When One Hole Closes, Another One Opens | Step 390 

Sounds like good practice to do so

100% correct. Rule 1 - Sharp corners create stress concentrations, leading to local high stress areas, greater incidence of localised crack formation and increased risk of early failure. Rule 2 - Radiused corners distribute stresses progressively throughout surrounding structure, reducing localised stress concentration, obviating cracking and considerably extending life to failure. (Now retired mech engineer: 30 years motorsport R&D / 15 years marine. Extensive high performance composite structures design experience throughout) However, I still like the basic concept of this project and the thought process that led to it. Fair play to the guys, they’re eternally willing to experiment, question and to learn. In my book those are all admirable characteristics that many either lack the confidence to take on board and carry out, or are dismissive of their value in a world where conformity is the norm.

Actually, the fiberglass will be following the natural arch of the deck or ceiling, depending on whether you’re inside or outside. The plywood core they put in will be easier to fit without having the rounded corners not that it’s hard to round the corners on the plywood. It’s when they make an opening in the fiberglass to put the new hatch in that they want to make sure they have rounded corners so that there’s no stress to cause cracks.

@@robm.4512 actually not 100% correct. Yes sharp corners do create stress concentration but that’s when you cut the opening not when you’re patching a hole. The fiberglass will follow the arch of the deck or the ceiling inside of the cabin. There will be no right angle to concentrate stress at. It’s not till they cut the opening for the new hatch that they need to worry about the rounded corners because the opening with its right angles Could cause the stress that could crack it.

@@duanemiller5606 a weakness remains a weakness even when becoming proportionally so small.

A worthy reply, and it is of course their choice. That being said, I always come away from each episode wanting to better understand why they elected to put so much time, money, and effort into what is fundamentally an old, small, and (forgive me) rather middling performing hull design. In the end, no amount of love, or modernization is going to make her fundamentally more than she is. As much as I enjoy every episode (and I do), I can't help but wonder how much more transformative for their lives, and future sailing, it would have been had they put the ingenuity, skill, knowledge, and resources they are lavishing on Uma into a better-designed, higher performing 10-20-year-old design. Either way, I'll be here watching!

@@jeffkovacs6521 They might end up sailing Uma for a year or two and then trading up.

@@jeffkovacs6521 unless they want to show what can be done with a 50 year old, small, mildly performing ...... Plus Uma will be way safer if anything else.

Who was your inspiration before that ? ❤❤❤❤

@@jeffkovacs6521 True but they know their audience its not hard to find an old boat that needs work, its achievable for a lot of people. They want to show that its not that hard to learn what you need.

In the British navy they have shore estalishments with ship names, like HMS Excellent, a ship of the line used as gunnery school, moved ashore and continued to be called HMS Excellent. Such bases are called stone frigates.

The Uma Bunker!

Nautical but not descriptive: Barnacle Barn.

So many people in this chat know my exact life trying not to smear epoxy all over and get a new glove across the room while in a locker or small head area with sails, supplies around 😂

While the epoxy is starting to set soon 😂

Honestly, I wasn't sure at first, but it looks like they're going to nail it. What a ride! Can't wait to see how it all pans out.

I believe that Dan being an architect is beneficial.

@@MarceloPaciorek. They are both architects.

PizzUma?

… it’s like you can predict the future! ;)

I agree. Personally I’d also do the port lights feathering from the outside. Obviously it would be a much harder job, but the main force of shipping water will be from the outside, so it would push the infill into the gap rather than out of it in case of any future delimitation issues. I know nothing about fibreglass though. You guys are amazing! ❤

You beat me to it. At Boeing we flipped things over or rotated 90 degrees, to take advantage of gravity.

@@SCFoster Yeah that's not aging well right now. ;)

@@justsomeguy6474 What does that mean? What does any of the QA post production issues have to do with composite design/build? I love the armchair keyboard warriors, that utter this nonsense. Something you wouldn't do in person, would you? Go back to playing with yourself and let the adults have an intelligent conversation.

Something like Airex would be best....not too expensive as it is a small area.

Or just use balsa correctly and make sure it doesn’t leak ;)

I agree! With all the holes that go through the deck, why use a material that absorbs water? A boat deck, like a building with a flat roof, is guaranteed to leak.

Was the sarcastic tone necessary?

“pandora” might be the best name yet.

I was wondering the same thing about balsa vs foam coring. Does one have better insulating or strength properties?

Good for you bro Gods speed

Got some catching up to do

Actually the load of a green wave coming down on the deck will push the sides OUT since it will crash down with all it weight on the flat cabin top since it has the most surface area. It’s that outward bending force we’re combatting by adding core to the side deck. But also properly installed glass on a well prepared surfaces does “pop off” is super secure.

Interesting point

Since we’re grinding and tapering the glass edges down and laminating them in from both sides, it’s not really an issue. If the hole was staying in the boat, then, yes, radiused corners are best.

@@SailingUma I hear you, but for that to be true, the edges of your grind have to approach transparency.

I been watching since the beginning but it’s been a minute since I watched you guys, Don’t buy a couch!!! Lol 😊

Yup, looks like you’ve got some catching up to do.

We’ve tried that method too. It’s just much harder to get air bubble out after than it is to remove them as you go.

Maybe if we win the lottery.

The 50 year old hull

The keel!

Maybe. The future is unknown and unpredictable.

Nope. Start small, end large. There is a lot of debate on this subject. But we’ve never seen a professional boat builder start large and end small.

@buza1300 completely agree, never seen a boat yard fill a hole small to large

Was thinking the same, start with the larger piece 1st then next smaller and so on. I think I saw it on another sailing channel. If there's a lot of debate on this, lets chime in, it'll increase revenue for the build.

@@SailingUma Interesting. Composite material scientist here, so I follow this debate with interest - and it is certainly a debate! From what I've seen across a number of boat restoration channels and published how-to guides, I'd say the balance of opinion is actually to start large - but it probably doesn't make a huge difference provided the layers are well-bonded in either case.

​@@SailingUmaWest says in his Fiberglass-Manual-2015: "Cut an appropriate number of pieces of fiberglass fabric the same shape as the hole. The first piece should match the outside edge of the bevel, with subsequent pieces gradually getting smaller. The final layer should match the inside edge of the bevel at the hole." I don't know anything about it and years ago I only built a small wood/epoxy boat myself, that's a completely different world. But these bondings between a new and an old laminate always scare me, I remember your saildrive installation....😱....it seems to have held. MfG Jan

Yup! YT has changed how it does things. It super sucks for us creatives and our audiences, but I guess YT doesn’t care. It now only shows you what IT thinks you’re interested in, even if you tell it (by subscribing and clicking the bell) what you’re actually interested in. You basically have to check your subscriptions feed manually if you want to actually see them. Sry. Wish there was a better way.

1 year. On the current refit. But last year was very slow as we had A LOT going on off camera.

@@SailingUma Ok, I thought it’s been longer … 🤪😁 it’s a huge and long project with ups and downs. Keep up the good vibes ! You will be rewarded 🥰