MiToS re-built/fit- versilcraft Mystery43

[Deleted User YDKXO]

I agree you must avoid low spots but there is nothing wrong with a shallow gradient. A gradient is a gradient and the stuff in question will flow to the tank even with a 3 degree (say) gradient. (Indeed, in domestic plumbing you make sure to have shallow gradients to avoid stranding the solids, as V you will know from architecture knowledge).

In any case, the gradient will increase as you rise onto the plane

Yup, if the pipes keep the gradient. Trouble is they sag over time between supports and a slack gradient makes it more likely that low spots form. Also, its actually quite difficult to route pipework through a boat and keep a constant gradient because the pipes have to be routed around obstructions. I once owned a Broom 37 and had a holding tank professionally fitted under the aft cabin because that was where there was a convenient space but the pipe from the forward heads by necessity had a very shallow gradient. After only a season, there was a holding tank whiff in the boat and it took a lot of head scratching to work out that it was coming from a length of pipe that had become porous due to standing liquid in it. Yup when the boat planes, the gradient increases but as soon as you use the heads in harbour the standing liquid returns and stays there attacking the pipework until you use the boat again. No way would I have a holding tank under a sleeping cabin or have long lengths of pipe after that experience

 

[vas]

pipes and **** yet again...

A few replies and clarifications re tanks and pipework

mike: never said I'm not going to fit a black water tank, just pointing that quite a few ppl down here don't use them
I wouldn't do it! As far as legislation is concerned, yes you need to have one, although I don't know of any marina that has the hardware to suck your waste tbh. Definitely not available in Volos and the marinas in the neighbouring islands.

Regarding the piping I've mentioned a few times what I'm planning to use but got no comments, so I'm stating it again hoping for a comment (to make that easier I hope you'll excuse my formating ) :

I'm planning to use Valsir PP push fit hardware as I'm using in residential setups.
Excellent quality material (homo-polymere [whassat???] polypropylene), never leak, etc. HOWEVER being push fit (with a special o-ring that you smear vaseline onto) I wonder if all the moving and shaking in a boat is going to create problems.

Regarding placing the holding tank under the service batteries just aft of the engines, means that I definitely have decent ventilation with no effort and a reasonably long/short run. Distance from the heads is approx 6m.

I fully understand (and have suffered from bad workmanship on this respect!) the 3-4% slope on wastewater pipes. Mind you on NON macerated solids, you SHOULDN'T go over 7-8% as the fluids run faster than the solids and you get blockages due to solids staying in the pipework (the 3-4% apparently means that shi1it "floats" so to speak on the liquids and moves down the drain). Anyway, not important as we are talking about mashed shi1it here
My idea was to run the pipe on the edge of the hull, securing the pipe on each and every stringer (we are talking about one every 300-400mm!) so that there's no way there's going to be any sagging. Checked routing and with a questionmark on the tanks that live to the front of the engines all routing is clear. In order to get my slope right, I'm planning to lift the waste 200-300mm from the heads and let them slowly/naturally drop to the tank. Will investigate further if that is feasible and I wont have an wastewater pipes visible about, but I'm pretty sure it's ok.

So hopefully this will end the black water tank saga.
Ah, and I'll mostlikely fabricate it out of GRP as JTB has one that seems to be okay.

In order to keep issues tidy, I'll post another message on the scrapping/wood constructions etc.

cheers

V.

 

[vas]

ply restoration

following is for BurgundyBen

Spend the whole day today scrapping and sanding the helm roof that was all cracked and in a sorry state. I was exceptionally lucky as the weather resembled a typical "good" summer day in the UK (misserable, windy, a few patches of sun and a few drops of rain in the morning, mid twenties) so I was able to work all day without getting a sunstroke...
There are two patches I've identified and a bit more sanding to finish the area.

next two side pics show a two tone primer (carmine is called around here) does that imply some painting scheme I'm not aware of?

the following two pics are the finished article, waiting for nailhead sealing and priming.

One issue I have is that although boat has half a zillion bronze screws inside, on the exterior, the plywood panels are nailed onto the underlying framework (with 35yo galvanized 3-4inch nails. I know the theory that nail has better holding power to certain type of screws, but it's also cheaper and easier to implement So now I have quarter of a zillion nails (OK, maybe a dozen or so per sqm) recessed, with rusted heads pushing up the filler on top and creating nasty patches in the paintwork (which anyway I removed but don't want that to happen again). I'm going to wire brush them clean (as much as I can using my dremmel ) but I need to find a proper material to treat them before starting applying the primer!
Thought of even using hammerite type of paint that deactivates the rust process and makes a material good for painting/glueing etc, dunno, looking for comments.
Ah, needless to say that I'll add new ss screws in between all nails so effectively improving the rigidity of the whole shell (and I'll resess them in the plywood and seal them over before priming obviously)

also the edges at places are delaminated and need thorough cleaning as well as replacing bits of plywood.

The primer and top coat is still not finalised, but looks like I'll go through the 3-4 thin coats of west systems resin (one coat with the microfibers to add strength and fill holes) and think about the top coats. On a side note, is there any online or mail order place for West at cheaper/reasonable prices? I paid 220euro for 6lt of resin matching catalyte or whatever you call that thing and a bag of microfibers. I know it's good stuff, but painfully expensive (I gather I'll need 60+lt of the stuff!)
The alternative of glass cloth and resin doesn't really appeal to me as then I'll need a few more coats on top to get a decent/smooth finish and anyway we're talking about 35yo plywood!

Any suggestions welcomed although I'll probably wont change the first few coats of sealing and waterproofing using West. Needless to say I have to be reasonably quick on that as it does occasionally rain (usually evenings) so I want to seal and secure the interior ASAP before I start working on the hull.

W/E and next week plan is to finish with all paint removal on everything that's above the teak level, prime/seal it the week after next and then continue with the "teak" deck in the bow as well as building the new f/b control as posted a month or two ago.

Next one probably for jfm, MM, Bart and others

Now then, on Monday in Athens I visited again the best known speciallised timber merchant in Greece (apparently) a v.knowledgeable bloke in his 40ies with a PhD in material science, selling timber keeping the family business going I did sketch and explained the layout and the fact that under the current marine ply deck is a delaminated thing of unknown origin and he also recommened going for Burma teak (after removing all things down to the crossmembers/stringers/trusses dunno how you call them at deck level!). Currently working on calculating every single plank I'll need for a final offer. We are talking 27mm (probably clears to 24-25mm thick and 150 or so wide so just under 50mm wide teak strips which is about right, correct???)
Unfortunately autocad says I need around 15sqm (without the leftover bits reasonable to give a 10$ over methinks) which means I'm in for around 5+K euro teak. That's a quarter of the price I paid for MiToS and it's only for the bow and sides, NOT flybridge (where I'll probably use teak veneer as there's a sound underlay) and NOT aft deck which will need again full size teak. Clearly the largest chunk of money to spend on the rebuilt, but I prefer to do it properly (not sure what my back will think after the sikaflex sessions though ) unless there are other options that are structurally sound.

So hopefully coming June I'll strip the deck and before the end of the month I'll have the new deck on. Then I'll refit the railings properly and start working on the hull knowing that no rain water is leaking in.

I'm closing with a pic of the bathing platform from below and a few comments based also on the excellent BA thread. No, I'm not interested on a hi-lo platform, it'll cost more that the whole boat...

What I'm thinking is of cutting a door in the transom (port side whereabout the steps are now) and replacing the pathetic platform with a usable one.
I will soon remove the internal panels in the transom to check the construction and how the port davit is transfering its lateral forces to the hull but the idea is to have a smallish opening (400-450mm is plenty) by adding a lower step cantilevered over the platform and a top one within the transom thickness (sketch to follow in the w/e, haven't measured the slope accurately yet so not much point in drafting it...)
That means that normal waterline to intransom step should be around 450mm. I guess that's OK?? Aft deck should be around 750mm (rough estimates will measure accurately over the w/e)
Also I'm planning to built a bench all around (well almost) the aft deck. I'd like to see Alf and Pete's/MarcusM aft deck layout, but I'm facing a wee problem. I have the cleats for the main mooring lines 150mm up from the aft deck on the gunwale (if that's the right term for the side wall so to speak) so ropes exit the craft from the two oval holes you see either side on the transom.
Effectively means I cannot have a U shaped bench going port/rear/stbrd. I wonder if it's okay (should be easy!) to relocate them on the top of the gunwale level with the bow deck effectively and be done with (this also helps me shift the door I want to cut on the transom a bit more to port and out of the way...)

