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Forum Index : Windmills : Wind Turbine Blades
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isaiah Guru  Joined: 25/12/2009 Location: United StatesPosts: 303 |
I have several sets of wind turbine blades cut out of 10 inch pvc pipe ( $5.00 frn at local salvage yard for 10 foot length) and would like to know the best recommendation to paint or coat these with to help slow Ultra Violate damage ?? The disadvantage to the pvc pipe is that the wall thickness is inconsistent and makes problems getting them to balance. My blades are 28.00 Inches .711 meter. If you make Blades A Meter or more they will flex too much without stiffeners. We do have some radio antennas up on pvc and several fiberglass antenna's ( antron 99 Shakespeare big stick.) and the sun and U.V. takes a toll. URL=http://www.motherearthnews.com/Renewable-Energy/1973-11- 01/The-Plowboy-Interview.aspx>The Plowboy Interview[/URL> |
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| lichong712 Newbie  Joined: 04/01/2010 Location: GermanyPosts: 8 |
Yes, I also think PVC becomes fragile when it's exposed to sunlight for long periods of time, I search it on Google someone said "By putting two coats of UV protective paint on them, they'll stay nice and strong for as long as you use them". I also intend to build wind turbine blades with PVC pipe, your info is helpful, thank you very much! If you are intent to reduce your power bills,why not pay wind power cost? |
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| isaiah Guru Joined: 25/12/2009 Location: United StatesPosts: 303 |
The Dayton Mill (can be viewed here http://www.windynation.com/phpbb/viewtopic.php?f=15&t=262 ) has a set of 6 blades that are 5 inches at the root and taper to 1 1/2 inches at the tip of 28 inches. My other mill ( the Graham mentioned else where on this site ) has 6 blades at 5 3/4 at the root and tapers to 1 1/2 at 28 inches. At this time I cant say which is better. When you start your lay out do not go square with the pipe drop what will be the tip down some from the center line of the tube . When you then get the pattern cut out and look at the blade from the end you will see it has a twist to it something like looking down the inside of a rifle barrel. My blades the bottom edge is straight and the top is the one with the tapper. I have cut some out rectangular and played with tapering ends and radius's angles etc. and I think the above works better. I also cut out some pieces about 1 inch wide and 3 inches long and drill the same hole pattern in them as the blades . I put them on the front side of the blade this helps preventing the washers from compressing into the blade and making a weak spot. you can use 2 or 3 if you wish. Maybe some one else will come up with a design and process. All I have for tools is a saber saw ( hand jig saw ) ,sander, and some files. I have a balance weight baby scales that I used on the last set to try and make them the same weight! BTW the Dayton has a peice of that 10 pvc fashoned to make a weather shield, this gives the motor plenty of room for air circulation for cooling and still some weather protection. I have designed some what of a laser balancer but due to winter weather here Im not able to give it a good test yet. If some one is interested Ill explain what I have done for the laser balancer. URL=http://www.motherearthnews.com/Renewable-Energy/1973-11- 01/The-Plowboy-Interview.aspx>The Plowboy Interview[/URL> |
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imsmooth Senior Member  Joined: 07/02/2008 Location: United StatesPosts: 214 |
Try sprayig with Auto Clearcoat from a car shop. |
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| Joblow Regular Member  Joined: 05/01/2010 Location: AustraliaPosts: 54 |
If there is an inconsistency in the thicness of the PVC material I don't think just getting them the same weight will be good enough for balance at speed  The man who never made a mistake never made anything |
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| KarlJ Guru Joined: 19/05/2008 Location: AustraliaPosts: 1178 |
you can get plastic primer, then use a "normal" enamel spray paint, just be careful to get it even on all the blades as 50g here and there is the difference between smooth and vibrations. Karl Luck favours the well prepared |
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| isaiah Guru Joined: 25/12/2009 Location: United StatesPosts: 303 |
' '
Thank you Karl When the weather warms up here above freezing and the white grass is gone turning green again Ill try that process. That primer may be a way to help balance those pvc blades. I could take the light ones and give them a coat or several to bring it into weight then put a light color or clear on. URL=http://www.motherearthnews.com/Renewable-Energy/1973-11- 01/The-Plowboy-Interview.aspx>The Plowboy Interview[/URL> |
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| KarlJ Guru Joined: 19/05/2008 Location: AustraliaPosts: 1178 |
indeed, adding paint is an easy way to balance blades, I've done it myself Luck favours the well prepared |
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| isaiah Guru Joined: 25/12/2009 Location: United StatesPosts: 303 |
Karl What kind of life span should I look for on these blades cut out of pvc pipe? One set so far survived the Michigan winter -020 deg f., 50 mph winds one night! I don't know the age of the pipe as it came from a salvage yard. I may when it warms up a bit just cut out another set for spares. I use a 2 inch hole pattern for the blades to hub, and I make a stiffener to put on the outside 1 inch X 3 inches about 1/4 inch thick I have not had any troubles with this. My son has a set of aluminum blades that didn't use this technique and several blades broke out by the bolts in that 50 mph wind! URL=http://www.motherearthnews.com/Renewable-Energy/1973-11- 01/The-Plowboy-Interview.aspx>The Plowboy Interview[/URL> |
