HOME FAQs BOOKS JOBS: Help Wanted Suggestions you are here: Hotline/Forum => Letter 19056
DECENT PROPOSAL?
+++
What are your thoughts on the following proposal:
Spray System
Current Process:
Substrates = HRP&O, grit blasted HRS, shot peened HRS
Pretreat - Alkaline Clean, Rinse, Iron Phos, Rinse, Rinse (non-chrome sealer is used on the grit blasted substrate to reduce flash rusting)
Proposed Process:
Substrates = HRP&O, grit blasted HRS, shot peened HRS
Pretreat - Ambient Water Rinse, Iron Phos, Rinse, Rinse (no sealer)
We aim for 720 NSS hours at a failure of 7 (ASTM 1654) single scribe. We meet this with the current Process but want to reduce costs. This new process was proposed by a competing pretreat supplier not the current pretreat supplier.
Can we expect to have the same performance? What about cleaning?
Looking forward to your comments.
Chris Ellen- Oakville
+++
Hi Chris,
The competing supplier is probably pulling your leg if he's trying to convince you that a cleaner/phosphate with no sealing rinse will perform on an equal basis with your current process, which is an ideal set-up for a five-stage line. A cleaner/phosphate can be adequate for substrates which are not heavily soiled. HRPO does not normally fall into this category.
The only way to know for sure, however, is to do a side-by-side comparison between your current process and the new process. The new process may be cheaper in $/gallon, but can you put a price tag on the decrease in quality of your finished parts?
George Gorecki- Naperville, Illinois