Enough of Cobles: I've sold it anyway, and she's now on a mooring just 100 yards from her old one, so I hope to have the odd sail in her now and then.

Having sorted that out, the next thing was to do some work on my little twelve foot clinker dinghy, the one whose purchase at the Wroxham Auction I described in an earlier article. Due to our move to Southend, and so on, 'Cobweb' had not been in her element for some three or four years. The last time we'd sailed her, there had been a fairly bad leak all round the base of the centreboard casing, indicating that the bedding compound had given out. This was therefore the main priority, and I also decided to double-up the garboard strakes (on either side of the keel), as these had a number of 'digs' in them, and in one place one was actually cracked across, where, I suspect, my dear little Scouts had been clambering over its inverted form!

The following account might help others with similar problems who, like myself, have not tackled this type of thing before.

Firstly the centreboard casing (CBC). With the boat inverted I removed the brass runners and dug out the filler in the screw holes to reveal a shattering blow: steel screws! They were probably plated with something or other when they went in, but now they were just rusty stumps, only the odd one having even any trace of a slot. Help!

Help came from a friend who often crews with me, in the form of a 'hollow drill'. He in turn got the idea from a friend who restores old pianos and organs, where the same problem of rusty screws often arises. A hollow drill is simply a tube with a serrated end. One has to remove the remains of the head of the screw by drilling, then the drill is placed over the stump and down you go, until you estimate that it has reached the joint with the CBC. Having done that to all 18 screws, the CBC should be free - just like that! Why, I wonder, did it take me two weekends?

Where does one get a hollow drill? I don't know, as my friend kindly made it. I don't know if you can buy them. To make one, you need silver steel, either in a tube if you can get it (probably not), or a rod of about 4" or so - enough to go in your Black & Decker and still go down deep enough into the wood. It should be big enough to be a fairly close fit over the shank of the old screws, diameter-wise. The rod will have to be drilled out to leave a reasonable thickness of wall (1/32" to 1/16"?), and the business end should then be attacked with a small triangular file to create serrations.

In fact I attacked both ends, making one quite fine and the other pretty coarse. Something in between is probably best. The device then has to be hardened, which is why you need SILVER steel; this involves heating the end till it's cherry red (not white or red hot), then quenching it by stuffing it straight into a bowl of cold water. If you don't do this, it will last 20 revs before wearing smooth. Even with hardening, there were times when I found it hard going, smoke belching, and no more serrations! File out, re-harden and off we go again!

Before doing this, I had bought an extra long drill of about ⅛" diameter, and drilled down between the grotty screws so as to give locations for the new screws, right through into the CBC.

Once the screws were 'released', I turned the boat over, i.e. right way up. On 'Cobweb' there is a fairly standard arrangement where the thwart goes over the CBC and is screwed to it to steady up everything. This means you can't just lift out the CBC. I removed the thwart screws and then the ½" thick capping piece from the top of the CBC to give a bit more room. I then unscrewed the sides from the end 'posts' of the CBC, in effect, reducing it to individual bits. I was able to tilt the sides and lift them out one at a time, complete with a row of very unpleasant looking rusty 'pegs'. (The centreplate itself had, of course, been removed before the operation started.)

The replacement was comparatively straightforward. The rusty pegs were removed by clumping them this way and that till they broke off some ⅛" below the surface - better than hacksawing flush, I feel. The various surfaces were sanded and I gave the inside faces of the CBC several very generous coatings of International's Swedish Wood Oil (more anon). Despite care, the mahogany sides 'moved' a little. I assembled the CBC before I tried it. It was possible to refit it in one lump, with a bit of a push, as the long 'stumps' were no longer there. I had 'jointed' the parts of the CBC with black Sealastic jollop, and used lots more at the base. The thwart screws were replaced, the boat re-inverted, and the end pairs of screws refitted. The keel guide holes should have already been enlarged to take the shanks of the new brass screws, and their counterparts in the CBC were also re-drilled to the correct size.

There was an article in a recent Wooden Boat magazine all about screws, guide hole sizes, etc, and I have now come to appreciate the importance of correct drilling for the various parts of the hole to take the screw. Apart from requiring less elbow grease, it is far more efficient. Talking of grease, some people dip screws in grease before fitting them; I hear this is not a good idea, and usually use soap myself. I'm told that dipping the screw into pink priming paint is very good.

One then works one's way along the holes, fitting the long screws as one goes. I found I had to counteract the slight warping by applying leverage to the CBC. The screws were fully tightened and a satisfactory bead of compound appeared all round; and there we were. I forgot to add that the old screw holes were tidied up and hardwood dowelling glued inside.

Next, the new strakes; so turn her upside-down again. First a template must accurately be made. I got some file covers from the office (stiffish card) and cut them into strips about 12" long (the length of the folder), and just wider than the 'trough' where the garboard strake is. The sides of each strip must be straight. Take a strip and place it up against the keel at the transom end. Leave about ⅛" overhang beyond the transom and sand this level once the strake is fixed. Mark on the card at either end the place where the next strake crosses it; join these with a ruler and cut off the surplus. The card should then drop accurately into the trough.

Take the second piece of card, place it forward of the first piece, overlapping it by about ¾". Repeat the marking and cutting and drop that into place - still overlapping. Take some reasonably wide Sellotape and tape along the join, half on either side. Repeat this again and again until you have gone as far forward as you wish. If this is more than 8' (length of a sheet of ply), you will have to do a scarph joint, making sure it 'leans backwards'. Contrary to what you might expect, the keel side will NOT be straight, which is why you must use fairly short lengths of card to follow the curve. I took the new strake forward to just past where it starts to twist at the bows. I had to do this as the crack referred to was fairly well forward, and I radiused the front corner away from the keel.

Having done one side, I 'flopped' my template over to the other side and, much to my surprise, it came nowhere near fitting! There's a handmade craft for you! So I had to repeat the performance for the other side. To make the templates a bit more rigid, I turned them over and sellotaped the other side of the overlap joints. Then to copy them onto plywood and cut them out, do the scarphing and try them for size. I had made them marginally too wide, but they were soon sanded down to fit.

For this and many other jobs I have found the orange plastic Cintride block very useful. It takes a metal sheet with (I think) Tungsten Grit stuck to it in three different grades. The surface is flat, they last for ages, and the back is hump shaped, which fits the hand quite well.

Next I drew a line a suitable distance in from each edge (½" to ¾", but check with your own boat), and marked along it where the existing rivets were. These went through the original strake and ribs, so if the new rivets go midway between the old ones, they would miss the ribs and give plenty of bonding, especially as I was proposing to use glue too. Where the crack was I did extra holes on either side of the crack. All the holes had to be countersunk to take the heads of the clinker rivetting nails.

The glue I used was Ciba-Geigy Aerodux 500M, with 501 hardener. It is a resin glue and is totally waterproof, unlike the Aerolite available in the shops. C-G will send you an information sheet (0223.832121), but their minimum order is £50. There are only two outlets for this glue, one in Bromley and one in Leeds! Fortunately someone in my office lives in Bromley; I don't know if they will post it. Two 1 Kilo tins of resin and hardener cost about £9. Cascamite do a similar glue - not the fairly common sort in the shops. I can't recall the name, but it is in a few shops, especially chandlers, and is in a 'two pot' kit. I think it is a bit dearer than Aerodux, but might be more convenient. I think their performance is pretty much the same, and they harden in about 5 hours in average temperatures; one doesn't want it going off halfway along a strake! The 500 'M' indicates Medium. There are quicker and slower resins available. It mixes to a thickish dark brown consistency rather like heavy gear oil, which is about right; not too thin, but sufficiently viscous to squeeze out under pressure, thus filling any cavities between layers.

So, final positioning of the new strakes, drilling through the original strake, spreading the glue and finally the rivetting - Oh my God; the bloody riveting!! I forget the number, but I think it was 200 plus, of 12 gauge 'nails' and roves (washers) to match. The latter are a tight fit over the nails - you can't push them on with your fingers, they have to be hammered down the nail with a hollow metal drift. You need a pretty heavy weight (sledge-hammer in my case) flush up against the head to counter-balance the hammer blows, and obviously it is a two-person job unless you have four arms 8' long! (Many thanks to my wife.)

I screwed the aft end into the bottom of the transom, then had to work my way methodically along the strake, working forward, dodging the glue as it dripped out. I raised the boat at one gunwale to about a 45º angle and sat underneath, giving Valerie quite a good position to hold the hammer-head. The domed roves must not be flattened as this will lose their spring, which gives tension. The rove will grip the nail and not move, for a while at least. Once it is tight, you snip off the remainder of the nail with side-cutters or similar, leaving about ⅛" protruding from the hole in the rove. Keeping the counter-weight on the head, and preferably with a round ended ball-pene hammer, you hit the end of the stump at different angles until it is nicely rounded over the edges of the hole in the rove, and will keep it in place. Then the next one - only 199 more; how do you fancy building a whole boat?! Near the bows, where there is an increasing angle to the keel, you cannot get to the head of the rivet. So here, longish screws must go through into the keel on that side. Due to the changing angle, the rounded corner of the new strake tends to stick out, away from the original one. Here I resorted to small, countersunk-headed screws, over-long so that you can bend down the corner to get the nut started, and then tighten it up to pull the plank down, working towards the apex from either side. And there you have it. Wipe off the surplus glue, sand down the surface when good and dry, then varnish.

Earlier I mentioned the Swedish Wood Oil by International Paints (usual disclaimers on all products mentioned!). I think they have re-discovered this again from years ago. It is similar to the considerably more expensive Deks Olje (which David McClellan has used on the bright bits of his Roamer). They say the advantage over normal varnish is that, being an 'oily' sort of thing, the wood will soak up much of it to give in-depth protection, and it certainly does soak it up. As my boat had not been varnished for several years, I felt something like this was needed, rather as old, dry leather needs a good saddle soap or oil. It is also said that the wood oil does not 'lift' the way varnish does - you know those light bubbles under the surface - but only time will tell. It goes on like good varnish, slightly more easily perhaps, and needs a couple of coats to get a hint of a shine - although the shine on my hardwood blocks was quite good after two coats. On the hull, seats, etc. I used about five, which gave a nice gloss finish. Deks Olje have a special finishing varnish. The finish, despite the name, is not oily. I took the old varnish off with water washable Nitromors, and a scraper and copper scouring pad.

That was the main work. The rig had been gunter, with a blue jib and rather baggy main. I decided to change to brown standing lug and jib, which I'm just sorting out. I'd better leave that until another time when I can also tell you about our visit to Coniston Water, and our entry in the 1984 East Coast Old Gaffers Race where we came a resounding last, after 7 hrs. 20 mins. of sailing. Still, we had a grandstand view of some super boats, and 'Cobweb' was the tiddliest tiddler entered.

I am no expert, and many will know more than me about the above techniques - and may well be able to suggest improvements. But if, like me, you have to find your own way, I hope they help. If you want to query anything, do give me a ring.