This is not a joke , but some honest questions.
Is 316 stainless steel recyclable?
Does it have any scrap value?
What do riggers do with the old stuff that is dropped off there?

PS.
Microbe,
Many thanks for posting.
I am sure down the road someone else from WA will find your information very useful.

gary

100% recyclable;

www.assda.asn.au/technical-info/environment-health-and-safety/recycling

actionmetal.com.au/what_we_buy/stainless-steel/

Would suggest that bolt is 304 stainless not 316. Need 316 for new ones.

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r13 said..
Would suggest that bolt is 304 stainless not 316. Need 316 for new ones.

If memory serves me correctly, 304 is stronger but 316 is more corrosion resistant, either way regular inspection is the key.

Loving this thread looking forward to the next stage

As per here 304 is not stronger than 316 - they are very similar in yield and tensile strengths, and 304 has less corrosion resistance as you indicate. 316 is commonly called "marine grade" for this extra corrosion resistance reason but there are many marine grade stainless steels. Good point re the regular inspection and rust weeps are a sure sign of issues. Best to ensure all fasteners are sealed from water contact.

www.anzor.com.au/technical/stainless-steel-overview/the-dos-and-donts-of-stainless-steel-fasteners1

Specific yield and tensile strengths of 304 and 316 stainless in plate or fastener grades depends on the standards they are made to. See a good summary here.

www.atlassteels.com.au/documents/Atlas%20Grade%20datasheet%20-%20all%20datasheets%20rev%20Aug%202013.pdf

Good summary for bolts here;

www.portlandbolt.com/technical/faqs/stainless-yield-tensile-strength/#:~:text=ASTM%20A276%20does%20have%20minimum,316SS)%2C%20and%20ASTM%20F593.

As per a prior comment I have made make sure if you are replacing stainless fasteners with 316 that the original was not a very high tensile strength grade - eg a Bumax 88 or A4-80 which is commonly used for keel bolts. If you replace these with 316 the strength will not be adequate.

www.anzor.com.au/technical/strength-and-mechanical-properties/stainless-fastener-tensile-comparison-chart

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r13 said..
As per here 304 is not stronger than 316 - they are very similar in yield and tensile strengths, and 304 has less corrosion resistance as you indicate. 316 is commonly called "marine grade" for this extra corrosion resistance reason but there are many marine grade stainless steels. Good point re the regular inspection and rust weeps are a sure sign of issues. Best to ensure all fasteners are sealed from water contact.

www.anzor.com.au/technical/stainless-steel-overview/the-dos-and-donts-of-stainless-steel-fasteners1

Specific yield and tensile strengths of 304 and 316 stainless in plate or fastener grades depends on the standards they are made to. See a good summary here.

www.atlassteels.com.au/documents/Atlas%20Grade%20datasheet%20-%20all%20datasheets%20rev%20Aug%202013.pdf

Good summary for bolts here;

www.portlandbolt.com/technical/faqs/stainless-yield-tensile-strength/#:~:text=ASTM%20A276%20does%20have%20minimum,316SS)%2C%20and%20ASTM%20F593.

As per a prior comment I have made make sure if you are replacing stainless fasteners with 316 that the original was not a very high tensile strength grade - eg a Bumax 88 or A4-80 which is commonly used for keel bolts. If you replace these with 316 the strength will not be adequate.

www.anzor.com.au/technical/strength-and-mechanical-properties/stainless-fastener-tensile-comparison-chart

Hey, I don't have the time or inclination to google my heart out and quote every link I can find, I merely quoted the advice a couple of business that sell the stuff, with whom I regularly deal, that 304 is the stronger of the two.

Thanks for that UncleBob. I remember reading somewhere that 304 was slightly stronger than 316, but I only use 316 for anything in my boat for its corrosion resistance.

Thanks for your detailed reply r13. I appreciate the time you are putting in to help me out with your advice.

When it comes down to material selection I'm really at the mercy of what's on the shelf at the local chandlery.

Regardless, there was no trace of any sealant anywhere near that bolt that failed. I suspect water had been able to pool under the head and caused the corrosion.

I had noticed the rust and was intending to replace at least the bolts before this season.

Thanks all for your contributions to this thread.

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Microbe said..
Thanks for that UncleBob. I remember reading somewhere that 304 was slightly stronger than 316, but I only use 316 for anything in my boat for its corrosion resistance.

Thanks for your detailed reply r13. I appreciate the time you are putting in to help me out with your advice.

When it comes down to material selection I'm really at the mercy of what's on the shelf at the local chandlery.

Regardless, there was no trace of any sealant anywhere near that bolt that failed. I suspect water had been able to pool under the head and caused the corrosion.

