Alumilite not curing

[darrin1200]

Had a bad experience yesterday. As of this afternoon, 30 hours and still liquidy.

I decided to do a large, for me, pour yesterday. I wanted to make some large burl/resin blanks, to make a ring for my daughters birthday.
All my wood is dry and the house is not overly humid. I also baked the molds with the burl in them for 30min before pouring.
I was doing an 800 gram batch, which I would then split into two colours.
I mixed the main batch in a small throw away bucket, it was to much for my mixing cup. I use a drill with a paddle to mix my resin, about two minutes worth.
I then split into two clear cups added about 20-25 drops of dye in each as well as a small 1/4 tsp of silver metalic to each cup.
I mixed the black with a spatula, about 30 seconds, and poured into its mold. Then I did the same with the blue.
I popped it into my pressure pot at 60psi.
That was at 11:30 am.

Came home at 4:00 pm, and popped open the pot, still at 60 psi.
The resin was still liquid. It almost looks like the molds bubbled over, a bit of a mess.
I did a quick wipe up, put everything back in the pot and repressurized.
I have a small cup that I keep on my bench for excess resin. This wasnt hard either. This is what is confusing me.
I thought maybe, that my compressor was introducing moisture into the pressure pot. I don't have a water filter, but I will soon.
Will moisture cause the resin to foam up? If so, that would explain that portion of the problem, but not the lack of curing. The little bit, about half a pill bottle, isn't curing either.

When I left the shop today at 3:30pm, the resin in the pill bottle still hadn't hardened. I understand that this might be because there is not enough resin in the jar.
I haven't opened the pressure pot today. I had to go to work at 4pm, so I figured I would give it until I get home tonigt at 9pm. WhenI do, I will take some pictures.

Anyone have any comments or ideas?

Thanks

 

[guylaizure]

The foaming is from moisture in the wood or in the Alumilite.I had to scrap several castings because the Alumilite absorbed moisture.

 

[BSea]

I don't have a clue why it didn't cure. Even with moisture alumilite will cure. About the only thing that might have happened is you mixed 2 part B's together for the 1st color, and two part A's for the 2nd color. If that's the case, I don't know that you have much choice other than to scrap everything, and mark it up as a learning experience. Did the resin get warm before you poured? If not, I'd bet that's the problem.

Based on the amount of dye & pigment you added, that doesn't sound like it would be an issue.

A half pill bottle will harden just fine as long as the mix was good. I've spilled drops when pouring, and they set up.

 

[Brooks803]

I don't have a clue why it didn't cure. Even with moisture alumilite will cure. About the only thing that might have happened is you mixed 2 part B's together for the 1st color, and two part A's for the 2nd color. If that's the case, I don't know that you have much choice other than to scrap everything, and mark it up as a learning experience. Did the resin get warm before you poured? If not, I'd bet that's the problem.

Based on the amount of dye & pigment you added, that doesn't sound like it would be an issue.

A half pill bottle will harden just fine as long as the mix was good. I've spilled drops when pouring, and they set up.

I think Bob's on to something.

When you get home try mixing 20g of A & B together with nothing in it and without pressure. See if it hardens and if it does then you most likely did as Bob mentioned.

 

[TimS124]

I've mixed very small amounts of Alumilite Clear and had it set just fine. Yes, due to the tiny amounts, it doesn't generate enough heat to fully harden on its own. But it will finish curing over time so I simply wait a few days before trying to do anything with the tiny batches.

Even when I've left a small amount of a bigger batch in the cup, it sets just fine (resulting in a 1/4" or so thick disk shaped like the bottom of a mixing cup).

If they didn't set at all, I would suspect it's all just Part A or all just Part B....Darrin was clear in his initial post that he mixed all of the measured amounts in one batch, then split the mixed goo into two chunks for coloring. So, the risk of mixing two A's together and two B's doesn't match his description...leaving the risk of everything being just A or just B
as a possible culprit (but that should be easy to verify by checking the jugs the resin came from...while we mix by weight, they're not horribly far off by volume and an 800 gram batch would make a very noticeable difference in how much Part A vs Part B was on hand).

Or, there's another cause and we can all hopefully learn from whatever bit Darrin.

 

[BSea]

I think Bob's on to something.

When you get home try mixing 20g of A & B together with nothing in it and without pressure. See if it hardens and if it does then you most likely did as Bob mentioned.

