Bottom of mast coming apart, broken at rivets

I’m surprised the mast stayed together this long. This boat is from 1987. The rivets were barely in the mast, some with no “meat” holding it in place. Do I need to make new holes and replace the mast base, or is there an easier fix?

Posting pics:
https://www.hobie.com/forums/viewtopic.php?f=18&p=42885#p42885

It sounds like you are talking about the mast base (not step). It's common practice to drill new holes and install 3/16" SS rivets if/when you do have some "meat" in the mast and base to hold them. You only need a few. Also, some may suggest that you seal the mast/base joint, but that's not necessary...there should be a foam plug above it. Check the condition of that plug while you have the base off.

_________________
Jerome Vaughan
Hobie 16

The rivets holding the mast base to the mast should not normally be getting loose or "no meat" at the holes in the mast.

The usual causes of failures in this area is due to improper mast stepping or corrosion due to saltwater trapped inside your mast.

The mast base and mast step were designed to be under compression when sailing NOT tension from improper mast stepping. You have to make sure that the ball of the mast base NEVER rides up on the forward lip of the mast step when stepping the mast. If it does, there is so much leverage there that your mast base and possibly mast step and mast step link may fail.

If someone is helping you step the mast have them make sure that the ball on the bottom of mast base stays above the socket of the mast step. If stepping the mast solo, use the push/pull method (top hand pushing the mast up (from the shoulder position) and the other hand pulling the lower section of the mast backwards). This method will make sure that the mast base's ball always lands in the mast step properly.

Also make sure you are using the H16 hole of your mast step link for a H16 (and not the H14 hole). I use a Phillips screwdriver to pin the mast step link to the mast base. The handle of the Phillips screwdriver and tapered point make it easy to put it in or pull it out. Also, the bright colored handle makes it harder for you to forget to install it (before stepping) or remove it (after stepping).

I have been using the same Murray's step link for over 20 years on my previous 82H16 and on my current 84H16 and never had a problem with it. On both of these boats I had installed the newer style Hobie mast base and mast step (for more mast rake, etc.). I leave the Murray's step link on the mast step all the time using the SS bolt, spacer and nylock (that came with it).

After stepping the mast or before lowering the mast, you may have to use one hand to pull down some on the taut forestay (to make the mast pivot forward more), in order to make it easier to pull out or push in the step pin (Phillips screwdriver) with the other hand.

_________________
Tim
84 H16
82 H16
87 H14T
Tortola Sails: 115222
Blue Prism Sails: 88863
Clearwater, FL

Sorry, trying to figure out pictures.

That front rivet looks abnormally low, like the hole in the extrusion may never have had much material to support the rivet. That may have been the start of the problem. You may want to pull the mast base out of the extrusion and take a measurement so you can ensure that you place new rivet holes centered on the overlap between the extrusion and the base.

Then pound the base back into the mast using a wooden or rubber mallet. Add three or four new S/S rivets to hold it in place. As long as you use proper mast stepping technique as described above, it should be fine.

sm

Yup...looks like some material has already been trimmed off the bottom of the mast.

_________________
Jerome Vaughan
Hobie 16