89er

[Beatrix]

Thanks Julian, that is plenty clear enough for me, and makes perfect sense If I am right that you put the three pieces(with the glass and basalt tapes) into the mould, clamp them firmly, and the foam compresses a little to make room for the layers of glass. (Less the thickness of the waxed paper)
Neat!

 

[JulianB]

The strips of CSM under the waxed paper, is what makes the space for the Bi-Axial/Basalt LE, TE and Spar layers.
The Pu foam is H160, so no amount of clamping will ever compress it.

 

[Beatrix]

The strips of CSM under the waxed paper, is what makes the space for the Bi-Axial/Basalt LE, TE and Spar layers.
The Pu foam is H160, so no amount of clamping will ever compress it.

Thanks Julian

 

[JulianB]

And yes I have been slack, reporting on progress.

Boat is back upstairs, I hung the rudder yesterday, will finish it off today.

With 20mms to spare, had to get the trailer wheels up on jacks to make it work, it goes 1.2m into the water.

Allways makes you grimic as you cut into a rudder at the max stress point, but I am no where near the major structual laminates.
You can see the unie wraps around the rudder tube (Brass), they go down 75mm and back onto the spar, the thickening of the basalt you can see is all localised. Rudder is 35mm thick.

The fence that will go on today, its 130mm Dia, 3mm thick, it goes into a moulded recess in the underside of the boat. The ruddder LE goes almost 60mm under the back of the boat. Expectation is that we will be able to cut the rudder down 100-150mm mostly due to this, but we go sailing first and trial it.

Other expectation is that we will get Spreaders on today and the mast all but finished.
Make shrouds tomorow in laod them to 300% (OL)

Boat goes to Gosford on Wednesday to be hung so we can gasket the fin/hull interface.
Back Thursday, maybe sailing Sunday.

 

[Varan]

Exciting. Please have a photo boat tag along on that first sail. Cheers!

 

[JulianB]

Exciting. Please have a photo boat tag along on that first sail. Cheers!

Highly improbable on the 1st outing, it's likely to be a quite subdued affair. But I do have a mate who is a professional drone pilot and he wants to capture it before Christmas, in which case I will post the footage for you.

 

[Steve Clark]

A slurry of microballons will expand under vacuum. essentially it’s impossible to mix the balloons without entraining a bunch of air, which expand in low pressure. Essentially epoxy foam without any additive, you don’t want to fill the cavity so the foam can grow.
Just thought I’d mention it.
SHC

 

[JulianB]

A slurry of microballons will expand under vacuum. essentially it’s impossible to mix the balloons without entraining a bunch of air, which expand in low pressure. Essentially epoxy foam without any additive, you don’t want to fill the cavity so the foam can grow.
Just thought I’d mention it.
SHC

From memory it's a 3 part mix, A, B and a foaming agent. The board ends up under pressure, there is a blow hole at the top of a specific size, which regulates the pressure.

They seem to have it down pat.

29er board are also made with Milled cores, seems to make almost difference which process is used

 

[JulianB]

Hi all, had a fun day bedding in wires, some super interesting results.

So this is my test bed, happens to be right outside my house, had 1/2 the neighboure hood watching, so plenty of colaboration if needed.

Basically Chain around Armaco posts, chainblock to take the slack out, good to 1 tonne, but held over 2. Hydralic ram, good for 5 tonne, only got to 2, decided that 3 x Working Load [WL] was prudent. Tape is a Cert 2 tape, happens to be a milwakee but any Cert 2 tape would sufice (also happens to be 10m which is really nice).

Orange box is my load cell, it's good for 1.1 tonne. Loogs gaugue is America (it's in pounds) think it's a PT-2 but the writting is scrubbed off, no idea who's it is, but it's mine now.

Latter when I went to 1.5 tonne, got rig of the extraneous bits.

Primary shroud is at >3 x WL or approx. 1.4 tonne, Black mark is 1 tonne. again, at these loads I watch for changes in oil pressure to a) determine the load and b) to detect creep.


