I've been working on casting some of my battletech models and I've noticed quite a few of them are getting slightly oval shaped parts that should be round. Like the gun barrels.
I'm scratching my head as I don't recall this happening on previous models and I haven't changed anything in the way I do the casting. I'm not sure if it's due to silicone shrinkage while it's setting up or maybe I'm over tightening the rubberbands and compressing the molds?
What is odd is that it's even occuring on faces that don't have a mold lines centered on them, making me think it may be an issue with over tightening.
A lot of my molds are stored near a heat duct for my basement maybe the heat has warped them?
Another possible source is I stack them about 3-4 molds high maybe the weight is compressing them?
The obvious first test is to loosen the molds slightly on the next cast but do you think maybe the mold wall thickness isn't enough if it's distorting?