fairing for control rods

fairing for control rods

Postby tigger » Mon Jul 28, 2014 9:36 pm

Mould for fairings. Wasn't happy with my" le snack" fairing on the new P2k glider so made up a half tooth paste tube shape from balsa and gave it two coats of varnish. I then sprayed it with some silicon spray from repco/red shed and mixed some plaster of paris and found that you need twice as much as you think so some fast whipping and poured it into a small container and then just sat the balsa shape in it with a suitable weight and left it over night. Came out not too bad and has been drying for a couple of days.Obtained some Norsky glass tissue and will use this with some polyester resin later in the week when the mould is totaly dry. Think i'll just spray the mould withe the silicon and see if it will release as easy as the balsa shape.
Cheers Tigger
tigger
 
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Re: fairing for control rods

Postby tigger » Tue Jul 29, 2014 8:40 pm

Okay couldn't wait any longer so have mixed up 15 mils resin with 8 drops of catalist, popped in 2 pieces of the norski tissue glass cloth and some chopped strand then some more tissue. I think i should have left the chopped strand out as it was too springy and kept pushing the cloth up.I do split the c/strand and crumple it up a bit so it lays down but this could be my downfall this time. Still, i'll check in the morning and post a photo,good or bad.
Cheers Tigger
tigger
 
Posts: 153
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Re: fairing for control rods

Postby tigger » Wed Jul 30, 2014 8:26 pm

Not too flash but half expected after my mistake with the chopped strand and i also damage the cloth when brushing the resin in. Happy enough with the resin, hardener mix and will stay with it. Never had any thinners to clean up with so used an old trick i came across years ago and that is to just wash hands and brush in some "Handy Andy" takes longer than thinners but cleans as well if not better,more friendly on the hands too. A lot of people are quite surprised you can clean resin coated brushes in the sink.
Tigger
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moulds 2 002.jpg
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Re: fairing for control rods

Postby tigger » Wed Jul 30, 2014 8:33 pm

Altered the mould so it will be easier to lay the cloth in and remove the fairing when cured. Also gave the mould a coat of varnish and will go with the silicone spray for the release agent. I think this time i will use multi layers of the glass tissue.
Okay, catch you later in the week.
Tigger
Attachments
moulds 2 019.jpg
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Re: fairing for control rods

Postby tigger » Mon Aug 04, 2014 8:51 am

an improvement, but scary. I had given the mould a coat of water based varnish and only uesd two layers of tissue glass with the grain running length wise. The whole thing went really smoothly and looked great then about an hour later i realized i never sprayed with silicone!!!! so left it a while longer and removed while still green [semi soft] and luck would have it out it came.
Tigger
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moulds 4 019.jpg
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Re: fairing for control rods

Postby tigger » Mon Aug 04, 2014 9:01 am

Looks not too bad and will give it a slight sand up to finish it off and i'm happy with this one so will make another with the same formular.
2 x layers of Norski tissue cloth
15 mls of polyester resin + 9 drops of catalist
I think with the grain of the cloth running length wise it makes it easier to lay up but also looses some strength along the crease lines. Still,plenty strong for fairings and oh so light. That's all and thanks for having a look.
Cheers Tigger
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moulds 4 023.jpg
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Posts: 153
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Re: fairing for control rods

Postby tigger » Thu Aug 07, 2014 1:19 pm

Post Script for fairings.
Okay, sat down and thought about what went right and also the bits that went wrong.
Negatives: sprayed silicone on the mould when i should have coated it with varnish first.
Negative: used water based varnish when i should have used spirit based.
Negative: used chopped strand,too springy for little mould.
Negative:used silicone for a release agent,got away with it but would use proper release agent in the future.
Positive: norski tissue glass cloth, 2 layers is perfect.
Positive: 9 drops of catalyst to 15 mls of polyester resin worked out well.
Pos/neg: used plaster of paris for mould. Maybe a proper moulding medium would give better results.
Any thoughts on all of this please feel free to post them up here.
Cheers Tigger
tigger
 
Posts: 153
Joined: Tue Dec 31, 2013 8:07 am

Re: fairing for control rods

Postby tigger » Sat Aug 09, 2014 8:15 pm

Spot the fairing competition.Fitted the fairings to my foamy P2k wing and quite pleased with how they look.
A dollar for each one you find and Admin will see you right.
Cheers Tigger
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p2k fairings 001.jpg
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