“mud” all over, first layer followed by epoxy resin inside tomorrow and then sanding outside and second layer, etc !
ClaudioD
Hi Claudio,
Looking at your ‘working drawing’ of the sheeting arm servo operating in the vertical plane, would it not be restricted by the diagonal shroud to keel base rod? I’ve not been able to model it in any way but the thought crossed my mind so thought I’d ask…
Also, for Alan, what’s the ‘light weight modelling filler’ called? Having used both ‘Bondo’ polyester based car body fillers and also the WEST low density filler powder with epoxy, while being relatively easy to sand, I’d imagine both might be a little too hard for using with balsa wood.
Regards,
Row
Translation = Super light weight filler for model building.
It’s two pot mix using 2% harderner and going by the smell I’m guessing it is polyester based only bad part is it goes off in two minutes so have to work in small quantities or quickly :lol: but is ready to work on after 30 minute and it sands very easily (perfect for blasa) unlike fillers used for cars etc.
Good point on arm position restricted by shroud rod, Claudio how about positioning it in front of mast box where ther is lots of space ?
Cheers Alan
Row and Alan,
you have a point, I need to check also because it is my intention to turn the spreaders backward and therefore also the shrouds.
Moving the servo in front of the mast, will force to move the battery pack backward. The boat inertia will be modified and the boat will suffer of more pitching with the increase of waves.
Cheers
ClaudioD
PS :
You very right, the space of the arm is sufficient for the second shroud strut but not the first unless is recessed by 1cm at the base of the mast box.
The images below are showing the facts with the constructed mock-up.
Some arrangements can be introduced including the shape modification of the Fin Box to permit the servo shift as depicted in the drawing :
Rectified the Fin Box to allow servo backward shift and give more room to the pivoting arm !
My thanks to Row and Alan for hilighting this aspect !
see pictures
ClaudioD
Thanks Claudio for all the trouble-shooting you have done with excellent mock-up …makes me think about if two carbon struts are really neccesary, maybe one would be enough ? Using the carbon foam sandwich as bridge over top of the mast box, it should be as strong as “brick shet house !” 
Now just need to check-out how to secure the servo laying on it’s side in this position, access to screws inside the hull …through the hatch opening with my short fat fingers :rolleyes:
Cheers Alan
Question about Resins:
I’m planning to laminate the mould using 2 x layers of 80 gsm FBG hopefully within next 7 days, however with winter coming on quickly in these parts I have been watching weather & we have 80-85 R.H in last few days with lots of foggy days (no rain).
I have been storing cloth in dry place & will be using with the attached resin from R&G
I’ll need to laminate in my workshop in these conditions (no heating or dehumidifier) and thinking to make up corragated cardboard box to have freshly laminated mould cure inside for 24 hrs using hot air blower circulating heated air around the mould @ 50 degree C.
My question is: Will expose of the resin & cloth to these high RH conditions for short period of time (30 mins) before having it inside make-shift curing box, cause any problems ?
Cheers Alan
Hi Alan,
Unless you have a very sturdy hull plenty of ribs, the struts are a good choice :
My old wooden Dragon did not made use of struts while the modern fiberglass Dragon do make use of struts (only one per side).
For the servo mount, it is better to first integrate and glue the metal bolts on the beams, while the nuts can be applied with a bending key (I do not know the right name).
Cheers
ClaudioD
PS :
The first coat of resin was previously mixed with talcum powder !
Did you get too much on your Birthday Claudio 
what purpose does it serve, thicken the epoxy same as micro ballons ?
The bending key is called and “Allen” key …now I know where my parents got my name from, I’m good to go only with nuts :lol:
Cheers Alan :zbeer:
Yes it is, just replacing the micro ballons that I don’t have.
Bending key, I found the name : flexible socket wrench :
couple of exemples below
Cheers
ClaudioD
Universal Joints is what those two things are. They always used to be on the drive shafts of cars, but you only really see them on steering columns now.
Regards
Row
Usually not a problem. Your on the right path, keeping the fibre in good condition etc.
With SP Resins, I find they have a tendancy to go a little milky in the pot when you mix them in high humidity conditions. Then returns back to normal during curing, quite normal…
High humidity can speed up the reaction time too - But for your particular brand of resin, I cannot say.
Are you bagging your job when done or just using peel ply?
I only ask as if your not bagging, be aware that the peel ply will tend to bubble off the laminate if you change the enviroment drastically.
IE: heat it too fast…!
2nd resin coat including resin preparation and added talcum to increase density!
ClaudioD
Hi Jim,
Applied 1st coating of epoxy resin (no cloth) inside the plug last night and instantly noted how it turned white when mixing it up, 12 hrs later it was clear again as you say.
I will only be hand-laminating the plug (don’t have vac equip) and will be hand finishing it before doing hull lamination.
For the hull lamination planning to use latex method again & was thinking of using peel ply as 1st layer on the plug to give textured finish for better bonding of fittings inside the hull later, but your point about peel-ply bubbling under temperature has me now holding that thinking now
Thanks for your expert feed-back, always valuable 
Cheers Alan
P.S Great job to get Azzam back on the water so quickly after her dismasting and back into the Volvo, only sorry to hear they later decided to pull out of the first leg again to get into Cape town on-time for the next leg…the guys on board must be raring to get into it !
While waiting for epoxy to cure (2 days in hot water cupboard) to strengthen the mould for next stage of sanding to final stage of shaping of the plug, I’ve now printed another set of frames and glued them to 3 mm plywood in prep for the next stage.
