Interesting Casting Failure

[CabinetMaker]

This was a second attempt at casting a horse hair pen. The tubes were painted black and the hair was glued to the tube with medium CA. The name tag was brass plated, CA glued to the horse hair and then the whole thing was cast in Amazing Clear Cast. When I pulled it out of the pressure pot, I noticed that there was a white discoloration around the name tag. When I pulled the blank out of the mold, there was resin inside the tubes. I easily knocked the resin out, put it on the lathe and started turning. Eventually I learned that the way I had put it together would not work with the pen kit I am using. I decided to turn the casting off the tubes so I could reuse the tubes and this is what I found. The brass tube had corroded completely away.

An interesting learning experience though I'm not sure exactly what I learned as I don't know what caused the reaction. I'm on to attempt #3! This time no painted tubes or name tags.

 

[tomtedesco]

What have you been feeding that horse?

 

[Bob F]

wow -thats crazy Tom , i'm not sure what to think of the tube and what caused that ,I have a few thoughts for you on the rest - The white was most likely from moisture or oil from the hair or possibly a reaction with the CA , I have done horse hair before and the first few attempst failed , I believe because of the oil in the hair , it can be vary oily , after the first few fails i soaked some of it in alcohol for a few hours and it seemed to remove / strip the oily residue -after it had dried for a awhile i then put it in a desicant for a few days to help remove any moisture from the humidity in the air and then I cast it --and this time all was good -- these where hybrids so i didnt have a tube to worry about gluing to - i hear from people doing lable casts that CA doesnt play well with some resins ( i dont know with with the epoxy you used ) --although it sounds like some people have success with CA holding things in place before casting ( again -dont know if thats with epoxy ) , but i know they recommend letting the CA dry for a few days for sure to off gas completly

 

[Woodchipper]

Hmmm.

 

[CabinetMaker]

wow -thats crazy Tom , i'm not sure what to think of the tube and what caused that ,I have a few thoughts for you on the rest - The white was most likely from moisture or oil from the hair or possibly a reaction with the CA , I have done horse hair before and the first few attempst failed , I believe because of the oil in the hair , it can be vary oily , after the first few fails i soaked some of it in alcohol for a few hours and it seemed to remove / strip the oily residue -after it had dried for a awhile i then put it in a desicant for a few days to help remove any moisture from the humidity in the air and then I cast it --and this time all was good -- these where hybrids so i didnt have a tube to worry about gluing to - i hear from people doing lable casts that CA doesnt play well with some resins ( i dont know with with the epoxy you used ) --although it sounds like some people have success with CA holding things in place before casting ( again -dont know if thats with epoxy ) , but i know they recommend letting the CA dry for a few days for sure to off gas completly

For my next attempt, I have taken the hair and washed it really well with Dawn to get all the oils off the hair. I have been using the Alumilite Urethane for the casting, on their recommendation. I made a blank and didn't have any problems with the tube. I did have a little failure with the casting pulling away from the hair after I turned it. I suspect oil on the hair so, as mentioned above, I washed it again. Thanks for the input!

 

[ctfolmar]

Horse hair holds alot of moisture. Very accurate hygrometers are made with tail or mane hair.
"When the relative humidity begins to rise inside the humidor, this hygrometer's horsehair begins to expand. The ever-expanding horse hair, as the relative humidity of the humidor continues to rise, eventually moves the wound springs inside the hygrometer, thereby indicating high levels of humidity on the hygrometer's external gauge. When the humidity begins to drop, the horsehair contracts, the springs retract into tightly wound coils again and the hygrometer's gauge drops."