Procedure for installing the Annapolis Rigging Spreader Thru Bar kit

Spreader through bar installation ( mast up ) 1/5/08

-Release tension on the upper shrouds, both sides.
-Securely tie a 16’ ladder to the inner shroud. When working aloft tie a safety line around yourself & the mast. You will need two hands when working the pop rivet tool.
-Remove the spreader attaching hardware & end caps and take down the spreaders.
-Refinish the spreaders while you’ve got them down & replace the flag halyard block.
-Using a center punch, drive the mandrel of the existing pop rivets into the rivet bodies.
-Drill out old spreader bracket pop rivet outer flanges with a ¼" drill bit.
-Using a ¼ " drift drive the rivet bodies into the mast.
-Remove old spreader brackets. Look for cracks around the rivet holes. Clean off corrosion and refinish area.
-Remove the thru mast stiffening tube. It may interfere with the installation of the thru bar and once the reinforcing plates are installed you can’t get tube very easily.
-Assuming no cracks, install the Annapolis Rigging reinforcing plates using the supplied ¼" pop rivets with the Harbor Freight $20 pop rivet tool. Use a small vice grip around the mandrel between the pop rivet tool and the pop rivet to prevent the mandrel from being pushed inside the mast. The reinforcing plates install using the existing spreader bracket holes.
-Using the reinforcing plates as a guide, cut the mast holes for the through bar. Drill a 1/8" hole in the corners and use a healthy AC powered roto-tool like a DeWalt with an aluminum capable blade such as a Dremel 1/8" roto bit. Set the depth of the cutting tool to the minimum required to spare the halyards and wiring inside the mast. ( A reason to use a ladder in case a halyard gets cut )
-Insert the spreader bar from the port side of the mast making sure to get all the wires & halyards aft of the spreader bar. One tap with a hammer got the thru bar in place. Center the bar using the marking on the aft side of the spreader bar.
-Reinstall the spreaders and attach them to the spreader bar with two ¼-20 bolts per spreader. The spreader bar protrudes from the mast about 5 ½ " on each side.
-Restore upper shroud tension.
-Go sailing.

Completed spreader thru bar installation

Here are a few more shots of the completed spreader thru bar installation. Using a center punch sped up the removal of the port side bracket & rivets. The center punch drove the mandrel into the rivet body so there was less metal to drill out. After drilling off the rivet flange I then used a drift to drive out the remains. The Harbor Freight pop rivet tool was tamed be using a small vice grip to prevent the mandrel from being driven inside the mast while cycling the pop rivet tool.

Two 1/4" bolts 1 1/2" long were used to attach the spreader to the thru bar. The thru bar went in with one tap of the hammer. The small thru rod interfered with the thru bar and during the installation it fell down inside the mast. It was not welded as previously thought. It is a little scary to see the amount of metal removed from the mast to install the thru bar. Hopefully no masts have come down with the thru bar installed.

We have a race tomorrow so that is why the last photo is after dark...

More shot(s) from the spreader thru bar

Installation of the Annapolis Rigging spreader thru bar

Here are a few shots of the ongoing spreader thru bar with the mast up. The starboard plate is almost completely installed. There is a tube welded internally in the mast that connects the port & starboard sides of the mast. According to Jay Herman the bar can be left in as long as the halyards are behind it. ( one of the jib halyards is not behind the tube ). The Harbor freight 1/4" pop rivet tool is not completely fool proof and I messed up two pop rivets that will have to be redone. In removing the old pop rivets I used up about one drill bit per rivet. So far there is no cracking observed in either the mast or the old spreader bracket. The DeWalt roto drill was able to make the cut out with harming the halyards.

A shot of 16' folding ladder I'm using to get up to the spreaders. The ladder is tied to the lower stay and I tie myself to the mast while up there.