Martin Dilly 1 Posted November 20, 2020 Share Posted November 20, 2020 Given that balsa is a material with a very variable density,- anything between 4 and 14 lb/cu.ft or so, it seems odd that it shouod be used as core material for turbine blades. It must surely cause quite a balancing problem, with a density variation of more than 3:1. Does anyone on the forum have any firsthand knowledge of turbine blade manufacture? I'd have thought a high density foam would have been far preferable from the consistency point of view. How would forum members set about making a blade, bearing in mind they are, what,100 feet long or more? Would a balsa core be produced, probably in sections, and then skinned with carbon? That would need a fair-sized vacuum bag and autoclave, but such things are probably available and used in current aircraft production. Mould the two skins first and glue them to the core? Produce the skins as a single unit by bladder moulding in a female mould and then injecting foam as a core? Ah, but they use balsa cores, we are told. There you go, something to stimulate the brain cells. Quote Link to comment Share on other sites More sharing options...
Chris Walby Posted November 20, 2020 Share Posted November 20, 2020 Martin, Someone else posted a manufacturers video on a different thread. IMO it looked like they used a very thin balsa sheet in the skin of the blade so I can't see where all the balsa is going unless they waste a tremendous amount of balsa ). Perhaps it just does not pay (farmers) to grow balsa in the first place? Quote Link to comment Share on other sites More sharing options...
Cuban8 Posted November 20, 2020 Share Posted November 20, 2020 Seems to depend on the individual manufacturer's method. Some Youtube vids show balsa in the construction but as far as I've seen the really massive blades are all glass and carbon etc. Quote Link to comment Share on other sites More sharing options...
Former Member Posted November 20, 2020 Share Posted November 20, 2020 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Trevor Crook Posted November 21, 2020 Share Posted November 21, 2020 Martin, some of the blades are now over 100m long, and the offshore turbines they are used on produce 12 MW of electrical power. Looking forward to feedback from Barrie's contact. Quote Link to comment Share on other sites More sharing options...
Former Member Posted November 21, 2020 Share Posted November 21, 2020 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Gary Murphy 1 Posted November 21, 2020 Share Posted November 21, 2020 I think you guys are missing the point. Balsa is not used in the construction of the blades. The balsa is burned to power the Chinese factories that make them. Then me buy the wind turbines to save the planet,the same turbines that spend more time not spinning than spinning in the UK, well at least the ones near me. Quote Link to comment Share on other sites More sharing options...
Former Member Posted November 21, 2020 Share Posted November 21, 2020 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
kc Posted November 21, 2020 Share Posted November 21, 2020 I think the turbine use may be a cover. It could well be they are buying up all the balsa supplies suddenly to put Western kit makers out of business. Then we have to buy kits from China....... However it was stated decades ago that balsa was used in racing car construction sandwiched between 2 sheets of alloy, called Mallite- Bruce Maclaren himself introduced it for his Can Am sports cars and then his F1 cars if I remember correctly. So nowadays balsa may be used in some similar way for any number of composite constructions. Edited By kc on 21/11/2020 11:13:13 Quote Link to comment Share on other sites More sharing options...
Former Member Posted November 21, 2020 Share Posted November 21, 2020 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Erfolg Posted November 21, 2020 Share Posted November 21, 2020 The comments made in general all make sense. It is hard to see where balsa makes sense in blade production. Even with the sandwich methods, there are almost certainly better materials (consistency and weight). Yet there appears to be some one using it, other than us and the traditional users. Quote Link to comment Share on other sites More sharing options...
Former Member Posted November 21, 2020 Share Posted November 21, 2020 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Former Member Posted November 21, 2020 Share Posted November 21, 2020 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Gary Manuel Posted November 21, 2020 Share Posted November 21, 2020 I read somewhere that each blade can use 10 cubic metres of balsa. Not sure where I read it. Quote Link to comment Share on other sites More sharing options...
Gary Manuel Posted November 21, 2020 Share Posted November 21, 2020 Depicts a typical wind turbine blade with all of its interior components broken down into different layers and materials. Balsa wood or polymer foam are the core materials for both the shear web and the shell of the blade. The shell itself is composed of resin, fiber laminate, a balsa wood core, and structural adhesive. Edited By Gary Manuel on 21/11/2020 14:07:37 Quote Link to comment Share on other sites More sharing options...
Dickw Posted November 21, 2020 Share Posted November 21, 2020 Posted by Gary Manuel on 21/11/2020 13:54:42: Depicts a typical wind turbine blade with all of its interior components broken down into different layers and materials. Balsa wood or polymer foam are the core materials for both the shear web and the shell of the blade. The shell itself is composed of resin, fiber laminate, a balsa wood core, and structural adhesive. Edited By Gary Manuel on 21/11/2020 14:07:37 Looks like a typical moulded model wing. Been flying models made like that for many years with usually either Rohacell or balsa cores - not made by me I hasten to add! Dick Quote Link to comment Share on other sites More sharing options...
Trevor Crook Posted November 21, 2020 Share Posted November 21, 2020 Posted by Gary Murphy 1 on 21/11/2020 10:42:13: I think you guys are missing the point. Balsa is not used in the construction of the blades. The balsa is burned to power the Chinese factories that make them. Then me buy the wind turbines to save the planet,the same turbines that spend more time not spinning than spinning in the UK, well at least the ones near me. Well some must be spinning somewhere in the UK. Just checked a live power generation website at 10.15pm on Saturday evening, and wind power is generating 9.29 GW, 34.5% of the grid demand. Quote Link to comment Share on other sites More sharing options...
kc Posted November 23, 2020 Share Posted November 23, 2020 The info that wind turbine use lots of balsa has come from UK balsa suppliers and is the reason for lack of supplies. I wonder whether other countries have received the same info & whether their supplies of balsa are also short. Has anyone seen any comments on this on modelling websites in mainland Europe or USA etc? Quote Link to comment Share on other sites More sharing options...
Frank Skilbeck Posted November 23, 2020 Share Posted November 23, 2020 From what I read on SLECs website, the issues came about because of new owners at the plantation/mill they ha been dealing with the 30 years. Looks like things are moving again but there maybe some shortages from PNG and they have now also sourced a new supplier in Indonesia. Balsa trees are a native of central/southern America so the US probably gets theirs from there not the Far East. Quote Link to comment Share on other sites More sharing options...
Former Member Posted November 23, 2020 Share Posted November 23, 2020 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
kc Posted November 23, 2020 Share Posted November 23, 2020 My question was " has anyone seen reports from any other country stating lack of balsa supplies due to balsa being diverted to wind turbine production" Quote Link to comment Share on other sites More sharing options...
Former Member Posted November 23, 2020 Share Posted November 23, 2020 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Gary Murphy 1 Posted November 23, 2020 Share Posted November 23, 2020 Posted by Trevor Crook on 21/11/2020 22:18:57: Posted by Gary Murphy 1 on 21/11/2020 10:42:13: I think you guys are missing the point. Balsa is not used in the construction of the blades. The balsa is burned to power the Chinese factories that make them. Then me buy the wind turbines to save the planet,the same turbines that spend more time not spinning than spinning in the UK, well at least the ones near me. Well some must be spinning somewhere in the UK. Just checked a live power generation website at 10.15pm on Saturday evening, and wind power is generating 9.29 GW, 34.5% of the grid demand. Could you please keep me posted daily ,then I might change my mind. Perhaps the ones in east sussex only work at night. Quote Link to comment Share on other sites More sharing options...
Tony Richardson Posted November 23, 2020 Share Posted November 23, 2020 Balsa is in short supply here in Canada too, I do not believe they are burning it in factories as they have ample coal supplies for that purpose, the story this side of the pond is the same as yours, wind turbine blades are constructed with a balsa core which is using a huge amount of the available balsa. Hopefully suppliers will meet that demand and have some decent wood to supply those of us that like to build, maybe as its a fast growing tree an increase in plantation size or the number of plantations will achieve this, until then we sit and wait patiently.. Quote Link to comment Share on other sites More sharing options...
dave windymiller Posted November 23, 2020 Share Posted November 23, 2020 See secrets of the mega factories on more4 now! Shows your balsa supplies disappearing! . Edited By dave windymiller on 23/11/2020 22:48:13 Quote Link to comment Share on other sites More sharing options...
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