Selden In-Mast Furling Conversion from Line Driver to Hydraulic — Instructions

Components Required for the Conversion

Discontinued model – documents and spare parts as printed.

Converts a manual (line driver) in-mast furling mast to hydraulic drive. It can be done on a fully rigged boat. Two copies of drawing PS-277 (one to cut out as a pattern) and one of PS 312 (holes for the hydraulic hoses) come with the instructions.

A tack assembly (qty 1) is also listed, without a part number.

Removing the Line Driver & Cutting the Mast

1. Remove the sail. Slacken the backstay and lower shrouds so the mast stands perfectly straight; reduce upper shroud tension to approx. 500 N.
2. Remove the covers (as in in-mast furling instruction 595-063-E).
3. Remove the lock retaining screw and push the locking tube up.
4. Turn the reefing winch anti-clockwise with a winch handle until the luff extrusion is slack.
5. Remove the upper plastic plug and the extrusion adapter; remove the lower split and clevis pins.
6. Undo the reefing mechanism (8 screws) and remove it.
7. Remove adapter and spacer wheel from the lower extrusion, then unscrew it from the tensioning screw.
8. Cut out the PS-277 pattern, tape it to the mast and check its position vertically and horizontally. Draw round the areas to saw away.
9. Make sure the hole clears winches and other mast fittings (move them if needed; outhaul fairleads are no longer needed). Leave free turning space for the winch handle.
10. Saw to the marks without over-cutting. The straight upper and lower edges of the drive unit must fit the hole exactly: file it true using the drive unit as a pattern, starting from aft.
11. Mark the hole in the inner wall 15mm from the upper edge of the opening (PS-277). Drill a 5~6 mm pilot, then open to 12 mm. Deburr and smooth all edges.
12. Keel-stepped masts: if the hoses run through the coachroof inside the mast, do that work now (see below).
13. Remove all chips from inside the mast.

Fitting the Drive Unit

1. Fit the new lower extrusion (adapter and spacer wheel off for insertion, refitted after). Tighten the tensioning screw home.
2. Place the drive unit and fasten the bottom plate with two MFX 8x40 screws into the existing holes.
3. Insert one stainless bracket in the mast and fit the drive unit upper screws (MFX 8x25) to it. The bracket holes are asymmetrical.
4. Extend the tensioning screw enough to fit the adapter to the drive shaft.
5. Put the supplied winch handle in the motor, grip the locking sleeve firmly and turn until the sleeve starts to slip in your hand: tension is then correct. The motor must be connected to the deck gland with the by-pass valve in Manual; close the valve when finished.
6. Push the locking tube down over the lower part of the luff extrusion and secure it with its screw.
7. Fit the cover plate over the upper half of the hole and the remaining bracket to its lower holes (MFX 8x25). Push the cover plate down and fit the two upper screws (MFX 8x40).
8. Apply the emergency reefing transfer (591-303) next to the winch handle socket.
9. Lay out the hydraulic hoses around other mast equipment; three clips are supplied.

Through-Deck & Through-Mast Fitting

• Deck-stepped mast: mount the through-deck fitting without sharp hose bends; ask the yard if unsure about its position.
• Keel-stepped mast: threading hoses through a rigged mast is difficult; Selden recommends the deck-stepped method.

1. Lay out the hoses from the drive unit, clear of other fittings, and join them to the through-mast fitting.
2. Mark the centre of the through-mast fitting, measure the diameter of its bottom part and add 1mm; drill or saw the hole.
3. Mark and cut an oval exit hole at the mast heel; deburr and smooth.
4. Make a hole in the mast seal at deck level, thread the hoses through the seal and out at the heel; seal with Sikaflex.
5. Fit the through-mast fitting and adapter ring.
6. Seal the hose run in the seal carefully; Selden recommends its cable glue (312-301-03). Do not let glue run down into the boat.