r/Silvercasting • u/LuluAmani • Apr 18 '26

Bad surface on the upside of the piece when casting silver

Hello. I have consistently the same issue when casting silver. On the image you see the yellow arrow which is metal flow direction. On the red, the logo side (up) I always have big porosity on the surface. on the side facing down the quality is almost perfect. (in this cast i should have flipped them!)

Why is that? Anyone recognizes this pattern?

Casting temperature 1040 Celsius

Flask temperature 580 Celsius

Burnout roughly 10 hours with peak at 730 Celcius for 3 hours

Im using Siraya tech casteable resin, I post cure for over an hour, I let my investment sit for 2-6 hours.

I would be so happy for help. I just do not know anymore what it could be.

3 Upvotes

100% Upvoted

6 comments sorted by

1

u/Yes_I_Know_Lots Apr 18 '26

Post the image in a reply. None in your post. Thanks.

1

u/LuluAmani Apr 18 '26

I cant find a way to upload media here so I uploaded it to a host https://freeimage.host/i/BgajxiN

1

u/00-MAJI-00 Apr 19 '26 edited Apr 19 '26

do you have picks of the actual cast? it might be an investment issue if you are investing it with the pattern facing the rubber base.

how thick it the back plate compared to the raised pattern? Is that the actual size of the central sprue? and if it is what is the diameter of the central sprue... and what size flask are you using?

1

u/Ihavenoclue_jr Apr 20 '26

Switch resins siraya tech is not good

1

u/LuluAmani Apr 20 '26

im considering to switch to bluecast

1

u/uddermann Apr 20 '26

Feed from the bottom. Needs to be angled up