Broken mast step

S

seo

New Member
Hi, I'm new to this forum, but have had a Laser since 1975, or was it '76? Anyway, yesterday my son and I were out sailing on Penobscot Bay, Maine, in about 18 kt wind, with a fairly steep chop. Going along pretty well, in spite of having about 320 pounds of people on board, when there was a rending noise, and WTF! the mast is lying horizontal on the water, while the hull is still upright. It turned out that the mast had levered the step, whatever (if anything) secured the bottom of the mast tube to the hull broke loose, the deck broke with four cracks radiating from the mast tube.
We got the sail off, the mast disjointed and back on board, and then had to go "under power" for a big over a mile with the wind and sea kicking up. "Power" was supplied by me sculling with the rudder, while my son kneeled in the cockpit, wielding the upper mast tube like a kayak paddle. My big worry was of waves slopping on deck and the hull filling with water and sinking out from under us. It would have been a long swim in cold water.
We got home all right, and I was able to inspect the deck fairly well. The tube is intact, the deck appears to have been cored with some kind of foam.
I'm curious if this is something that happens to these hulls. It's had a pretty easy life, living in a boat shed, not sailed much. The glass did not look to be embrittled, and the resin is not granulated.
My immediate thought was to repair the deck as well as possible, and then add a glass reinforcing layer on top of the deck around the mast tube.
I'd very much appreciate any advice. Also, I'd like to know what's inside one of these hulls. Is the mast tube fastened to the hull? Is there any flotation foam, ethofoam stringers, anything like that?
Is the bottom of the mast tube supposed to be fastened to the hull? How is that done in a repair?
Thanks in advance,
SEO
 
I don't know how to fix it, but inside, there should be lots of space but also thick plastic air bags for flotation, I believe one in the bow and one of either side of the cockpit where it sticks down in the boat.
 
welcome, sorry you found us the hard way.. Yes, the bottom of the tube sits in a plywood base on the hull, surrounded by a "donut" made of "bog" or resin putty to keep it from moving. What usually happens is either the bog breaks apart over time, the tube starts to move in the base and/or the base rots.

It's a common failure on old boats, regardless of use or condition. There is a ton of info in thread here, search on "mast step repair" and also check out the following:
http://www.schrothfiberglass.com/maststep.htm
We can give a little more advice if you post up a pic of the damage to the deck and tell us about your fiber-glassing skills.
 
Thanks very much. I vaguely remember hearing that this was a problem. I will do some reading on the threads at this site, and figure out how to post pictures. It looks like I have to post to Photobucket, or something like that?
 
You can post directly here, use the "Upload a File" button and then insert the pic as either a thumbnail or fullsize
 
Here's a couple of pictures of the broken step.
IMG_1263.JPG
The one above shows the core and laminate. It's interesting that the FRP broke quite cleanly, with almost no separation along the laminate layers. Almost like it was vacuum-bagged, or really well rolled out with a bubble-popper.
 
This picture shows the damage from a little further off, showing the laminate ruptures radiating from the mast step:
IMG_1264.JPG

My guess right now is that I'll have to repair the mast step by cutting it out of the deck, along with a hole big enough to reach back to good deck, and then glassing a horizontal flange around the top of the tube. Glass the tube into place, more or less free-standing, and then either:
1) use plywood as the repair deck
2) Make a repair deck of cored laminate on the bench, lower laminate and core. Either way, feathered out at the outboard edge.
Either way, after that's glued to the deck, build up an epoxy/glass laminate over the repair deck, running down onto the original deck.
That's my idea, without having done the destructive disassembly that will show what's going on inside. Any comments will be greatly appreciated. I've done quite a bit of glass work, and have designed structural repairs on larger boats. I work as a marine surveyor for a day job... But this will be my first foray into repairing such a lightweight, highly loaded part.
 
For this type of repair, you will need a complete mast step repair kit. The link is below. You can also get them from APS. However, please be advised that they are pretty pricey and given the age of your boat, it will may not be worth it. If this is the case then you have a candidate for a man-cave decoration. I have a 1979 boat and did the "Schroth" type repair as a preventative measure a couple of years ago. IMHO, if you have a boat over 25 years old, reinforcing the bottom of the mast step is a necessity in order to avoid what you experienced.

http://www.diversifiedfiberglass.ca/laser-mast-kit-repair.asp
 
Thanks very much for the links and comments. It's apparent that my boat is not the first to experience this failure. I'll send more pictures as I take the thing apart. That will be autumn, because life (summer) is short here in Maine, and so I guess it's time to switch to Hobie Cat sailing for the duration.
 
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