I had noticed the rust and was intending to replace at least the bolts before this season.

Thanks all for your contributions to this thread.

Please keep us updated and some good clear photos , I fear there are to many production boats out there sailing with only a good gust from losing their mast.
having lost a mast in a gale on Port Phillip bay after a stainless fitting opened up I would never want to experience it again . I was young then and can remember how exhausted I was from the rough seas and trying to recover the broken mast .
Port Phillip may be a bay but a westerly gale can throw up a fine sea, no wonder the mighty little Top hat yacht was designed to sail there .

Next question: how to fix the bulkhead? I've seen controversies raging on line about whether to fit the bulkhead snug up against the hull or to leave a gap filled with foam and tab the bulkhead in with glass tape. The idea is that the foam method avoids hard spots on the hull.

Given that I'm planning a semi bulkhead what does everyone think would be the best approach?

Here's a photo of the template in place. Will be using 18mm marine ply for the actual bulkhead.

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Microbe said..
Next question: how to fix the bulkhead? I've seen controversies raging on line about whether to fit the bulkhead snug up against the hull or to leave a gap filled with foam and tab the bulkhead in with glass tape. The idea is that the foam method avoids hard spots on the hull.

Given that I'm planning a semi bulkhead what does everyone think would be the best approach?

Here's a photo of the template in place. Will be using 18mm marine ply for the actual bulkhead.

Can you step us dumb dumbs through how you got the shape ? I have had no luck with this so far ??

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Zzzzzz said..

Microbe said..
Next question: how to fix the bulkhead? I've seen controversies raging on line about whether to fit the bulkhead snug up against the hull or to leave a gap filled with foam and tab the bulkhead in with glass tape. The idea is that the foam method avoids hard spots on the hull.

Given that I'm planning a semi bulkhead what does everyone think would be the best approach?

Here's a photo of the template in place. Will be using 18mm marine ply for the actual bulkhead.

Can you step us dumb dumbs through how you got the shape ? I have had no luck with this so far ??

I did it the hard way. I held a piece of ply in place and used a spacer to mark of the distance to the hull, cut some off the ply, held it up again, marked it off again, cut some more. I kept repeating that until it was a reasonable fit. There's still a few gaps.

Looks great. Good article here;

www.nbayracing.com/bulkhead.htm

The Witucki article referred to in the above link is assumed to be this;

www.epoxyworks.com/index.php/replacing-damaged-bulkheads/

The foam strip method is discussed here;

www.thevirtualboatyard.com/2013/05/a-tabbing-we-will-go.html

Good comments here;

forums.sailinganarchy.com/index.php?/topic/198115-tabbing-in-bulkhead-advice-on-cloth/

How is the cabin rear ply bulkhead secured to the hull? I would expect it is glued and (say) 20mm radius bog fillets each side then ~3 layers of ~6oz glass tape. Would suggest doing it the same way as that bulkhead - no foam needed - use biax tape. Is there a hard spot showing on the topsides adjacent to it? The longitudinal stringer along the topsides will assist to avoid the hard spot.

There are no other bulkheads in the hull. About 50% of the Spaceys that I've seen have a forward bulkhead about halfway between mast and bow. Not sure if it was an option to have a boat without that bulkhead, or a change in design, or a trend to cut them out. There's no evidence that one ever existed in my boat, so I suspect it was never there.

Perhaps the kitchen moldings act to stiffen the hull. I'll check how they are attached to the hull and copy that.

But the cabin rear bulkhead - does it not go out to the hull below the deck level?

No, the rear bulkhead of the cabin is part of the deck molding. It is not attached to the hull and leaves a space for the quarter berths.

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Microbe said..
Next question: how to fix the bulkhead? I've seen controversies raging on line about whether to fit the bulkhead snug up against the hull or to leave a gap filled with foam and tab the bulkhead in with glass tape. The idea is that the foam method avoids hard spots on the hull.

Given that I'm planning a semi bulkhead what does everyone think would be the best approach?

Here's a photo of the template in place. Will be using 18mm marine ply for the actual bulkhead.

Looking good. Have you considered running the bulkhead vertical from the outboard radius parallel with the inboard edge, this would extend it up the cabin side in a taper and when glassed in you would have a butt joint under the deck, where the join would be in either compression or tension, and the portion extending up the cabin side would be in shear, a much stronger proposition with very little weight penalty.

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Zzzzzz said..

Microbe said..
Next question: how to fix the bulkhead? I've seen controversies raging on line about whether to fit the bulkhead snug up against the hull or to leave a gap filled with foam and tab the bulkhead in with glass tape. The idea is that the foam method avoids hard spots on the hull.

