The Magic moment is arrived this morning 24h later !!!
See the pictures showing the working sequence that is more talkative then a long blabla !!
Before cutting the contour I drilled 4 holes to be used as centering guides.
The molds came away very easily.
ClaudioD
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Hi Claudio V -
Just a reminder that the majority of members on this forum - read/speak English. If you are going to post links to websites or “Epoxy Manuals” - I believe the end location/manual should also be in English if you expect them to be of help and service to the readers. To make your links useful, a translation would be helpful for our readers than those that are only in Italian, French, Spanish, etc.
Please consider this request in any future posts and remember - “No Commercial Advertising For Profit!”
Let me or the forum owner know if you have any questions. Thanks, Dick
It seems that you didn’t put some tape or wax on the gel coated flange. Does it mean that wet gel coat on dry gel coat doesn’t bound?
Bonjour Sylvain,
the first time the interface was a wooden plate acting as ‘template’ and this is why I used PVC ribbons on top of bristol carton use to trim the hull shape.
For the second half mold, the ribbon was not necessary anymore since the wax was sufficient to allow the separation. In previous post I wrote about wax coats for the second mold too. No sticking effects between two body with epoxy gel-coat if wax is used.
This is just similar as when you laminate inside the female mold where only wax is used. Some use also the polyvinyl alcohol, PVA.
Cheers
ClaudioD
Sorry Dick,
just to avoid confusion, since too many “claudio” are sitting around, your observation is addressed, I suppose, to a certain Claudio Vigada .
For politeness, I never suggest or invite others to visit others Forums then this one, unless via ‘private message’.
Cheers
ClaudioD
Some body was asking in pm, how I toke the wooden Master out from the mold.
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Simply keeping the combined mold and master in one hand and knocking with the palm of the other hand on the mold side. Suddenly, 5 seconds later, the master pop up by a couples of mm from the bow side, the rest was easy !
ClaudioD
Hi Dick,
excuse me if I’ve written any “not proper” parts in mine post, it isn’t mine intention to withdraw your forum rules.
I think that post a link for a Epoxy Manual that is gratis, free of charge if you buy a little amount of material (20 euros I think that could be sufficient) is not and advertising… especially because I’ve no personal connection with that internet site that sells composite materials and parts for models.
For the link to www.baronerosso.it I thing that is not a problem for the “English speaking members”: google translator is very useful for them like for the Italians when I link any post from your very interesting English forum.
In B.R. Italian forum is not forbidden put link to technical post of other “speciality forum” also in English languages, if here is not allowed, excuse me and please show me/explain the “local” Rules, because I didn’t find where it is written.
The Epoxy Manual is of course in Italian but the sequences are explained with very clear drawings that are understandable for all and are the complement to well understand the sequence that I described in mine post.
It seems, reading the question in this topic, that the realization technique of monocoque hulls from a two halves mould is at least unknown from the majority but in other models branches (aeroplane/gliders) is normal working and also Sailsetc make a lot of hull with a similar method.
That technique could be very useful and on the net I’ve never found on the net/public similar construction sequences so well described as in that Manual… so I post that link.
I also has got an electronic scanned pdf copy of this Manual, but I think that is not correct that I make public a document that is not mine property or public /“on the net”.
Anyway, if you consider my related posts a “Commercial Advertising For Profit”, for me it is not a problem and, please, remove it completely…. Absolutely no problem about it.
If in the future I’ll find any similar documentation material not in connection with commercial internet site, I’ll post it.
Bye
The 2 molds are properly cleaned and waxing operation started for a minimum of 6 coats.
The wax used requires 6 hours drying before polishing.
ClaudioD
claudio vigada,
if you wish to explain how the dual molds technique is implemented, I suggest you to open a dedicated tread instead of interfering the discussion on the Footy Esterel and using all means to make publicity to “barone rosso” “urca project” and what else.
I recall for those that ignore it, that your are also the moderator of “barone rosso”.
You can withdraw yours posts yourself too.
ClaudioD
Hope to continue smoothly to carry on with the “build log” for the D-Footy Esterel.
Here the lamination progress of both 1/2 molds.
The glass tissue used is the 105g/m² Twill type.
Among the Twill, I also cut the glass tissue diagonally in order to facilitate the lamination particularly in the sharp turning corners.
The Peel Ply ribbons are used to absorb the excess of epoxy resin. The basic lamination is always on my models at the ratio 50/50
Just to remember that excess of resin will not improve the mechanical strength, but will add only weight.
ClaudioD
PS: A couples of films about dual molds lamination :
http://youtu.be/0tx6ob-1vnE
http://youtu.be/Vbe0eAxMzPE
http://youtu.be/zeLC-miXSwo
The cotton flock I found interesting !
CD
This morning I separated the two laminated hull’s shells.
They appears rater sturdy while the polymerization is not yet completed. I’m expecting more sturdier outcome.
Probably I should have used the 80g/m² instead of 105g/m² or even less.
The measured weight is about 40g, with the 80g/m² the weight will be 30g !
Still inside the calculated budget by 19g (529g total displacement)
ClaudioD
Claudio,
An excellent result! Have you decided yet which method you’ll be using to bond the two halves together?
The YouTube films in your previous post were certainly interesting although I’m intrigued to know how the chap in the 2nd film managed to work so cleanly when he appeared to be handling wetted out pieces of cloth with no gloves etc. If that were me I reckon I’d have ended up with me & the mold very strongly and securely bonded to the work bench with fingers very definitely stuck together!
Many thanks for your earlier words of support - my back continues to be a pain in every sense although in fairness the last lot of surgery was more about dealing with sciatic issues which has certainly given improvements. I’ll just keep taking the little pink pills for the time being and keep fingers crossed that I’ll get some workshop time in the new year.
Once again, congratulations on a fabulous result!
Regards,
Row
Hi Row,
Thank you .
I fill pity about your back. If may be a consolation, my femoral nerve and L2 - L3 discus are squeezed since 82 and this because I was bending to pick up a small luggage. Pain every day especially when I get out of bed. In general warm exposure is pain relieving.
About the shell connection I would like to try the charged epoxy. Instead of cotton flock I will use silica.
Sample test is ongoing. Probably I will insert a glass tissue in between when joining the parts.
Take care
Cheers
ClaudioD
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Cross sections of the epoxy charged meniscus
ClaudioD
Rudimentary Pull Test after 12 hours of bonding period .
Up to now the joint support 6kg pull weight.
The weights are stays hocked for a while !
I consider the joint strength enough for the purpose.
ClaudioD
As the late Footy Guru Angus pointed out:
“The maximum hydraulic force on a Footy hull is roughly equivalent to pouring water from a jug onto the back of your hand from a height of a foot!”
See Brett’s posts for details of the light glass hull. Footys can be built considerably lighter than 500 grams, but the winning yacht in most international competitions is the heavier Stollery design! You can argue for either. The biggest difference now that the battery rule has gone, is to use a 5-10gm LiPo, and perhaps a balanced rig so a small sail servo can be used. Roger’s swing rigs are reputably driven with a 9gm slow servo and his Power Lever arm design!
But the important thing is to get it finished for the Nephews Christmas?!
Hi Rusty,
someone was telling me once : too strong never break ! heheh !
Of course the weight remains under control !
The servos are : HS 85MG - 22g for the swing rig and HS 65MG - 11g for the rudder.
For the battery have not decided yet.
When will be finished ? good question ! heheh!!
Cheers
ClaudioD
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Great work Claudio !!!
I want to offer my condolences and my sincere sympathy to all mothers and fathers and all persons that are suffering for the tragedy of Newtown.
ClaudioD
Thanks Alan
ClaudioD