-In Members Don't See This Ad
rlofton

rlofton

Member
Joined
May 30, 2008
Messages
349
Location
Spring, TEXAS
I tried an Alumilite cast on pine cones Wednesday night (4 days ago). I mixed 14 ozs. of each Part A & B of clear Alumilite with a small amount of Alumilite red dye and a small popsicle stick end of silver PearlEx. Pressurized for 3 hours at about 50 psi.

After four days it looks beautiful but has not cured. It has been under an incandescent lamp for two days trying to make sure it stays warm and hoping it will cure. The top surface flows like water.

My guesses for the failure are;
1) condensation in one or both parts of the Alumilite
2) problem with the dye (which I have used before without problems)
3) problem with the PearlEx (which I have used before without problems)
4) moisture in the pine cones

I'm sure that some of the Alumilite experts here can enlighten me on how not to waste 28 ozs. of this liquid gold. Any help will be appreciated.

Thanks!
 
Signed-In Members Don't See This Ad
I can help you narrow it down a little.
Condensation and Alumilite = FOAM .. so if you're not getting foaming, then
water is probably not the issue. Dry pigments should not affect the cure,
either. So .. we're left with the type of liquid in the dye, or something in the
pine cones. (likely not the water)

I haven't cast pine cones, so I'm only throwing out a theory here.
But some of the moisture in the pine cone may be something other than
water. The pitch contains resins and acids that might interfere with the
Alumilite, I don't know for sure. But it would seem to me that the cones
would need to be prepped in advance, and having made pine cone wreaths
as a kid, I can tell you they're a bit of work. Turpentine, alcohol or acetone
will break down the resin (or is it rosin?) so there's some type of solvent in
the pine cone already. I used to clean then in turpentine and then wash
them in soap and water, usually soaking in the turps for a day.
Drying took weeks, but I'm sure there's a way to do it faster. Careful with
oven drying, that will often change the colors.

Again, I have no idea what's happening, just throwing out some ideas for
consideration.
 
Rudy, it sure sounds like the culprit is the pine cones somehow.

We know the alumilite dyes are probably not a problem and we all use the PearlEX powder so doubt that's the problem either unless your "small popsicle stick end " is more like two tablespoons! :smile:

If it were me, I would try an experiment by taking a small portion of A and B and mixing it well and just let it sit without adding anything else. It won't be a total waste or resin as you can use the clear glob to act as a pen stand when taking photos of your pens! If it cures within an hour, the problem isn't the resin and leaves only one culprit, the pine cones and whatever chemical reaction they are causing.

With all that said, your comment "The top surface flows like water" after two days makes me wonder about something and prompts me to ask the really dumb question. Is there a chance that you accidentally mixed equal parts of B with equal parts of B or A with A? :eek:
 
Last edited:
Thanks for the feedback. I'm very careful about keeping A and B separate so that's not the problem. It appears that the bottom half of the cast has at least somewhat cured but the top is very watery. I'm going to take it out of the mold and see what I have. Probably a big mess.

I have cast some blanks from the same batch of pine cones and had some slow curing issues but nothing like this. There was no foaming so I suspect it's not water.

I will mix a small batch of clear as you suggested, George, and see how it turns out.

Thanks again for the suggestions!
 
Rudy,

Are you sure you got it mixed THOROUGHLY? Mixing a large quantity like that it would be very easy to not get it mixed completely. You should have been mixing for at least 1 minute. Moisture would not be the problem as stated above since it would foam with moisture. Pine cones should not be an issue either. Pearlex, even if you put the whole pack in, would not cause it to not cure. The Alumilite dye would not be a problem either. That pretty much leaves either not getting it mixed completely or improper ratio. Having some cure and not all leaves me to believe it was not mixed thoroughly.

When I mix 20 ounces total I mix for at least 1 minute with a rubber spatula. I use clear plastic cups so I can see when it has been mixed. When you first pour them together, they look cloudy. When completely mixed, it will become clear with no streaks.

I have cast just about everything under the sun with Alumilite and have never had one single failure to cure. I have had some foam due to moisture but that is it.

The only other thing would be bad resin.

If you need more help, feel free to shoot me a PM and I will send you my phone number so you can call me.
 
I took George's advice and mixed 1 oz. each of A & B to test the Alumilite. In 30 minutes it was a solid clear block. I weighed both parts of the mix Wednesday night so the ratio was right, unless I really screwed up. Since I have cast pine cones--from the same location, collected at the same time, and stored the same way--without problems, I don't think that is the issue. I'm left to believe that Curtis is probably right that mixing was it.

I added the dye and PearlEx to part A before mixing the two parts together. Is that correct? Going to give it another go tomorrow night and will mix thoroughly.

Thanks for all the information.
 
Rudy,

Try mixing A and B first, then add the dye and pearlex. I know Alumilite says to add the dye to A, then add B but I don't like to do it this way. If you are not using clear cups, get some! If you are doing say, 20 oz total, put your cup on your scale and zero it out. Then pour in 10 ounces of A and then go up to 20 oz with the B. Look into the cup while mixing. You will see it start out cloudy with streaks. When it is COMPLETELY mixed, there will not be any streaks and it will be perfectly clear. Don't worry too much about bubbles when mixing. The pressure will get rid of them. Don't beat it to death but do mix it pretty vigorously. Scrape the sides of the cup as you go to make sure it is getting it all mixed in. Once clear, add your color and pearlex. Mix and pour. It will work perfectly, guaranteed!
 
I have to agree with MM. I too was having issues with larger batches and it turned out to be the mixing of the two parts. Once resolved - I have not had a failure since.

I also went to gallon containers with a pump mechanism which allows me to get a gram-to-gram ratio dead-on; which helps immensely with the curing. Ounces will work - but I found the grams to be more accurate.

just my 2 cents worth...

David Simmons
 
dasimm said:
I have to agree with MM. I too was having issues with larger batches and it turned out to be the mixing of the two parts. Once resolved - I have not had a failure since.

I also went to gallon containers with a pump mechanism which allows me to get a gram-to-gram ratio dead-on; which helps immensely with the curing. Ounces will work - but I found the grams to be more accurate.

just my 2 cents worth...

David Simmons
Click to expand...

I just picked up a digital scale at Ocean State Job Lots that measures in
1/10 of an ounce, and it even has a tare setting. Put on your container,
Press TARE and then it reads zero. Measuring is pretty accurate that way.
The scale was $10 on sale..
 
It wasn't moisture or some unknown substance seeping from the pine cones. It wasn't the dye or the PearlEx. It was very simply not mixing well enough. It wasn't the amount of parts A & B---they were weighed on a scale within 1/10th of an ounce of each other.

I thought I had mixed the two parts together very well but have started mixing more vigorously and using a larger stirrer and every cast since doing so has been cured very quickly. Thanks to everyone for the tips and suggestions.
 
You must log in or register to reply here.
Back
Top Bottom