Wing Root Fairings

[Dave Reid]

With my fuselage now sitting temporarily on the centre section, I've started thinking about how I'm going to make the wing root fairings. Having just successfully made the windscreen attachment surround out of woven fibreglass cloth (the first time I've ever used fibreglass), it occurs to me that a more ambitious project with the same material might work for me on the wing roots. A search here and on the EAA forums doesn't throw up anything useful, so perhaps someone can help with suggestions.
I'm not expecting to be able to make an alloy fairing myself, but firstly is fibreglass going to be an OK material for this application; secondly, I'm after suggestions on a method of creating a mould in situ.
Thanks in advance for a wealth of information!
Dave

[mikeblyth]

Hi Dave

I used plaster cheap and easy to form, took a cast, then made fairings out of fiberglass. Polyester
I think they look good (G-BMET) and have stood test of time 25 years. Its a good job for the winter.
MB
PS. Remove plaster before flying.

[Dave Reid]

Thank you Mike, I'll certainly have a look into plaster...

It surprises me how few responses this forum gets - a swift look at our cousins' EAA forum shows what could be learnt from others.

Cheers, Dave

[Brian Hope]

Yes Dave it is a shame that more people don't use the forum but I guess there are so many fora, including those for specific types, that the queries and answers are spread across them. It should also perhaps be noted that EAA has around 160K members to our 8K !
Re the root fairings. if I were doing it I would seriously consider the moudless composite technique of using blue foam to shape the fairings and then laying up glass cloth on the foam as the actual fairing, trimming the excess cloth and discarding the foam to give a finished part (other than final smoothing and paint). This is basically the Rutan technique. Careful shaping and lay up will give an accurate surface that needs minimum filling and smoothing with a microballoon filler.
Rgds, Brian

[ColinC]

Hi Dave,

I'd go with Brian's suggestion. Don't forget to think about how you are going to fix them as early as possible. Currently you have everything accessible so can fit blocks to screw to if necessary. May be worth looking at what Roy has done on SV?

You should send Brian some notes and pictures for the magazine. Your work might inspire other potential builders to consider a proper wooden aircraft!

Colin

[mikeblyth]

Hi Dave
Replies, yes it’s a shame. It’s a confidence thing don't want to look a pratt. I’m worrying less about it these days due to being born very young.
You don’t say type wood or metal. Where are you based?
Brian. Would be nice if members put their location.
.

Mike

[Dave Reid]

Brian, thanks; that's exactly what I was looking for. Is there anywhere you know that I can read up on this? I'm a complete beginner... where do I find blue foam? etc. As I explain many times to people, I've put up the odd wonky fence in the past, but never done any proper woodwork stuff.
Mike, I think you've got part of the reason people don't post - I'm always a bit concerned in case people think I know what I'm talking about. Or not! From the foregoing, to answer your question, you'll have guessed it's wood from plans and I'm near Norwich.
Colin, There are at least 2 or 4 (including you of course) of the same type being built which are far better quality than mine, I'm sure. I'll think about it.
Next question (not related to wing root fairings): Can anyone give me some ideas on rigging up a cable operated brake system? 2 levers for independent operation? (it's a skidded taildragger).
Dave

[MORGS]

Try a copy of - 'Light Airplane Construction For Amateur Builders' - by Ladislao Pazmany; mostly about constructing a PL2 - but quite some detail on making the wing root fairings and cowlings in GRP. Was available from LAA.
Worth a read.

[Brian Hope]

Dave, there are bound to be some composite construction blogs etc on the web that detail the techniques involved. Steve Brown, who often posts on the forum, is a VariEze builder and very knowledgeable with composites so he may come on with some ideas of where free info is available. I'll drop him an email. If you want to buy a book we have several specifically on composites in the LAA Shop, click the Book Shop link, then Technical Books, then Composites.
We also run a course occasionally called Composites for the non composite aeroplane builder which covers things like preparing spats, cowlings. fairings etc, plus making composite parts, although the specific reason for the course is to show RV builders how to glass their canopies into the canopy frame. We do not have a course sheduled at the moment but I could probably get one into the programme for early in the year, say March time, if there is any interest.

