Casting issues

[Tiger52]

I have literally just started casting pen blanks. Pulled the second one I've done out of the pot and it has a thin, milky white surface in what would be the top of the blank. I'm casting in my garage where its 60° +/-. Could that also be an indicator of moisture in the tank?

 

[its_virgil]

I have literally just started casting pen blanks. Pulled the second one I've done out of the pot and it has a thin, milky white surface in what would be the top of the blank. I'm casting in my garage where its 60° +/-. Could that also be an indicator of moisture in the tank?

Resin type would be very helpful

 

[Tiger52]

Resin type would be very helpful

Alumilite casting resin from Woodcraft

 

[its_virgil]

Alumilite is not a resin type but a brand name. Which Alumilite? Epoxy or urethane. Amazing clear cast is the epoxy and clear cast and clear slow are the urethanes.

 

[Tiger52]

Alumilite is not a resin type but a brand name. Which Alumilite? Epoxy or urethane. Amazing clear cast is the epoxy and clear cast and clear slow are the urethanes.

Sorry, its the clear slow

 

[its_virgil]

White and milky is caused by one or both of two things: incorrect ratio or insufficient mixing. Correct ratios are not difficult to obtain. Most often the mixing is the culprit. The sides and bottom of the mixing container must be scraped to insure all of both parts are incorporated into the mix. If the two parts are poured into two containers then one added to the other be sure to scrape the sides and bottom of the one added to get all of that part from its container to the second container. This is often where the ratio is off...insufficient mixing. Smaller casts, such as one or two pen blanks are more sensitive to these two things: ratios and mixing.
Do a good turn daily!
Don

 

[Tiger52]

White and milky is caused by one or both of two things: incorrect ratio or insufficient mixing. Correct ratios are not difficult to obtain. Most often the mixing is the culprit. The sides and bottom of the mixing container must be scraped to insure all of both parts are incorporated into the mix. If the two parts are poured into two containers then one added to the other be sure to scrape the sides and bottom of the one added to get all of that part from its container to the second container. This is often where the ratio is off...insufficient mixing. Smaller casts, such as one or two pen blanks are more sensitive to these two things: ratios and mixing.
Do a good turn daily!
Don

Good to know, thanks

 

[JohnU]

Like Don said, it's probably the mixing. It's a common problem when the B side is thicker and harder to get mixed. I would suggest warming the B side to around 80-90 degrees prior to mixing. Try using an electric drill to stir the resin. It will go much fast and do a better job. Also, pour side B into side A while mixing. If it is still thicker, it will reduce the thick resin from staying in the bottom and along the edges.
good luck! And hope we see some of your success posted here!

 

[Kenny Durrant]

Another thought after reading John U reply. Before I start I want to make it clear that this isn't a contradiction to what he suggested just a different line of thinking. I admire his work and have purchased his blanks so I'm not suggesting this is better or worse just different. Anyway personally I like weighing up the B side first. I warm it up then weigh up the A in the same cup. I use small batches so I don't have to worry about any residual resin not being transferred and throwing off the ratio.

 

[1080Wayne]

I second Kenny`s approach for small batches .