Casting Fail: Alumilite Clear Completely White!

[lhowell]

Tonight I decided to cast two label tubes that I had spent the majority of last night preparing. They were a logo surrounded by HVAC tape "armor plates." I had a brand new set of Alumilite Clear A and B side, mixed them 1:1 and poured into the tube molds. Into the pressure pot they went and a few hours later I was shocked to find a completely opaque white cast around my label cast tubes! The only differences were:

New set of Alumilite...could be bad? Maybe they sent Alumilite White in clear bottles?
Previous ambient temperatures of successful casts were mid 80's. Tonight was mid 60's
"Armor plates" were "antiqued" using Testors gloss black acrylic enamel paint versus normal enamel. Maybe that had something to do with it?

I have included a picture but any help would be greatly appreciated as this was a costly mistake that I would rather not repeat!

 

[lhowell]

P.S.- I have painted tubes with that same Acrylic enamel model paint when casting abalone blanks and had no issue.

 

[robutacion]

I'm not an Alumilite user from the pic, it seems to me you, you had the white instead of the clear Alumilite, I can't see how anything else in the mix could have make it that white..!

Cheers
George

 

[1080Wayne]

Any chance the air from your pressure tank was not fully dry ? I have had totally opaque white casts with that as my problem . You have had some pretty wet conditions lately .

 

[jttheclockman]

May I suggest you try a simple test and do a seperate pour with no painted tubes or anything and see what happens. Might as well start at the beginning. Make sure you do not do anything different than this pour. If they made a mistake they will stand good. If it is something else we start calling off the possibilities. No sense guessing until you get past first test. Good luck.

 

[TBCbushings]

That happen to me once. I warm my molds prior to casting. Also if you mix in small amounts the the ratio might be off a little bit.

 

[lhowell]

1080 Wayne: Could be as I do not have a filter on the air compressor

John: Yes, that was my next attempt is to either use blank tubes or no tubes and cast

Nikitas: I have heard to warm the molds and it was only a small amount; just enough to cover the tubes in the PtownSubbie molds. But, I have done this previously with a high rate of success!

Next question is, is there a way to salvage the blanks out of this or is this just throwaway? I've thought about mounting them on the lathe to see how deep the white goes but my assumption is it is completely white...

 

[Kenny Durrant]

Another issue could be the ratio. It's 1:1 by weight. If thats off it will turn white as well. I started with a $20 scale from Harbor Freight and it worked well for quite a while. Then I started having problems and a friend said his H.F. was acting up so he bought a better scale. I asked where and he said a local head shop. If you don't know what that is then good for you just let that part go. So I went to one, the first time I've ever been to one, and spent $75 on a nice small digital scale. I asked about a warranty and they laughed and said no. Since I'm getting old that's when I decided to look on the internet to find out about a warrenty and found the same scale for $8. If you think that might be the problem look on Ebay or Amazon first. At 28 grams an ounce make sure the scale will weigh the amount you need. Some of the ones I looked at maxed out at 50 gr.

 

[jttheclockman]

You are not going to change what the blanks look like by some magic so turn them down and see what the final look is. If it does clear up you are ahead of the game. As far as soaking in something to dissolve it I have no clue there. I do not use alumilite.

 

[1080Wayne]

The white will go all the way through but the opacity shouldn`t be too high . I would turn them down to size , sand them and see what they look like . Some of my nicest pieces have been Alumilite/moisture wrecks .

 

[lhowell]

Thanks all for the feedback! I'll go ahead and turn them down to see what they look like and cast some of the new stuff by itself to see if similar results occur and if so adjust my method.

 

[lhowell]

So I pulled the cup I used to mix the resin out of the trash and it was pretty white too which is leading me to believe that I got a batch of Alumilite white labeled as clear. Going to do a stand alone cast tonight before jumping to my final conclusion.

 

[DLGunn]

Where did you get the Alumilite? I'm guessing it says clear on the bottles/jugs of Alumilite?

 

[jttheclockman]

So I pulled the cup I used to mix the resin out of the trash and it was pretty white too which is leading me to believe that I got a batch of Alumilite white labeled as clear. Going to do a stand alone cast tonight before jumping to my final conclusion.

That is the best thing to do. Of course if it is white then you will not be able to see the logo label or the other parts casted in the blank. Sorry about that. Good thing it was not a watch part pen casting. That would hurt.