Final concern is the actual bathing platform. On the ply/wood hull, bolting a robust platform with three or four sections of ss onto the hull (presumably matching the fixing points to inner framework members) makes me very nervous. I mean a wrong manouvre while backing into berth (med style), a stuck throtle lever or whatever may mean a hard(ish) bump to the deck that could lead to ss frame puncturing the hull and boat sinking... Am I a bit OTT or is that a valid concern? Not to be confused with GRP hulls where most bathing platforms are integral part of the hull, in this case it's completely different.

So I'm currently sketching a frame that will fold up to relieve the stresses and avoid problems if stress is too big to be handled from 3 shock absorbers I'm thinking of integrating down there. Sketch to be scanned and added in the w/e. Thoughts welcomed as always!

I think I overdid it with this message, so I'll shut up now and come back with clarifications and sketches over the next couple of days.

cheers

V.

 

[wakeup]

Have a look for Galvafroid, it is a galvanising aerosol that you can use on the nail heads. Should be better that hammerite.

Wow what a project.

 

[jfm]

V
1. I'm nervous about ripping off the deck and ftting 27mm thick planking. That's a massive skilled job, lots of effort/money, and I'll bet it leaks soonish. You gotta do this in marine ply and teak veneer. I appreciate Mr PhD's knowledge, but no modern boatbuilder is doing what he says, so go figure... Burma teak is very hard to get and a bit tricky morally; Equador is the new source of teak

2. Transom gate idea sounds nice. I wouldn't worry about smashing the swim platform. Just drive carefully. You have other priorities imho rather than desigining a shock absorberised platform

4. I'm in Antibes, sunny, and will get you those photos

5. Ref the delaminating plywood, top of windscreen, could you just trim 30mm off to tidy it up?

 

[MapisM]

I'd like to see Alf and Pete's/MarcusM aft deck layout

Your wish is my command - below a few pics. Assuming I'm the one you were thinking of as MarcusM, that is!

Aside from the pics, which I hope can give you some ideas, I must tell that I second 100% jfm worries on the total deck rebuild.
If building a teak deck on a wooden boat is probably 7 to 8 on a difficulty scale, while the boat is being built, doing it afterwards properly is off the scale.
My guess is that if you would make a very accurate estimate of costs and time involved, eventually you'd better double it (at least!), if you want to have an idea of where the land lays.
Besides, blimey, 1" thick!?! Cost aside, that's also a lot of weight. I don't think any planing boat has ever been built with such a massive deck.
Is that just along the lines of "better safe than sorry", or do you have any other reason?

Re. the "foldable" platform structure (btw, below you can see mine, in one of the pics, and it also has the potential issue you're talking about), yep, that definitely sounds a bit OTT...
Besides, don't you have a w/tight compartment astern? If yes, even in the worst of the accidents, you should still stay afloat.
That said, the idea is nice, I for one would be curious to see your sketches.

With regard to the transom door, I also considered to open one years ago, right after I bought the boat.
But after the first season, I realised that sitting on the stern and pass above it one leg at a time is actually very easy, even for elderly guests. So, I decided to not bother about it.
Of course, if you have in mind a regular use for diving - as Bart has for instance - the transom door is almost necessary.

 

[vas]

Have a look for Galvafroid, it is a galvanising aerosol that you can use on the nail heads. Should be better that hammerite.

Wow what a project.

hm, thanks for the pointer, but will it work on royally rusted tin, or is it meant for extra protection on new metal?
I think they are called cold galvanising sprays down here and they are good for new, not for heavily rusted stuff.

will check!

cheers

V.

 

[vas]

teak

jfm and MM,

never said I liked the idea of putting full thickness teak but I have to admit that I thought that at the time (70ies) the wooden boats were built that way hence I thought it's okay to do it this way, seems that I'm wrong, so happy to save loads of dosh and do it properly
(Mind you JFM, shouldn't be that bad as on Mysteres teak chalking goes straing bowtoaft not curving like in various yachts or new mobos)
Now that you mention I've read something about sustainability of the Burma teak but I'd not paid attention back then, will have another look.
Definitely happier to do the plywood deck and teak veneer on top.

NOW, need to clarify that I'll HAVE TO remove everything down to trusses/crossmembers/stringers/however you call the structural members as the current marine ply is on top of a fully delaminated yet unidentified thing.
So, will go down to plain timber, treat it, clean it, glue/screw new marine ply on top and when I finish painting the hull and making any other mess, I'll lay teak veneer. Hope you guys are happier with this approach, I am for sure
Further I can start the dismantling of the deck right now and I don't have to wait to finish all paint scrapping of the superstructure before I begin and my right wrist would definitely by v.happy and hurt less in the process (old pushbike accidents from my early 20ies that comes back whenever I do something v.physical )


JFM, thanks for taking the photos as I'm removing and scrapping all w/e (just had a short break as it's too fcking hot to work outside and I'm back for a late evening session in a few mins) and I spotted various odd things and lots of holes that imply that fittings were in different places to where they are now.
Top of windscreen edge, yes, the plan is to mark a new curve and cut 30-40mm off it. TBH, this ledge is a bit too much and I'd not mind reducing it a bit anyway.

MM, thanks for your aft deck photos, will comment on them late at night if I have any strength left, but I'm also hoping for MystereMarcus that owns one of the Colin Chapman GRP Mysteres to post some photos of his layout. IIRC you are a Mario he's a Marcus, right
BTW, only comment for now is that you have too many cleats mister! and you don't have railings on the aft deck, I have some awful one that I'd happily scrap altogher as there's no way I can move the cleats to the top of the gunwale with the railing as is. Not sure on safety with smallish kids (7yo the youngest regular) without railing though. will measure and discuss.

cheers

V.

 

[burgundyben]

Galvafroid is very good on rusty old metal. Feel the weight of the tin and you'll know about the zinc content, its heavy paint.

In the 1970's nobody was putting 27mm of teak onto a plywood boat deck I'm sure.

My deck is ply, epoxied and painted, looks nice, easy peasy to do, feels cool under foot, is cheap, low maintenance, will not need recaulking, lightweight, but its not teak. I'd rip all that old dekc junk off, back to the beams, epoxy prep the beams and any repairs needed, then a new ply deck with epoxu cloth and nicely painted with some grit added for nonslippyness.

On that bit of cabin roof that is getting rough at the edges, either tirm back as JFM says or syringe epoxy into the gaps and through some little (3mm) drill holes, clamp/screw or tape until it sets.

I pay £80 for 6ltr kit of West.

 

[Divemaster1]

........ I'd like to see Alf and Pete's/MarcusM aft deck layout.......

During a spring clean .... you need to see the cleat layout etc., as well ?? ... going to boat tomorrow, so can take the pictures you want ....

 

[vas]

During a spring clean .... you need to see the cleat layout etc., as well ?? ... going to boat tomorrow, so can take the pictures you want ....

yes please Alf, a few pics all around the aft deck would be nice. Good to see that the aft teak deck is cleaning after all the mess that was put on it over winter

cheers

V.

 

[vas]

Galvafroid is very good on rusty old metal. Feel the weight of the tin and you'll know about the zinc content, its heavy paint.

OK, I'll try to get hold of it. Mind you how did you treat old screwheads and nailheads in your restoration project? Did you lightly sand or emery the rust out? Is dremel with a tiny wire bit or stone going to be ok? Don't want to overdo it as I'll be removing ply that helps hold the thing together..

In the 1970's nobody was putting 27mm of teak onto a plywood boat deck I'm sure.

My deck is ply, epoxied and painted, looks nice, easy peasy to do, feels cool under foot, is cheap, low maintenance, will not need recaulking, lightweight, but its not teak. I'd rip all that old dekc junk off, back to the beams, epoxy prep the beams and any repairs needed, then a new ply deck with epoxu cloth and nicely painted with some grit added for nonslippyness.

OK, I'm converted!
However since I'm not extremely happy with plain epoxy and paint, I could do a first step of ply deck epoxy coated for starters and maybe continue with a teak veneer later on if I'm happy with it.

I've tried the grit for nonslippyness on epoxy coating my old house bathroom and I have to admit it's a disaster, whenever I get in there I'm annoyed by the lack of uniformity of the grit. I wonder if there is a trick for that, but it's not for right now!

On that bit of cabin roof that is getting rough at the edges, either tirm back as JFM says or syringe epoxy into the gaps and through some little (3mm) drill holes, clamp/screw or tape until it sets.

I pay £80 for 6ltr kit of West.

yep I'll use that trick elsewhere, think I'll just trim it back for now

80gbp is 100euro and I paid more than double! I'll have to trace a company that will mailorder a few 6lt containers to me down here!


I'm also struggling with detailing the edge of the deck (no mater what material I choose) to the hull.
There's no pulpit (if I get the word meaning right) around the bow deck and atm there is a tiny inverted V section of hollow alloy bolted on the edge.
I definitely don't like it and detailwise I need to do something better.

Ideally I should have a strong thickish timber section that lays flat on the end, protruding over the hull edge and be wide enough to bolt my lining supports on it. I'll attaching a small sketch of what would be ideal in a message later on tonight.
This way:

A. I don't have to find a rubber or alloy-rubber combo that will bolt on the edge to protect it from bumping about (if ever...)
B. will reduce the posiblity of water leaking around the supports
C. create an end for my sealing creating a proper ending
D. help in dropping fewer things in the sea

Problems are that:

A. quite difficult to do as I need to start with larger pieces and get the curvature right as I move towards the bow (good thing is that it's level so no need to curve on Z axis as well
B. if the securing against the ply deck fails water will be sipping in, but I guess I could use a line of sika on the edge
C. slightly tricky if I decide to add teak veneer later on...
D. maybe easier to find a bendable rubber/alloy section for this edging after all


l8r

V.

 

[Divemaster1]

yes please Alf, a few pics all around the aft deck would be nice. Good to see that the aft teak deck is cleaning after all the mess that was put on it over winter

cheers

V.

Not this year's spring clean ... still left to do the aft deck..... but here's a picture from the other side....

 

[BartW]

Vas,

Re. the roof top.
These steel screws are a real pain, (I have a few small spots of these on BA aswell)
Have you considered replacing some old plywood completely ?
Or glue a extra layer, new 12mm plywood on top of it ?
Personally I would suggest the Glass cloth, but your solution with resin and microfibers will probably achieve the same result.
This needs defo some good attention, I’m not your man on this.


Re. Pipework,
Tubing of the toilets in BA is also gravity driven,
And they used solid black PE tubes , will post a picture later.
These tubes are strong enough to have fixing only every 0.6m to 1m (I believe)


Re. Deck, agree with comments on 25mm planks,
The deck of BA is made from marine plywood, and originally treated with a resin to make it waterproof,
Now, this treatment is old, seems and corners are cracked, and the deck is not waterproof anymore, we suffered a few leaks inside. (saloon, 1 cabin and E/r)
While doing the recaulking, the workers tried to fill all gaps, or underlying spaces with a very fluid caulking product (will send you the name of the product) they claim it’s the best there is,
But the boss expressed his concern that even now its not completely watersealed. (he suggested renewing the teac, and epoxying first, what I din’t want)
So I would strongly recommend (like Bben) that you put epoxy or similar on the plywood, to make it completely watertight.
And then I would place solid teac 10 mm in stead of teac veneer.

Re. Transom opening,
Contrary to how much I defended my idea for the new stairs on BA,
Imho on your boat this opening is not crucial,
I believe with the usage you have in mind, you can do without that, without feeling compromised on your bathing activity’s, just like MapisM.
So I would at least postpone that plan, leave this for later, for a possible second rebuild…. ;-)

Same thing for the deck benches,
try to get you boat finished with a cockpit space as big as possible,
Start using her, and after one or more seasons, you will have a lot more and new practical and usefull idea’s.
(my new bench has a dedicated function, cover the transom-door opening above deck level)

Re bathing platform,
What do you mean with “pathetic platform” ?
I don’t understand,
to me this seems a usefull and big platform, I wouldn’t worry about the potential risc/shock absorber issues.
I would clean it, polish the tubes, put teac on top, and reuse it as it is,
I don’t see an advantage in a complex folding system, certainly not on a 30(?) yo boat

In a first attempt, I would try to keep the boat as much as possible original, but with a quality and sustainable finish,
And skip all less important / non fundamerntal issues, until later.
All imho, and with much respect for your courage, commitment and devotion.

 

[jfm]

Regarding the deck edging:

1. I need to send you those pics. 6Mb each. Can I send you big emails (18Mb?) or should I attach one per email (I have 20 pics to send). I have your office email and i am in office today, so fast conenction

2. The one in antibes has a teak deck edge, no metal like below. But it has no toerail at all, which looks unsafe to me, esp as the side decks are very sloped. I would want to fit a toe rail

 

[vas]

Vas,

Re. the roof top.
These steel screws are a real pain, (I have a few small spots of these on BA aswell)
Have you considered replacing some old plywood completely ?
Or glue a extra layer, new 12mm plywood on top of it ?
Personally I would suggest the Glass cloth, but your solution with resin and microfibers will probably achieve the same result.
This needs defo some good attention, I’m not your man on this.

replace, yes originally, then realised that it's more hassle than good and discared the idea. Will go for proper treatment, maybe even removal of the rusted nails (if possible) addition of ss screws in between the nails, and west with fibers to stabilise/treat/seal the ply.

