Eyebolts for Cast Iron Keel

[strawbs]

I have a cast iron lifting keel that is held by dyneema strops connected to eye bolts screwed into the top of the keel. I replaced these a couple of years ago with (I think) galvanised steel – they were described as “M14 Self Colour Collared Lifting Eyebolts SWL 0.50T”. The eyebolts are not normally in the water and I’m not particularly happy with the state of them after only a couple of seasons.


I’d like to do this properly this time and I have a few questions…

• Is there a different material that I should use for these? Would stainless steel be better?
• Is there a particular supplier that is recommended?
• Should I use any kind of thread coating before screwing in?
• Given the above, what are the best shackles to use to attach the dyneema strops to the eyebolts (I used Crosby galvanised shackles previously which have lasted better than the eye bolts)?

I notice that Wichard eye nuts advertise a breaking load much greater than eye nuts from other manufacturers. I don’t think eyenuts would work for me due to the difficulty of getting studding of the right length but I’m curious as to the difference.

Thanks
James

 

[Motor_Sailor]

'Self Coloured' means they were plain cast material.

You would be better to use galvanised.

http://www.mackay.co.uk/beta-m14-lifting-eyebolts-galvanized-8040e-zm14-and-nuts-robur-items-beta-tools-brands.html

Then slather the eye and thread in Lanocote.

 

[AntarcticPilot]

Vyv-cox would give a better opinion, but isn't this exactly the sort of application where stainless is NOT suitable? Damp and salty conditions sound ideal for crevice corrosion.

 

[strawbs]

Thanks both. I'll source proper galvanised ones and see if that's better. Fortunately they're easy to access and change so I can replace them if they don't look good.

 

[vyv_cox]

Vyv-cox would give a better opinion, but isn't this exactly the sort of application where stainless is NOT suitable? Damp and salty conditions sound ideal for crevice corrosion.

I don't think crevice corrosion would be the biggest problem, but there is something of a galvanic mixture. Iron, graphite and stainless steel is a good combination, with iron being anodic to the other two. I would expect corrosion of the keel first but crevice corrosion of the stainless second.

 

[strawbs]

Thanks Vyv. So I guess galvanised steel is still the best option. Is there any benefit in putting anything on the thread before installing?

 

[vyv_cox]

Thanks Vyv. So I guess galvanised steel is still the best option. Is there any benefit in putting anything on the thread before installing?

Yes, I think the galvanised steel is as good as you will get. Painting it might help, etch primer followed by a decent top coat but I would not buy whole tins just for one eye bolt! A sealant such as Sikaflex/Puraflex on the threads would do no harm.