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

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

Post by TheGuvnah » Mon Jul 10, 2017 12:08 am

And Lady Luck digs my crumpled number out of the bottom of her handbag yet again!

They're demolishing the old local Nat West bank branch, looks like it was erected in the 50's and having used it a couple of times I remember it being crammed with teak skirtings and architraves, mahog counter tops and god knows what other desirables. Had a quick scout of the wood pile through the fencing and bingo, there's the end of a 6 foot plank of 6" x 1" mahogany poking out. And that; if I'm not mistaken, is a complete hardwood door frame and lintel set (so that's going to be 6'6", case = 6ft long...) gimme gimme gimme! Tomorrow's first job then is to get to the site foreman before the skip driver does!
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Re: de-bodging an Osprey centreboard case - advice req'd

Post by TheGuvnah » Tue Jul 11, 2017 12:53 am

Aaaaaargh bums!! No no no no... :shock:

Didn't get there until 1pm and horror of horrors I spot a massive red skip underneath the demolition grab which as I park is dropping a quarter of a ton of timber into it. Legged it across the road and collared the charge hand...

I explained my urgent need and fair do's he sent his oppo into the maelstrom of falling bits of lumber (the skip driver wasn't for hanging about for anyone) to retrieve the few juicy bits that remained chief among which is a ten foot plank of what I'm 95% sure is solid teak. Hell's bells, nice one Cyril :D Well that's the replacement thwarts sorted, and for free!

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Looking at the cross graining that's going on and the way it's splintered I'd swear it for teak. I'll polish up some end grain tomorrow and have a close looksee but I think I've got a hundred £'s worth of timber there. Can you even get ten foot planks of teak these days?

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What I will also do early tomorrow is trot back to site and chuck these fellahs a crackley each for their trouble. There's also a bit more of the building to come down and they've said they'll keep any hardwood they spot to one side for me but more to the point how many of these things are they contracted to demolish? :idea: who's your Contract manager/Clerk of Works? A word in his shell-like and y' never know.

I recall even now (always with an inner growl) the spate of banzai rip and refurb contracts being carried out around central B/ham in the early eighties and on which I earned a crust as an electrical foreman, these were 50's and 60's built multi-storey office blocks all fitted out with the full compliment of solid hardwood interior fittings. Literally miles of 4" teak skirting boards were stripped and skipped, fire doors and their frames, foot wide dado boards!! in the skip it all went :twisted: :twisted: :twisted: just a tragic waste. Also they won't be the only firm engaged in this work. Hummm...

I didn't really pay much attention when they first started demolishing it so can't say whether the really nice fittings were binned at the start or removed for retail salvage. It's a very tight site so they wouldn't have been able to stockpile the timber for later collection, removal from site would have to have been every other day I'm guessing, Sooooo... if these boys can give me a heads up on whether, when and where their next tear down job is I can hopefully get in there DAY 1 and fill one's boots as it were.
The bloke said they'd got no commercial interest in it ("s'juss scrap to us mate") and said they'd chucked rakes of the stuff in the skips over the last week or so. Well not any more if I can possibly prevent it. Better rent another bay in the factory then - and buy a better claw hammer to get the chuffing nails out! :?
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Re: de-bodging an Osprey centreboard case - advice req'd

Post by neil » Tue Jul 11, 2017 8:59 am

Nice to see some skip diving activity.

15+ years ago I found out our Students' Union was getting refurbished. The bar top was the best part of 100' of 1" Mahogany. I went halves with a mate (think it cost us £30) and we went in on a Saturday morning and had the lot out in an hour and on the roof of his Land Rover. Took me a number of years to use it all up in various projects.
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Re: de-bodging an Osprey centreboard case - advice req'd

Post by TheGuvnah » Tue Jul 11, 2017 9:49 pm

neil wrote:Nice to see some skip diving activity.

