Reasons to READ before leaping!

[KiltedGunn]

So, after a quick demo of casting labels using Alumilite at Monty's, I broke down and ordered a ResinSaver mold from Charlie (Worked Great by the way!)...

Spent hours and hours, and quite a bit of ink, figuring out the correct sizing of the images for the tubes (Sierras and Jr Gents) and got them mounted and trimmed...Got my pressure pot back from a buddy and gave it a try...

I didn't have a scale so, like Ron in his thread that I just read, I SWAG'd it (actually went by volume). I mixed until it looked clear then filled the mold. Then I put the mold under 40-50 psi for 1 1/2 hours (hoping the longer time under pressure would compensate for using volume instead of weight).

After reading Ron's thread, I guess I'll go buy a scale...and then I'll move everything inside out of the 95 degree/95% humidity garage into the air-conditioned kitchen!

Any other ideas why these castings came out crystal clear EXCEPT for all of the bubbles around the labels???

 

[RAdams]

glad i could help! Wish i could help more!

 

[Mark]

I'm not a casting pro by any means...

My guess (just a guess) would be the CA still off gassing from adhering the labels.. Or possibly moisture from the ink?
Did you use CA?:biggrin:

 

[KiltedGunn]

No CA, just stuck the self-adhesive labels to the tubes...and let them dry overnight before casting, so I don't think that was it.

Bu thanks, I forgot to mention that part! :wink:

 

[Mark]

Lee, The only other source of air I can see, would be what was trapped under the label when it was pressurized. IDK, hopefully someone here can answer the question.

Good Luck..

 

[KiltedGunn]

Hmm, could be Mark but I rolled them pretty tight. I actually put much more effort into rolling them this time than I did for the ones we used at Monty's...and those came out clear as a bell!

Monty's shop has A/C so that helped with the high heat and humidity...but now I'm trying to remember, did he say stir until clear or stir until milky???

Curtis?

 

[KiltedGunn]

As I read a little more I see where moisture can be a problem...

I thought I was being smart by filling the mold with water then pouring the water into a measuring cup to get a target amount.

I'm pretty sure that I got all of the water out, but next time I'll be sure the mold is dry before I start!

Headed to Target for a scale...can't bring myself to go to the local head shop to buy one!

 

[Mark]

I'm guessing that is your answer.. Just not sure why it accumulated around the labels.

Looking forward to the next go around..

 

[PTownSubbie]

I think the labels probably had some humidity in them. If they are moistened by the humidity and then cast, the moisture will leech out causing the reaction you saw.

If that is not it, maybe allow to sit a bit longer before casting them.

Do you have any moisture in your compressors air stream? How often do you blow down your compressor tank?

 

[KiltedGunn]

Fred, I have no idea what you're talking about. So I guess the answer is "never".

I should empty my compressor? Is that what you're saying?

 

[PTownSubbie]

Fred, I have no idea what you're talking about. So I guess the answer is "never".

I should empty my compressor? Is that what you're saying?

There is usually a drain plug on the bottom of your compressor tank and allows you to blow it down and get rid of any liquid in your compressor tank.

Do you leave your compressor pressurized all the time? This stop **** I am talking about is the same one that you depressurize your tank with if you do that between uses.

 

[KiltedGunn]

Yeah, Fred, I leave it plugged in and pressurized all the time...but now I'll go empty it and see if anything drips out! :wink:

Found a scale at my local tobacco shop so I'm gonna go back to work on printing labels...

This time, I'll let the labels dry INSIDE instead of moving them to the garage!

Then we'll give it another run!

Thanks for all of the advice guys...more results later tonight I hope! :wink:

 

[KiltedGunn]

Yeah, I'm gonna bet that the 6 - 8 OUNCES of water I drained out of my little 2 1/2 gallon pancake compressor might have had something to do with moisture getting into the freakin pressure pot! :redface:

But, hey, now I know! :wink:

 

[dogcatcher]

...and then I'll move everything inside out of the 95 degree/95% humidity garage into the air-conditioned kitchen!
QUOTE]

Better read this first, http://www.alumilite.com/MSDS/Alumilite Regular.pdf
Just because it doesn't smell bad doesn't mean you don't need to use proper safety precautions.