These one set of frames will serve three purposes:
- Cradle frames will used as template for checking final shaping of the plug when sanding.
- These same frames will then be fitted to building board and used to cradle the hull cradle for stable platform for fitting-out the hull.
- And the internal section of the template will be used as “loose” bulkheads that will maintain hull shape in the cradle & used as double check on measurements such as cockpit deck etc.
Firstly, I’ll trim the frame pattern to allow 10mm shoulder at top of cradle and have 60mm LWL for all frames fitting into the building board allowing 10mm clearance for the building board braces.
Using jigsaw I’ll cut the templates along the outer template hull line, the jigsaw blade is roughly 1 mm thick this equates to approx my guess-it-mate thickness of the final laminated hull, bit tight but I’m fussy on precision from here on in to have best possible retention of Claudio’s hull plan dimensions.
Cheers Alan
Claudio,
Alan,
I laid out on a longitudinal axis, in a CAD, a constructed side view of Claudio’s set of shadows. Trying to match a natural curve at the top and bottom clearly showed that the set of frame drawings I was working with comprises the problematic shadow #2 (see post #36). I believe I am presently working with the same file as yours as it is dated previous to November the 1st, when Claudio raised the problem.
Derived from measurement taken on the Setup.pdf drawing, and later confirmed on the main plan/elevation drawing, I concluded that shadow profile #2 was perfect, only the leg extension was too high (about 3mm). I corrected it and everything now looks fine, according to the creator’s plan.
Since your stringers seemed to already have been glued when the problem was raised, I was wondering if you have both only corrected the deck line by letting the first plank curved naturally on the skeleton… or you have gone the whole way and cut the leg(s) to drop the whole frame? The later should be the proper course if we want to preserve the intended bow line and not end with a somewhat bulbous bow.
Pictures in post #50 may lead us to think that only the easy correction was done (gap on the top stringer of shadow #3 and the 1st plank not following the deck stringer on the left side (starboard I think). [EDIT we clearly see it in post #63]. I am less sure from Alan’s picture set.
I am asking this because I don’t want to end up with the only boat with an “as designed” bow curve! It may cause me problems later if I follow your adjustments and tweekings. Or maybe it won’t make such a difference .
Please forgive me if I got this all wrong and I made you needlessly worried.
Sylvain,
I think the 1st part of 3rd paragraph is what was done to correct the line, which to my way of thinking would introduce a ‘hump’ at frame 2 on the bottom of the hull although this isn’t apparent on either Claudio’s or Alan’s plug. Hmm…
Regards,
Row
Hey Alan,
My concern for the peel ply bubbles would only apply to external application without using any means of compression.
You will be fine using peel ply against the mould in combination with the latex, also externally with latex for that matter.
If I explain a little further - when you apply the peel ply there are small amounts of air trapped in the matrix usually too small to see by eye. The air is at ambient temp. When you place it into a warmer environment the air expands and then becomes visible and also lifts the peel ply off the surface.
To avoid, allow the part to remain at a stable temperature until cured, then post- cure at an elevated temp to achieve the correct mechanical properties. This way the peel ply stays put.
There is a secondary force at work here, that is the resin also contracts a percentage and this adds another dimension particularly when laminating internal right angles and intricate shapes.
In your case, you have the peel ply “restrained” by the over laminate and then this is 100% kept in check by the tension in the latex membrane.
There is no such thing as a free lunch, and the latex method requires extra attention is paid to air extraction. You are rewarded, however, with a a fantastic finish for a male moulded hull.
I do feel that a vac bag system is more reliable at getting the air out because you need a ‘breather’ fabric for the vac to function correctly.
As for the Volvo, I cannot make any huge claim to helping directly, however we are very much a team here and we had just finished their second mast which assisted in the fast turn around. The old mast and rigging are now under the microscope and the whole incident is being examined in extreme detail.
Perfectly right Sylvain, Now I understand why I got a funny bump when putting the central strips
I went checking the shadow 2 and is true that there is an error but not the one you mention about the legs too long. The shadow 2 was referenced to the deck line of shadow 3.
Similar mistake was mentioned by Alan in telling me that the shadows where wrongly named 2 instead of 3 and viceversa.
I apoliges for this unforgiveable mistake. Pratically the shadow 2 need to be lifted up by 2.5mm but the water line strip location shal be corrected too.
Two drawings, one to exlain the mistake and the other in pdf for the corrected shadows 2
I’m very sorry for you all including Alan
ClaudioD
During sanding I need to recover this little bump since part of the problem was recover during planking. I wonder why Alan, that is so precise in his work, he did not mention the problem !
Dear Claudio,
Please, no need to apologies! With the price you charge us 
for using your great designs and the time you spend to patiently answer our questions, we should be the one to feel sorry about abusing your generosity.
You are right on the origin of the mistake. I only looked at the end result, the legs length being the difference between the deck line and the 110mm over the water line. Thank you for pointing me the water line strip difference which had eluded me. I will use your new frame.
I have another issue that bugs me more than it worries me. Somehow, the Corel to PDF to Corel (or Illustrator) conversion induces an approximation of the line vectors. Well, at least on my system. The imported/converted drawings are always a bit scaled off. And even if I try to rescale them, I can’t get consistency even inside a single drawing. We are only talking tenths of millimeter here and all the important measurement are written clearly. But still… your 2,5mm become 2,9 on my side (just the simple difference between the legs of the old and the new drawing) or the 98,5mm spaces between the sections become anywhere between 98,3 and 99,0mm. When we had up a few of them, it may make a difference at some point. Do you experience the same problem Alan?