de-bodging an Osprey centreboard case - advice req'd

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PeterV
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Re: de-bodging an Osprey centreboard case - advice req'd

Post by PeterV » Wed Jun 21, 2017 6:49 am

When I replaced the centreboard case in my Fairey Finn I made a replica of the original by using Robins Super Elite 6mm, doubled up to 12mm to replicate the original mahogany boards and stiffeners. It's been in for about 10 years now, and still looks new. All glued, coated and bonded in with epoxy.
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TheGuvnah
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Re: de-bodging an Osprey centreboard case - advice req'd

Post by TheGuvnah » Sun Jun 25, 2017 1:43 am

PeterV wrote:..It's been in for about 10 years now, and still looks new. All glued, coated and bonded in with epoxy.
That's the plan here; the actual case will be one homogenous epoxied unit but its connection to the boat will be bedded on a sealant (which one t.b.c.) such that it can be easily removed in future.

After phoning just about every timber stockist in the Midlands I've just scored an 'offcut' of 18mm marine ply for the knees from a chap 800yrds down the road! :!: He'd bought a load at £75 a sheet to redo the soffit boards on his garage and had a 3' x 8' slab left over. For £15 I snapped his arm off!
Just the 12mm for the case sides to get this coming week plus the screws (s/steel) and the epoxy and I can finally crack on with it. In fact Pete, can I ask what recipe of epoxy did you use?


I've got a concurrent project on the go in the shape of an electric jockey wheel to assist in getting these two up the slips and maneouvering them around the dinghy park. The plan is to source and adapt an old 'spares or repairs' mobility scooter, remove the seating and use the seat post as the hitching point to hook up to a launching trolley.

Today I picked this thing up from over Derby way ...

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God knows how old this is but it's got an early 80s airport baggage truck retro look about it, Tri-Rolls are American I believe and the styling tends to confirm that but I can't find any info at all on the web about them.

The business end... it all breaks down into easily car bootable chunks

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The meaty belt drive is a nice feature...

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...and it has what looks to be a pretty meaty motor and transaxle. The difference in build quality compared to the ubiquitous chinese offerings on modern scoots is marked.

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In fact come to think of it, if it can haul the average XXXL American around it should have no problem 'assisting' a dinghy up the Draycote slip. Those grippy looking large diameter off road knobbly tyres were the clincher in preference to the little 4" semi slicks that the average modern scoots wear. They should be able to get a grip on the concrete no matter how wet it is.
The batteries look mint but their capacity is an unknown at the moment as are the control electrics. Tomorrow I'll whip a meter over them. S'gonna be amazing watching my 8yr old Charles hauling out and parking an Osprey one handed. :shock: :lol: 8) I particularly like the fact that the t/axle incorporates an auto brake so if it starts to go pear shaped you can just 'hands off all' and the brake will kick in and it'll hold itself on an incline.

Cost (so far :roll: ) ... 20quid! Can't argue with that.
...well if it was easy everybody would have one.

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trebor
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Re: de-bodging an Osprey centreboard case - advice req'd

Post by trebor » Sun Jun 25, 2017 9:07 am

Why not just fit a towing bracket/shackle thing to scooter ? Weight of driver sitting in chair will aid traction.
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Re: de-bodging an Osprey centreboard case - advice req'd

Post by TheGuvnah » Sun Jun 25, 2017 4:12 pm

trebor wrote:Why not just fit a towing bracket/shackle thing to scooter ? Weight of driver sitting in chair will aid traction.
I'm thinking about it Trebor because as you observe I'm not sure if the nose weight of the boat on its launcher will be sufficient on its own to keep the driving wheels in firm contact: it all depends on whether I can keep it at the club as I don't really want to haul the whole unit around every time we go for a sail . I was thinking of shortening/removing the deck bit and rejoining the steered wheel to the transaxle leaving something that resembles a motorised 3 wheeled sack truck.

