Alumilite soft?

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mywoodshopca

mywoodshopca

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How long does alumilite take to cure?

I made a few blanks about 2 weeks ago and was about to turn one tonight, it was a little "soft".. if you put something hard against it for a second, you would see an indentation.

I mixed it 50/50 with a manual scale. Would the mixture off by a small bit from using a manual scale make this problem?

I am picking up a digital one tomorrow to see if this fixes it :)

Thanks Jason
 
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Most likely cause is inadequate stirring . Easy to tell on clear because the mix should be crystal clear when properly mixed . No experience with colours , but would suggest 2 minutes should be plenty .
 
The only time that has happened to me was bec I used the wrong part "B". (I was mixing clear and added the part "B" from white) Was the shop really cold when you did the cast? You can try sticking the cast in a toaster oven at about 140-150 degrees for about 20-30 minutes. When you pull it ot make sure you lay it on a flat surface then let it cool down...if this doesn't fix it then maybe it was a ratio issue

Eugene
 
Thanks guys,

Mixed for about 60 seconds.
Shops warm, its in the basement.(furnace is about 40ft away)
Left in pressure pot about 10 minutes. did do a toaster oven for about 10 minutes as well right afterwards then let it sit.

It must have been a ratio or a mixing issue. I just picked up a digital scale so I should be more accurate now :)

I did seperate pours of the part a & b then poured it into a third dish to mix. Any problems pouring part a into a dish, zeroing out the scale then pouring the same amount of part b on top then mixing? This would eliminate extra pouring steps and save cups.

Thanks!
 
mywoodshopca said:
Thanks guys,

Mixed for about 60 seconds.
Shops warm, its in the basement.(furnace is about 40ft away)
Left in pressure pot about 10 minutes. did do a toaster oven for about 10 minutes as well right afterwards then let it sit.

It must have been a ratio or a mixing issue. I just picked up a digital scale so I should be more accurate now :)

I did seperate pours of the part a & b then poured it into a third dish to mix. Any problems pouring part a into a dish, zeroing out the scale then pouring the same amount of part b on top then mixing? This would eliminate extra pouring steps and save cups.

Thanks!
Click to expand...

What I do is pour A then pour B in the same container then mix. Let's say I need 10 oz, I pour 5 oz of a then pour then pour part B until it marks 10. Using 3 containers may affect the ratio since some of the resin will stay in each of the cups. Especially if you are mixing small batches, 1/2 oz of resin may not seem much but in a small pour it will affect the 50/50 ratio.
 
ElMostro said:
1/2 oz of resin may not seem much but in a small pour it will affect the 50/50 ratio.
Click to expand...

Two problems with small batches. Eugene nailed the first one here. A small difference in measurement accuracy makes a big difference in final percentages. The cup residue differences could also make a big difference.

Secondly, Curtis helped me through a drought by reminding me that small batches may have trouble kicking off, especially in lower (I didn't say cold) temperatures. I had problems with Charlie's resin saver molds and alumilite, until, at Curtis' suggestion I started pre heating the molds. No problems since.

I bet you'll be fine.

Tom
 
2 weeks is a long time for it to take to set, what did you add to it to color it? I am remembering that some nail polish did that to me once. Heating it in a dedicated oven would help.

The way I pour is by the gram, I usually pour 80 grams at a time of "A" and then right in the same cup pour 80 grams of "B" and then stir, after it is clear( no strings running through it) I break it into smaller portions and then add my coloring agents.
 
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mywoodshopca said:
Used some michaels resin dyes. It was only a small amount made, enough to make one pen so I must have been off on my mixtures :)
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I am a lot more comfortable using powdered micas or Alumilite dyes, they are always compatable. It almost sounds like what the nail polish did to me, it hardened after 3 weeks.
 
mywoodshopca said:
Sounds like it. Note to self: dont use nail polish or this if I want to turn the same month lol
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I would mix up another small batch and see if it happens again, but split the resin into 2 groups before coloring it and compare the results in an hour or two. That should tell you for sure if that is it.
 
I would almost guarantee you did not get it mixed properly. Measuring with a manual scale is not the issue. That is the way I do all of my casting. I do not use a digital scale and have not had any problems with it setting.

Are you using clear plastic cups? If not, I would highly suggest doing so. Then do as Eugene said and skip the 3 cups. You are only making things more difficult If you want to have 10 ounces of mixed resin, put your cup on the scale and zero it out. Then pour one part until it reaches 5 oz. Then switch to the other part and finish pouring until you get to 10 ounces. If you are off just a little, it will not be a problem.

Now use a rubber kitchen spatula and stir aggressively, scraping the sides and bottom of the cup as you go. With the clear cup, you will be able to see into the resin. When you first start out, the resin will be cloudy and full of streaks. Once it is completely mixed, it will become clear with no streaks at all. Now add your dye and mix thoroughly. Do not rush things.

The next time you do a batch, make just more than you need. Leave the excess in the cup and watch it to see how long it takes to go off. This will help you realize that you do not need to rush things like you may think.

Another suggestion is to stick with Alumilite's dyes. They are made to be compatible and are not any more expensive than other dyes when you consider how concentrated they are. One drop per ounce gives great colors in the clear and a small bottle will last you a long time.
 
Yes, I was using the small mixing cups that the hobby store I got the alumilite at had.

I just tried mixing up an ounce and its hardening pretty good now.

First few times I mixed for 60 seconds, this time I mixed for about 2 minutes then added a few dye swirls and put into the pressure pot (just enough to make a pendant)

Reason I got the casting resin is the hobby store didnt have any alumilite dyes in stock, even though they show they had it on their site..
 
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