Given that I'm planning a semi bulkhead what does everyone think would be the best approach?

Here's a photo of the template in place. Will be using 18mm marine ply for the actual bulkhead.

Can you step us dumb dumbs through how you got the shape ? I have had no luck with this so far ??

Make a joggle stick (sometimes called a ticking stick) ..... just google it

Here's a couple of pictures of the bulkhead and chainplate arrangements on the spacey 22 I sailed on last week. Above deck fitting was a welded t shaped arrangement running fore and aft with caps and lowers both attached to it.

Looks good, neat workmanship.

Yes, I like it. I'm coming back to the original idea of a semi bulkhead. I'd started thinking of extending the bulkhead to the seat edges to create a semi-private forward cabin with double v berth. But what I was actually creating was more work. The semi bulkhead would give me more flexibility and require less materials and time.

So, here's an updated mockup. The red hashed section of the bulkhead template will be discarded. There will be a chainplate on either side of the bulkhead and they will be in line fore and aft, so will have to share the same bolts. The cap shroud plate will be in line with the mast and the plate for the lowers will need to be 80mm aft of that. I'm planning a 30mm hardwood spacer on either side of the 18mm ply bulkhead to give me that space.

(excuse the rough drawing)

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Microbe said..
Yes, I like it. I'm coming back to the original idea of a semi bulkhead. I'd started thinking of extending the bulkhead to the seat edges to create a semi-private forward cabin with double v berth. But what I was actually creating was more work. The semi bulkhead would give me more flexibility and require less materials and time.

So, here's an updated mockup. The red hashed section of the bulkhead template will be discarded. There will be a chainplate on either side of the bulkhead and they will be in line fore and aft, so will have to share the same bolts. The cap shroud plate will be in line with the mast and the plate for the lowers will need to be 80mm aft of that. I'm planning a 30mm hardwood spacer on either side of the 18mm ply bulkhead to give me that space.

(excuse the rough drawing)

And to think this all started from a post on how to paint the decks

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LooseChange said..

Zzzzzz said..

Microbe said..
Next question: how to fix the bulkhead? I've seen controversies raging on line about whether to fit the bulkhead snug up against the hull or to leave a gap filled with foam and tab the bulkhead in with glass tape. The idea is that the foam method avoids hard spots on the hull.

Given that I'm planning a semi bulkhead what does everyone think would be the best approach?

Here's a photo of the template in place. Will be using 18mm marine ply for the actual bulkhead.

Can you step us dumb dumbs through how you got the shape ? I have had no luck with this so far ??

Make a joggle stick (sometimes called a ticking stick) ..... just google it

I just googled Ticking stick.... A simple yet effective technique. I'm struggling to see how it would work on the radius of the hull though.

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Toph said..

LooseChange said..

Zzzzzz said..

Microbe said..
Next question: how to fix the bulkhead? I've seen controversies raging on line about whether to fit the bulkhead snug up against the hull or to leave a gap filled with foam and tab the bulkhead in with glass tape. The idea is that the foam method avoids hard spots on the hull.

Given that I'm planning a semi bulkhead what does everyone think would be the best approach?

Here's a photo of the template in place. Will be using 18mm marine ply for the actual bulkhead.

Can you step us dumb dumbs through how you got the shape ? I have had no luck with this so far ??

Make a joggle stick (sometimes called a ticking stick) ..... just google it

I just googled Ticking stick.... A simple yet effective technique. I'm struggling to see how it would work on the radius of the hull though.

It used to do my head in when I was younger but I see a bit different now I assume it is just away of taking measurements as you go down the hull from a fixed point then join the dots doing it with a ruler. Would be similar

Yes a good example of lateral thinking and continuous improvement to nail all issues in the one project. This is going to turn out really well.

See here a good concise example of the tick stick - this uses a notch as well as the line underneath to give accurate locating - works on any shape hull.



Agree with the semi bulkhead - the red hatched area inboard of it is constricting the interior for no reason - it will not add much strength.

Have 4 suggestions;

1 The point ending of the lower corner of the semi bulkhead gusset will cause a lateral in plane stiffness reduction going into it - will cause a stress concentration at that point ending. Realise the bunk shelf stiffness will assist to reduce the impacts of this but it is better to widen the bulkhead say 50mm at this lower end and add the (say) 50-100mm radius ending to it as per the below photo from one of the links above. Realise you probably won't have the hull bulkhead under the bunk shelf as below but the softer ending will still be well worth it imho. Will use more ply but not much.

See suggestions 2, 3, 4 below.



