Request for Spec Clarification 12.docx

N32205-15-R-1009

USNS RAPPAHANNOCK (T-AO 204)

REQUEST FOR SPECIFICATION CLARIFICATION - #012

NAME OF CONTRACTOR:

SPECIFICATION ITEM NO.: 904

PARAGRAPH / SECTION NO: WI# 904, Para 7.2.5

TITLE: FREEBOARD PRESERVATION

In review of work items 904 we note the requirement for Sweep Blasting the remaining surfaces of the freeboard that do not receive “Spot Blasting” surface preparation. We take exception to this method of surface preparation as the existing urethane top coating can often fracture and result in a complete system removal to remove fracturing. Standard practice on Freeboard hulls is to chemically etch the urethane surface after spot blasting with a cleaner (Devprep) to etch the surface in preparation for receiving the final application of a full coat of urethane paint.

7.2.5 Sweep blast the remaining freeboard surfaces to remove any lose non-adhering paint on the surface. Any edges shall be feathered. Contain and dispose of all sweep blast media in accordance with all national, state and local regulations as a part of this work item.

Note; any loose non-adhering paint coatings on the surface will be removed during the 3,000 psi washing process.

QUESTION:

Recommend paragraph 7.2.5 be revised to exclude grit sweeping the Freeboard and include chemical etching using “DEVPERP” prior to paint application.

ANSWER:

The contractor shall perform work in accordance with the Work Item as stated. No changes will be made as a result of this request for specification clarification.

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