In one scenario I'd devise a proper swiveling post/fixed hitch to rigidly mate our launcher to the dolly but that means fabricating a custom fitting specific to our Osprey's launch trolley which would mean it would only be of use to me. If I can store it on site I'd rather like it to be available for anyone who might feel the need to use it but that means it has to somehow be able to connect up to any old launcher with some sort of universally adaptable hitch. Indeed, having gone to the trouble of making one I'd like to be able to use it on the Enterprise as well. That's easy when you say it fast but ain't so easy to conceive.
On the plus side 95% of launching trolleys are just variations on an identical theme of two side rails converging at the front in a "V" and which then bend upwards at 70-80 degrees but they all vary somewhat in dimension and arrangement so any hitch I come up with has to be widely adaptable.

The Ent's trolley looks like this...

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All pretty standard modern iteration but the Osprey's is like this at the front...

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The only common feature between them being the converging tubes. This makes me think of employing some sort of expanding "wedge of cheese" shaped block that can be quickly adjusted for width to sit between the bottom rails with perhaps a screw down plate secured by a big wing nut on top to clamp it all down rigid.

??? think think think...
...well if it was easy everybody would have one.

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Re: de-bodging an Osprey centreboard case - advice req'd

Post by SoggyBadger » Mon Jun 26, 2017 8:22 pm

I don't think your scooter thing will work. I seriously doubt that you'll get sufficient traction without an adult sitting on it. Plus the thing is going to have survive immersion when launching and recovering the boat.
Best wishes


SB

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Re: de-bodging an Osprey centreboard case - advice req'd

Post by TheGuvnah » Tue Jun 27, 2017 5:16 pm

SoggyBadger wrote:I don't think your scooter thing will work. I seriously doubt that you'll get sufficient traction without an adult sitting on it. Plus the thing is going to have survive immersion when launching and recovering the boat.
Both fair points: traction? I'll have to suck it and see. That said there's a lot of nose weight at the hitch point of the Ozzy's launcher and the unit itself is a good 30+lbs but you could well be right.
Immersion? I'll be honest, I hadn't even considered that it might have to but I reckon I can get her out of the water by a dinghy's length without too much grunt or at least sufficient to hook her up. It's the rest of the slip and the uphill trip to her parking spot that I'm/we're gonna have trouble with. But then as you suggest why not just leave as is? Whip off the seat, replace with the hitch and stand on its deck, the boys can then razzz around the 5 mile long lakeside nature ramble which I know they'll be totally up for.

Fiendish plan A involved sinking a spike/ground anchor/bit of 're-bar' into the turf at the top of the slip and doubling a line from the spike down to a 'ghetto' snatch block I machined up out of some spare Delrin plate and an offcut of the meranti I used to rebuild the rudder stock on the Ent. With the block hitched to the trolley it'll halve the effort so it should be a doddle to walk her up the slip.

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Not pretty I know but bloody strong! I've even put some thought to devising an automatic brake such that as soon as the strain comes off the rope, it engages a pawl to jam both the standing and running parts in the manner of the safety brake on elevators. Not sure they'd go for folks hammering spikes into the ground though but why no bollard or hitching ring at the top of the slips just for the purpose of hauling out the bigger stuff, Hawks,Wayfarers et al? I can't be the only 'knackered bloke/hefty boat' member.
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Re: de-bodging an Osprey centreboard case - advice req'd

Post by SoggyBadger » Tue Jun 27, 2017 6:38 pm

I don't know about your club but in every other club I've been a member of or visited there's always been plenty of people willing to give a hand pulling a boat up the slip.
Best wishes


SB

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Re: de-bodging an Osprey centreboard case - advice req'd

Post by TheGuvnah » Thu Jun 29, 2017 12:05 am

Had a first good look at one of the batteries this morning, ooh 'ello, gel cells, they're pricey items, (£120-150)... (each!) and a pair of them as well 8) nicey.
Except that clapping the meter across it gives a terminal voltage of 1.9v :roll: Rats! That's the voltage across a single cell so I'm guessing five of them have an internal short. It looked like it had been standing a while, certainly more than a year so they're both irrecoverably ronnied. Looks like Lady Luck's lost my ruddy phone number again. (and how's about that for a bit of alliteration? :oops: )
SoggyBadger wrote:I don't know about your club but in every other club I've been a member of or visited there's always been plenty of people willing to give a hand pulling a boat up the slip.
Oh I'm sure peeps will be pretty amenable and available for 90% of the time but there'll be those times we trail her to a coastal slip or I rock up for a bimble, say midweek, in Winter... Made a rod for my own back though; I mentioned the word "Tot-Rod" and of course the lads started a'googlin' and now I'm getting veiled hints that I could perhaps build a Land-Rover shell for it, "...no, no, Morgan, Morgan, it's got 3 wheels!" ...or a Bearcat or "no, what about that Transformer-car thing we saw that unfolds?". Jeez give a guy a break - you'll get a soapbox in shuttering ply!

Which brings me neatly back to the matter at hand; ply.

Cropped a length off the sheet to gauge its integrity and compliance with the label. Here's the mill mark...

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There are a few very minor voids visible when running one's eye along the edge but at this point I'm happy enough that it will do decent service. The whole thing will be filled, faired and epoxy coated before re-installation, I know there are a couple of local re-finishers who could probably do the final spray job for not too much geld.

I took a template off what remained of the least damaged knee brace. Paper? too big to fit on A4 and nowt else to hand. Cereal box? nah not really resilient enough. Hardboard? still a bit soft to keep an edge... aha...

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I have a stash of leftover floor tiles that make superb backing pieces for whenever I have to make a penetrating cut through a work piece on the miller/lathe. I can get away with it because it's a wonder of mass production being universally flat to within +/-0.002" anywhere you care to measure it, it's very resistant to compression (it's a floor tile) and dimensionally stable, takes double sided tape and hot glue; top stuff.
For this job it's beauty is you can cut it very accurately with a Stanley knife or even a craft knife and a finish with 400grade around some dowelling to get nice smooth curves with crisp edges. I think there's a significant asbestos content though so I sand it outside with wet paper and stay upwind to avoid breathing any dust. :shock: Then I have a fag :shock: :shock: :shock: :lol:
Last edited by TheGuvnah on Sun Sep 10, 2017 2:09 am, edited 1 time in total.
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Re: de-bodging an Osprey centreboard case - advice req'd

Post by TheGuvnah » Thu Jun 29, 2017 5:50 pm

Oh you are kidding...!
:twisted:
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Got the shape scribed out and its mirror onto that bit of 18mm 'marine' ply and this morning trotted across the road to a local firm who cut it out on the biggest fretsaw you've ever seen. Yer man handed me the first one and... a void in the ply, and a bloody big 'un, dead on the centre line, right where I'm wanting to land one of the outermost through hull screws! :roll: Anywhere else I could just about live with but here of all places.
So do I mark out another and take the chance that I'll get clear edges all round? Doesn't seem likely. Do I spile in a sliver of veneer? Can I live with that? a penny gets a pound that if I took the top veneer off I'd find plenty more, and the guy paid £75 a sheet for it??? BS1088???

Now what else does BS stand for...?

While he was nibbling out the second brace I realised that "hang on, why is there a ton of plywood all over the place?" Correction - mighty fine looking plywood all over the place? Turns out they make press dies to cut out laminate forms and the backing for these is birch ply into which they computer route grooves to accept the knife edged cutting blades. Well if it's considered strong enough to be used as die press tooling then it suggests it chuffing hard and has good homogeneity i.e. no piggin' voids to fracture as soon as the pressure comes onto it.

I gave it a good looking over and it does look beautifully laid up with a much finer grain to the surface veneer than this eucalyptus stuff. All the veneers are of equal thickness unlike this 'marine' grade, NO VOIDS, class 3, nice stuff.

"It's birch ply mate" came the answer to my inquiry, "take a piece with you and if you need any we've got a sheet and a half of 12mm up on the Dexion somewhere".

Putting the two side by side reveals much difference.

