Alumilite woes

Signed-In Members Don't See This Ad
TomW

TomW

Member
Joined
Mar 23, 2009
Messages
1,436
Location
Allen, Texas
I got some manzanita scraps and left in 150 degree oven for 24 hours. These were less than 3/4 inch cross section and 2 inches long, with lots of voids, etc. Cast with Alumilite Crystal clear, some red alumilite dye and a little Pearl-ex. Left in the pot at 60psi for 45 minutes. The result was all the fishers in the wood were filled with little bubbles, and a failure.

Put the wood back in the oven for another 24 hours.

Poured Alumilite white, with blue alumilite dye and pearl-ex. 60psi for one hour. Great result (photos later).

Repeated the Crystal clear above on same day as the white....got lots of little bubbles.

Is it possible that the Crystal clear is that much more sensitive to moisture in the wood? Could it be the red dye, or different pearl-ex?

The wood has now been back in the oven at 150 degrees for 2 more days.

Any suggestions appreciated.

Tom
 
Signed-In Members Don't See This Ad
The dye is certainly not the problem. Could be moisture since I have seen that CC does do things differenctly with moisture. Give me a call tonight if you want some more help. It would be easier to trouble shoot your problem if we could actually talk through your steps. I helped develop Crystal Clear so I know a little about it. My number is 512-738-0775 anytime after 7pm until midnight.
 
Pearl-Ex powders like to wick moisture. Put the powder in a metal tin then in your oven for 15-30 minutes shortly before you cast to drive off any moisture. When it is dry it should be very loose- not clumped or compacted. Then add to your mixed Alumilite
 
Thought I would give CC a try as well for some small inlay. Was hoping to take advantage of the higher gloss. Also had some of the earlier water clear version. For me, the CC had a significantly higher tendency to bubble right out of the bottles. Degassing both A and B for 30 minutes in ultrasonics helped, but still saw a difference in side by side with same pigment. I'm sure pressure will help, but for this particular application, it is a little impractical. Still undecided.
 
MesquiteMan said:
The dye is certainly not the problem. Could be moisture since I have seen that CC does do things differenctly with moisture. Give me a call tonight if you want some more help. It would be easier to trouble shoot your problem if we could actually talk through your steps. I helped develop Crystal Clear so I know a little about it. My number is 512-738-0775 anytime after 7pm until midnight.
Click to expand...

Curtis,

Thanks for the offer. I'm currently out of pocket (Villahermosa Mexico). Let me get back and give one try to the Crystal clear without any dye and the 3 day dried blanks. then i'd love to talk.

Thanks
Tom
 
I've had manzanita bark cause PR to not set at all. Everywhere there was no bark was solid but there the PR touched bark, it was just like jelly. Ended up having to dig it all out with dental picks and recast.

Maybe you had some bark still in the nooks and cranies and the new CC reacts to it more like PR.

Just a thought.
GK
 
I don't know if microwaving the wood would help instead of baking it....normally you have to be careful microwaving b/c of cracking but for this purpose that might actually be a plus! I have used microwaving in the past for drying wood and it's worked well, but I've never used CC so feel free to ignore my ignorant suggestion!
 
****EDIT***

***SPOKE TOO SOON***

***PLEASE SEE POST BELOW***

Ok, I tested the "3 days at 150 degrees" wood and had no problems at all. To me this means the Crystal Clear is ~very~ sensitive to moisture.

In summary:
1 day at 150 fails with Crystal Clear Alumilite (thousands of tiny bubbles) and passes with Alumilite White.

3 days at 150 works fine with both.

Thanks for the suggestions and support. Hope this helps others.

Tom
 
Last edited:
After last post, I poured a clear Crystal Clear Alumilite blank with a small piece of mostly manzanita bark, from the "Dried 3 days batch".

***This one has multiple large bubbles all over the bark.***

Looks almost like white fungus growing all over the bark (tiny bubbles), along with a few large identifiable bubbles.

Next step is to try different wood...

Any other suggestions?

Curtis, I may need to take you up on individual help...

Tom
 
Although moisture can be a problem, personally I think that the majority of the bubbles come from either dissolved air or other gases in the resin and/or the curing reaction generates a gaseous byproduct which if not held in solution by pressure fizzes like a shaken soda bottle. Would love to hear from the company or Curtis if either of these theories is true. If so,to me the reported benefits of this newer version are not worth the cost of potentially bad casts. We still need the improved gloss, just not at the expense of bubbles.
 
