The dangers of boat construction!

coopec

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I am currently building the toilet door. I'm being very careful to make the door a close fit to try to make make the toilet shower sound-proof.

Yesterday I carried the door up to the yacht, down the gangway and inserted the door into the toilet. It was just a little too wide in places so I gently pushed the door in, got out the permanent marker and marked the high spots.

Then I tried to remove the door but it wouldn't budge. I looked around for something sharp (like a screwdriver) so I could lever it out but there was nothing. I guess I was starting to panic as I was assessing my fate!

Then I discovered a pack of screws (unopened) so I took one out and screwed it in the gap between the door and the frame and tried pulling it, On the fourth attempt I was successful! PHEW!

I'll try fitting the door again tomorrow but this time I'll have hinges attached and door lock.



Screenshot 2022-05-27 at 17-58-21 (SEE BELOW) Fiberglass trim around door frame in compression...pngimgonline-com-ua-resize-JIerEAsmDerXJy.jpgimgonline-com-ua-resize-3qlgA0uMIiTyR.jpg
 
I thought about distortion due to stress loads but that is not possible as the doorway is located within the main mast compression bulkhead

It's entirely possible. Plywood stress/strain diagram...

Flexural-stress-strain-curves-for-plywood-reference-panels.png


0.1% might not sound much, but on a 2m bulkhead that's 2mm. Boatbuilders build doors with a noticeable gap to the frame for exactly this reason. A non jamming door is much more important than keeping farty noises out.
 
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Always have your phone with you when you do something like that!!

A freind told me of the time he fell head first into the bilge under the engine and was stuck. Luckily someone came by and heard him shouting.

It briefly crossed my mind that I might have to shout but my wife would have never heard. She would have become concerned that I had not come in before dark. My son would then have been summoned to investigate.

I used to have a small "Seniors" pocket phone but I thought I bring myself up-to-date and got a "smart phone". That was just about the most stupid thing I've done in ages. :rolleyes:
 
It's entirely possible. Plywood stress/strain diagram...

Flexural-stress-strain-curves-for-plywood-reference-panels.png


0.1% might not sound much, but on a 2m bulkhead that's 2mm. Boatbuilders build doors with a noticeable gap to the frame for exactly this reason. A non jamming door is much more important than keeping farty noises out.

My compression bulkhead is made up of Jarrah (Australian Hardwood) planks encapulated in19mm plywood and fiber-glassed so there's no way it will flex.

Screenshot 2022-05-27 at 20-30-56 Yacht9.png
 
Please tell me i'm not the only one who finds this really funny.

If I am, I apologise :)

The Science of Schadenfreude
It is part of being human to laugh at someone's misfortune.

There is part of our brain that gets turned on when we are rewarded at someone else’s expense. Schadenfreude is when we laugh at someone else’s misfortune. Schadenfreude comes from the two German words, Schaden and Freude, harm and joy. We’ve all done it, even if we are not proud of it. Your friend trips and spills coffee on their shirt. You may feel compassion, but part of you also chuckles. If your boss trips and spills coffee you may laugh a lot, but perhaps not out loud! Even if you think you are joking, laughing at someone else’s expense, that other person may not take it as a joke :censored:

Maybe some time down the track I'll see the funny side:(
AND I've decided to get a "Seniors" phone ie one that I can put in my pocket.(As CapPugwash suggests):)
 
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Always have your phone with you when you do something like that!!

A friend told me of the time he fell head first into the bilge under the engine and was stuck. Luckily someone came by and heard him shouting.
My son was working on his own in the aft locker, aka lazarette, when the lid slammed down and latched. Unable too get out he luckily had his phone and made a phone call for rescue.
 
I don't think it is recommended to make boat joinery anything like what one would consider a tight fit. Normal marine moisture levels will be adept at causing things to swell, given a chance. This is doubly important if cruising in tropical climates.

[#11, DDB types faster than I do.]
 
Regardless of your confidence, I would be inclined to leave a large gap all round. The boat will move; plus moisture will cause parts to change shape. It would be a pity to get everything finished & have to re fit. Furthermore, such movement does not look so bad if the original joint is large ( but evenly spaced)

Good point. But I don't think moisture will be a problem as it is all fiber-glassed.

I have adhesive backed rubber strip to go between the door and frame so maybe that will be sufficient anyway.

But as you say "It would be a pity to get everything finished & have to re fit."
 
All materials flex under load, your bulkhead will definitely do so. I agree with the above advice, leave a large gap.
(I had the heads door jam on me once in the Dover Strait, I instinctively booted it off the hinges..if I had waited until the other side of the wave, it would probably have unstuck itself..)
More advice, don't make heads doors too secure, the latch isn't to keep out robbers but just for privacy. There should be a way of opening it from outside in case someone bangs their head or faints, while seated upon the throne!
 
My compression bulkhead is made up of Jarrah (Australian Hardwood) planks encapulated in19mm plywood and fiber-glassed so there's no way it will flex.

View attachment 135928

It doesn't have to flex to change dimension. It will stretch, compress and shear in column. As the stress/strain diagram shows, at 25% of ultimate strength plywood will have a strain of 0.1%. That's enough to jam your door. No material is absolutely rigid. Engineers and naval architects take this into consideration, and boat builders have learned this the hard way. Sadlers had a reputation for jamming their interior doors at times.
 
All materials flex under load, your bulkhead will definitely do so. I agree with the above advice, leave a large gap.
(I had the heads door jam on me once in the Dover Strait, I instinctively booted it off the hinges..if I had waited until the other side of the wave, it would probably have unstuck itself..)
More advice, don't make heads doors too secure, the latch isn't to keep out robbers but just for privacy. There should be a way of opening it from outside in case someone bangs their head or faints, while seated upon the throne!
I'm almost certain the vacant/occupied lock can be opened from the outside with a screwdriver. I'll check that out in the morning (most important)?
 
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