Friday, December 15, 2006

Shaping Rudders

Having to take some time to get the cash machine cranked up again so little progress on the boat.

Have put several hours into fairing the foam on the first rudder after making a series of saw kerfs down the length of the blade with the depth set according to the templates screwed onto the ends of the foam blank.






After slicing the foam with a blade to the rough shape I've been using a 'Shure-Foam' plane to shape the blanks to within an 1/16" of the guide marks and then using a longboard with 40 grit. Goes pretty quick. The foam is amazingly loud to sand so Led Zeppelin has needed a bit of extra volume to keep things right. For some reason, sanding to Physical Graffiti, Volume I has been more productive than Houses of the Holy.

Sunday, December 03, 2006

Wheels and an oven

Epoxy cure times are quite lengthy based on a shop temperature of 60 degrees. Getting into winter here in Maine the shop is rarely at 60 and usually well below 45 when not in use. Epoxy will take days (if at all) to cure at these temperatures.

Clogging the sandpaper up with three swipes is frustrating at best so a solution was needed.

As an alternative to heating up a sieve-like 3200 cubic foot shop I built a 5' x 10' x 1' box out of 1x3's and some styrofoam we recycled from some work done to the house. The R value is a mere 5 on the foam so we lined the inside of the box withthe radiant heat insulating bubble wrap to bring the R value up to 15. With a small heater and an unsealed (at this point) box (oven) we still got her cooked up to 90 degrees with a whimpy Walmart heater in about 20 minutes. This should cook the epoxy in 4-5 hours according to the specs.





Also applied the first layer of epoxy box. First time I've bogged anything. Quite nice. I say this now but I can imagine it becoming less romantic after a while. I tried the West System 407 which is #2 (behind 410) on the light and easy to fair scale. It's off the charts expensive but I thought I'd try a small bit as something to compare my own mixtures to. We're going to try the SM Fair and a concoction of 3 parts microballoons and 1 part aerosil (cabosil). Since fairing is going to be like a step parent it seems like one should learn to get along with it and make the best out of it.



Hard to imagine a baker not thoroughly enjoying himself on a bogging project.

A bit of school of hard knocks today as the E-glass decided that a strong relationship with the plywood spokes was not in it's best interest. One could say that the relationship was doomed from the beginning with the plywood not getting nearly enough of what it needed to form the strong bond. Enough epoxy. Laminating 101 was forgotten as I rolled out the glass on the table and layed it directly on the spokes without wetting the spokes out first.



I thought about it in bed last night thinking there would be a problem and sho 'nuff. Peeling the glass off the plywood you could see dry glass where the plywood sucked the resin out of it. A minor screw up so no sleep lost on this one.

I imagine there will be many such 'learning endeavors' along the way. The goal will be to mitigate the losses and keep the errors under control.

Layed the goal out for December to finish two rudders and two wheels. This would be a good first month in my book..

Friday, December 01, 2006

Wheels

Wheels seemed like a good 'small shop' project so we've begun tackling them over the past few days. The plans called for laminating 8 strips of 1/8" plywood over a male mold for the rim however the yard was out of 1/8" so we're going to use more of the corecell. I've added and extra 1/4" to the diameter of the rim since my meat puppets always got tired on the weenie 1" diameter wheels.







Since the foam rim is going to be flimsier than the laminated plywood we'll need to add a bit more glass. Probably getting too clever here in using the foam but this is part of the fun. Until my noodle rim becomes useless that is.

The hub is a 7" diameter of 3/4" ply with a groove in the edge that the spokes will fit into.



The router is starting to meet it's maker as it is falling apart at the seams. The switch broke yesterday so it was removed from the equation and the 'Z' adjuster is starting to wear out. The locking mechanism also died. At some point a router is nothing more than a spindle. I think I'm there. I've had this router for several years so it's time for a replacement. The Ryobi stuff seems to be a good brand to learn with and then move on to something a bit more robust and with a dust port. It's amazing how much dust a router can spew!

Also filled the slot in the trailing edge of the rudder with some chopped fiber and and epoxy. A bit of a deviation from the plans here that called for glass in the slot but I liked the idea of having the slot be void free and I'm not sure I could have done that with the glass.



Lastly, got the spokes crackin' today. The jigsaw had a lovely time trying to get through 1 1/2 inches of plywood for the spokes. Everything is taking a bit longer than I'd imagine since everything is a learning process at this point.




So far boat building has been 80% jig building. Getting the router sorted out to cut rounds took a while as did sorting out a way to get the groove in the side of the hub.

Very rewarding stuff when the jig is set up and the part comes out as planned.

If I were to start over with the wheels I might try simply cutting and shaping the wheel core out of plywood or foam, glassing over it, adding bog and then painting. Building the wheel by building up a rim, hub and spokes is an effort. However, I liked the idea of having the hub be offset from the rim and this seemed like the only way to do it and the plans were as such. Once more, the Harryproa boys have already built it this way so it seemed like re-inventing the wheel (how often does that fit literally) would have been a road with more 'learning opportunities".