There are no more bubbles with CC that there is with Water Clear. Both require pressure to get rid of bubbles. Without pressure, you will almost always get bubbles with either one.

Try a different wood and see what happens. I have never use CC with manzanita since it does not grow here in Central Texas and I only work with local woods. I have used in on cactus, mesquite, escarpment cherry, brasil, live oak, spanish oak, mescalbean, agarita, and osage orange, with no problems, though.

If you still have problems, give me a call. Don't call for a few days, though. I have laryngitis and can not talk!
 
MesquiteMan said:
There are no more bubbles with CC that there is with Water Clear. Both require pressure to get rid of bubbles. Without pressure, you will almost always get bubbles with either one.

Try a different wood and see what happens. I have never use CC with manzanita since it does not grow here in Central Texas and I only work with local woods. I have used in on cactus, mesquite, escarpment cherry, brasil, live oak, spanish oak, mescalbean, agarita, and osage orange, with no problems, though.

If you still have problems, give me a call. Don't call for a few days, though. I have laryngitis and can not talk!
Click to expand...
My experience was quite different which is why I posed the question. I have some water clear that has been sitting on my shelf for over a year and some crystal clear that I just got. I am mixing very small batches side by side (about 2 mls) The CC fizzes like crazy while the water clear has no bubbles. I am not using any pressure for this application. My guess is still that it is air in solution which has come out the the old water clear (just like flat soda after sitting) and that the CC still has the dissolved gas. If the theory holds, the CC will be good in about a year. Would still like to know if there is a gaseous byproduct if you know.
 
BRobbins629 said:
My guess is still that it is air in solution which has come out the the old water clear (just like flat soda after sitting) and that the CC still has the dissolved gas. If the theory holds, the CC will be good in about a year. Would still like to know if there is a gaseous byproduct if you know.
Click to expand...

Do you have a vacuum pump to attach to your pressure pot? If so, you
could pull a vacuum on an open bottle for a half hour or so to test
this theory.
 
NewLondon88 said:
Do you have a vacuum pump to attach to your pressure pot? If so, you
could pull a vacuum on an open bottle for a half hour or so to test
this theory.
Click to expand...
I do and also use ultrasonics to degas. I did degas for >30 minutes, normal for my PR is 5-10 minutes, it got better but still fizzed quite a bit.
 
Mine too, but I hadn't degassed yet. As I was typing that I was deciding to try it
tomorrow morning and see if it changed my own results. Tried a piece of cherry burl
over the weekend that puffed up like foam insulation. ouch.

I found that the powdered porcelain I put in it made the Part A look like Alka Seltzer.
But the humidity was high, and powdered stone soaks up moisture. Pigment powders
didn't do that, though.
 
I cast some cherry burl last week that still had bark and even some dried green mold on it. There were no unusual problems to speak of. I do find that tiny crevises on the bottom of the wood where it contacts the mold are bubbly, but the bubbly area is shallow and will turn away. Been seeing that alot lately with everything though. It's like there isn't enough squeeze at the very bottom because the mold itself won't allow air to push up? I don't know..but it isn't an issue if there is some bubbles at the surface only.
 
I've been working (finally) on using the Alumilite I bought late
last year.

In some cases, I'm getting bubbles after I pour, mostly
on swirls.

While they could certainly be air, some of the recipes I've
been playing w/ have used ArtStuf liquid dyes. My
test pieces look fine/no more bubbles in the dyed ones
than ones w/ dry pigments only.

But they all pour fine. And some of the biggest bubbles are
in areas that were a pigment-only mix.

If Alumilite foams, when does it foam:

1) As soon as the liquid hits part A?
2) When parts A and B meet and get mixed?
3) While curing?

Just trying to track these down and understand why.
That or I'll have to go back to PR.

My basic procedure:
1) Measure part A
2) Add pigments/dyes
3) Stir w/ popsicle stick and ultrasonic
4) Add part B
5) Stir w/ popsicle stick and 20-30 seconds in ultrasonic
6) Pour
 
It foams after the 2 parts are mixed and begin to react. Depending on how much water you have, it may show up quickly or it make take a little longer. Don't use any dye with water in it and you will not have a problem.