So today I did the f/stay which had been previously loaded and I did the Primary shrouds, they being the highest loaded shrouds on the boat. WL is nominally 490-500kgs. yes, you can get more, but not a lot. Much more and you simple capsize. You already have 500kgs (PS) 245kgs (Caps) & 326kgs (D1's) so well over 1 tonne holding 1/2 tonne (off crew weight) out of the water, the rest is running through the boat (Plus mainsheet), getting you some f/stay tension, whose WL is 400kgs. If 9er numbers are anything to go by, +10%, you capsize, period.

Not defending 3 x WL as an "ideal" number, but what I have found is going to 3 x WL you tend to eliminate creep or settling or bedding or whatever you want to call it.

First up was the M5 shrouds, highest loaded ropes in the boat, nominally 490-500kgs load (base which is 12-14 knots WS), very interesting.
This started life as a loop, so approx. 20m of M5 SK99 duck guts Marlow Dynema.
I got a initial 160mm of settling (I have called it settling because creep infers on-going, which is was not) and that was surprising, what was even more surprising was less then 16mm of settling in the splice "bedding in". The whole reason I did this was to see how much "disturbance" doing a splice made, and it was not a lot, 16mm in a 250mm (M5 x 50 = 250mm) is not a lot, 6-7%, which was surprising, but 144mm in 10m so 1.4% settling in pre-loaded Dynema seems a lot.

Initially I was trying to determine tension via the loogs gauge, a mistake, quickly went and got my Load cell, but initial settling determined by the loogs was 10 = 9735, 20 = 9760, 25 = 9785 & 30 (on the loogs gauge) = 9820, so already 85mm of settling.

So, I went and go the load cell, put it in the system, and you can see that and that extended the measurement.

Started at 100kgs tension = 9 on the loogs, then went to 200kgs = 9915 (& 14 on the loogs), 300 = 9925(14), 300 = 9925(19) 400 = 9933(22) 500kgs load=9946 & 24 Loogs, 600 = 9955(26) At which point the chain block was well past what I thought was its operating load, (1.2 tonne) so I stopped. Took some measurements, back the load off and went downstairs and did some individual splices.

So, from my original mark, the rope at the length of my Primary shrouds which is 8480mm they had grown 160mm, of which 16-17mm was the bedding in of the splices (I had a separate measurement going.

While I did those splices, I took the F/Stay which had previously been bedded in and loaded it right up. So, this is M6 SK 99 Dynema

So, load cell load = 50, F/Stay length = 9350, Loogs Gauge = 6 so 50 = 9350(6)
100=9355(8), 200=9357(14), 300=93262(24), 400=9371(27), 500=9380(31), 600=9386(32), 700=9394(34), 800=9401(36.5) & 1000kgs = 9412mm (37.5 on the loogs)

I did not want to "bugger" my loads cell, so I back it off.

Took the load cell out and quickly went to 1.5tonne (I was ducking), held it there for 20-25 mins, monitoring "creep" and it did for about 5 mins, then it stopped, held 230kg/mm² (approx. 1.5tonne) and did not move for another 20mins.

So I back it off and put my load cell back in, within 30 secs, and took it back up to 400kgs which is WL and it was now 9425mm ( Target is 9450), I dropped it back to 360kgs (WL less 10%) it may have move 1mm, took it up to 440kgs and again may have moved up 1.4 - 1.5mm (from 360Kgs) so at +/-10% WK I'm getting +/-1mm effective length. Recoil dropped to 15mm.

Back to shrouds (it was a biggish day, this and the bulb, and the bag)

So now we are now loaded up each individual shrouds, just load cell, no loogs gauge (got that already)

200= 8415, 300 = 8425, 400 = 8433, 500 = 8446 & 600 = 8455 (Target was 8448 and include the Blue wave Turnbuckles, which started life open), not sure why I stopped there but I did, and took my load cell out, and then took each shroud through to 1.2 tone, The photo with the oil gauge is the shroud in this process.

Then I took them back down to WL and again I got +/-1mm and +/-10% load.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
What I am arranging now is a bit of M6 SS wire, plan to do the same thing to it, but given that it has been on a boat for 4 years at say 80% WL in the sun, rain, hail whatever, I think I can assume it's seasoned.

 

[Jethrow]

Those rigging numbers are all well and good Julian, but the real question everybody wants to know is does the road have a bulge or dip from the ends being pulled together!

 

[JulianB]

Got a couple of queastions as to why I think 3 x WL is a good idea, and some even asked why I think 2 x WL is max expected load.

