Casting Ribbons

[kevrob]

Over the weekend I tried my hand at casting ribbons using silmar 41. I didn't seem to have many problems with the ribbons, but when I tried to turn the cast tonight, it all fell apart and it happened right where the ribbon was. Have any of you had this issue and is this common? Any guesses as to what the issue might have been? Was I too aggressive while removing material? Did I let the ribbons set-up to much before casting them a again (It did go a few days and i did have to heat them to make them flexible), but didn't seem to have any issues.

 

[Brooks803]

I remember reading a similar post a while back, might be worth a search. Did you cast the ribbons under pressure?

 

[kevrob]

Brookes, thanks for the feedback, I will search again, but didn't see anything the first time. No, I did not use any pressure.

 

[Brooks803]

I found it...as well as another, might prove useful: http://www.penturners.org/forum/showthread.php?t=67255&highlight=casting+ribbons http://www.penturners.org/forum/showthread.php?t=51063&highlight=casting+ribbons

 

[kevrob]

Brookes, found it. Thanks again, I must have had my brain in my pocket when i looked the first time!

 

[djpnevans]

You could try and sand your ribbons then cast them.
David

 

[PTownSubbie]

You could try and sand your ribbons then cast them.
David

I second this statement! You need some roughage on the surface for the PR to bond to. I know PR will bond to itself but in this case, you are better to do light sanding of the ribbon and then ensure it is clean before you cast it.

Don't know why...but if you do this, I can all but guarentee a better success rate.... YMMV but it works for me.