Sheer stringers and more clamps

One thing we have learned is that gluing one floppy thing to another floppy thing means you're going to need a ton of clamps. Not wanting to spend the money on 30 or 40 spring clamps we went with the PVC clamp method.

It started with spending way too much time cutting 1" sections of 2" PVC pipe with a pull saw, then taking a short cut and using the circular saw, then realizing you have created a 10' radius of PVC chips in the yard and then finally shop-vac'ing your lawn to get it all cleaned up. But in the end we had plenty of clamps to get the hull sides ready for stitching.

Boston has finally warmed up enough that we can work outside again which was a treat after all that gluing in the basement. The stringers are held with the clamps and a few staples from the underside to keep them from sliding around. We also glued on the doubling blocks which go at the lashing points for the beams and mast stays.

We also glued the small extension on our replacement bow panels that we couldn't glue before while we had the chance. When these are dry we don't want anything to keep us from stitching up the hulls.

Here is hull side #2 sunning and hull side #3 glued and clamped up. By this point we have given each panel a final home as to which side of which hull they will become. Only the outside face of each hull gets the supports for the mast rigging so we put the two panels with the roughest seams on the inside where they will only be seen by the fishes.

The forecast says rain tomorrow morning but sun again in the afternoon so that should be enough of a window to glue the last hull side.

Gluing the mast halves

Yesterday I rounded the edges on the sprit with a router which means the gluing table is clear so now we can work on the mast. The plans call for a box section with epoxy fillets which is then rounded using the normal progression of 4-sided to 8-sided to 16-sided to round. 

The first step is to make the two 'U' shaped halves, insert the mast foot and halyard sheaves and then glue the two halves together. Wharram suggests using screws to temporarily clamp the square pieces onto the larger flat pieces then remove and fill with thickened epoxy. Here is our plan to avoid screw holes showing in the final piece, though we ended up angling the screw to provide more depth.

The last thing we want is for the fir to split so each screw location s pre-drilled with a countersink bit. Here is the bit set for the right depth and the angle we decided to use.

To get the spacing right we used 1 1/2" wide cutoffs as spacer blocks. the square pieces are 1" square so that makes a 3 1/2" diameter mast.

Once both halves were aligned and screwed we could back out the screws, coat epoxy and then re-assemble.  It was a long day but getting the spars done will be a huge landmark on the way to sailing this spring.

Gluing the cross beam halves

There is still one pair of beam pieces to cut from the plywood and a few hours before the Super Bowl starts so no time to waste. I'm still waiting on longer clamps to arrive so in the mean time Cam is using the tried and true butt clamp method while he saws. Using the saw at a very shallow angle seemed to help the blade follow the curve of the cut nicely.

The shim helps prevent the plywood from grabbing the saw blade.

Next the beam halves are matched up and glued using the butt blocks. Small nails keep the butt blocks from sliding and a board, clamps and shims apply the pressure. The girls have been making all kinds of snacks while we've been working so now it's off to Cam's house for the game while the epoxy sets.

Starting on the cross beams

The Hitia 17, like most cats, uses three cross beams to hold the hulls together which also support the mast and platform. The plans call for curved and tapering I-beams using plywood for the vertical portion and douglas fir for the tops and bottoms. All three beams share the same profile, but are cut to different lengths to follow the taper of the outside of the hulls.

The beam template is made from cheap plywood and a bit taller than the plans call for to increase the strngth of the beams. We drew a line  perpendicular to the factory edge before cutting it out and then drilled holes along this line. This will allow using the big t-square to mark perpendicular lines on the good plywood and sight through the holes as a reference point later on to make sure the template is square so the beams all end up with the same amount of curve. To lay out the patterns I marked six lines on the plywood spaced so that there was a 1/2" margin between each piece to allow for cutting.

Then it's as easy as lining up the template with the line by sighting through the holes. This allows for much greater precision than just trying to line up the short edge by feel.

With all six beam halves traced the plywood got clamped to the new workbench and cut with the Japanese pull saw.

And then the edges planed down to the pencil line with a jack plane I picked up for $6 at a yard sale last year. I don't think there is any faster way to get to a piece of wood to your exact template than a hand plane.

Next come the butt blocks that join the two halves of each beam. These are also 1/2" plywood and curved to match the top of the beam.

So that's it for today. The center and aft beams are cut and shaped, the fore beam is waiting for longer clamps so I can safely cut it, and all three butt blocks are cut and shaped. The plan is for all three beams to get glued together tomorrow morning before the Super Bowl starts. Maybe now that we can lay out the plans and work at the same time we won't keep making so many mistakes!

Making new bow panels

It's been almost two months since we worked on the boat last. Between weather, busy schedules and a bit of burn-out we needed a good break. Yesterday we finally got going again and not only made significant progress but proved that our skills are improving.

Last time we caught a mistake we made in measuring the bow panels using the right measurement from the wrong reference point. As a result we cut the angle too steep and made the bow triangle piece too small. Here you can see what we cut and the line that is what we should have cut.

So that leaves us with this weird shape for a new bow panel.

A quick go with the Japanese pull saw and here is our new bow panel. We then used this piece to mark and cut the other four panels. We're a little worried about the narrow point breaking when the panels are stitched but hopefully the epoxy will hold it all together

Next, all four panels got two coats of epoxy on their inside faces making sure we had two 'lefts' and two 'rights'. All told it only took 2 hours and we were back on track. 

Next up for the day was gluing the last two of the main hull panels, but we'll save that for the next post.

Improved deck supports

The deck curve at bulkhead #2 is a full 1" which means that our 1" wide deck supports would be too thin on the ends to offer any support. You see the outline of the 1" support against the curve at the top of the bulkhead here.

I could have just added a strip at the bottom to make the whole piece taller, but I thought i would do something a little stronger and lighter. I actually gave the solution away in the first photo, it's the triangular pieces on the far right. They will fit below the full length strip making the whole piece about 1" thick and orienting the grain properly at the edges. Not as fancy as laminating up a curved support but more than enough for a stitch-and-glue beach cat.

I started by marking out the shape on a scrap strip of the 1" x 1/2" fir.

I wasn't sure how to cut this at first, but finally decided to just do it by hand with my new Japanese pull saw. The more I use that saw the more I think power tools are over rated.

And here it is all glued up and again held with staples. Staples aren't the prettiest, but it worked and it's all going to be painted later anyway.

Finally, here it is with the glue dried and two coats of epoxy.

One more afternoon of glueing and all the bulkheads will be assembled and coated. I'll trim the top edges on the router table and they'll be ready for stitching into the hulls.