 

[louie]

If you leave your compressor on, you might want to get on of these:


http://www.homedepot.com/webapp/wcs...langId=-1&catalogId=10053&productId=100027474

I put one on my compressor to make sure no condensation interfered with my castings. Make sure you get the proper size for you compressor.

 

[bruce119]

Now I got my own ideas and see something else in your photo that wasn't discussed.

First the issue of the air silvering. Now I don't use Alumilite anymore but I do know and hear that it does not like a moisture at all. Also I was a printer for over 40 years so have some experience in this. Now paper is like a sponge it will soak up moisture out of the air. You said you were working in 95% humidity a little exaggerated I suspect that's like working in the rain. That would be a probable source of a lot of problems. One of the reasons I switched a long time ago to Polyester resin not quite as sensitive. But there are a lot of pros and cons too many to get into now.

Another problem you used pressure. I used to, and still do in some cases, use pressure. But with labels not necessary and could also be the source of the problem. Paper has air in it the adhesive from sticky labels has air in it (CA would have been better) Now by using pressure you squeezed that air down and when the pressure was released the air exploded to the surface of the label why you see the silvery air layer. I have seen this in snake skin cast. Also you can't use that kind of pressure 50 lbs with the silicone resin saver molds. Now the resin saver molds are great but can't handle pressures over 10 lbs. Look at your cast I can see the ends of the tubes extruding from the resin. Now when you put them in the resin they had wiggle room rite there was space on each side. What is happening is when pressure is introduced like the air the silicone mold is being squeezed and the mold it self shrinks the resin does not shrink. You have now damaged your mold check the tube **** grab them gently and wiggle them you will see were the tube has cut into the silicone. I have learned this the hard way. Your molds are still good just be gentle and be aware.

There's a lot more to talk about and still even more unknowns isn't casting fun. It can be very frustrating at times. Some people make it sound so easy and they could give you a step by step instructions but that dose not mean success. There are a lot of variables like humidity and just technique the way we stir the time the little things that can't be explained that a person would need to see but that's getting too deep.

Enough
Good luck let us know how you make out

 

[splinter99]

I bought a sample size Alumilite water clear and used it for worthless wood casting and several other things.. I had read about the crystal clear so asked for the 2 gallon size for Christmas..Also bought 4 of the resin saver molds..Well, I have yet to produce one sucessfull casting with the crystal clear..even just coloring it with pigment powders causes it to foam..It spent a few extra days in sub freezing weather due to a ups shipping error but I called them and they said that wouldnt hurt it.. I use the white and never had a problem..could I have got a bad batch??

 

[KiltedGunn]

Well, judging by the way last night's batch came out (Very well, thank you!), I'm gonna have to point to all of the water in the compressor!

Again, now that I know its there, I'll work on preventing it. And thanks, Lou, for the tip on the filter.

Yeah, Bruce...standard joke about high humidity, I'm sure I was exxagerating and I have no idea what it actually was, but if you look up average relative humidity for Houston area it says 92-93% for the summer months. :wink:

Anyway, I lowered the pressure like Charlie suggested, warmed the mold and the labels and they turned out fine.

AND I was able to refine the pictures and get better images on the second set of labels, so it wasn't a complete waste! :biggrin:

Thanks again for all of your help! I'll be back next time I screw something up! For now, I'm gonna go see how many of these I blow up on the lathe!

 

[bruce119]

I know all about heat and humidity I live in Florida. Looks like you mite be still using a little too much pressure. From the photos I can or it appearers that the end of the tubes are sticking out. You can get away with it for yourself with the Sierra & Gents but it wouldn't work with cigars they are not forgiving. Try casting with no pressure if your carefully you should have no problem doing simple label casting with no pressure. Now embedded stuff and things like snake skin is another story and a whole different can of worms.

Am I seeing the photos correctly are the ends of your tubes sticking out. How much pressure did you use on that cast.

Getting better isn't this fun.

 

[KiltedGunn]

Yeah, Bruce, but y'all have a BREEZE!!!

Anyway, yes, the tubes are just barely feelable sticking out the ends of the Alumilite...and you're right, when I put them on the nibs/teats/whatever I left some of it exposed to try to prevent this.

I used 25psi this time...as opposed to 40psi the first time. Next time, I'll try 10psi...and give one a try without any pressure at all, like you suggested, just to see how it works.