Wind turbine - best material for the tail

[David HK]

Hitherto I have used plywood that has been sealed and well painted, but the laminates are now peeling due to water ingress.

What other long lasting minimum maintenance material can I use?

Aluminium springs to mind but what thickness?

My turbines are Hugh Piggott's 8 feet (2.4m) swept area - upgraded versions.

Ideas welcome.

David in HK

[tomw]

David;

On one of mine, a 10 foot piggot style, I have used a piece of solid PVC "signboard" it has been fine for like 3 years now. in everything from -40F to +120F. Rated for 50 years exposure.

I got this material used with some printing on one side  at an industrial surplus place for like $1 for an approximated 4X 4 foot piece. It cuts and drills with  woodworking tools and you can glue it with PVC solvent cement.

So far, so good and when the plywood on my 12 footer finally rots far enough I will put a PVC tail on it.

If it was a bit too flimsy for your taste you could easily glue on some stiffening strips or bond 2 thicknesses together with PVC solvent cement but I find it works fine as is. I think they make paints for plastics now. Krylon comes to mind.

Not a great picture but this is it The other side is pure white with no lettering.:



Tom

[David HK]

Tom.

Thank you for the note.

Yes, PVC has sprung to mind, but the problem is that here in Hong Kong, we have so much sun year round that anything 'plastic' based rots in no time at all.

Except for the magnet discs, my entire turbine bodywork is stainless steel and I am trying to find something that will last 20 years or longer, 50 years would be glorious, and 100 years icing on the cake!

Dave

[RP]

Galvanized sheet metal from an air conditioning shop?  You could have them cross-brake it if you want to stiffen it through the middle.

[rossw]

Galvanized sheet metal from an air conditioning shop?  You could have them cross-brake it if you want to stiffen it through the middle.

Lots of water-pumpers here in Australia that have lasted 50+ years with galvanised iron blades.

[bj]

    Just from experience on my defunct 5 footer David, I don't recommend aluminum.
Three years, and  lots of turbulence, it had lots of cracks.  It was 3/16 thick.  There was
no thought put into the alloy however, it was just what I had laying around.

[niall]

hi  David

if the ply isnt marine and prone to delaminating you could re- inforce it with a box of small pozi screws around the edge ...maybe about 6 cm apart and grind the pointy bits flush on the back
 

mine is the real cheap ( dodgy ) 6 mm ply ...but the screws have kept it in shape so far ...

[David HK]

Thank you for the comments so far - very interesting.

I would like to float the idea of tempered glass with pre-drilled mounting holes with nylon through washers?

Dave

[David HK]

How silly of me for not thinking - I can use the existing shape to make a tail out of fibreglass. That should last for years?

David in HK