15+ years ago I found out our Students' Union was getting refurbished. The bar top was the best part of 100' of 1" Mahogany. I went halves with a mate (think it cost us £30) and we went in on a Saturday morning and had the lot out in an hour and on the roof of his Land Rover. Took me a number of years to use it all up in various projects.
Ain't it nice when that happens? :wink:
As an apprentice spark I recall a job at Dunlop's aviation works to strip out the plating works were they re-plated aircraft brake discs. Apparently and for some unexplained reason their own maintenance boys didn't want to know about it?? The spark and I rocked up on the Monday and immediately saw why they'd cried off: it was the filthiest, most neglected, dingy and oppressive **** hole I've ever worked in, all the steels covered in pigeon carp, just minging. When it was active it must have been a waking hell working in that in Midsummer! It had been shut down for ten years but the fumes in the air still caught your throat with every breath.
"OK everything comes out!" said the contract manager and buggered off. Then we looked around and saw that what we thought were conduits feeding all the plating tanks were in fact 3" solid copper busbar with equally delicious solid bronze couplings. Miles of heavy 75mm/sq lead armoured feeder cables abounded and all hung on bronze clamps, we grinned at each other at the thought that the tat value was going to be roughly 2 months wages each. We set to with tackles dropping 50 or more of these 12ft copper bars to the floor and stacked them ready for our driver to have the lot away at job's end on the Friday along with all the armoureds and the non ferrous hardware, happy days. Every conduit we cut through dripped blue, green and brown sludges down the hacksaw blade and up your arms, no idea of the dangers of chromium and nickle salts back then and if we did it wouldn't have stopped us.
Thursday a'noon we got called to their site manager's office on some pretence and in the half hour we were off site the ******* maintenance gang whipped the lot. :roll: :( :x :evil: :twisted:

I've boycotted Dunlop product ever since... but I'm not bitter about it... still...

Anyhoo: huge satisfaction with Cut Profiles who have routed out 4 x knee braces from my supplied drawing for £30. That would have taken a week of chewing saw dust and they still wouldn't have equaled the accuracy of the CAD/CAM process.

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The intention is to laminate them together in pairs thusly...

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Thought I'd better have the centre board to hand whilst I'm doing the pre-assembly and marking out and drilling the pivot. I've yet to give it a good looking at in particular an ominous looking crack in the blade.

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It looks as if it's endured more than a few heavy hits as it has shed the bead of epoxy that had been faired into one of the glue lines from a previous repair...

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The bolt is also way too loose in the board for my liking so I'll be bushing the pivot, if I can score an old crown green bowl I'll do it in lignum vitae in preference to Delrin.

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As previously mentioned I'd like to replace the brass bolt and nut pivot arrangement with a turned pin with a tethered 'R' clip. Somewhere under the lathe I've got a bar of 3/4" diameter beryllium copper, tough and beautiful stuff with a rose pink hue that would look fab in there.

Aha! I also as promised bunged the lads a fiver each and more importantly found out that they do indeed do a lot of these, yes the main counters were taken out before they arrived on site and yes (through the black country accents) I managed to get the phone number of the boss of the demolition firm. As advised I'll "cop 'olt of 'im tomorrow" and see if I can work up a deal with him. Hey the more I take the less they will have to pay in landfill charges. :wink: Trebles all round!
Last edited by TheGuvnah on Wed Aug 02, 2017 12:00 am, edited 1 time in total.
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Re: de-bodging an Osprey centreboard case - advice req'd

Post by TheGuvnah » Mon Jul 17, 2017 10:03 pm

At the stage of cleaning up and reducing a bit of this teak planking...

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...to make the 2" x 1" vertical strengtheners and the cappings.

