Blog time : it’s mid June 2021, almost midsummer and almost overnight it’s changed from cold and wet or cool and damp all the way to actually warm and dry. I had to put off the centerboard gluing-up job a couple of times because it was just far too warm under the shelter even late in the afternoon ; i ended up doing the job on a cool and damp morning and even then nearly lost control of the cure. Anyway, iv’e made the blank for the centerboard, done the initial clean up – mainly chipping off the epoxy drips, squared the ends off and as i write i’m almost ready to mark out and start to shape the aerofoil section of the centerboard.
In fact, i got a bit carried away when i was preparing the lammells for the centerboard – such that i ran all of the stock i had through my new table saw and by accident produced nearly enough ‘waste’ strips from that i could immediately use to make a blank for the rudder as well. I think i had to make 2 extra lammells from pieces that i made for the centerboard but didn’t need – i made too many, and then i almost had the 2 boards made…..only lots of shaping and smoothing to do !. Just before packing the whole project away and heading off for a break (car-camping) i spent 2 whole days making a huge pile of shavings from my expensive hardwood boards….strange to think how much material iv’e taken off them .
In line with the way i’m trying to write these posts then :
On the bench this week.
All of this week’s work has been taken up with preparing the hardwood stock, gluing the lammels together for first the centerboard and then the rudder, marking out and cutting out negative and positive aerofoil sections for both and then as i said above – 2 days spent just shaping the centerboard and a third one just working on the rudder. I did have a first try at marking out the shape of the top of the rudder blade, i marked out the length at one side and from there the angle where the radius portion will be but then i got completely lost in trying to work out how to mark out the angle where the radius of the cheek section meets the trailing edge cut-out. After a break and lots of thinking about i think iv’e worked out that the angle relates to part of a radius of the circle that the area within the cheeks forms…and is i guess a tangent off that. Anyway i did a gentle marking out experimentally and it sort-of looks ok but i’ll leave the final marking out and shaping of the top until after our break away.
Tool/technique review – Shaping tools.
At the start of this project i posed a question on designer John Welsford’s FB page about what tools other builders had found most useful – i already had some of them which was a good start, invested in a few other basics (the Japanese pull-saws have been a boon) but generally taken to heart one answer/advice which was not to buy tools until i needed them ; but then when i did need a tool to get a good one . Up until this stage i haven’t had to buy very much but with the centerboard and rudder blank construction i really couldn’t see a way of doing it without either a table saw or finding someone locally who has one to do the work for me. I do know a local woodworker who is very good and has all of the machine tools (table saw, bandsaw and thicknesser-planer) but he’s a very busy bloke and wasn’t at his workshop when i dropped by to ask him about my job. Because of that i used the entire month’s boatbuilding budget to buy the table saw and a secondhand jack plane…..the latter to help me true-up the edge of the bottom panel which came out a bit wobbly .
For the shaping of the aerofoil section of both boards i did a lot of the work with my Ryobi 18 volt battery planer and then primarily the smoothing plane, block plane and coarse half-round rasp which i already had. The planer gets through it’s batteries pretty fast – i have 2 batteries and could do with a 3rd…..by the time i’d used both batteries and had one still on charge i often reverted to the coarse rasp to start shaping in the taper section at the top end of each underwater portion of board where the aerofoil section meets the square section. By the time i’d done a half hour of hand shaping and with a battery still charging i usually took a water and coffee break because it was hot work under the shelter. The half-round rasp i found very useful for either taking off wood quickly or later on for flatting out of the section that i created mainly with planes….at the end i just used a simple sandpaper longboard to really get the section smooth.
What i had intended for this post was a review of a tool that iv’e used in the past, but now owned, that i ordered specifically for this work….and that was either out of stock and/or still hasn’t been delivered : that’s the excellent Shinto saw-rasp from Ice Bear. We used them once for hand-shaping bows from Ash staves and i had thought to use one for this job…..whatever, they seem to be out of stock everywhere.
The last thing i’d like to mention is that i found a pair of heavy work gloves essential, especially when i was working with the rasp ; it’s coarse and rough on both surfaces and to use it well i had to have one hand ‘driving’ it and my second hand ‘palming’ it flat from above…..even then i ended up with some new blisters.