Thursday, November 20, 2008

Survey Observations.....

The following Observations and or Non-Standard Conditions were noted at the time of survey:

The vessel has been well maintained and very presentable with the machinery space generally accessible and clean. The vessel was found to be currently undergoing major restoration and refit.

Vessel was found to be in very good condition. Hull top-sides, foredeck, and interior appear to be good condition and structurally sound (given the survey limitations as mentioned herein) with no signs of grounding or other damage and or structural failure except as follows.

- The undersigned wishes to disclose that USCG NVIC 8-95 was used as guidance in the structural inspection of this vessel.

- The vessel’s underbody and underwater hardware were not inspected. No exterior hull fasteners were opened up or inspected for serviceability and or alloy breakdown.

- It was reported that the vessel’s hull planking (5/4 cedar) was completely refastened (original #10 fasteners replaced with #12 sized bronze wood screws) in 2004. It’s understood that all hull seams were re-caulked during this haul out.

- Interior structural members (bent white oak and other wood species) are secured with a mixture of bronze and galvanized steel fastenings. In some place, most notably in lower bilge area, these fasteners are showing minor to moderate rusting and should be inspected and replaced as required as part of the vessel’s regular maintenance program.

- The vessel’s keel bolts, where accessible, were visually inspected and hammer punched – filed to observe the condition of the underlying material which visually appears to be serviceable. All keel bolts should be inspected and replaced as required as part of the vessel’s regular maintenance program.

- Visually observable corroded bronze transom platform knee fastener (?) found just to starboard of the vessel’s center line at the stern just aft of the rudder stock. It would appear that a potential cause of the fastener’s wastage might be due to a mixture of dis-similar metal fasteners found in this area of the vessel. This fastening\ should be replaced with a like marine-grade fastener. In addition, further investigations should be made to reduce future alloy breakdown of all fasteners in this area of the vessel’s structure.

- It should be noted that at a floor timber amidships – a slight amount of movement between the faying surfaces of the top of the keel structure and floor timber was observed – the undersigned suggests that the securing keel bolt be thoroughly examined during the vessel’s next scheduled haul out. In addition, two (2) (amidships) athwart intermediate frame straps (between floor timbers) have become (vertically) detached from the keel as a result of wasted steel fasteners and should be reattached to prevent movement – leakage at the garboard seam – see Recommendation made herein. The undersigned cautions that care should be taken in the refastening of these strap or bridge frames so not to induce cracking and or structural damage.

- The condition of existing steel fasteners in the engine foundation – engine bearers should be closely examined with any and all rusted, non-serviceable and or damaged fasteners replaced with marine-grade fasteners of size and specification appropriate for intended service.

- It was observed by the undersigned that localized galvanic current activity in the vessel’s interior wood structure(s) (evidenced by the production of sodium hydroxide on damaged wood fibers - when you have dis-similar metals in wet wood – a galvanic cell is established. When, from various reasons, the current potential reaches 300 – 400mv, the galvanic current creates alkaline substances in the wood which breaks down the lignin (organic polymer or glue) which keeps the fibers bonded together) at the floor timbers (viz., at the upper most surface of those affected floor timbers at the and radiating from bolt head) and other interior hull structural members. The undersigned advised ownership to clean affected areas with a wire brush - vacuum clean and treat with white vinegar. In addition, penetrating epoxy could be applied as well to stabilize affected area(s). All wood structures should be regularly inspected for rot fungi and or alkaline corrosion damage (excessive galvanic current activity).

No comments: