||Phone Martin Carolan about getting a 5kg tin of gel-coat as I've got hardly enough hardener left for another 100g mix. He says he'll get some that size in by tomorrow. Notice a low spot on the rudder port face catching the light from the window. Re-apply dry guide coat and go over it again with 240 grit wet. As before, several other low patches also appear again. When finally satisfied, unclamp and start to clean up root end with strip of 240 emery see-saw fashion. Some contour lines appear, probably because the root (and the tip) were not scrupulously cleaned of guide coat and sanding slurry before re-painting port side.
||Take rudder to Martin Carolan for his advice on the thin spots and to collect 5kg gel-coat. He advises at least 3" overpaint all round thin areas, and rub them by hand, not with a block (as they are sticking up, a hard block will just scalp them again). Feathering the edges of such touch-ups is much easier, of course, if it's sprayed on. He offers the option of me getting the parts to the present state all over and then him spraying a final coat (or coats). I'll have to think about that - pride insists I should do it all myself! For concave areas, Martin uses bits of plastic pipe slit lengthways with a wooden stretcher inserted to vary the radius as required. He suggests I check locally for good prices on wet-and-dry paper at (for instance) Brown Brothers. He agrees 240 grit is a good starting point; he then moves on to 400, 800 and 1200 or 1000 Abralon. Call in to Brown Brothers and get 25-packs each of 400 and 800 paper. Their own brand is 9.00 + VAT and 3M is 13.00 + VAT. Dearer than some of the mail-order places, but no postage to pay.
||Rub down rudder root and tip with Perma-Grit and 240 emery to get rid of grey contour lines. Clean up starboard side TE. Also remove Martin's pencil line around CS29 rivet re-paint area (3" radius) as graphite is both black and slippery, and we need neither of those under any new coats. Remove nibs and runs from LE vee, starting with coarse Perma-Grit and working finer.
||Clean up rudder all round with damp sponge to remove sanding slurry. Rub down a couple of places still showing contour lines and wipe off again. Spin the point of a small drill bit in the 2 pinholes to clean them out and, by enlarging them slightly, make them easier to fill. Dry up and wipe over with acetone-soaked tissue. Mix 15g+1.5g gel-coat (really intended 10g+1g but over-shot badly). Place tiny dots of it onto pinholes with small artists brush. Paint onto rivet area with same brush and brush out away from centre so that the edge of the overpaint is as thin as possible. Continue on CS29 recess, and on thin patches of root and LE. Gel-coat starting to thicken slightly in mixing cup and so can be laid in thicker layers without running away. Actually that was a bad idea as when I come back it has set lumpy because it didn't flow out at all, and will need much more rubbing down. About an hour after the first coat, mix 6g + 0.6g gel-coat and re-paint all areas except pinholes (which clearly don't need any more). After another hour, repeat again with 6g+0.6g gel-coat.
||Try rubbing the CS29 rivet area with 240 grit wet on 1/4-sheet rubber block. Works (surprisingly) well, smoothing central area and blending periphery into main surface without any real difficulty. Stop and apply dry guide coat after first short session as it's obvious I'll need help to see the low areas. Get area round CS29 to a reasonable state with no signs of getting too thin. However, where I've taken the sanding along the root end, a couple of thin patches appear again. The TE end of the root seems OK, so 2 out of 4 successful, although I haven't started on the LE yet.
||Rub remaining painted patches on rudder with 240 wet on rubber block. Pin-holes disappear well, and the LE near the tip is OK, but near the root 3 thin patches re-appear, also more on root end as I try to remove more ripples. Clean off and dry. Wipe with acetone-soaked tissue. Mix 13g+1.3g gel coat and paint onto all thin patches and inside CS29 recess where previous coverage was poor. Use up remainder on lower (starboard) side of root end. After about half an hour, mix 8g+0.8g gel coat and paint second coat on thin patches. After about another hour, mix 8g+0.8g for 3rd coat on patches. Use up small excess amount of 2nd & 3rd coats on bottom of LE vee.