I bought my Mirror 16 No.231 second-hand in mid-July 1974. It looked pretty tatty sat on a ‘lash-up’ road trailer, and was full of water — at least the main buoyancy tanks were. There was also an ugly looking dent in the port side just above the chine. The paintwork was fair and the sails first class, including a spinnaker. It had a good mast, boom, spinny pole and other bits and pieces. I made an offer against the asking price of £220, and my Mirror 16 was bought.

When I got her home I found the transom ply was delaminating in a couple of places also. Despite the rude remarks from my family, who could foresee the departure of the family GP14 (in pristine condition), I set to work to patch up the ‘16’ so that no sailing time would be lost.

The water in the tanks did not appear to have done any damage except to the transom. The dent in her side was caused by the trailer squeezing her sides (a fault of the original ‘16’ trailer). This had ultimately put a permanent set in the ply and weakened the glass-taped chine joint over an area of 12-18”. A new strip of tape and two tubes of Araldite soon fixed that, and the Araldite SV & HV 427 wood filler soon made the transom look good. A quick dab of paint over the repairs and away to the water.

I must say that I have never sailed a boat that has such acceleration and ease of coming up onto the plane. The amount of space in her is also very desirable as I have 4 children, and find that we can all sail in her without an elbow being put into some tender spot. This winter I have been sailing her with a friend at Grafham Water, and have had some really exciting sailing.

During this time I had been thinking about the ‘winter re-fit’, and decided that the only way to stop an annoying small leak through the centreboard case was to sheathe the hull in glass cloth and resin. The one thing that I was a bit worried about was the condition of the under floor buoyancy chambers. I toyed with the idea of taking up the floor, but decided to wait until the transom came off, then have a good look around. A most interesting point about removing the transom was that the epoxy wood filler was in first class condition and still adhering well to the good parts of the ply. This was a little surprising, as the transom had been quite damp when the filling took place (against manufacturers recommendations). I could see that the side tanks were okay, but couldn’t see beyond the first rib in the under floor tanks; not that I was too worried now, because this section would have had the water lying in it for the longest time, and gave the appearance of being unaffected.

So I let her dry out upside down in the garage, and proceeded to get the paint off — a very dusty, dirty, time-consuming job. I burnt off the main coats of paint, but had to sand off the metallic primer as it was well ingrained into the hull ply. This sanding, using an ordinary power drill and discs, is a most important operation, and must be carried out with care and diligence. Care is needed so that the sanding disc does not dig into the plywood, and diligence to be sure that all the metal filler in the primer is removed. Certainly no more than 10% of the surface area can be left with filler showing, and this must only be in small patches. The resulting surface finish is ideal for applying resin to. The rear end of the boat had dried out quite well by this time, so I carefully cut ply to the correct shape, having first made a cardboard template as a guide. I remembered to paint the area on the inside face where the transom closes off the side tanks, then glued and pinned and screwed the new plywood into place.

The hull was now ready for sheathing. I first sheathed the inside of the centreboard slot, which proved to be the most difficult part of the job. It seems that resin and glass cloth have minds of their own when you try to get a layer placed in a narrow slot so that it comes over the keel and around the inside. All I used was a piece of timber 18” long x 1½” wide and 1” thick, and plenty of swearing. Plus a good pair of rubber gloves — most essential, as resins can be tricky with the skin.

As I am an ex CIBA-GEIGY man, I chose to use an Araldite laminating resin, CY219 with hardener HY219 plus accelerator. This choice was mainly due to the fact that epoxy resins are better in adhesion than polyester resins, also they are more hard wearing, tougher and less ‘smelly’. The glass cloth was a woven material, type 181/120, which is a closely woven, thick material, chosen because it was readily available; almost any type would do. As a trial, I covered the transom first, overlapping the hull by 2” but stopping just short of the top edge of the transom, as I wanted to leave the mahogany showing. This all proved very simple, so I pressed on with the rest of the hull. I first tried on the glass cloth dry to see if any tailoring was required. Then I applied the mixed resin to the hull — in areas of approximately 1 square yard — by home made scraper, starting in the centre. The glass cloth was placed on the resin and smoothed out by gloved hands and a small roller to remove all the air bubbles and impregnate the cloth. I took one piece of material from the transom to bow on both sides then covered the area alongside the keelson with half moon shaped pieces. It is very important to make sure that all air bubbles are removed, otherwise problems will occur with paint preparation or with entrapment of moisture at some stage in the boat’s life.