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Now I know birch per se is not considered durable but the boss willingly informed me that he had made a 'knocked together' ramp to get his lawnmower up some steps out of the same stuff, hadn't varnished, painted or treated it in any way and it's still perfectly good; that was ten years ago!
With a glassed epoxy finish and prompt maintenance of any scratches it sounds like a decent option for the case sides, especially for £42 a sheet. I mean they built aircraft out of birch ply (and probably still do for all I know) and they were used and laid up outside in all weathers and climates.
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Re: de-bodging an Osprey centreboard case - advice req'd

Post by TheGuvnah » Fri Jun 30, 2017 10:43 pm

Put my dibs on the sheet of 12mm birch ply which I'll pick up on Monday (touch wood :roll: ) but thought I should do a bit of ad hoc durability testing on a few scraps.

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A 40 minute simmer and not a sign of any delamination. With that established I've selected 4 offcuts which will be given different treatments and thence live out rough on the balcony for the coming year

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The plank on the bottom has been smoothed and lightly radiussed to present no sharp edges to the two coats of Coovars Yacht & Seaplane varnish.
The square has had the boil tratment and will have no finish.
The slighly larger rectangular piece has had two rubbed coats of Danish Oil followed by a coat of beeswax polish
The small sliver is fresh off the saw and left un-sanded to present as much porous fibre to the elements as possible, if it's going to fail or rot this should be the one to show it first.

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the youngest and his mate knock about out there so I'm sure these samples will get scuffed, knocked and incorporated into their Hot Wheels demolition fests. We shall see what we shall see.
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Re: de-bodging an Osprey centreboard case - advice req'd

Post by Michael4 » Sat Jul 01, 2017 9:06 am

TheGuvnah wrote:
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The last time I saw a label like that I was in Wickes...
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Re: de-bodging an Osprey centreboard case - advice req'd

Post by TheGuvnah » Sat Jul 01, 2017 5:04 pm

Michael4 wrote: The last time I saw a label like that I was in Wickes...
In a skip outside Wickes you mean? :lol:

Giving some thought about how to remove the most complete/least damaged side to use as a template for the 12mm replacement panels. I half heartedly drilled off a few of the screw heads hoping that the glue lines had deteriorated enough to allow me to 'pop' the panels apart with a twist of the hammer handle and a few strategically placed wedges. It was having none of it. :?

Did the finesse-v-time equation and the result was...

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The above does show how flawed it was to try and land screws there, they were directed into the end grain of the ply which they mostly missed and in consequence merely grazed it or split it.

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Better get the kettle on this could take a while... not wishing to risk my decent saws I used a cheap 'n nasty 'pound shop' hardpoint saw and it had no problem ripping through the bronze ring nails driven in every 4 inches and it's still sharp and serviceable! Quite impressed really. I left about a half inch uncut at the rear to keep the ends from flapping about as I turned the weaponry on the front and a quick final wallop with the chisel should part it.

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As it turns out, on the last stroke of the saw through the front block the two halves fell apart of their own accord. :D The two plastic bump stops are u/s but I've got a drawer full of ebony offcuts from which I'll mill up a new pair.

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The kitchen floor boatyard can log one more success, phew! I need to change me T shirt though! :wink: All that remains is to clean up all the old varnish residue and create a flat fair surface that will make a useable template.
Also need of course to re-make the spacer blocks out of something, but what? I'm thinking 1" ply?
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Re: de-bodging an Osprey centreboard case - advice req'd

Post by TheGuvnah » Sat Jul 08, 2017 11:46 pm

Shaping a 6ft board in a 9ft kitchen ain't easy... actually about 7ft when you deduct the depth of the worktops.

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Tools used were a cheap 'Silverline' plane and a top quality razor sharp rasp. The plane was unusable out of the box and as with most chinese cast product required extensive fettling to render it servicable. For the curve I wrapped some 120 grit around a handy bolognese jar! :P :P

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an improvised 3rd hand... yes it is the oven gloves protecting the end. :oops:

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one side done...

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And now we have two. The surface grain shows promise so I went straight to the cabinet scraper to try and bring out some of that beautiful, swirling, focus boggling, almost holographic quilted effect that birch and maple are apt to present.

