hardening a new top section

L

LarsenCanvas

Guest
I'm buying a new top section. How should I break it in, so I can harden it. I don't want to bend it on my first outting. Any ideas.
 
I'm not much of a sailor but I am an engineering student.
Work hardening only occurs where there has been plastic deformation, i.e. if you bend it, it ends up harder where it is bent.
You can try it with a coat hanger, if you bend it then try to bend it back it won't want to bend back in the same place.

So I wouldn't be too worried about your top section, make sure it fits in the bottom section and go sail.
 
You may also want to have a look at the previous threads on this subject. One important subject is the placement of the sleeve rivet. A lot of people place this facing the stern of the boat ie on the compression side. Being an engineer I think a better solution is to place the rivet on the side, on the neutral axis, where there is a low stress level. I like to alternate between the starboard and port sides to maximise the fatigue life. The other item is corrosion. Always wash the gap between the sleeve and the section with water to get rid of the salt.
 
I spoke to an engineer about this, he is also a top notch laser sailor. He first thought that the rivet should be facing the side. Then he realized that he had forgotten to take into account that the mast bends sideways. I saw someones top section break while sailing upwind because of placing it sideways.
 
My upper and lower sections have red arrows that you are supposed to line up. Doing so keeps the rivet at the top of the upper section in line with the boom gooseneck.
 
Re sideways bend I have concluded that the sideways deflections and hence stresses are several times less than the rearward deflection hence my recomendation. A poorly maintained top spar will break whatever direction the rivet is placed.
 
ive heard there is a substantial difference in the euro spars as opposed to the vanguard spars, the vanguard spars will bend slightly every time you sail then in 12+ therefore its vital to rotate them 180' every time you sail them. in this case i would line the rivet up on either the port or starboard side. if you get a better quality spar like the euro or aussie spars id just put the rivet on the compression (transom side), and keep an eye on the bend after every sail
 
Ron Witzel said:
has anyone ever been able to straighten a top section that is slightly curved at the lower end?
Click to expand...

Yes, it's a fairly simple process - you bend it in the opposite direction until you are happy. Once you have it straight you may want to consider end for ending it (it move the collar to the other end of the section). This will help avoid the section bending again in the same area.
 
The easiest way to bend it back, is place it in the lower section, and then place the lower section on your boat, and the top section on the ground, then press down in the middle in the opposite direction as the bend. It might take a couple of tries to get it straight. Be careful, to much flexing can break the top section.
 
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