2 The hardwood spacers under the 2 separate chain plates for caps and lowers - obviously run the grain vertically and epoxy glue them to the bulkhead ply to avoid them splitting. Suggest make them 5mm wider each side than the ss chain plate straps, and then also chamfer them 45deg out so that they don't look too chunky. So if the chain plates are 32mm wide as before, the hardwood would be 102mm wide initially. On the lower edge these hardwood spacers would be finished the same - so 5mm longer and an extra 30mm with 45deg bevel - so total extra length under the ss plate end is 35mm. The 2 mitre corners radiused say r5.

3 Note that in the photos of the other ss22 chain plates there is a short bolt - the rule of thumb is no less than 2 1/2 threads protruding out from the end of the nuts. Obviously this doesn't hold for bolts and nuts under cabin deck heads securing cabin top hand rails - use dome nuts to avoid piercing your head on bolt ends.

4 Put the bolts through from the cap plate chain plate side so that this chain plate bears on the unthreaded shank of the bolts.

All prior comments as relevant - eg ss plate covers over the chain plates, self tapped into the deck and well sealed with suitable adhesive / sealant.

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Toph said..

LooseChange said..

Zzzzzz said..

Microbe said..
Next question: how to fix the bulkhead? I've seen controversies raging on line about whether to fit the bulkhead snug up against the hull or to leave a gap filled with foam and tab the bulkhead in with glass tape. The idea is that the foam method avoids hard spots on the hull.

Given that I'm planning a semi bulkhead what does everyone think would be the best approach?

Here's a photo of the template in place. Will be using 18mm marine ply for the actual bulkhead.

Can you step us dumb dumbs through how you got the shape ? I have had no luck with this so far ??

Make a joggle stick (sometimes called a ticking stick) ..... just google it

I just googled Ticking stick.... A simple yet effective technique. I'm struggling to see how it would work on the radius of the hull though.

Note that the method only gives the curve of the hull in the one plane - the plane of the bulkhead.

Select to expand quote

r13 said..

Toph said..

LooseChange said..

Zzzzzz said..

Microbe said..
Next question: how to fix the bulkhead? I've seen controversies raging on line about whether to fit the bulkhead snug up against the hull or to leave a gap filled with foam and tab the bulkhead in with glass tape. The idea is that the foam method avoids hard spots on the hull.

Given that I'm planning a semi bulkhead what does everyone think would be the best approach?

Here's a photo of the template in place. Will be using 18mm marine ply for the actual bulkhead.

Can you step us dumb dumbs through how you got the shape ? I have had no luck with this so far ??

Make a joggle stick (sometimes called a ticking stick) ..... just google it

I just googled Ticking stick.... A simple yet effective technique. I'm struggling to see how it would work on the radius of the hull though.

Note that the method only gives the curve of the hull in the one plane - the plane of the bulkhead.

Thanks for that he makes it look easy I bet it's not .
is the the board just standing there or did he fasten it in place ?

The trick to the tick / joggle stick is to have the pattern piece fixed and have a known point of reference or preferably two. If it's a tricky shape I mark the the lightning bolt tick stick 1234 etc on one side and abc etc on the other to add to the confusion and make it more clear at the same time. Remember to high light obvious points ie the stinger on the the pattern. If you need to get the compound bevel aswell you could joggle both sides of the bulkhead, or take bevels at joggle points. Worth doing it in with cardboard just for fun to see how effective it is
just watched the video the tick stick used is a lot tamer than the curved lightning bolt I was shown but the process is the same

Would expect the board has been temporarily fastened in place - only way to get consistent results.

Yes compound bevel issue a good idea.

Possibly a good idea is to make the inboard edge of the gusset exactly vertical down from the cabin side / deck inner corner point, then put the radius on it to meet the bunk shelf.

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r13 said..

Toph said..

LooseChange said..

Zzzzzz said..

Microbe said..
Next question: how to fix the bulkhead? I've seen controversies raging on line about whether to fit the bulkhead snug up against the hull or to leave a gap filled with foam and tab the bulkhead in with glass tape. The idea is that the foam method avoids hard spots on the hull.

Given that I'm planning a semi bulkhead what does everyone think would be the best approach?

Here's a photo of the template in place. Will be using 18mm marine ply for the actual bulkhead.

Can you step us dumb dumbs through how you got the shape ? I have had no luck with this so far ??

Make a joggle stick (sometimes called a ticking stick) ..... just google it

I just googled Ticking stick.... A simple yet effective technique. I'm struggling to see how it would work on the radius of the hull though.

Note that the method only gives the curve of the hull in the one plane - the plane of the bulkhead.

Thanks R13... The video you linked to showed it better than the one I viewed. Obviously the tighter the radius the more points or lines needed for a more accurate curve..