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Those cappings will need rebating so to that end I've just landed this for the princely sum of £9

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I mean nine quid! The carriage cost more than the tool :D

Not exactly a prestige collector's 'bench queen' for sure but a competent tool in genuinely minty condition ("...used it twice and put back in the box") It's a long overdue purchase and I couldn't give a monkeys about it having a plastic handle so long as it does its job. I've toyed lengthily over the past month with the idea of opting for a router but - they need 230/110vac - they make a skull shredding racket - they kick out ferocious amounts of dust - can be chuffing dangerous to both man and timber if you slip or catch a hidden nail - nope I don't want that in my life. Plus by the time I've unrolled the extension lead, dug out the cutters. fitted and adjusted it, set up a fence/guide batten I can't see as how I'd even be saving much time over hand cutting them. If I had 300 yards of deck caulking seams to cut then maybe I'd be thinking differently but for my little jobs and the sheer pleasure of ownership I'll always be drawn towards manual tooling. I even thought seriously of going for one of those 100+ yr old beech rebate planes with the guide fence of which there are always a couple for sale on't Bay.

In contrast the plane:- can be powered by Weetabix, bacon buttohs, beer, coffee, persistence, cigarettes, pretty much anything really - the only sound they make is "shwfffft" - they produce a neat fall of shavings instead of respiratory failure - present minimal danger to boat or body - satisfy the tool fetishist in me in a way power tools can never do plus; a good usable tool can be had for a fraction of the price of a router of comparable quality and expected longevity. I can't envisage there being many "Classic Bosch Router" forums in 2100 or working Bosch routers come to that whereas I can well foresee one of my lads passing this on to their son/daughter?

I've also been contemplating the plan to epoxy the whole case prior to reinstallation but the more I read the less I want to do this. I'm thinking water entrapment, heavy duty chemicals, styrenes, acetone et al that are employed, risk of huge embuggerance down the line should it need to come off, potential for it to go 'orribly wrong, cost, complexity, unfamiliarity...
So plan B; what say you all to using this stuff followed up by 4/5 coats of Coovars' finest Yacht & Seaplane Varnish? I'm sure a few among you have tried International Universal Primer Sealer, how has it performed for you?

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Part of the reasoning for using it is the reputedly 'difficult to finish' oily nature of teak which might compromise the bonding of any topcoat I try to apply.
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Re: de-bodging an Osprey centreboard case - advice req'd

Post by SoggyBadger » Wed Jul 19, 2017 7:52 pm

Epoxying the inside of the case could be a good idea. It's so hard that it'll probably never wear though.
Best wishes


SB

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

Post by TheGuvnah » Thu Jul 20, 2017 12:39 am

SoggyBadger wrote:Epoxying the inside of the case could be a good idea. It's so hard that it'll probably never wear though.
Thanks Badger, that possibility did cross my mind briefly in conjunction with laying down some f/glass cloth in the cavity to further consolidate it (although if epoxies are that good would glassing it up be OTT?) and perhaps I shouldn't have dismissed it so summarily. I still want to use epoxy to bond the whole thing up though. so mentally running through the job...

...once all the parts are cut, planed and dry fitted...

1) fit the bottom rails each side of the case sealing the screw holes with a dollop of epoxy as they are driven in.
2) give the inner (waterside) faces and edges of the panels a goat of clear epoxy
3) do the same to the two spacer blocks but an all over coating
4) glue in the internal 1" spacer blocks fore and aft to one panel
5) glue on the remaining side panel
6) glue on the upright stiffeners (possibly tenoning them top and bottom)
7) followed by the braces braces either side of the slot
8 and then the two remaining sloped cappings
9) re-instate a hardwood pad to take a swivel cleat to retain the option of centre sheeting or to receive the fall of the aft rigged main sheet brought forward.
9) a coat of clear sealer on the outer faces to ensure the sound adhesion of...
10) lashings of lovely varnish to finish.
11) Refit case and admire handiwork 8)
12) crack open a few tubes :wink:

Still a bit confused on how much filler I'm going to need for thickening the glue-up mix. I've seen illustrations on one website of someone adding it in handfulls into a pint pot sized container but when I go looking to buy I see it sold in piddley little 25g and 50g pots not the 500g batches I was expecting???