On your proceedure...I recommend doing it differently. Measure part A, add part B. and mix THOROUGHLY. I popsicle stick does not work very well, btw. Use a clear plastic cup and you will see when it is completely mixed. There will no longer be any swirls or cloudiness. I use a rubber kitchen spatula that I wipe off after each use. After getting it mixed, add you colorants and mix. Then pour.

Also, I am not so sure using ultrasonics is the best idea with Alumilite. When using ultrasonics, you use water right? Seems to me you would be running the risk of introducing moisture at least. To me, I would want to keep water and high humidity as far away from my resin as I could.
 
I'm not sure if the ArtStuf dyes are water or alcohol based.

I'd use your procedure, except that doing a 3-color swirl I'm not fast enough. Especialy when using powedered pigments where I often spend 2-3 minutes stirring them in the ultrasonic bath to break up any clumps. But even if I used alumilite dyes, it'd be tight just pouring 3 cups and mixing, then getting poured (I've lost some already).
 
Last edited:
Jason,

First off, switch to Crystal Clear if you haven't. It has a 7 minute open time. I have done 3 colors at once before with regular Alumilite Water Clear and used metallics without any problems. I have also done Red, White, and Blue with Alumilite White which has a 2.5 minute pot life. Of course I did not have to add anything to the white but I still mixed the red and the blue seperate and got all three poured for a RWB cactus blank.

I am still not sure what the ultrasonic is doing for you. I cast stuff all the time with Alumilite and get bubble free casts without the use of ultrasonics. When I mix, I mix it very vigorously too. Are you using a pressure pot or just the ultrasonic?
 
MesquiteMan said:
Jason,

First off, switch to Crystal Clear if you haven't. It has a 7 minute open time. I have done 3 colors at once before with regular Alumilite Water Clear and used metallics without any problems. I have also done Red, White, and Blue with Alumilite White which has a 2.5 minute pot life. Of course I did not have to add anything to the white but I still mixed the red and the blue seperate and got all three poured for a RWB cactus blank.
Click to expand...

I did just switch to CC from WC, haven't had that kick on me yet.
But it was about 1.5-2 min last night measuring out the part B's
for the 3-color cast. Then mixing and pouring were on top of that.

MesquiteMan said:
I am still not sure what the ultrasonic is doing for you. I cast stuff all the time with Alumilite and get bubble free casts without the use of ultrasonics. When I mix, I mix it very vigorously too. Are you using a pressure pot or just the ultrasonic?
Click to expand...

I'm not using my PP for these blanks.

I use the ultrasonic mostly for mixing.
1) It does a fantastic job of de-clumping pigments.
Clumped pigments really throw off the color recipe.

2) It mixes A/B so a little stirring w/ a popsicle stick and I have no problems with uncured parts, even in the corners of of the cup. A downside of this great mixing is I think it decreases the pot life (I don't have quantitative data on that, but it seems to hold for both alumilite and PR).

It could also be partially my mold. It's a rubber mold, but the master was
philipine mahogany so the edges are relatively rough and I think tend to hold small bubbles. (these were test pieces so I didn't powder them)

Thanks for the feedback.
 
PTJeff said:
Is this true when you are casting with no wood?
Click to expand...

Yes. According to Alumilite's directions, you need to use pressure or vacuum for ALL castings done with their clear resins. If not, you will get very tiny bubbles that look like champagne bubbles. If you are doing a blank that is not transluscent then it may not be noticeable, though.
 
MesquiteMan said:
Yes. According to Alumilite's directions, you need to use pressure or vacuum for ALL castings done with their clear resins. If not, you will get very tiny bubbles that look like champagne bubbles. If you are doing a blank that is not transluscent then it may not be noticeable, though.
Click to expand...

This could be the problem then.

A later (hence thicker) pour w/ some air bubles combined w/
the ones from Alumilite naturally and no PP.

Even though I was doing an opaque blank, I used CC to match
up w/ the recipe.
 
jason_r said:
Neither did my clock.
Click to expand...

Sorry about that. It seemed from your message saying that you took 1.5-2 minutes just to measure and that you were considering that part of your pot life time.

The bottom line is...I have cast everything under the sun with Alumilite in nearly every color possible. I frequently mix and pour 18 ounces of resin at a time and I have yet to have a problem with not having enough time. I have not lost a single cast due to running out of time. This is mostly with cactus too which requires a slow pour to get the best results.
 