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| KarlJ Guru Joined: 19/05/2008 Location: AustraliaPosts: 1178 |
no idea how long they would last, again takes a long time to make a decent set and by the time you've finished, you might as well buy the PVC extrusion, you'll get plenty more performance and theyll never break the PVC as steel pipe carries the loads, I think they're very limited in size as they are too weak for any decent lenght.... Luck favours the well prepared |
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rippa01 Newbie Joined: 08/02/2010 Location: AustraliaPosts: 11 |
how about using blades made from food grade 200L plastic drums, would they be stronger (granted they would be restricted in length) chris  tell me, I hear show me, I see involve me, I understand |
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| KarlJ Guru Joined: 19/05/2008 Location: AustraliaPosts: 1178 |
to be honest performance is the key and airfoil section of a cut piece of pipe is going to be average at best and poor most likely. you can make blades out of paper mache if you wish, but wouldnt be much good. the comparison needs to be made back to the best material known to man for fatigue, workability, shape / ability to shape, damage tolerance and weather resistance. as far as advanced materials go, its till really tough to beat good old fashioned wood. input effort = performance. Although I love the blade extrusions sold on this site ultimately a good twist and taper will beat them but effort required is tough to justify Karl Luck favours the well prepared |
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DTV004 Regular Member Joined: 30/04/2009 Location: United StatesPosts: 65 |
hi this my opinion on pvc pipes the good one's are use by the water department. the are made for hi pressure. from one inch tick to 1/2 inch after i cut the blades the don,t bend or twist the are strong .cope can's of cheap paint and you will have good set of blades ....note: don't use cheap pvc pipes...have a good day, |
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| isaiah Guru Joined: 25/12/2009 Location: United StatesPosts: 303 |
'  'Well I dont know where the pvc came from that Im using, but I cut the blades similar to some of the commercial aluminum blades on the market today.
I didnt balance them as yet and they are working and have survived the Michigan winter and two storms of 50 + mph winds. I made up another set of my own design and they worked better. I have a wood blade I bought off ebay a year bachk and we took it down because it wouldn't start up. Then I bought a set of blades off ebay from Richard Mail and they are out performing anything we have had in the air so far.They are very good for low wind start up and the fact that they are cut from aircraft aluminum I think they will be around as long as any wood. The wood blades I'm told you should take them down every year and oil them . Living on a limited income and limited tools one dose what he can with what he has got or afford and if it works at all its a winner.' '''URL=http://www.motherearthnews.com/Renewable-Energy/1973-11- 01/The-Plowboy-Interview.aspx>The Plowboy Interview[/URL> |
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| domwild Guru Joined: 16/12/2005 Location: AustraliaPosts: 873 |
As mentioned before, plastic primer is the way to go. Also tip the axis of the shaft away from the horizontal, so that a flexing blade cannot hit the mast. A few degrees should be OK. Helicopter leading tape should also help protecting. Taxation as a means of achieving prosperity is like a man standing inside a bucket trying to lift himself up. Winston Churchill |
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| KarlJ Guru Joined: 19/05/2008 Location: AustraliaPosts: 1178 |
My opinion on that being involved with Heli maintenance..... too thick for the tight radius of a PVC blade go for aluminium tape expensive but sticks like shiiit to a blanket and will conform to anything tough as nails 3M make it and downunder its $50 a roll (which will last a lifetime!) Luck favours the well prepared |
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GWatPE Senior Member Joined: 01/09/2006 Location: AustraliaPosts: 2127 |
I have put the clear heli leading edge tape on my Carbonfibre Lakota blades, and also my 3m wooden blades. I would not use aluminium tape. The heli tape is polyeurethane from memory, and is very tough. Mine has seen over 3 years service on my Lakota blades, and still are like new, and these spin at up to 900rpm in a storm. The leading edge is quite sharp on these blades as well. You need to take a bit of care, ensuring the surfaces are clean and dry, and making sure the tape goes on smoothly. Aluminium tape soon becomes pitted, especially if there is any salt, and moisture in the air. I have aluminium tape on a weather seal cover on my mill, and this has corroded badly, and this is not even cutting the air. The heli tape works out at about $5/metre, for 50mm wide. You only need to protect the outer 2/3 of a blade, so cost should be about $15 for a 3m blade set. The problem is finding a supplier of the tape. There is a supplier here in Adelaide, in Thebarton, just off Main South Rd. I don't remember the company name, or exact address. I bought some a few years ago expecting to need to replace every year. I am still waiting to need to replace it. Gordon. become more energy aware |
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| KarlJ Guru Joined: 19/05/2008 Location: AustraliaPosts: 1178 |
fair cop, I guess the stuff i was using was thicker, as i recall comes in three thicknesses Luck favours the well prepared |
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