I WILL replace ply sections where it's compromised and unfortunately this is on the hull sides where rainwater has been leaking down from the rail support holes, so various easy patches will be needed I guess.
Just started scrapping a/f and coats of paint and primer off the hull (started on port side) so in a week or so I'll have a better idea of what needs replacing)

Re. Pipework,
Tubing of the toilets in BA is also gravity driven,
And they used solid black PE tubes , will post a picture later.
These tubes are strong enough to have fixing only every 0.6m to 1m (I believe)

if you can, yes please, also dia would be helpful, I guess 40mm?

Re. Deck, agree with comments on 25mm planks,
The deck of BA is made from marine plywood, and originally treated with a resin to make it waterproof,
Now, this treatment is old, seems and corners are cracked, and the deck is not waterproof anymore, we suffered a few leaks inside. (saloon, 1 cabin and E/r)
While doing the recaulking, the workers tried to fill all gaps, or underlying spaces with a very fluid caulking product (will send you the name of the product) they claim it’s the best there is,
But the boss expressed his concern that even now its not completely watersealed. (he suggested renewing the teac, and epoxying first, what I din’t want)
So I would strongly recommend (like Bben) that you put epoxy or similar on the plywood, to make it completely watertight.
And then I would place solid teac 10 mm in stead of teac veneer.

Nice to learn the name of this product, please post here in the thread if you find it.
Will epoxy the new ply deck for sure. Still contemplating if I'll go for 15 or 12mm, but since frame is so dense (200-240mm max), I'll go for 12mm to save weight and be able to add teak on top later on.
BTW, what I'm calling teak veneer (according to the timber merchants) is the 7-8mm solid strip of teak (produced by slicing the teak planks of 200X50) Cut this way means that the grain runs properly and it's highly unlikely it warps in the process or later on

Re. Transom opening,
Contrary to how much I defended my idea for the new stairs on BA,
Imho on your boat this opening is not crucial,
I believe with the usage you have in mind, you can do without that, without feeling compromised on your bathing activity’s, just like MapisM.
So I would at least postpone that plan, leave this for later, for a possible second rebuild…. ;-)

Same thing for the deck benches,
try to get you boat finished with a cockpit space as big as possible,
Start using her, and after one or more seasons, you will have a lot more and new practical and usefull idea’s.
(my new bench has a dedicated function, cover the transom-door opening above deck level)

I did a test yesterday and removed the extra railing from the aft deck. They were custom ss supports (no workmanship whatsoever in their construction) with teak handrail (in very sorry state...). Now, after one day up and down and working on the craft, I started feeling ok about not having the handrail at 1m. Mind you pulpit height is 580-660mm so should be okay with no extra railing. Why I'm saying that? Because with the handrail missing, climbing up and down the bathing platform is MUCH easier, so I may (just may) skip the transom cut, although it's tempting
The cut if done would be dead easy and simple like this:

(apologies for completely wrong sketch proportions (was done before acurate measuring and just slapped dimensions on top )
Regarding benches, even from the month or two she was in the water and I was using her, I felt I need some space aft for storing lines and a couple of fenders. So at least a boxy bench just on the transom side would do it and give a bit more space for sitting down there. So most likely will go for it. Now that I'm measuring up things and checking various details, I doubt I can get this bench U shaped as it would render the main cleats unusable (and would have to move them on the top of the pulpit) and interfere with the slots draining aft deck water (which atm seems to be finding its way to the bilge, to be further investigated soon)

Re bathing platform,
What do you mean with “pathetic platform” ?
I don’t understand,
to me this seems a usefull and big platform, I wouldn’t worry about the potential risc/shock absorber issues.
I would clean it, polish the tubes, put teac on top, and reuse it as it is,
I don’t see an advantage in a complex folding system, certainly not on a 30(?) yo boat

In a first attempt, I would try to keep the boat as much as possible original, but with a quality and sustainable finish,
And skip all less important / non fundamerntal issues, until later.
All imho, and with much respect for your courage, commitment and devotion.

thanks for stealing years from this old lady, she's 37atm
Platform is in a very bad state, it's a kludge, badly executed and it shows
Definitely not original equipment, as I can see from the Antibes example that JFM photographed and send photos a while ago (THANKS JFM!), there wasn't ANY platform on them originally! No way this thing is staying on MiToS.
Actually I tried to step on it today and I was shocked, it was all wobbly and flexing. Then I checked underneath and realised that two of the four supports are broken, nice! They have been rewelded on the same spot a few times... Surface material is thick ply with 30mm holes.
Further, it's only 800mm long means that with the transom slopping BACK unlike all recent crafts it only gives you space for one person just about standing on it (unless you grab the pulpit or davit to balance yourself!)

