Everyone swears by preheating the flask to 500 degrees for every job

I've seen way too many fine details get burned out on smaller castings because of that blanket rule. On a recent 15 pound aluminum gear pattern, I dropped it to 350 and the surface finish was perfect. When did we decide one temperature fits all pours?

3 comments

3 Comments

jesser791mo ago

Wasn't there an article about mold temperature affecting fill rates?

lily_singh21mo ago

Yeah jesser79, that Plastics Today piece showed a 15% flow difference just from a 20 degree shift in mold temp.

dakota_nelson431mo ago

That 15% flow difference is huge! I saw a similar study where they tested different gate designs at those higher temps. The faster flow actually reduced weld line strength in some parts because the material cooled too quickly after joining.

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