Have any of you noticed color variation from Federal white vs Lehigh white portland?
I used Lehigh for the first time today. I have always used Fed white only because its easier to get in my area.
After a miss hap in the shop we scrambled to recast 1 of 2 piece arrangement. I was only able to get Lehigh, which buts into a fed white piece. pigmented to light grey and will receive some light apps of BR glaze.
Any preference of one over the other in general?
Lehigh seemed to generate significantly more heat then Fed white.
Yes, there is a color difference between the two. When engineering mixes I use FW cement. FW is very reliable in color as it comes from the same location it has come from since the beginning and will continue to come from the same location long after we are gone.
Lehigh is a blend of materials that comes from several locations, each location has a different color and how it is blended depends solely on how much of what comes in at which time. (meaning there is no set ratio that they adhere to for blending to assure consistency, well none that I know of) Although the differences appear slight, I have seen the difference make dramatic changes in the final color.
I never saw much difference in exothermic reactions.