The bad news is that was the "Voice of Experience" talking . The good news (at least for me) was that it was only 2 blanks of each color when I mixed up my batches.

If they didn't set at all, I would suspect it's all just Part A or all just Part B....Darrin was clear in his initial post that he mixed all of the measured amounts in one batch, then split the mixed goo into two chunks for coloring. So, the risk of mixing two A's together and two B's doesn't match his description...leaving the risk of everything being just A or just B
as a possible culprit (but that should be easy to verify by checking the jugs the resin came from...while we mix by weight, they're not horribly far off by volume and an 800 gram batch would make a very noticeable difference in how much Part A vs Part B was on hand).

Or, there's another cause and we can all hopefully learn from whatever bit Darrin.

I see your point. He did say he mixed 1 large batch, then split them. If that's what happened, I'm back to square 1.

 

[TimS124]

Darrin - when you mixed with the drill and paddle....did you stop at two minutes because the mixture had turned clear? Or did you just mix for roughly two minutes?

Part A and Part B have difference colors and different viscosities, but when fully mixed, the results turn clear (and are uniform). If all of what was mixed was (and remained) either clear to start with or a bit yellowish, then we'd have the likely culprit.

I've never had to mix for that long to get the two parts to turn uniformly clear, but I've also never tried mixing on such a big scale.

 

[1080Wayne]

Were the dyes used from Alumilite ? Some others may not be compatible . Can`t think of any other possibility for a no or very slow cure that hasn`t been mentioned , other than a fungicide treated seed which needed 2-3 weeks when I did it years ago .

However , the bubbling is almost certainly from moisture introduced from the compressor . I learned this past winter that I need to purge the 50 feet of air line between my compressor and casting area every day if I don`t want to introduce some interesting colour effects (not all bad) to my casts . The water filter should help , but so will draining the condensate out of the compressor air tank on a regular basis .

 

[darrin1200]

Thanks for the input guys.

I got home last night and checked the pot. Sure enough, it is still liquid.

I am 99% certain that I mixed it long enough. It looked clear, but i was doing it in a white bowl, which can be a little deseiving. The responses got me thinking though. The A half is clear, so if I put double of that, it would look clear. I checked my jugs, and while there is a difference, it is the B side that is lower. It has been a bit lower since I got it.

It seems like the only thing that could really throw off the mix and alter the cure time, is temperature and the mix ratio. Right now the temperature is definitely not the problem. So that leaves the ratio.

I have a small Starfrit digital scale that I got from Canadian Tire. It has always appeared accurate, but what if it is off on the high side, and that as you increase the weight, it gets proportionally more out of wack. That could explain why this pour, which is almost double the weight of any of my previous ones, is not curing.

I have to head to Montreal today to drop off 4 pens. Coincidentally, they are all from my sucdessful pour s two weeks ago. When I get back, I will do some experiments with the scale to check it. I have another of the same model to compare it to as well as an old balance scale.

I wont throw out the pour though. I will put it up on a shelf, and see how long it takes to cure. Even if the ratio was off, it should cure eventially.

Thanks again.

 

[1080Wayne]

A few more straws to grasp at . This was not a new shipment of Alumilite - you have had good pours from it ? The throwaway bucket - HDPE or something else ? What had been in it before ? Did any of the skin of resin left in it harden ? Type of burl ? You baked it . That would cause oils and other volatiles to come to the surface . One or several of those could interfere with the cure .

 

[BSea]

If it isn't the mixing of identical resins, about the only thing I can think of is a bad batch. Even if it wasn't totally mixed, it should set up to some degree. At worst, you have pockets of uncured resin, not totally liquid. Even if you don't mix it at all, but just pour it together, you'll get some curing. When I started with alumilite, I accidentally poured the remainder of Part A back into the Bottle of Part B, or maybe B into A. It cured a small area in the bottle. Lucky for me it was close to empty (I've learned lots of lessons :redface. Basically, I don't think your problem is that it was of not being mixed sufficiently.

 

[Marko50]

So where does this mystery stand? I use Alumilite exclusively and have never come across such a problem. Weird.

 

[darrin1200]

So where does this mystery stand? I use Alumilite exclusively and have never come across such a problem. Weird.

Hi Marko.
As it is right now, it still hasn't cured. I have been reassigned lately to work on the honey do list. Changing bathroom vanities right now, upstairs done, downstairs next.