It will be almost impossible not to have a few small blisters, but these will be of no consequence if they are small, say ¼” x ¼”. Anything larger should be filled after the sheathing operation is completely dried by cutting the cloth away and filling with Araldite. The resin needs about 48 hours to harden off, and 7 days to be fully cured.

A telephone call to International Paints put me right on paint preparation of epoxy/glass cloth, the important point being that it is not recommended to use their glassfibre primer. Simply abrade to the cured resin/glass cloth; undercoat; fill if necessary with trowel cement; undercoat; finish coat. This is as far as I have got, but the next job is to turn the boat over and put a layer of glass cloth and resin onto the floor, paint it, and re-varnish the decks etc. If our newsletter compiler is agreeable, I will let you know how I get on with phase 2 of the project...

Having completed the covering of the hull, I now decided to paint it before turning it over to cover the floor.

I first sanded the whole surface to remove any high spots and flatten the areas of overlap etc. Care is needed to ensure all the dust is removed; I used a rag well soaked in white spirit, after vacuum cleaning, just to be sure.

Two coats of International undercoat enamel and two coats of finish enamel was applied, allowing a day to dry between coats. This gave a very acceptable finish, even though I did not ‘cement fill’ to smooth out the weave appearance of the glass cloth. I think if I had been a keen racing man I would have filled between undercoats, but as it is, I don’t mind a slight ‘woven’ appearance to the paint work, which is not discernable from 3-4 yards in any case. There is no necessity to use the more expensive paints, as the epoxy resin/glass cloth laminate will be impervious to water, even without any paint. To say ‘I turned the boat over, right side up’ is far easier than to actually do the job. Nevertheless, it did get turned over, and I started on the floor by removing ventilation hatches, the centreboard slot capping pieces, floor cross pieces etc., and any other removable items attached to the floor. It was then necessary to lay out the glass cloth and cut four pieces to the shape of the floor, plus an allowance for the overlaps, and the drape into the centreboard slot, and a 1” upturn for the edges against the side tanks; each piece being roughly a quarter of the floor area. It is not possible to accurately cut out for the floor strakes at this stage.

The next job is to remove all the varnish/paint etc. from the floor, which I did with Nitromors stripper, as I did not want to damage the side tank timber by accidental scorching from the blowlamp. Afterwards I sanded the surface with the disc sander. This surface was now okay for the laminating to begin. I mixed about 1 kg of resin, started applying it to the floor near the forward bulkhead, and worked back to the mast support. It is rather awkward to do a good job on this forward section without getting onto the resin, so I used a pair of knee pads made with rags to go forward and lay the glass cloth and smooth it out. This actually sounds worse than it was.

The next section included the strakes and part of the centre board slot, and gave the most trouble as the strake cut-outs had to be done, plus the drape into the slot. The cut-outs were done easiest by Stanley knife when the cloth was wet with resin, by cutting around the strake, then smoothing it out well; the drape into the slot was done in a like manner. The rear half of the floor was a repeat of the forward half, but a lot simpler as the whole surface was easily got at. The ventilation holes were glassed over and cut out when dry.

I did not leave the finished resin ‘au naturel’ as I originally intended, but gave it a coat of undercoat enamel, dark blue as per the hull. The centreboard slot capping pieces were glued (Araldite) and screwed on before painting. As the boat was inside the garage, I decided to complete the ‘refit’. I removed all the old varnish, and re-varnished with Blue Peter, giving her a very smart appearance, which I feel the family will accept as being good enough for them to sail in. I also put a mahogany capping on the side tank edge, which has improved her looks considerably.

I am sure readers will want to know the weights and costs of the job.

Resin : Araldite CY219 system weight : 7 kg resin cost : £14 3.5 kg hardener £8 approx.

Glass cloth — woven type 181/120, 150 ft² (from Fothergill & Harvey) weight : 7 kg cost : £10 approx.

Total weight added to hull and floor : 17.5 kg (38.5 lbs)

Total cost : £32

I did not log the time taken to do the job, as I was in no particular hurry, and therefore went for ‘quality’ rather than ‘quantity’, but as far as I remember the breakdown was:-

Stripping paint from hull 1 day Sanding hull ready for GRP 1 day Laying on GRP laminate 1 day Stripping floor of varnish and attachments 1½ days Laying on GRP laminate 1 day

Total 5½ days

This does not include time taken to cure the resin, or the other jobs I did as I went along. If anyone would like to see the finished results they are very welcome, and if I can help anyone who intends doing a similar job on their own boat with advice etc., please drop me a line or give a ring.