So the question is: for a 100ml of mixed resin how much colloidal silica (by weight/vol) will I need to be adding to achieve a workable adhesive mix?
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Re: de-bodging an Osprey centreboard case - advice req'd

Post by SoggyBadger » Fri Jul 21, 2017 6:05 pm

TheGuvnah wrote:So the question is: for a 100ml of mixed resin how much colloidal silica (by weight/vol) will I need to be adding to achieve a workable adhesive mix?
https://www.youtube.com/watch?v=2Nl09_h2ceE
Best wishes


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

Post by TheGuvnah » Sat Jul 22, 2017 1:09 pm

Perfect; thanks Badger. Yep that's what I thought, so I need to be looking at a 1:1 mix or thereabouts so now to find a 500g batch of silica. I nearly dropped me bacon sandwich at the thought of having to stump up for 20 x 25g sachets at £5:50 each!! = £110 :shock: :? Yer 'avin a giraffe!

This looks more like it...
http://www.ebay.co.uk/itm/Colloidal-Sil ... SwoBtW6RqA
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Re: de-bodging an Osprey centreboard case - advice req'd

Post by SoggyBadger » Sat Jul 22, 2017 10:18 pm

Remember it's 1:1 by volume not weight. Colloidal silica weighs virtually nothing.
Best wishes


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

Post by TheGuvnah » Tue Jul 25, 2017 12:10 am

SoggyBadger wrote:Colloidal silica weighs virtually nothing.
Aha, :idea: now I see. Just that little factoid helped me get a better mental picture of the process. Nowhere else have I seen that written. Cheers S.B.
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Re: de-bodging an Osprey centreboard case - advice req'd

Post by TheGuvnah » Tue Aug 01, 2017 12:31 pm

Cracking on: :? let's see what we've got and try a dry lay-up...

I decided to do something with the top of the case to improve its durability and provide a better anchorage for fittings than the prior iteration did. To that end I resolved to beef up the 'spine' of the case by letting in a solid teak capping in preference to the D/fir batten that was originally fitted. Previously the edge of the ply was exposed, this mod will keep it well protected.

Thusly...

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One other benefit of the rebate plane over the router (apart from being able to run it at 12 o'clock at night!) is the calorie burn required to achieve the above, not that I'm complaining as between you and me I need the exercise to reign in the midriff expansion which at 55 has finally kicked in :shock: Trying to do it in a Workmate adds to the workout because I have to brace/restrain it heavily as I'm cutting to stop it advancing along the slidey kitchen floor with every sweep of the plane. A bit of rubber backed carpet solved most of that problem though. I'm trying to work to 1/10th of a millimetre as an acceptable degree of accuracy. :lol:

Hoh yusss... liking that, that's much better.

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Just got to decide whether to terminate it there as per the original or to carry it on under the thwart. Ship - ha'porth of teak?

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Starting to look like an Osprey centre board case again.

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The knee braces took two days to sand and probably took two days off my life expectancy having post-processed most of the dust via my pulmonary system!

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For screws I've gone for A4 stainless c/sunks; the 1" x no.4s are to replace the ring nails used on the original. Like I said, not one of the brass screws had survived but every one of the stainless ones came out no problem and were perfectly fit for re-use. That's persuasion enough to go with stainless.

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Two weeks of gluing up and varnishing and she'll be ready to go back in the boat. On that subject: can anyone recommend a good mastic to seal case to hog?
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Re: de-bodging an Osprey centreboard case - advice req'd

Post by TheGuvnah » Wed Aug 02, 2017 1:12 am

Managed to get another few hours in so thought it wise to check the clearances with the foil in situ.

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So it's time to bite the bullet and drill for the pivot bolt. I transferred the position simply enough by laying the original ply panel over the new one, clamped it all secure and poked a 9.5mm bit through. A gentle 'dink' with the tappometer and I had a neat dent in the ply to centre a 2mm pilot drill.
That gave me a datum for the blade and thankfully everything looks to be swinging free and clear.

