Interior refit 1970's kit sailboat questions

[GILow]

I will never complain about winter in Australia ever, ever again.

Can you trim and resew the main?

[Spot]

Originally Posted by GILow

I will never complain about winter in Australia ever, ever again.

Can you trim and resew the main?

Possibly. Would you do the head or the foot? The head seems easier than redoing the tack and clew...but then there is the effect on the leech. Boat has no back stay so a roachy sail is not a big problem. Sail seems a little baggy at the foot but I am not experienced enough to say whether it's blown out or not. One gentleman suggested I just add in reefs and sail normally with the first reef in and shake it out when going downwind, he did that on a boat with good results. I met someone from the regional Catalina 22 club and he is going to let me try one of his old mains. Luff and foot would be in the right range but it will not be as full in the leech as it is intended to slide under a back stay. Getting something new made is around 800$ US, I'd like to have a better feel for the situation before committing that kind of money.

PS adding sail pics

[Spot]

As alluded to earlier, I did start the tarping process in the fading light of day and finished in the dark. I had to make a new mast crutch for the cabin top and I treated myself to some cam straps to replace the old halyard I used years before to secure the tarp. The solar panel is moved out the front hatch and peeks out of the tarp. The snow has started, about a day later and predicting a couple inches less but will still be a mess for commuting to work today.

I decided to have a look at the boom. I brought it in the house and then thought it would be a good idea to take it apart. Previous owner had broken one screw off an end casting and put another with rolled threads alongside it. So an hour later, three broken bits (wear your safety glasses friends), and other consternation to remove the broken screw, I got the roller ends off the extrusion. I was surprised that the fasteners were small screws (this still is the norm), there was little corrosion, and that the goose neck is held together by one cotter pin.

I bought a scanner a few months ago with the hope of being able to scan and reverse engineer parts. Most of the parts I have tried were either too shiny or too big or too this-or-that to scan correctly. After a few attempts, mostly due to poor lighting, I was able to get a top and bottom scan, merge them into a single 'lump' of STL data, and load it into Fusion360. There I did a half-model drawing over the top of the data. The final step will be to 3D print a mock-up and see if it fits. To do the cross section of the boom, I used an end view picture for the general shape/curves and caliper measurements for specific sizes and wall thickness. The boom ends castings are stamped 40444 and 40443.

[wingless]

Originally Posted by Spot

... and that the goose neck is held together by one cotter pin.

As you know a cotter pin (or a spiral cotter) is not used for mechanical strength, just to hold parts to remain in their correct position.

Assuming the reference is to the spiral cotter shown in this image. That doesn't appear to me to be an incorrect application of the fastener.

(We're back into the high 60s / low 80s temps, our "cold" snap has gone.)

[Spot]

Thanks WL. I have it from another source 80's in Texas today on the Gulf.
I agree the spiral ring is right as the pin goes through 2 tabs so the ring is not directly loaded.
The cotter at the end of the spring on the fork that allows the boom to rotate then lock at 90 degree intervals...is always loaded, although it would never see full sail load, yes? It might look worse on the bench as it would be in the boat. I did want to make sure nothing was corroded in the mechanism, hence the long process to take it apart.

[Spot]

The 3D print is done. For a second time through the workflow I am pretty happy. I would need to fix the following things to make a 'real' part:
1. joint between out haul tail and main casting is tapered on real part and fits better in boom track. Model rubs ever so slightly in track.
2. horseshoe collar is too high on model, should have measured real part to set this.
3. out haul hole placement and size could be better split between real (bridge too thin) and model (wrong size and location)
4. real part is not drilled at 90 degree increments, probably would match drill in real life along with the bolt hole for the straps for the end of the boom.

The process would be useful for obsolete/ out-of-stock parts, especially if one had an in at a foundry for a casting. Similar parts are still quite reasonable at Dwyer Mast, I have an email into them to see if this is 'one of theirs'....

Also adding a picture from the tarping event, I really enjoy the nightlight feature on my solar controller.

[wingless]

My speculation is that "critical" cotter mechanism exists to permit some small "light" load movement so the system will operate properly. It would surprise me if that part ever sees huge full spring compression loads.

Nice job on the new parts!

[wingless]

It looks like the sail itself prevents excess force from being applied to that spring pin.

Attachment of the sail to the mast and to the boom causes the sail to prevent more than slight force to those parts.

[Spot]

Thanks Wingless.
Yeah, it seem less vulnerable when one imagines the sail holding things together.

[Spot]

Sort of a cold, wet weekend here, temps hovering around freezing with rain/sleet/snow, and fog. I was glad the boat is tarped. I drug the v-berth cushions out into the boat to make a pattern for the keystone/throne cushion. When I was putting everything back, several groups of Canadian geese descended, honking, looking for a place to land for the night. That is the first I remember hearing them since fall. I had a revelation to hold the metal yardstick against the cushions while drawing the marker lines to keep the ink of the fabric. It's been a year since I have sewed on them so I will need to remember what to do: what to oversize, what to undersize, how to sew zipper plackets...Looking forward to trying the seam tape to see if that helps get the cover through the sewing machine with less slipping between panels.

[wingless]

Thanks for the update / images.

Why not just make the keystone / throne cushion to have a straight edge on the front?

Won't that be good enough? Won't that facilitate flipping the cushion for better wear? Isn't there a slight left / right dimensional difference?

My experience w/ basting tape has been very favorable as a sewing aid. I also used it when sewing through the Bimini top to aid in water resistance on the super slippery PTFE thread.

[Spot]

Originally Posted by wingless

Thanks for the update / images.

Why not just make the keystone / throne cushion to have a straight edge on the front?

Won't that be good enough? Won't that facilitate flipping the cushion for better wear? Isn't there a slight left / right dimensional difference?

My experience w/ basting tape has been very favorable as a sewing aid. I also used it when sewing through the Bimini top to aid in water resistance on the super slippery PTFE thread.

Thanks WL for the post and comments on basting tape.
The keystone is 'normal' in the sense that front and back are parallel and side converge at the same angle. My patterning and pics may make it look more complicated than what is really there. You remembered the old problem, that the keystone hatch is offset 1/2" or something port/starboard due to a measurement error that did not make sense to rip up and redo the plywood and framing in the berth. All the cushions are flip-able/swap-able per your advice.The compression post will not have an even reveal but that is about the worst of it.

50's F here today, getting excited to be working on the boat outside!

[wingless]

Great.

The cardboard pattern fooled me into thinking there was a small notch for the post.

Enjoy the warmer temps.

[GILow]

One more vote for the basting tape.

Project is looking good, can't wait for action photos of the boat under full sail though.

[Spot]

Originally Posted by GILow

One more vote for the basting tape.

Project is looking good, can't wait for action photos of the boat under full sail though.

Thanks Matt, thanks WL.
If all goes well I get to see the sail maker tomorrow and pick up my newly re-cut old sail. 22" (56 cm) off the foot so I have room between boom and cabin top. I wanted to try some sail sewing myself but talking to a couple folks made it seem like he was the guy to see for this job and one less item on my to-do list. I hit the schedule just right so I got in after other repairs and before their next new sail.

I got out my favorite 2 dollar electric knife and cut the keystone foam, trimmed the patterns, and made a hole on the ping pong table (not shown) to lay out the project. The foam does cut easier when there is 1-2 inches (2.5-5cm) past the blade and the off-cut is supported.