Cast mate

Date: 2/25/97
Subject: The Use of Dow Castmate

Trenton’s slip situation is as follows:

FMU Single NewRm. Battery LuxCell
Formula No. 58 58 58 58 58
Dow% 0 residual 0.275 0.275 0.275
SG 1.780 1.806 1.800 1.806 1.785
0’ 330315 325 325 325
BU 60 88 84 84 74
Baroid CR 89 99112 117 120
45’ funnel thickness n/a n/a 0.47” 0.48” 0.48”
60’ funnel thickness n/a 0.47” n/an/a n/a

As you can see, Trenton basically uses one slip formula but with and without Dow.

Our slip lab uses a baroid to judge the casting rate of all our slips. We feel it isimportant to take the plaster mold variable out of the equation.

Trenton’s baroid procedure is as follows:

• Fill a baroid with slip
• Press for 15 minutes at 80 psi
• Drain for 2 minutes
•Weigh the cake, paper, and gasket

Trenton has been using Dow in production since the late 1980s. Based on our experience, Dow:

• Dramatically increases casting rate
• Firms up the slip without aloss of plasticity
• Minimizes any inside to outside difference in feel
• Increases fluidity at the same BU ( ie., increases the 0’ )
• Promotes a cleaner drain
• Does not affect DMOR
• Must bediluted with water before adding to slip ( Trenton uses 50:50 )
• Should be added as late in the process as possible. The blungers used at Trenton render the Dow essentially ineffective.
• Should beadded as slowly as possible
• Initially thickens slip but if allowed to mix in, does not affect the BU
• Does not lose its effectiveness over time
• Dow does not recommend using more than 0.275%...