I go back to the 18teen and the 49er.

A 1/8" (3.2mm) bit of 1:7 304 SS wire F/Stay would last about 3 months on a GP (17ft winged, 1990-96) 18teen. A bit of 3.5mm 1:7 304 SS wire F/Stay would last years.
So if the 1/8" is marginal and 3.5mm is OK then:
(3.2/2)² x phi = 8.1mm²
(3.5/2)² x phi = 9.7mm²
I have 3mm Dyform BS at 9.8kN (SA = 7.13mm²) and 3.5mm Dyform at 13.2kN

We know WL of a 18teen F/Stay in those days was approx 5kN
Therefor if 3.2mm 1:7 became marginal it did so at about 10kN (double WL) which is very close to the MBS of 1/8" wire, but well shy of the MBS of 3.5mm Wire.

So my logic suggests that Double is a good target.

49er, we know that occasionally 3 x M6 MT on the 49er Chainplate would fail, where as 3 x 1/4" (6.4mm) don't, never have. Hanging onto the chainplate you have 2 x 3mm and 1 x 2.5mm Dyform wires, so max load is 9.8kN x 2 + 6.7kN so about 26.3kN, do the maths and again its about double WL.

~~~~~~~~~~~~~~~~~~~~~

Re the 3 x WL as the settling number, it's just by watch the rate of settling.

When I take it to 2 x WL then back of I get a lot of recoil (25-30mm) and I get largish movment at WL, so +/-2,3,4 mm when I go up and down 10%. When I go past 3 x WL, then the recoil drops to something reasonable (12mm), WRT the F/Stay yesterday, it when from 25mm of recoil to 12mm, but more importantly, when I went back down to WL, the variation was +/-1mm and pretty consistent.

Really this load should be rope diameter dependant, not WL, and maybe I'm just a bit scared to take the F/Stay to 2 or 3 tonne, I may leave that to those that a braver than me.

The F/Stay is unlikely to ever go past maybe 2 x WL, where as the Primary, D1's and Caps could easily go well past that, down wind, burring the bow and someone lets the mainsheet go.
Got 130kgs of lead and 1/2 tonne of crew to push through the water, the 18teen and 49er do not! And yes, it's all relative.

jB

 

[Varan]

If you get laid-up, bored, whatever, please consider writing a book to capture these insights along with many of the others you must have. Pictures too please. I am so enjoying following this thread. Thank you so much!!

 

[JulianB]

Those rigging numbers are all well and good Julian, but the real question everybody wants to know is does the road have a bulge or dip from the ends being pulled together!

😳😳😳

 

[JulianB]

If you get laid-up, bored, whatever, please consider writing a book to capture these insights along with many of the others you must have. Pictures too please. I am so enjoying following this thread. Thank you so much!!

I would need a ghost writter, can't see it happening. jB

 

[Sidecar]

Julian

How did your sail on the D24 (Diam?) trimaran go last week end?

What do you think?

 

[JulianB]

Julian

How did your sail on the D24 (Diam?) trimaran go last week end?

What do you think?

D24 is this coming Sunday, it's on it's way from Adelaide to Wangi via Melbourne/Sydney (the middle is flooded)

 

[JulianB]

Btw, grew some b--ls, took the M4 to 2tonne (also put the rope on the other side of the armaco). BS is 2 tonne, so I was waiting for the bang. Impressive stuff, but it still recoiled, about the same, grew 55mm over 5m so still just over 1%.

 

[allweather]

BS is 2 tonne, so I was waiting for the bang.

That is one way to measure the load?
That remains really impressive to hear! And I like seeing your set up, that is the basic "china" hydraulic cylinder, correct?

 

[JulianB]

Yep, got it on-line, they use them to pull cars back into shape after a crash. biggest issue was a) getting a suitable gauge and b) fitting it, by-passing the auto-blocks (of oil). & I'm not that smart.

 

[JulianB]

Big day yesterday, slung the boat in the air, this is the "pretty" shot.
Me underneath.

And this is the one from the other angle

Fin down, gasket in the bottom and top of the fin centercase.

Also got the fence on the rudder.

Big day by GT and me, in West Gosford, hours drive north, but we got it done and brought her home in time for dinner