I am going to try an experiment. I will take two samples of the bad pour, about 50gr each, and mix them with an equal amount of "A" and "B" respectively. If one cures and the other one doesn't, it will mean that after I wipe the egg off my face, I will really have to pay attention when I'm pouring.

If neither cures, I will toss the bad batch and move on. If it happens again, well, then we'll see.

Hopefully this week, I'll keep you posted. Now its off to install a ceiling fan in the bedroom, after properly rerunning the wires.

 

[BSea]

Hi Darrin,
At this point, it's likely that the resin has absorbed moisture from the air. So don't count on getting a useful pour. I did this a few years back with some resin where I was testing some colors. I mixed the A side, but didn't like how the color looked. About a week later, I mixed it with the B part. It foamed really badly. Your humidity is probably lower than where I am though, so it might work.

 

[Ed McDonnell]

Even if one of them foams and one doesn't it would still indicate an oops in the initial pour. I've always wondered if you could put foamed alumilite under vacuum (once cured) to break open the bubbles and then cast it in another color to fill the bubbles. Could be an interesting effect...but maybe super ugly!!

I think I would also do a small test batch with no additives to see what happens (making sure to use A + B this time).

Ed

 

[79spitfire]

I wish I'd thought of that! I had one that turned into a blue 'magic muffin', slicing vacuuming and re-casting would have been a great experiment!

 

[darrin1200]

Thanks everyone. I just wanted to touch back with a final note. I have come to the conclusion that I double poured the "A" side. I did a new pour yesterday and it worked fine.
The "A" side is a little thick , but i have heard that if i put the bottle in hit water, it will thin out again. We'll see.

 

[Sabaharr]

Great to get an answer. I was beginning to think that maybe you got a mislabeled bottle and you had 2 Part A but one was marked B. Never heard of this happening but......

 

[jttheclockman]

Thanks for the follow up Darrin. You do not see this often. It should be done more. Have a great day.

 

[ElMostro]

Thanks everyone. I just wanted to touch back with a final note. I have come to the conclusion that I double poured the "A" side. I did a new pour yesterday and it worked fine.
The "A" side is a little thick , but i have heard that if i put the bottle in hit water, it will thin out again. We'll see.

Are you sure the A side is the one that got thick? Bec the A side normally stays thin and the B side is the one that, when it gets cold or has been on the shelf a while, tends to get thick.

Oh, I have done the A with A mix also...have ruined some pretty cool blanks but also discovered some interesting colors.
Eugene.

 

[darrin1200]

Thanks everyone. I just wanted to touch back with a final note. I have come to the conclusion that I double poured the "A" side. I did a new pour yesterday and it worked fine.
The "A" side is a little thick , but i have heard that if i put the bottle in hit water, it will thin out again. We'll see.

Are you sure the A side is the one that got thick? Bec the A side normally stays thin and the B side is the one that, when it gets cold or has been on the shelf a while, tends to get thick.

Oh, I have done the A with A mix also...have ruined some pretty cool blanks but also discovered some interesting colors.
Eugene.

Your right. As soon as I went down to the shop, I realized my mistake. It was the B side. I put it in a sink of hot water for 30 min, and it thinned out quite a bit.

 

[TimS124]

Thanks everyone. I just wanted to touch back with a final note. I have come to the conclusion that I double poured the "A" side. I did a new pour yesterday and it worked fine.
The "A" side is a little thick , but i have heard that if i put the bottle in hit water, it will thin out again. We'll see.

Are you sure the A side is the one that got thick? Bec the A side normally stays thin and the B side is the one that, when it gets cold or has been on the shelf a while, tends to get thick.

Oh, I have done the A with A mix also...have ruined some pretty cool blanks but also discovered some interesting colors.
Eugene.

Your right. As soon as I went down to the shop, I realized my mistake. It was the B side. I put it in a sink of hot water for 30 min, and it thinned out quite a bit.

I've found that after soaking in warm water to fix the viscosity, the label tends to fall off some time later. Its glue doesn't seem to like soaking in water...which makes it difficult later to be certain what's in the bottle (was this clear or white?...side A or B?).

I suggest grabbing a permanent marker and writing on the bottle while you still know the answers. I found just simply putting "Clear - A" is enough to avoid confusion next time I'm going to pour.

Though if you only have that size jugs of just clear or just white, you can figure out what's left. I usually have both and sometimes use both in the same day....so the risk of getting them mixed is high enough that the waterproof label is quite handy..