Flipping upper mast

Thread starter #1
I recently purchased an older Laser (1973), and I noticed that the sleeve on the upper mast has three rivets rather than the standard one. I am worried about a mast failure destroying my new sail. I have read somewhere about flipping this mast end for end and am wondering if anyone has any experience or input on this.


Well-Known Member
is this something that you have done yourself?
No - the closest to this has been replacing a broken sleeve. Which was a pain as the new sleeve really didn't move along the mast like in the above video! But it was probably because it was a painted 1990 spar which is just a small fraction of a millimetre thicker. I assume the anodized uppers (the vast majority) don't have this problem.
It was easy....just do the proper measurement...If old just buy some new parts....from APS or Intensity...its worth it ! Nice fit later....Line up what you think is original hole...See that from the top of mast present. Then use a string to get proper line up at the new bottom. Use SS rivets.
I bought the metal puddy at Home Depot about $5.00 Then aluminum color spray paint about $5.00

When doing the puddy ..use a wooden dowl so it will stay in place and harden. ...your fingers work too
Sand the outside smooth ...then paint. Mine has been good for two seasons now.

I don't like filling the holes with more rivets !!!!!! plus could leak.

A good winter project.


Well-Known Member
If old just buy some new parts....from APS or Intensity...
To put it nicely, I heavily recommend the former. You will know that you're getting real parts.
Use SS rivets.
Stainless makes sense for the sleeve, aluminium for the others.
I don't like filling the holes with more rivets !!!!!
Doesn't matter what one likes or not. Class rule 26 (c) says Any holes in the top section of the mast shall be permanently sealed with a rivet or similar to maintain the buoyancy of the mast.
A good winter project.
If your winters are very short (minutes instead of months) :D


Former ISAF Laser Measurer
Buy a new top section and cut down the old top and convert it to a boom, which is also probably up for replacement.
I found out that you need quite a serious riveting tool to set stainless rivets of the size required for the boom hardware. The price of the tool (European leading brand Gesipa) is about the price of a new boom :(


Upside down?
Staff member
Here in the States we have stores that sell tools made in China. I got my heavy duty riveter from them for $15 or so. It's been a while, but my sailing buddies love to borrow it...
Thank you both for your feedback. We actually have stores like these here too. They sell Chinese tools under their own brand name. I asked at the store, but the staff told me that although it has the capacity to handle large rivets, it can not handle the loads for stainless rivets.
Maybe they meant to say: can not handle these loads in a professional working environment but occassionally is fine.
I really try to avoid buying cheap tools, but this would be one I would really rarely use.
It all comes down to can you borow one, if not how likely it is that the cheaper riveter will fail and how critical would that be, practically and economically. And sometimes for me how much time can I afford to spend with the question before I decide.:)