Batten Repair

One of the more significant costs of sailing a Dart 15 can be the replacement of broken battens - especially after a windy event. At some 12 each it is not too difficult to run up a bill of 36 pounds or more. In actual fact about three quarters of broken battens are repairable if you go about it the right way so why not give it a try by following these step by step instructions? You will require a few basic tools such as junior hacksaw, some 'G' cramps (2/batten), a few offcuts of wood (e.g. strips 25x15x250mm), some coarse abrasive paper (e.g. P60 - P80 Aluminium Oxide paper - the very rough / tough stuff for removing paint) and some fibre glass resin, a short lenght of old batten, electrical insulation tape (preferably red), an old paint brush and some cellulose thinners.

1.First inspect the batten. If it is broken within 250mm of the thin end then it is not repairable - this end is very flexible and the stiffening of a repair will change the way that the batten bends. Keep the pieces, however, to use when repairing other battens.
2.Clean up the area of the break, removing loose/frayed material so that the two ends butt together cleanly at the break. It might be necessary to cut out a few mms using a small hack saw. Do not worry if the batten has delaminated so the three layers are not stuck together so long as they are all present. It may well be that the break is staggered or on one side of the batten only. This does not matter so long as the parts can be fitted close together on a flat surface. If the break is in an area of the batten that has the rubber strips fitted then you must remove these strips and remove all traces of the glue with white spirit. Make sure that the white spirit is dry before moving on to step 3.
3.Now sand the outer surfaces of each half of the batten to break the surface for an area of 100mm from the break on both sides using the coarse aluminium oxide paper on a block of wood. This is very important to give the resin an opportunity to stick. Do not round off the edges - you want a flat surface.
4.Now take a piece of another irrepairable batten (you get in the habit of saving these - but you often find them laying around at the sailing club) and sand the outer surfaces over the whole length you intend to use (say 125mm for each batten you intend to repair). This is to be used for splints and I often make a lot of these up ahead of time. Now hold this bit of batten vertically in a vice and cut down the centre of the corrugated section of the batten so that you effectively separate the two outer laminations. You will find you can do long sections like this as the two outer laminates easily bend to allow the frame of the hacksaw to pass. Now cut up the sections of splint into lengths about 125mm long. They will be very rough where the corrugated layer has been cut off - clean off the loose stuff but don't bother too much as it is easier to deal with smoothing it off later.
5.Two of these splints are going to be used on either side of the break in the batten positioned so that the two smooth sides (outsides) stick together leaving the rough sides (from where the corrugated laminate has been cut off) on the outside of the repair. Conduct a trial assemble to ensure that it all fits together OK.
6.Now mix up a small amount of fibreglass resin and apply to the smooth sides of the splints (Note: You must use fibreglass resin. I have experimented with various glues - they were all a waste of time and quickly break again). If the batten to be repaired has delaminated apply the resin to all unstuck surfaces around the break using an old paintbrush. Now assemble the parts together with the batten standing on edge on a flat surface on some newspaper, position two strips of wood on either side and clamp the whole sandwich tightly together using two 'G' cramps one on each side of the break. This now needs to be left to dry overnight. The paint brush and other tools can be cleaned with cellulose thinners or acetone.
7.The next day when dry remove the clamps and the temporary wooden splints (which may need carefully prizing off as they usually stick to the batten). You can now smooth off the worst of the rough surface on the outside of the splints with the coarse aluminium oxide paper. Also round off any sharp edges. It is very difficult to get the outside of the batten very smooth so I now take the insulation tape and bind the whole repaired area with tape to improve the appearance of the repair and protect the sail from any sharp edges or irregularities.
8.Reapply the rubber strips if necessary and the batten is now ready to use.

I have repaired many battens like this and the small stiff section does not notice in the shape of the sail and they hardly ever break at the repair. You can often repair a batten twice but if the repairs are too close then there is a tendency to break at the section between the two repairs. When a batten is irrepairable keep the pieces - you can use them either for splints or sometimes you can make one good batten out of two broken ones. Finally have you ever felt how sharp the front (thin) end of a batten is? This quickly wears a hole through your sail inside the white plastic pockets. If you round off the edges at the end and wrap some tape round the end of the batten this greatly reduces the wear on your sail.

Bob Carter