HELP! Mainsheet block/hiking strap pulled out

laserxd

Member
I've never had this happen before with any of my previous lasers, the screws that hold the mainsheet block and hiking strap on ripped out of the deck, starboard side worse than port, luckily I found it in between races and didn't end up going for a swim.

I am in need of some ideas on how to fix this permanently and hopefully before this Sunday...

Thanks Again
 
The most secure method is to thru bolt and use the biggest washer that fits under the deck - easy if you already have a port installed.

If you don't have and don't want to put in a port, I've had success going to the next size (diameter) screw and epoxy it in place - just don't overtighten the screw when putting it in - you can also put a dab of 5200 between the layers (hiking strap, plastic hold down) - the more depth the screw has to bite into, the better it's holding power

(You can also try fasteners such as hollow wall or toggle bolt, but I've never had much luck finding stainless versions)
 
AFAIK, there is no wooden backer under the area where the hiking strap/mainsheet daggeboard brake - builder relies on the deck/hull laminate being thick enough to hold the screws
 
This happened to me several weeks ago - my mainsheet block and hiking strap were suddenly hanging off the mainsheet! Fortunately it was near the end of the race with light winds & I held my place for the finish. I stuffed a small piece of foam down the holes to plug the bottom and filled the holes with epoxy. After it cured, redrilled the holes and put the screws back in. The fiberglass appears to be fairly thick in that area - seems to be in a corner near the centerboad trunk. I have only sailed twice since then, but I did have the main block to block at least once with no problems.
 
Ummm...I'm all but 100% positive there's a wooden block there.

Straps/blocks ripped out on a few boats at worlds due to faulty block placement, I believe.
 
The most secure method is to thru bolt and use the biggest washer that fits under the deck - easy if you already have a port installed.

If you don't have and don't want to put in a port, I've had success going to the next size (diameter) screw and epoxy it in place - just don't overtighten the screw when putting it in - you can also put a dab of 5200 between the layers (hiking strap, plastic hold down) - the more depth the screw has to bite into, the better it's holding power

(You can also try fasteners such as hollow wall or toggle bolt, but I've never had much luck finding stainless versions)

Anyone know the size (I''m guessing #10) and length of the machine screws to thru-bolt this fitting? Thanks!

John Barrere
 
This happened to a friend of mine yesterday and ruined her day. Her hiking strap/mainsheet block was only held in by wood screws. Whether this was original or a fix done by a previous owner, I don't know. Wood screws holding this down is just crazy because the vertical force on the fitting is very high. Bolts are what you need here. (My boat is a 197xxx and must have nuts embedded under the deck because the screws have machine threads)

If the force is in shear like a cleat, then filling the hole with epoxy and redrilling it is fine. However, such a repair is totally inadequate for the mainsheet/hiking strap block where the force is pulling up vertically. I think the only way to fix this permanently is to install a deck port and fix with through bolts, held with a nut and washer.
 
I spoke to a previous PSA employee this morning about this repair.

There is an aluminium plate under the deck for the mainsheet block/hiking strap attachment. Australian boats come from the factory with a tapped and threaded plate there and they use machine screws. Sometimes people substitute self tapping screws which of course ruins the threads. There are two ways to go for the repair:

  1. Put in self tappers the next size up from those that pulled out and at least 1.5" long. They need to be that long to go through the thickness of the hiking strap, the plastic spacer, the stainless steel eye strap, the fibreglass and the aluminium plate. He said this will likely hold forever, or
  2. Take it to the factory and they will install a new aluminium plate, tap a thread into it and install machine threaded bolts. Of course this involves cutting and installing an inspection port, but he said they do a good job and your boat won't leak. The UK built boats just use a big self tapper into an alu plate and they seem to hold just fine, but the tapped thread method is the best. I would agree. The only issue might be is if the plate in your boat has bent or is corroded. (Same old issue as the spars, ie. stainless steel screws into aluminium sets up electrolytic corrosion) I would be inclined to go with the bigger self tappers as a temporary repair and take it to the factory in the off season for the professional repair. Peace of mind I think.
 
Not sure Ahab. There were slight differences in the way things were done on older boats in in different countries. In any case, I think the proper repair for this issue on any boat should be the same, ie. install a new threaded plate under the deck. You can buy cheap tap/die sets these days for about $10, so its not an overly difficult job. A bit of 1/4" (6mm) scrap alu should be easy enough to find.
 
Thanks for the #10 info, but I need length for thru-bolting using machine screws, not self-tappers. Perhaps 1.25"?

I think 1.5 inches is long enuf to thru-bolt. But buy 2" machine screws - obviously being too long isn't a problem. If for some reason the bolts ARE too long to seat, you can always cut them down with a hacksaw. Put a nut onto the screw, further down than where you're gonna cut, before you cut. Clean up the cut end a little with a file. Then when you take the nut off the screw, the threads on the nut dress + tidy up the threads on the screw.

Use ny-lock nuts (nylon insert). Use a big huge fender washer. You might find you need to cut a little off a side (or 2) of the washer with a hacksaw to get it to lay correctly on the shape underneath the deck, but you want to spread that load as far + wide as you can. And obviously use stainless steel everything.

This avoids the electrolytic corrosion that's inevitable when you screw steel screws into the aluminum plate.
 
If you don't have ports in your boat, you could also install "rivet nuts". These are sold under various brand names such as Rivnut or Nutsert. There are instructions for installing them without the proper tool on YouTube. These are also sometimes used instead of rivets on spars.
 

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