William Green wrote:
The waste holding tank in my Island Packet PC-35 is showing some serious
corrosion at the discharge fitting. This is a welded aluminum tank of 30
gallons. All other tanks (also welded aluminum) seem in perfect shape. I
have two questions. 1) "What happened?"

It's not uncommon. Urine is so corrosive that it makes salt appear
benign in comparision...it will typically eat through a weld at a seam
or fitting of any metal tank--aluminum or stainless--within 2-5 years,
the sheet metal within 10...making metal tanks a bad choice for waste
holding. So why would a top quality boat builder like IP continue to use
aluminum tanks? The early poly tanks were an even worse choice...poor
quality, highly failure prone, creating a unshakeable mindset that
aluminum or stainless is a better choice than poly, even though metal
waste holding tanks rarely last more than 10 years, while top quality
poly tanks last for decades.

and 2) Does anyone have experience
replacing this tank in the Packet Cat - it looks like it might require a
chop saw to extract?

It prob'ly will...you might ask the folks on the sailnet IP email list
if any of them have a Packet Cat. As for a replacement, your best
source IMO is Ronco Plastics (no relation to the Ronco VegoMatic
company)...they make TOP quality poly tanks for a very reasonable price,
and have more than 400 shapes and sizes to choose from, including over
100 that are non-rectangular. Their catalog is on their website at
http://www.ronco-plastics.com. I have no connection with them,
btw...just know their quality and selection.

Peggie
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Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://www.seaworthy.com/html/get_ri...oat_odors.html