Alumilite Problem

[Tom Albrecht]

For those of you who are experienced with casting in Alumilite slow/clear...
It has been a while since I did any pen casting, but this morning I made two different mixes within minutes of each other. All the components were at the same temperature, 72f. The picture shows some blue/green pen blanks that turned out perfect, and then two blanks poured with the same amber tinted mix. Both the pine cones and the cherry burl in the amber mix turned milky and are still very sticky. Any ideas as to what caused that?

 

[Ed Davidson]

Moisture in the pine cones and burl wood is most likely the source of your problem. Alumilite hates water.

 

[Tom Albrecht]

So, maybe heating the pine cones and burl in a low temp oven first?

 

[Ed Davidson]

So, maybe heating the pine cones and burl in a low temp oven first?

On the pine cones, yes...they need to be bone dry. Perhaps sealing them after the oven treatment would help as well. On the burl, are you just coating a blank with the resin mix, or filling voids? Can't tell by the posted photo. Check out this guy's YouTube videos...he covers everything related to casting: https://www.youtube.com/c/CaseyMartinWineCountryPens

 

[Keith Mombourquette]

Ed is right. Aluminized does not like moisture. I heat anything that is to be cast in aAlumilite, and wrap it in plastic zip bags until ready to cast. I have stabilized pine cones, but I don't think it is necessary as long as they are fully dried.

 

[Seth Belcher]

On the pine cones, yes...they need to be bone dry. Perhaps sealing them after the oven treatment would help as well. On the burl, are you just coating a blank with the resin mix, filling voids? Can't tell by the posted photo. Check out this guy's YouTube videos...he covers everything related to casting: https://www.youtube.com/c/CaseyMartinWineCountryPens

Ed's right, Alumilite Clear Slow, or any urethane resin, has a horrible relationship with moisture. I made some pen blanks about a year ago with CS and mini pine cones. Before I put the pine cones in the blank I baked them at 225 for 2 hrs and that seemed to prevent any reaction issues with any potential moisture.