Old Alumilite?

[Todd in PA]

I'm not sure what's going on, but my alumilite clear casts are all turning out white and gassy. This is dried baby's breath dyed purple. The front added yellow mica powder. The rear added battleship gray. The tubes were held at 45 psi for 24 hrs.

The front I'd say looks white because of bubbles at the flowers. But the back one is streaked with white.

I'm wondering if the alumilite has gone bad. I'm at the end of the bottles. I have new ones on deck. Change my recipe? Or just pitch the old and business as usual?

Thanks!

Todd in PA

 

[Kenny Durrant]

Polyurethane, Alumilite Clear, doesn't like moisture. It also has to be mixed thoroughly and by weight. If your heavy on the B side it will turn milky white. Also if your mixing small batches or not scraping the bottom and side any resin not mixed properly will streak white. As far as old resin some of the manufacturers say 1 month or a few months. I've use resin just over a year old with no problems. I warm the b side before mixing to help with bubbles and mixing. Good Luck.

 

[its_virgil]

Moisture causes foaming. Maybe your embedded stuff was not dry.

As Kenny mentioned, incorrect ratio or incomplete mixing will cause totally white or white streaks.
Do a good turn daily!
Don

 

[1080Wayne]

As the B side ages it`s viscosity increases , to the point where crystals form within it . Using it at that stage at equal parts by weight can give whiteness , even when the encased material is totally dry . Being cheap , I experimented and found that increasing the B side weight by 1 % reduced the problem . I made a number of castings at +3 % B , and some up to + 7 % B as my resin stock continued to age , all totally clear . I`m sure there may have been some degradation of other properties of the resin , but none that was as degrading as the whiteness .

All of that said , moisture is the most usual cause . The whiteness in the yellow one appears to be centered at the points where the plant branches . These would likely be the highest moisture areas , but are also areas where the plants chemistry may be slightly different . The gray one is more typical of what I see with aged B side resin .

 

[McKenzie Penworks]

There's dry... And then there's dry enough for urethane... If you don't dry them completely in an oven or dehydrator prior to casting there's a chance they've picked up enough atmospheric moisture to do what you're seeing. Urethane does not appreciate any moisture at all.

 

[MRDucks2]

As stated, that looks like moisture. Not much, but it doesn't take much. I have used Alumilite clear and clear slow old enough it has begun to crystallize. We simply warm mine up. Not had any issues.

 

[Todd in PA]

I measured by weight with a digital scale. I may have been deficient on the mixing because I realized after mixing I had no popsicle sticks, and used a flimsy disposable coffee stir. Hard to scrape the bottom with that.

I mixed enough for 3 rods, and after mixed, poured 1/6 into 3 cups with color. So I'm surprised that some have more white than others.

I have a dehydrator for fruit, and might do that for the next batch. I imagine a toaster oven is too much heat for flowers. I've had bubbles at the point of contact with whatever I'm casting… wood, flowers and pine cones. All were stored in my shop prior to pour. The shop is heated and a dehumidifier in there, but if allumilite is that sensitive, I'll need to dry my materials. From my perspective nothing has changed from previous successful pours, but it's summer now and relative humidity is up. I'll need to adjust.

Thanks to all for sharing your hard won experience.

Todd

 

[egnald]

For drying flowers a lot of the pro's use silica gel and sometimes silica gel and a quick blast in a microwave oven to excite the water. It is supposedly better (and faster) than dehydrator drying as far as color retention goes. I'm sure you can find information on the process by searching online. - Dave

 

[JohnU]

Sometimes stuff happens. I find my usual process with more failures at certain times of the year based on weather and humidity. Keep at it, you'll figure it out.

 

[Kenny Durrant]

It was mentioned earlier that humidity plays a part. I believe it does. My procedure is when I start working with what is already dry material I still put it in my toaster oven. To be more precise I set the molds up already sprayed with mold release and the tubes or whatever I'm casting in there. I'll put fhe whole thing in the oven for 15-20 min to make sure there's no moisture and to warm the mold. I feel that doing that helps the rain to flow around all the surfaces. I also warm the B side on a candle warmer before mixing to help with the mixing process. Sometimes if you can tweak the process it makes it easier to avoid problems.

 

[Penchant 4]

What was used to dye the Baby's Breath?

 

[Todd in PA]

It was off the shelf at Home Depot already dyed, so I'm not sure.

I did a new pour, which will probably be equally disastrous. I got out the new bottles, and thought "boy this is taking longer than usual to warm up." Turns out the new bottles are amazing clear cast, and not clear slow like the old ones. I mixed by weight instead of volume. 30 minute open time is nice, but I'm sure it's botched right from the start.

Chalk it up to another tuition payment.

 

[Kenny Durrant]

Todd you said you mixed by weight and not by volume. Both of those resins need to be mixed by weight. You'll figure out what the issue is and then you'll be set. We all have our share of troubles so when you figure out what works best for you, you can stick with it.

 

[Penchant 4]

It was off the shelf at Home Depot already dyed, so I'm not sure.

I did a new pour, which will probably be equally disastrous. I got out the new bottles, and thought "boy this is taking longer than usual to warm up." Turns out the new bottles are amazing clear cast, and not clear slow like the old ones. I mixed by weight instead of volume. 30 minute open time is nice, but I'm sure it's botched right from the start.

Chalk it up to another tuition payment.

IF the dye used was water-based, then the issue could be the incompatibility of Alumilite Clear Slow with the dye.

 

[Todd in PA]

Update.
The second batch turned out nice and clear, but seem a little soft. Like I can bend the rods with my hands slightly. I'll give them a week to continue curing in case that would help.

The label in amazing clear cast definitely states to mix by volume.

(New rods at the bottom. Old ones toward the top)

 

[MRDucks2]

My wife uses versions of amazing clear cast often. They will remain flexible for a few days to a week or more depending on mix and temperature. They are also more susceptible to heat, getting softer again if left in direct hot sun for a bit.

If you plan to use them for pens, it will be a challenge to drill due to the heat sensitivity. I tried turning a square piece round and it didn't work so well without a tube to help stiffen.

 

[Todd in PA]

I hope this won't cause issues. I have a 2 gallon set I just opened. It was a gift from my sister. I sent her a link, but it's easy to get confused between all the similarly named products.

Anyone tried freezing ACC it prior to drilling?

 

[Todd in PA]

Here are my results. I poured these for making bottle opener handles, but deemed them too soft. I switched to use them for keychains instead so they'd have the support of the brass tube.

See how soft!

They turned ok, but I could easily scratch the surface with my fingernail, so I coated in CA and polished that for a protective finish.

I wonder if they were soft because of the ratio off, or if I bought the wrong product.

What do you use Amazing Clear Cast for if not pens?

 

[MRDucks2]

Jewelry, key chains, figurines, embedded objects. She will occasionally overcoat with UV resin as a doming agent for surface blemishes but not to harden. Says you have mixed something wrong if it is still that soft.

 

[MRDucks2]

Highland Cows

 

[Penchant 4]

Here are my results. I poured these for making bottle opener handles, but deemed them too soft. I switched to use them for keychains instead so they'd have the support of the brass tube.

See how soft!
View attachment 338049

They turned ok, but I could easily scratch the surface with my fingernail, so I coated in CA and polished that for a protective finish.
View attachment 338050

I wonder if they were soft because of the ratio off, or if I bought the wrong product.

What do you use Amazing Clear Cast for if not pens?

Has Alumilite offered any advice on what the issue might be?