Keel roughed out and hull panels stitched

Finally got to dedicate some time to the 550. I spent about another 3 hours finishing the roughing of the keel, the worst places are within 1/16th of the foil templates and with a little more fiddling I should be ready to start glassing. My plan is to do two layers of cloth then fair to the final shape being very careful towards the top end to make sure it will retract.

The keel bulb is the next keel related project. I haven't completely decided what shape I am going to use nor have I determined the attachment method.

I discovered it is possible to stitch the three major hull panels together single handed. I don't recommend it but as long as I went slowly it worked fine.

After stitching panel #1 (the bottom panel) every 6 inches I pre-drilled the holes along the chine of panel 1 and placed the zip ties. It was then a matter of aligning the sides and starting from the bow. I did both sides at once alternating port and starboard doing two holes at a time. With a couple of straps wrapped around the hull to take some of the load it went pretty well.

Once the bow and transom frames were in place I went back and replaced every other tie with a new tie and a piece of 1" PVC cut to about 1-2 inches. This really helped keep the panels butted edge to edge. With the holes drilled 3/4" from the chine edges the ties and PVC help center the joint.

My plan is to start the filleting in a day or so, I'm hoping that as the hull sets in the final shape the panels relax a bit.

I'm also considering re-cutting the bow frame. It is 1 1/2 inch hardwood per the plans but I think I will tapper the aft edge to more closely match the hull panels.

There are photos but they are on my phone, I'll post them when I get the chance.

Finally a little more progress

After a busy month or so I finally got back to work. I've been dreading the keel shaping because there is a lot of material to remove. Yesterday I just jumped in and experimented.

The process I finally settled on was to use a planner set to remove 1/32 and roughed it in going lengthwise. once that was reasonably close I switched to going diagonally removing 1/64 per pass. With practice I could get pretty good results.

After three hours and ~20 gallons of shavings I switched to a belt sander with 6o grit. Another hour and a half and I had the port side roughed to within about 1/16 inch of the final shape and more uniform than I thought it would be.

My plan is to flip the keel and rough in the starboard side before trying to get any closer to the final shape.

I figure another 4-5 hours to rough the rest of the shape and that much again to get it to the final shape for glassing.

I want to have the keel complete before stitching the hull so I have a better idea of the final keel box dimensions.

Oh yeah, the CST bowsprit arrive a couple of weeks ago! Beautiful piece of work! Can't wait to have a boat to put it in! The thinking with ordering early was to have it in hand as the hull is being formed and as additional motivation!

It was too dusty to expose (no pun intended) the camera but I'll take and post photos later this week.

A little more progress

It has been a little slower than I hoped the past week. The keel blank has been epoxied and the (very) rough shape has been cut. The long, slow process of getting the foil shape formed has started. I'm still not sure the best way to go about it. I have the templates printed and will transfer them to some particle board but the material has to come off the keel blank somehow.

Frame 216 has been fully reinforced and the holes for the tiller and rudders (I decided to go with two) have been over drilled and epoxied.

I managed to cut a bunch on 1 inch OD PVC to use as alignment spacers for the stitching and even ran a couple of tests with scrap pieces. I think I am going to round the edges of the hull panels where they meet, it seems like that will allow for more adjustment and hopefully let me align things with less kinetic persuasion.

Hull Panels (take 2)

Didn't get quite as far as I'd hoped yesterday but I did manage to get the three hull panels lofted and cut. Kind of tricky moving those floppy 5.5 meter sheets around by yourself.

I did have some company, the Admiral and Captain paid me a visit and did a little supervising!

A decision needs to be made about the rudder(s), I think I am going the dual rudder option and I figure if I can lay them out now I can over drill and fill the transom prior to stitching. As long as I get it right I think that will be easier than trying to fill the holes after assembly.

I sent C-Tech an email requesting more information about their carbon spars but no response yet. The bowsprit needs to be figured in and it would be nice to have the sleeve(s) on hand during the early assembly.

If time permits I'll finish the re-enforcing of F214 and cut F0 tonight, then post some photos.

Hull Panels

Managed to get some time Friday to join the hull panels. Decided to use the butt block method of joining. I just used scrap Okume cut in 6 inch wide strips short enough to leave room for the shear and room to work at the chine. I made sure the grain orientation matched that of the large panels. Not sure if this maters but it was easy enough to do.

The strips were epoxied using MAS with a little thickener. I've used MAS Low Viscosity epoxy in the past and always had good luck. I like the zero VOC and no blush...

I should know later today if the blocks effect the ability to get a fair curve.

Assuming everything is properly cured (I made a test piece for destructive testing just for the heck of it) I hope to get the hull panels cut, frame 214 (transom) re-enforced and the keel blank epoxied.

I also spent some time at the computer running some keel bulb calculations and have what I think is a decent compromize between wetted surface and drag. It looks like a flattened shape is going to work and be fairly easy to build. I need to verify the center of gravity is close to the design.

The future Captain complete with a little drool.

Added Photos

I've added some photos of the lofting to a previous post but haven't been able to get much more accomplished. A little work has been done on the keel foil and bulb shapes. I'm planning to use CompuFoil3D to layout the templates.

I did manage to layout the hull bottom and sides and double check the location of the butt joints in relation to the frames and it all looks good. I'm still uncertain about whether to use tape and epoxy or 6 inch ply strips to create the butt joints. I don't want a bunch of extra fairing to do on the hull but I worry the extra material will cause issues while trying to get a fair curve.

My current inclination is towards the ply strips.

Lofty goals this weekend

This weekend produced a good start on the build.

The strips for the keel blank were ripped Thursday, the Okume was delivered Friday and the 165 pounds of lead arrived Saturday. The mail man was puzzled to say the least! Three flat-rate boxes +50 pounds had them scratching their heads. My wife explained it to him and he couldn't wait to tell the folks back at the office. "If it fits, it ships!"

Saturday and Sunday I spent lofting and then cutting the frames, I managed to complete them all minus frame 000. That should be an easy one. I discovered I am better at following a line with the jig saw than I am using a straight edge. I pay closer attention with the line.

After cutting (and routing the inner edges) I measured and the worst frame was only out 1/16 of an inch. Good enough for me! I normally work with metal and that seemed horrible but I'm told that is pretty close. This quality of wood is a pleasure to work with.

I took a bunch of photos I'll try and post a couple.

Next up is to layout the hull bottom and the sides. I did learn that the Okume is NOT 96 inches long! It is 98.5 (2500 mm)! Good to know because it would have put the forward butt joints nearly on top of frame 18. Glad I measured it.