Thursday, April 21, 2011

Hull fairing.....and lamination



That was another milestone in my boat's construction and İ wanted to make sure my hull was as nice as possible .

So İ spent a great deal of time fairing the hull BEFORE lamination. One area of concern İ had was the starboard bow panel which was concave. İ guess this assymetry came when İ glued the bow piece in place and clamped everything together. The starboard panel "gave in" forward of f18 but İ only noticed that later in the build. My garage is indeed a bit crampy and İ dont have much space in front of the bow.

So İ basically had one side slightly bulging inwards while the other one was bulging outwards...Not sure what the best configuration is for the bow but İ sure was not going to finish off the boat with 2 different sides. So İ opted to build up the concave side since it was easier for obvious reasons than trimming down the other one :)

Anyways, İ solved that issue by initially taking quite a lot of measurements and comparing one side to the other to better locate the place and dimension of the assymetry.
Once İ had determined the importance of that assimetry, which was quite significant ie about, i realized İ could not simply fair it with fairing putty. So İ glued a large piece of high density Airex foam, the same material İ used to build the rounded edges, and later shaped it with almost all the tools İ had at hand in my garage. İ finally settled with hand planer and surefoam. Worked great on that hard to grind foam.



İt looked pretty good so İ took new measurements and discovered that İ still had a big gap to close. İ did not hesitate and glued another large piece. More grinding, shaping ,and fairing (on many different occasions !) and a couple of days later İ had a pretty symetric bow. İ then carefully worked out the final fairing to achieve the smoothest possible panel. İ reached the point where with my eyes closed and just using my hand İ could not tell the difference between the foam part and the ply panel. They merge perfectly into a nice curve.

BEFORE SHAPİNG SECOND FOAM PANEL


AFTER SHAPİNG, FAİRİNG AND LAMİNATİNG


İ also had to deal with more fairing in some other spots, mostly at the bottom to side panel chine. İ then got to understand how important it is to perfectly align those panels when stiching the hull together. Any slight deviation will turn out to be a hollow spot to be faired later. Dont rush that stitch part of the build !



So İ had about 6 spots to fair mostly along the chine, plus the bow which did not have the nicest V shape to it. İ used different types of sticks which İ would lay flat on the hull to better locate those spots to be faired. Marked them with a pencil, fair, sand, measure with the batten, apply more fairing, sand, etc...until the low spots were no longer there. Fairly easy process, and rather enjoyable.


Once all that fairing was done, i move onto the lamination per se. The main concern İ had was with the size of the fiber roll İ bought here in Turkey which is just 80 cm wide . So İt took a little thinking to optimize the cloth layout and the resulting overlaps and seams. İ ended up with a seam at mid panel on both sides and one on hull bottom center line .

The cloth was carefully lined up with the help of my wife and hold in place with the now famous pins (work perfectly for that) which İ have used in many occasions on my build. Then we started laminating. My wife on one side, and me on the other one runnnig like crazy back and forward to help her with the most difficult spots and making sure everything was allright.We ended up doing a pretty awesome job, really squeeging all excess resin out.

To finish it off, İ wrapped the whole hull with peel ply. İ am really starting to love the stuff ! Unfortunately, when we laid the peel ply the resin had started to cure somewhat and since our lamination was pretty dry, there was not much resin left for the peel ply to glu on. But we applied it all over anyways.



The next day, İ called my wife and younger daughter to rip it off. Although it did not seem like it, it was well glued in most places and was a bit hard to rip. We really had fun doing it and discovering the awesome surface that laid below !



That peel ply makes for a really beautifull, perfectly textured surface. Even the seams which İ feared a bit were pretty low and smooth...







So overall the hull was almost ready for the over coat. All İ had to do was sand the edges of the overlaps ,fair and sand smooth again. İ really got the hang of sanding those edges and using my rectangular orbital sander, a smaller block and 120 sanding paper İ was able to completely remove all traces of those edges in a relatively small amount of time. İ am getting good for the next boat !


Because İ had spent a good amount of time preping the hull before laminating, only minor additional fairing was necessary before the float coat. İ do believe this is the right way to do it. All fairing is underneath the fiber, hull looks pretty fair.

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