Backing Plates

[TXS-ALAMO]

One of my dockmates owns a Pearson 34. (he says its a 35). He just finished cleaning the bilge and noticed that the ss keel bolts were backed by aluminium plates that were white and crumbly. He asked if these aluminium plates were standard in Pearson building practice and whether he should replace them with ss? Does anyone know the answer? I find it hard to believe that a builder like Pearson would use al plates on ss keel bolts. Help.

[Goodnewsboy]

Aluminum plates are pretty common and should not pose a serious problem as backing plates under the deck.

Plates that are submerged frequently are another matter.

Who knows what Pearson's practice was for every boat. I'd change to stainless ASAP.

[jasp]

Not sure how old the boat is, but those plates could be an add-on....salt water and alminum...not a good mix

[SailorMitch]

Apparently the owner posted a message about this issue in the Pearson section. Agreed that aluminum plates would be most unusual there and were probably an add on by someone who thought he had a better idea. I asked the owner what year the boat is to gauge whether it might be one made by the Cal-Pearson group in the mid-90's, after the original Pearson went belly up in 1991. The Cal-Pearson boats that were made (probably no more than a handful) were built by Bristol Yachts, which itself went bankrupt in the mid-90's pulling Cal-Pearson down with it. Anyway, those boats could have some strange things in them.

[arrghigotaboat]

Hi, I have a 1986 Irwin Citation 32 with ss keel bolts. The backing plates on these appear to be aluminum. There is always 1/2" or so of water sloshing around in the bilge that the pump can't get. I noticed white crusty corrosion??? on the backing plates. The previous owner says he never saw any such thing when he had the boat. According to his meticulous records, he had the keel bolts retorqued about every three years. Should I replace the aluminum backing plates with ss and should I be worried about anything else with the keel bolts? (yes I know, with an Irwin you should worry about everything ). thanks

[sailingdog]

I would replace the aluminum with stainless steel. The white corrosion is the aluminum being eaten away by a galvanic reaction between it, the seawater and the stainless steel bolts. Not good.

[Morgan3820]

You would think that Pearson would know better. But while looking at Pearson365s I noticed that every mast step wwas made out of mild steel. An aluminum mast with a steel step - in the bilge!!!!. Needless to say everyone was in dire need of replacement.