 

[1080Wayne]

The amount of whiteness in the cup is not inconsistent with a bit too much A side , maybe 2-3 % ??

 

[lhowell]

The amount of whiteness in the cup is not inconsistent with a bit too much A side , maybe 2-3 % ??

Bingo! Poured same amount tonight into a cup and put in the pressure pot similar conditions as last night and a little white around the cup rim but came out clear as a bell...

I turned one of the blanks down for fun and something was off. The blank was extremely soft and the ribbons did not want to pull off the lathe mandrel like normal Alumilite. I think 1080Wayne nailed it. Somehow my ratio was off. Mixing only enough to put in the tube molds can be easy to mix too much of a prob side...

Thanks for your help everyone!!!

 

[lhowell]

Where did you get the Alumilite? I'm guessing it says clear on the bottles/jugs of Alumilite?

I did get it off Amazon but it said from Alumilite Corp. ships and sold by Amazon. Indeed it does say clear on both bottles.

 

[SteveG]

I understand the stuff is EXTREMELY sensitive to proper proportions. Then, after that, it is VERY sensitive to moisture. :wink:

Is this where that authoritative voice from off camera says: "Pay attention...you might learn something." :beat-up:

 

[mg_dreyer]

The problem is really the margin of error on small pours. My guess is it was the ratio. Here is the problem - if your scale is +/- .5 oz and you are pouring only 2 oz of each liquid the .5 represents 25%. Meaning if you thought you poured 2 oz you might have poured 2.49 oz (margin of error). Even if your scale is +/- .1 oz that is 5% (on 2 oz.) you might be off. If you are doing a larger pour, say 8 oz at +/- .1 you are now at ~ 1%. This is just my opinion - and yes I have had the same thing happen on small pours.

 

[lhowell]

The problem is really the margin of error on small pours. My guess is it was the ratio. Here is the problem - if your scale is +/- .5 oz and you are pouring only 2 oz of each liquid the .5 represents 25%. Meaning if you thought you poured 2 oz you might have poured 2.49 oz (margin of error). Even if your scale is +/- .1 oz that is 5% (on 2 oz.) you might be off. If you are doing a larger pour, say 8 oz at +/- .1 you are now at ~ 1%. This is just my opinion - and yes I have had the same thing happen on small pours.

That would be my guess. This mold only takes about 1.5oz total (0.75oz of each A and B) so the margin is extremely tight. The pour that turned out white I poured the B side first, zeroed the scale and poured the A side. Typically, I pour A side first and the B side. I am assuming either my scale was off when I poured the B side or when I zeroed it to pour the A side something happened. I'll stick with pouring A side first as my casts doing that have turned out ok.

From Alumilite forums it seems that if anything you want to short A side just a hair if you are having issues so I'll stick with what has worked for me in the past and pour A Side first then B side!

Thanks!

 

[jsolie]

Where did you get the Alumilite? I'm guessing it says clear on the bottles/jugs of Alumilite?

I did get it off Amazon but it said from Alumilite Corp. ships and sold by Amazon. Indeed it does say clear on both bottles.

I've purchase Alumilite from Amazon before. The B part was very viscous on the last batch I ought from Amazon. I was able to get some decent pours out of it, but it never did quite behave right. Before you say "too cold," I got this batch in early Summer, and the last pour I did with it in late July/early August, it was pushing 100 degrees outside.

My next batch was from Alumilite directly. I figured that the stuff sits around in Amazon's warehouses a lot longer than it does in Alumilite's. So be careful ordering Alumilite from Amazon.

 

[Hawkeye53]

The "B" side thickens over time. Yes, it's temperature related, but the table is set so to speak by time. Many videos on this issue, check out Zac Higgins NVWoodWerks.com and his youtube.com videos. It's an easy fix.

 

[MesquiteMan]

You problem is absolutely a mix issue and nothing more. The white in the pictures are not white enough to be Alumilite White.

All Alumilite Clear B side will thicken over time. Notice it even mentions this on both Alumilite's as well as my site. Completely normal and it can happen quickly or it can take a long time. It is all humidity and temperature related. To thin it, all you need to do is get a pot of very hot water and place the jug in it until it thins back out. It will then stay thin for a good while. Do not use it while the B side is hot or it will cure much faster than normal.