Strut backing

[JimmyG]

Ok boat is all painted, working on rub rail and my last area to clean up and paint is from the fly bridge walls back, i'm removing the fuel tank and replacing all the floor bracing and I came across the strut backing area. It looks alot different from my old 1972 (I replaced those waterlogged backers) this boas is a 1980 and the strut backers go all the way back to the transom incorporating the rudder shafts, they are a lot thicker, did Bertram change them in the 80's? Any good way to tell if they have to be replaced? I probably should God knows i have replaced everything else just starting t run out of steam.

[CaptPatrick]

Jimmy,

Sounds like they've been replaced... What sort of glass work is over them and have you tested them with a moisture meter? Any pics?

[JimmyG]

its hard to tell but my best guess is that its been replaced my old one was 1/2 the length and thickness. I'll have to get that meeter, usually I just rip it out and replace it.

[CaptPatrick]

Sure looks original... Check with moisture meter and sound out with a hammer.

[Pete Fallon]

JimmyG,
The backing plate at the strut looks like it was original (Green Glass), the rudder post backing (clear glass) with plywood showing thru looks like it might have been redone. Like Capt Pat said, sound with a phenolic hammer or get a hold of a moisture meter to see if there is any water intrusion around the opening where the rudder shaft goes thru the hull. The knee at the transom doesn't look like any original part that I've seen in surveying over 30 31's. The area between the inside stringer and the outer deck support usually has nothing in that area, rudder table just goes across the top of those supports. In the latter models they might have changed but I don't think so. Looking at that piece of 3/4" plywood it looks like it has started to delaminate from the hull tabbing.
Pete Fallon

[JimmyG]

Just purchased a meter on Amazon, what percentage is considered bad? I have to replace the rudder shelves an knee's marine plywood or maybe Coosa?

[Stephan]

JimmyG
Mine has a knee where yours is. The rudder tables are individual and do not go all the way to the outboard stringer. The exhaust passes between the rudder table knee and the outboard stringer on my boat. I do not have the large combined backing plate like you do.

[JimmyG]

They are out and yes they were bad!