Glassed In Bobstay Chainplate

[benjiwoodboat]

I just removed my bobstay chainplate. It is a Y shaped, welded piece, that's glassed in... was a bit of a pain to remove, but doable. I'm wondering what the general thought is on that installation. I was considering redesigning and using two seperate bars on either side of the bow, bolted in, like a more traditional chainplate. But I don't want to get into redesigning the wheel if this glassed in approach is considered to be a decent approach. I'm going to have to do glass work either way, so it doesn't matter to me. But NEXT time, avoiding the glass work and difficult removal/installation would be a nice bonus.

http://lh6.ggpht.com/BenEriksen/SESd...JPG?imgmax=512

http://lh6.ggpht.com/BenEriksen/SESb...JPG?imgmax=720

http://lh3.ggpht.com/BenEriksen/SESb...JPG?imgmax=512

[Brian Duff]

Ben ,
As you can see from the condition of the fitting, being buried in the hull was not healthy for the stainless steel

On all custom fittings we design they are bolted outside the hull with heavy backing plates

Also, being so close to the waterline you probably should not use stainless anyway, the stuff sucks in wet enviroments.... consider bronze for longevity, or at least use a zinc to protect the stainless from corrosion.... or paint the stainless that helps too...

fun fun

[benjiwoodboat]

Thanks Brian,

I'm consdering Bronze for all my chainplate replacement. Still undecided.

[Brian Duff]

Bronze
Ulitmate Tensile Strength 85000psi
Yeild Strength of 55000psi
elongation at failure 20%
rockwell hardness B90

316 Stainless
Ultimate Tensile Strength 89,900psi
Yeild Strength 60,200psi
Elongation at failure 45%
rockwell hardness B91

As you can see bronze is only about 5% weaker ultimate... as far as maintaince goes it is much better as long as you don't mind the green patina it will get... if you do then powdercoat clear after polishing.

Skene's charts for chainplates have identical dimensions for stainless and bronze, and thats how we;ve been making stuff...

[benjiwoodboat]

Brian, thanks again. Where are these numbers from? Did you get my email?

[Brian Duff]

onlinemetals.com