The rather simple solution for a support that I'm attaching as MM wanted to see it (it's a 20min thought, 10min sketches...), just stretches the SS support plate UP and not only down as effectively the first 150mm or more is NOT usable as a platfom (unless you're a midget...) So I'm pushing the platform aft, not joining it to the transom and have an effective 1200min useable length for it. Still should be well shorter than the existing pasarele (which is non-foldable, non-electric job that is not falling apart yet and looks ok, so is staying)
The slanted T shaped SS members could incorporate a simple ss spring, on the horizontal section under the platform, that could take the 100-150 kg each and compress (or extend depends what I find...) for around 70mm or so helping on nasty bumps.

BTW, MM, there is a door from the lazarete to the e/r (which I always leave ajar at best, wideopen at worse...) and not sure if I close it it makes a sealed compartment to save sinking if I go astern at WOT to the dock


sorry for the longwinded reply

V.

 

[MapisM]

BTW, MM, there is a door from the lazarete to the e/r (which I always leave ajar at best, wideopen at worse...) and not sure if I close it it makes a sealed compartment to save sinking if I go astern at WOT to the dock

Ok V, I'll tell you a secret: going astern at WOT towards a concrete dock is NOT a good idea, regardless of the platform structure!

PS: I'm not sure if the problem is with my connection (which is slow and unstable at the moment) or with your server, but FYI I can't see your pics...

 

[jfm]

I can't see the pics either
I agree with Mapis - dont waste time making a crash-deformable platform. You know how to drive a boat so don't hit the dock. In 10 years of 40-80 foot boating and stern-to mooring I have never ever thought "I wish my platform had springs"

BTW, here is stern showing the angle. It's not that much of an angle V?

 

[jfm]

A I'm planning to use Valsir PP push fit hardware as I'm using in residential setups.

on NON macerated solids, you SHOULDN'T go over 7-8% as the fluids run faster than the solids and you get blockages due to solids staying in the pipework (the 3-4% apparently means that shi1it "floats" so to speak on the liquids and moves down the drain).

Oi, you're nicking my science! i explained all about "floatability" of shi1it and paper on shallow gradient pipes above

Going back to your Valsir pipe proposal, I think in principle using the polypropylene domestic pipe is a perfectly good idea. I wouldn't use the push fit joints though. I would use a long length of the pipe to run from bathrooms to stern, and at each end use short lengths of white marine WC pipe. You have to get polypropylene whose OD is 38mm to match the 38 ID of the white pipe, but that should be ok. Overlap the joints a lot, like 100mm, with double jubilee clips, and heat-gun the white pipe if it is not quite the right diameter. Also, chamfer the polypropylene pipe on the inside of the cut ends to avoid a step to catch bog paper and stuff. Should be perfectly fine imho

 

[jfm]

A I'm planning to use Valsir PP push fit hardware as I'm using in residential setups.

on NON macerated solids, you SHOULDN'T go over 7-8% as the fluids run faster than the solids and you get blockages due to solids staying in the pipework (the 3-4% apparently means that shi1it "floats" so to speak on the liquids and moves down the drain).

Oi, you're nicking my science! i explained all about "floatability" of shi1it and paper on shallow gradient pipes above

Going back to your Valsir pipe proposal, I think in principle using the polypropylene domestic pipe is a perfectly good idea. I wouldn't use the push fit joints though. I would use a long length of the pipe to run from bathrooms to stern, and at each end use short lengths of white marine WC pipe. You have to get polypropylene whose OD is 38mm to match the 38 ID of the white pipe, but that should be ok. Overlap the joints a lot, like 100mm, with double jubilee clips, and heat-gun the white pipe if it is not quite the right diameter. Also, chamfer the polypropylene pipe on the inside of the cut ends to avoid a step to catch bog paper and stuff. Should be perfectly fine imho