[mikeblyth]

Hi Dave

“What’s wrong with plaster” My moulding techniques using plaster are probably superior to foam IMHO
I should try running a course on it. Then you can use what’s left for decorating.

Same thing applies to brakes. I have a two levered system that works really well.
using push bike cables and same scale levers. Simple and effective. Could send or post pictures if required.

Mike

[Dave Reid]

Thanks to all for the suggestions; I now have some stuff to aim at. Mike, yes please for some photos. I'll pm you shortly.
I'd put myself down for that course Brian, if you get one up and running, March would be perfect timing for me. When it comes to the EAA having 160k members as against only 8k here, I'm sure the quality of knowledge here will match the quantity there!
Dave

[Rob Swain]

Re. replies.

The old (PFA?) forum was a vibrant, helpful and friendly resource. Unfortunately it never really recovered from being relaunched.
All the old members had to re-register and have real names published, and a lot couldn't be bothered with the rigmarole of the email application/vetting process and/or losing their anonymity.

The content of the old forum wasn't carried over either, the powers-that-be refusing to recognise the valuable asset it represented.
I know the old content is supposed to still be available somewhere, but it is hard to find, hard to navigate/search, and just too much trouble for most people to use.

Other positive suggestions haven't been taken on either - like the Forum Strut. The scope for online seminars and lectures, instructional videos, online chat etc that such a presence would have afforded was not recognised.

Progress, eh? New name, lousy website address (why they didn't go with www laa.aero like I immediately suggested I'll never know), stripped and stupidly customised forum. A missed opportunity for a really good online presence!

The site is improving now (thanks Brian), but unfortunately the baby was thrown out with the PFA bathwater.

[mikeblyth]

Rob
You been drinking? could say that about most things. Things change (wots wrong with candles) and life goes on. Same thing happened with Taylor Mono site really going well then gone. Brian’s doing a really good job. It’s easy to criticise, improving things takes effort and sometimes money.
Just bought an Aware, comes with a mount suitable for an HGV, so spent happy hour or so constructing mounts to suit my stead. Nice bit of kit but of course not perfect.

Happy New Year Mike

[Rob Swain]

Brian’s doing a really good job.

I heartily agree.

As far as I'm aware he was only involved with the magazine at relaunch time.
If he had been involved with the website etc I expect it would have been far better handled.

And please don't have a go at me! Somebody wondered why this forum is so little used, and I simply replied.

Re the Aware: I considered it, but went with Skydemon instead - the Android version is hugely capable and very affordable. Maybe you should have consulted the forum on the subject - there's a thread I started about it that debates issues / shortcomings etc.

[Julian Bone]

PVC foam sheets of approx 6mm are very quick an easy to form by hand into compound shapes on a rough jig made of plywood and stiff wire.
3/16 stainless steel rod works well to make good curves naturally. Plywood ribs across fairing, rods running chordwise. Leave rods long.
Wire rods to ribs as necessary to pull to desired shape.
Adjust ribs to make all rods one curve not an S bend in the middle of the fairing.
Use a hair dryer or greenhouse heater held in one hand to gently warm the foam to its softening forming temp of approx 55 deg. C.
A bit tricky at first, go slowly both sides, it is a pretty forgiving material and after a few goes you should get the hang of it.
Recommend Airex R63.50 foam, see http://www.impag.co.uk
The foam naturally bends to cover gaps of a couple of inches.
The foam is fairly flexible so will fit the aircraft easily.
Once happy with shape disc edges to bring to a knife edge.
Set aside jig and fit just the formed foam to the aircraft
Apply parcel tape to aircraft contact areas to allow removal of fairing.
Sharply curved leading edge area can be made with on site mixed urethane expanding foam twin pack type. When hard, carve with a breadknife and general abrasives to hand held metal template.
Cover urethane area with cling film to prevent becoming part of the fairing.
Apply micro to PVC area.
Apply 2 layers S glass, (it's 30% lighter than E glass).
Add tape at edges say 4ply.
Leave as appropriate to set.
Drill remove etc for fixings .
The PVC foam is a permanent part of the fairing.
Jig time a couple of hours.
Foam form say 20 mins each.

Slap up cloth say 2 hrs each fairing.

Done .