Sunday, June 10, 2007

Float fairing done, and other stuff

I had hoped to have at least one of my floats in primer by now, but it didn't work out that way. The weather over the last three days was crap and it didn't stop raining until today so I decided to hold off.

So what's been done otherwise? Well, the big news is that both floats are done with fairing (at least until the primer is on and I can see how bad things look). The port float hatch holes have been cut out and had their edges epoxy-filled:

I decided with most of the fairing done, that it was high time to do a clean up job on the tent floor, especially underneath the strongback where all of the dust settles:

The above picture is post-cleanup. It may not look great until you realize that the dust was 2-3 inches high under there, so it's a big improvement.

I also worked on the chainplate slots. (If you're wondering after reading this, yes I basically followed the procedure that Henny used on his F39 float chainplates.) First I measured and marked where the cuts should go, and then got out the hacksaw:

After sawing down to close to the right mark, I used a router with a long straight bit to chop through all of the excess wastage:

And once the depth was close to where it needed to be, I used a file to take it down the rest of the way:

Quite frankly, working around a laminated-in-place chainplate with saws, routers, and files is nerve-wracking. I don't remember why I let this job wait until this point, but I highly recommend to other builders that they do this work before the chainplate is laminated in place. What if you slip while cutting and do irreparable damage to the chainplate? It's a lot of work to remove and replace it at this point!

In case it is not obvious, Ian's current (tentative) choice of Precourt deadeye for the F22 is the SBDI model and as far as I can tell, his slot measurement specifications in the plans are spot-on for that model.

I wavered between using the "washer" insulation method, or trying to mold in an epoxy-layer for insulation. Eventually I decided on the latter, and Henny with his Most Awesome Blog came to the rescue again to show me how to do it. One of my neighbors was kind enough to plane down some maple wood blocks to the specified slot thickness (17mm) and drill a 3/8" hole at the right spot; this then locates the block precisely using a temporary steel pin:

(You only need two blocks to do both chainplates simultaneously; my neighbor prepped an extra for me just in case.)

Next I wrapped the blocks in masking tape, and cut away the tape from the pin hole. I tried to wrap the pins in tape as well, but the clearances were tight enough that this didn't work; thankfully it turned out to be not necessary anyway, the epoxy doesn't stick to the steel very well. I mixed up a batch up of high-density putty, stuffed some in a cake-icing bag, and did my best to squirt as much into the cracks on either side of the blocks as I could:

I was worried how well things would release after curing, but it turned out to be easy. A sharp rap with a screwdriver and hammer knocked the pins out, and the blocks themselves only needed one or two small hammer hits to release as well. Here's what it looked like right after removing the block:

I didn't get around to cleaning up the wastage yet, but that should be the easy part after all this. I'm glad I've got this job mostly done, so when I prime the floats, the interior of the chainplate slots can get primered too.

The other thing I worked on today, was making a new daggerboard case mold. I had already made a mold late last year, using the method outlined in the plans. Unfortunately, I used 1/4" plywood for the main surface and the more I thought about it, the more I felt that this would bow under the vacuum pressure. So I decided to scrap that one, and do a new one in a more solid design style.

After getting some particle board from the hardware store, my neighbor (same one - thanks Sean!) ripped three pieces to the right width for me, since my table saw is not quite wide enough for the job:

Next I screwed them all together, sanded the edges, and did my best to produce the "slight taper" that the plans call for:

Last thing I did for the night, was carefully cover the whole thing in masking tape:

That's all folks. Tune in next time to see if Jay can actually get some primer out of the can...or not. :-)


Anonymous said...

Good post Jay, and I think good advice about the chain plates.

Jay said...

Thanks Grant.