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Happy with that I put the two panels back to back, chucked up a 2mm pilot drill and went for it. That was followed in by a 1/2" spur bit drilling halfway through from each side.
Old 'scrap' V-blocks in a couple of sizes (1" to 3") are the perfect aids to keeping a drill bit running at a perfect 90degs in two axes simultaneously.

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Better double check...

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... if it's out at all we're talking gnats knackers here. I'm still intending to bush the pivot holes with replaceable turned lignum vitae bushings if I can get an old crown green bowl for around a fiver. If not ebony will have to do. :oops: oh the squalor!!! :D
One further strengthening mod I've opted for is to properly house the joint where the two forward rails meet the rear upright with a half-lap joint. I did mention the possibility of dovetailing the for'd uprights into the top and bottom rails but tempus fidgets and now is not the time to play cabinet maker when there's two young lads itching to get afloat.

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Jobs like this are why I bought the rebate plane after all and for the little extra work involved it can do nothing but help with the case's overall rigidity. S'all going suspiciously well. :?:
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Re: de-bodging an Osprey centreboard case - advice req'd

Post by pierre » Thu Aug 03, 2017 5:34 pm

I am loving all this stuff you are doing on the Ospreys you have.
First off thanks for the account of it all with pictures.
Second... That is going to be one solid stiff boat by the time you've finished.
Marvellous stuff.
Looking forward to seeing the finished floating item.
Carry on :D
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Re: de-bodging an Osprey centreboard case - advice req'd

Post by TheGuvnah » Fri Aug 04, 2017 1:12 am

pierre wrote:I am loving all this stuff you are doing on the Ospreys you have.
First off thanks for the account of it all with pictures.
Second... That is going to be one solid stiff boat by the time you've finished.
Marvellous stuff.
Looking forward to seeing the finished floating item.
Carry on :D
Well thanks Pierre, pleased that you're enjoying it all. :D You're not wrong there. Seriously Pierre you would not believe how rigid this stuff is at only 12mm. That must be down to the quality and homogeneity of the laminating job, I haven't found a single void over about 2mm anywhere on any cut I've yet made.

Here's a few more pics of that joint showing how I've rebated two sides into the upright to create a haunch, it'll increase the loaded/glued area the better to resist any twisting. If I'd thought it through a bit further I would probably have fully bridled the top timber over the lower.
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In fact the plane was of no use for final leveling up of the land but a neat, easy (and very accurate) way to achieve it was to go through the scrap bin an fish out a bit of aircraft ally plate at bang on 10mm thick. A few strokes of a properly sharp chisel across the land had it parallel to within the req'd 1/10mm according to my Vernier. 8)

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Another V-block (1") pressed into service to aid cutting square laps. Aligning it to the marking knife's scribe and sliding that super-sharp chisel down its face allows you to incrementally shave off the final slivers perfectly square and // to the work.

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The result is tight as a drum; I'm happy with that.

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Right then, the kettle's on and you know how it is, you've got five minutes to kill, the chisel's lying there on the bench... I'd threatened to do it... ahhh what the hell... let's have a crack at a quick half lapped dovetail ... :roll:

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And the tea was still warm when I'd finished it! 8)
(Editor's note - Guvnah, yer foolin' no-one here matey!)

OK, hands up; it took me about 6 chuffing hours from setting it out (which I still buggered up-witness the two erroneous scribe marks :oops: ) to finally achieving the required tight push fit. I'd be happy to peg it and leave it there but a slap of glue should make this thing nigh on bomb-proof.

And on that subject I'm now back to about 80% in favour of going the epoxy over coating route. About time I got into the 20th century I suppose. It's the (lack of) durability of Birch that's niggling at me constantly. Having gone to the trouble it would be nice to get at least 10yrs of service out of it, epoxy will hopefully offer that possibility. Plenty of time to save up for and lay down a stash of pukka m/ply anyway. Right now I'm checking the weather forecasts for signs of the next imminent hot spell and I'll be ordering in half a litre of gloop and filler.
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