Ooh nicey... :D

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Perhaps not lustrous enough to be genuinely called "quilted" but darn close and damnably attractive and can only be enhanced by four or five coats o' the good stuff.

Next question is the best timber to use for the side rails? Locally I've been offered Utile or Sapele or Meranti (too red). I can however source some mildly up-sized (i.e. 1" x 1 1/4") Iroko from English Hardwoods but that comes with a £20+ carriage charge - yikes!

As for the knees/braces: My chap at Cut Profiles doesn't have any 1" ply off the shelf at the moment but I do have plenty of the 12mm still left so why not laminate two together to make knees at 24mm thick?. The marginal increase in weight I can live with for the increased bearing area at the hull contact points. I'll need four of them absolutely identical so the case is made for drafting the outline in AutoCAD and generating a tool path for C.P.'s computer guided vacuum bed router. All four done in 10 minutes! 8) Got to be the way to go.

A further thought occurs: If I'm up-sizing the width the increased strength means I can safely and usefully open up the drain/limber holes considerably such that they don't get blocked by the first windblown willow leaf that finds itself inside.
...well if it was easy everybody would have one.

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Re: de-bodging an Osprey centreboard case - advice req'd

Post by bornagainmothie » Sun Jul 09, 2017 9:36 pm

I'm enjoying reading about your exploits and some good ideas coming up. If you can get the launch scooter to work there's a fortune to be made at Osprey, Finn and GP14 meetings!

If you haven't already discovered them, there is an excellent range of timber at Sykes in Atherstone http://www.sykestimber.co.uk/

Iroko is best used for bringing underweight boats up to minimum weight without having to fit lead in the wrong places. My guess is a classic osprey won't be needing much of that :wink:

Keep up the good work

Lyndon

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Re: de-bodging an Osprey centreboard case - advice req'd

Post by TheGuvnah » Sun Jul 09, 2017 11:57 pm

bornagainmothie wrote:I'm enjoying reading about your exploits and some good ideas coming up. If you can get the launch scooter to work there's a fortune to be made at Osprey, Finn and GP14 meetings!
The possibility hadn't escaped me; maybe 10% of the motivation. :wink: As for ideas; if I do nothing else in this life than teach these boys the qualities of ad hoc improvisation, adaptability, effective bodging followed by conscientious repair and the realisation that "yes you can actually FIX THINGS rather than chuck 'em" then I'll consider my work well done. Surely anyone who sails has that improvisatory skill, sort of goes with the territory really, in fact the more I think about it jury rigging and 'in extremis bosunry' should be a standalone RYA module.
bornagainmothie wrote:If you haven't already discovered them, there is an excellent range of timber at Sykes in Atherstone http://www.sykestimber.co.uk/
Yeah I'm sure I've browsed them at some point but they'd dropped off my radar :oops: they're back on it as of tomorrow morning....now that's what I call a timber yard! and close enough to pick up.

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bornagainmothie wrote:Iroko is best used for bringing underweight boats up to minimum weight without having to fit lead in the wrong places. My guess is a classic osprey won't be needing much of that :wink:
Too right it won't! The original case made from 5/16" ply and what I'm sure was Douglas Fir, could be picked up between finger and thumb, not this one! I haven't weighed the old pile of parts but I'm definitely interested in how much ballast I've added into the bottom of the boat. Maybe 20lbs +. Still less than a Wayfarer though, and way faster! :lol: :lol: :lol:
bornagainmothie wrote:Keep up the good work

Lyndon
Fully intend to Mothman, it's a bit of a "heads down - @r$e up" and just keep swimming" situation for sure and you have to clear away everything each meal time to turn the boatyard back into the kitchen. The bonus is I'm only ever 2 yards from the most vital boat building tool - the kettle! Whilst the roast was... roasting this a'noon, I knocked up the lines for Cut Profile's sucky bed computerified router (tech term for it)

Construction lines...

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...and the polyline DXF which they'll turn into G-Code to feed the machine.

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(For any browsing Osprey owners who might be contemplating knee surgery on their craft the included angle is 74deg)

Cheers Lyndon, glad you're enjoying it. :D
...well if it was easy everybody would have one.

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