Vacuuming the A & B prior to mixing them together will decrease the amount of time needed to effectively degas the A & B once mixed together. If time is an issue, by all means vacuum them seperately before mixing them.

Another thing I picked up while reviewing this post. Most pigments (powders) love to pick up moisture (our microballoons, porcelain, and many others as well). Some time drying them is required if moisture contamination is a big concern (typically more with clear casts than oqaque).

Last point, just because a dye or pigment is an alcohol base does not eliminate a moisture content. Typically anything under a .2% moisture content will work for Alumilite resins. However, if you get anywhere near .5% moisture in an alcohol based dye (which is common) you will have considerably more issues with the water reacting with the resin and creating carbon dioxide bubbles. Typically a certificate of analysis and sometimes the MSDS on the dye will list a moisture content.

Even Alumilite's reactive dyes contain moisture but the levels are all under .1% which is the key.

Mike
Alumilite
800 447-9344
 
Mike,
thanks for the followup, it's nice to get the company involved in our activities as well. My questions stem from the need to make a large sheet of cast that will not fit in a 2 1/2 gallon paint pot. So I was trying to get around the pressure step during the casting process. but...to quote Curtis "The nature of urethane resin is that is creates bubbles when it cures."

as a result, i am having to re-engineer my process, which is OK for now but much better than pouring 32 oz and seeing it bubble
 
Mike,

Any explanation why Manzanita reacts with Crystal clear and White Alumilite doesn't? I'm having success with Crystal clear every time except when Manzanita is the base wood.

Thanks
Tom
 
Alumilite said:
the water reacting with the resin and creating carbon dioxide bubbles.

Mike
Alumilite
800 447-9344
Click to expand...
Mike - If there is no or very low levels of moisture in pigments and the resin components are degassed such that dissolved air is out, will carbon dioxide still be generated during cure? Or is it generated only if moisture is present.

Also - is there any difference in the volume of gas generated during the curing reaction (assuming no moisture present) between crystal clear and water clear?

Thanks - been trying to get an answer to this as it will help decide my path for future projects.
 
PTJeff - Most people that cast parts with the clear resin rarely use pressure unless necessary with complex contours due to the added step. Most will simply mix equal parts thoroughly, degas, and pour. If you are simply doing a big open pour, this process should work great for you. To start I'd probably even degas A & B prior to starting, then mix, degas, and pour. "Nature of urethanes ..." not necessarily but practically yes, there are many factors that play in the creation of air while urethanes are curing. Some are just so small they never are a factor, others are more noticeable and do become factors.

Tom - You guys are the wood experts however I will add the longer the moisture has to react, the more prevelent the bubbles tend to be. Porosity and density play a big role in wood. Honestly I'm not familiar with Manzanita at all and wouldn't have a clue as to a comparison with other wood. But longer open time materials tend to create more foam or bubbles than quicker resins which would be one reason the White doesn't seem to be as problematic as the Crystal Clear.

BRobbins629 - Moisture, inducing air, and porosity are the primary ways that really play any significant role of air showing up in your finished part. Water Clear vs. Crystal Clear ... honestly don't have a lot of comparison data with sensitivity to moisture due to most of the casting done with both products are free from any additive other than small amounts of our dye and/or fillers which have very little moisture to begin with. Some of your testing with different wood and comparing the products head to head that are exposed to slightly higher moisture contents are more than what we have tested. Comparing moisture sensitivity between products has not been in our scope of testing products. This is the first time in my 11 years the question has ever been raised. I simply don't have an answer for it yet.

So unfortunately I don't think I have any conclusive tests results that will lead you in one direction or another but will continue to look into this and see what information I can dig up that may help.

Mike
Alumilite
800 447-9344
 
Degas the two sides individually until they both pretty much clear up. Normally it takes the polyol side a little longer. Might take as much as ten minutes but this will significantly speed up the required time to degas when they are mixed together.

Mike
Alumilite
 
Closed vs. Open

A solution may have surfaced to my issue with spongy results inside a carved out 30.06 bullet. Even though I have been heating the bullet casing with a mini blow torch, the object was being placed in to a tube, vacumed and baked with less than hard results. I believe these should be cast OPEN, not inside a tube.

What do you think?
 
You must log in or register to reply here.
Back
Top Bottom