Lug sail for a dinghy - mast size and material

[MarioOfTheLake]

Thanks for pointing that out!

No need to worry, I think I actually bingewatched a ton of videos on handheld circular saws on youtube (bless that site, btw) before going into this mast project, and carefully heeded the advice on kickback and standing in the way of the blade. There weren't any issues, except for the first few cuts being rather imprecise.

 

[MarioOfTheLake]

BTW any thoughts on the tolerances for the mast fitting? I was thinking 5mm wider than the mast should be OK - judging from the pics at pdracer.com. I am planning to essentially copy this fitting:

https://www.pdracer.com/free-plans/bucket-ears/frame-bulkheads/unstay4.jpg

I presume there is some reinforcement behind the plywood where the mast holders are screwed to. Any advice on this?

 

[Tops]

I don't see anything so wrong with that fitting but I would make it a little tighter so the mast does not knock around.
I have seen a similar one like that with a metal strap that swings out of the way (edit: on the upper block) to make stepping easier.
Adding a plywood backing plate in the air box is a good idea, 13-15-18mm or so.
My PDR had a fairly elaborate mast step / fore deck assembly, some of it driven by having access to CAD and CNC.

Is there a small boat get-together in your area? Ours is this current weekend and I got to attend yesterday and see 20-some boats and ride in a couple.
Those are nice events for meeting other builders and seeing how they handled details on their boats. My current project needs gunwales so I was eyeing up the sheer lines and seeing how everyone handled this detail.

 

[seasquirt]

Make your mast and bases as neat a fit as possible to avoid the mast flopping about. If you do end up a bit loose, some leather or rubber wrap around the mast will fill the gap and act as a buffer. Or a thin rubber wedge on a string (or two), to wedge in after the mast is in. A moving mast puts uneven strains on the footing, and shock loads on the upper holes when it slaps about. If your sail uphaul and luff downhaul go to cleats on the mast, there is minimal down force going through the foot, so less wear there.

 

[TeddyDiver]

^ what Tops and seasquirt said + you can always shave a bit of if the mast fitting is too tight..

 

[MarioOfTheLake]

Tops,

how much does your mast weight? I was working on the mast fitting and I started to worry mine might be too heavy.

How much should such a mast weight?

 

[Tops]

Tops,

how much does your mast weight? I was working on the mast fitting and I started to worry mine might be too heavy.

How much should such a mast weight?

My mast is no more but estimating 2.5" diameter x 16 feet x pine (radiata) = 16.28lbs or 7.38kg
I had to take the square root of the circular area to use in the calculator.

Lumber and Hardwood Weight Calculator https://www.inchcalculator.com/lumber-weight-calculator/

Your mast will be shorter and possibly lighter, your boom is shorter too but I did not have a yard spar.
You could increase the thickness of the boat at the mast base and/or add some fiberglass and resin to shore up that area.