SailNet Community - View Single Post - winching up the mast,
View Single Post
  #15  
Old 01-07-2013
Omatako's Avatar
Omatako Omatako is offline
Senior Member
 
Join Date: Sep 2003
Location: Auckland New Zealand
Posts: 2,376
Thanks: 0
Thanked 25 Times in 22 Posts
Rep Power: 11
Omatako will become famous soon enough
Re: winching up the mast,

Quote:
Originally Posted by AirborneSF View Post
I like mast steps, just have a problem with screw points sticking inside of mast, cause with MY luck something is going to get messed up.
I use "blind" rivets, don't know what they're called where you live, could be pop rivets. The Monel 5mm rivets are easily strong enough to hold the weight of a human being, I have used them for years on steps and never had a failure. They have a blunted end inside the mast that will do no damage to sails, halyards or electrics.

The Youtube clip below shows two 5mm Monel rivets fitted in 1.6mm steel plates and tests them to 730lbs before failure. Normally a mast step would be fitted with a minimum of three and mostly 4 rivets and the material thickness of both the mast section and the step material would be thicker than 1.6 so the shear would be enhanced. You would probably have a safety factor of 300% or more depending on the number of rivets used.


Just be sure not to use ordinary aluminium rivets, they're nowhere near as strong as Monel.

Just thought this may help.
__________________

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

__________________

"Two possibilities exist: Either we are alone in the Universe or we are not. Both are equally terrifying."

Arthur C. Clarke
Reply With Quote Share with Facebook