Casting Chiyogami First Result

[Lathemaster]

First let me say to all the generous and talented turners and casters here I stand on their shoulders and benefit from their knowledge sharing.

So here is the result from my first attempt at casting Chiyogami with PR. It is a simple design Chrysanthemum on blue. There is a small bubble that was trapped along the seam that is "hidden" under the clip. It's twin cast at the same time had 2 bubbles trapped along the seam as well. Normally I would not have assembled the Pen but my wife fell in love with the polished blank. Kit is an older Sierra that was kicking around the parts box.

So two lessons here. Keep the seam on top in the mold and for the second cast that followed I degassed the resin in my vacuum chamber for 5 minutes before pouring.

Thanks for looking.

 

[sbell111]

What is your casting method? Do you cast under pressure? How did you affix the paper to the tube? Did you the seal the paper with anything prior to casting?

 

[Lathemaster]

Steve
There are great and plentiful articles in the library and many threads on the topic but that said in a nutshell.

I attached the paper to the tubes with decoupage.
I did not choose to paint the tunes as chose to do a slight overlap joint that would ultimately be under the clip.
After applying the paper to the tube it was allowed to dry and cure for 24 hours.
After curing I sealed the wrap with a coat of thin CA glue and allowed it to cure and degas for 24 hours.
The tubes were placed in a Resin Saver Mold available from a member here with paper joint facing up.
Tap polyester resin with 3 drops of catalyst per Oz of resin by weight.
Resin mixture into vacuum chamber for 5 minutes at full vacuum.
Slow pour into mold. Mold time at shop temp 85 F plus for 6 hours and cured in house at air conditioning temps for 24 hrs.

Hope this helps
Mike

 

[sbell111]

Thanks, but I wasn't looking for help. I was asking you those questions to try to help you with your bubble issue (which is related to your not casting under pressure, by the way).

 

[Lathemaster]

Steve

So easy to misread forum posts.

I use pressure for Alumilite casting. For PR I am not using pressure mainly because of the silicone molds for tube on casting. Concerned that pressure might distort the mold and force resin into the tube. Concentrating on a process that keeps bubbles out of the resin altogether.

Cheers
Mike

 

[seamus7227]

Concerned that pressure might distort the mold and force resin into the tube. Concentrating on a process that keeps bubbles out of the resin altogether.

Cheers
Mike

It is possible to cast those silicone molds using pressure. However, with that said, a few steps you mentioned might need to be tweeked slighly. I would consider trying CA to glue the paper to the tube and be sure you have the tube on a flat surface as you roll it so essentially all of the air is pressed out. Then if you are going to CA over the paper, use a light coat and let it sit for longer than 24 hours(IMO) I have found that in dealing with my snakeskin blanks that if they sit for several days that my failures are less than 1% over the course of casting somewhere in the range of 50 blanks, so i think thats pretty good. Another issue is making sure the ends of the tubes are plugged really tight. As the resin heats up, if the ends of the tubes are not plugged "snug" enough, i believe the air inside the tube is heated and expelled where ever the path of least resistance is(usually a silicone plug not tight enough).

I realize we all have our owns ways of doing this, but if you havent tried multiple ways, you really never know what method is really going to work the best for you.

Also, i think the whole degassing process of PR via vacuum is a complete waste of time. But then, i use a pressure pot too.

 

[Lathemaster]

Good intelligence. Thanks