Author Topic: Glueing/Laminating fir for "prop" (rotor)  (Read 2628 times)

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steak2k1

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Glueing/Laminating fir for "prop" (rotor)
« on: September 01, 2005, 06:18:28 PM »
Well I am about to embark upon the unknown and begin to build (a few parts thereof), a small little genny loosely based on the Wood AX/Dans Wood AX.


I have seen in one of the diaries or posts, can't seem to remember which, that one of the builders here used laminated fir..? for his rotor. I have 2 lengths of 1" (nominal) X 6" X 10' Fir boards with no knots and nice grain throughout.


I plan to make a 3 bladed rotor ~ 2 - 2.5' length blades. I have enough material to laminate 2 pieces together for a through T of 2" and will have enough material to actually make 4 blades (one spare, I figure can't hurt eh?)


What would you all recommend for a proper glue to use..?? As well as one that is fairly easy to procure (Home Depot/Cdn. Tire etc). As for clamps, I have plenty of bessey's to use and will find a good perfectly flat pce of material to use as a jig/backing board...couple of 6" X 2.5' mild steel flat bars or plates should do the trick.


Once completed/balanced, what type of outer coating would be recommended for the wooden fir rotor..?


any other recommendations are greatly appreciated.  


Thank you,


stk

« Last Edit: September 01, 2005, 06:18:28 PM by (unknown) »

richhagen

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Glueing/Laminating & Coating Rotor
« Reply #1 on: September 01, 2005, 12:43:04 PM »
For the coating, a few good coats of linseed oil seem hard to beat.  It doesn't cost much, is widely available, leaves a little bit of a rubbery surface which seems to wear well, and can be recoated each year.  It's what DanB uses, and I've used it on small blades with really good results.  As for the laminating, I lack experience, however I've heard people tell of using West System's epoxy and other epoxies, even carpenters Glue, although I would be skeptical of carpenters glue's ability to withstand moisture.  I recently obtained a small bottle of some polyurethane glue made by Elmers, I believe it is similar to 'Gorilla Glue' and probably would work fine for blades as well.  Keep us posted on your findings and results.  Rich Hagen
« Last Edit: September 01, 2005, 12:43:04 PM by richhagen »
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MountainMan

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Re: Glueing/Laminating & Coating Rotor
« Reply #2 on: September 01, 2005, 01:44:23 PM »
Any of the "Poly" type glues such as Gorilla Glue should work great for glueing up your wood.  It is completely impervious to water.  Often used for high quality wood working, especially in situations where water might be relevant (and also when you're too impatient to wait overnight for regular wood glue to harden).


jp

« Last Edit: September 01, 2005, 01:44:23 PM by MountainMan »

Daggs

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Glueing/Laminating
« Reply #3 on: September 01, 2005, 02:07:03 PM »
Gorilla Glue is the biggity bomb of glues.  Strong and waterproof.  As Elwood said, "This is glue.  Strong stuff."
« Last Edit: September 01, 2005, 02:07:03 PM by Daggs »

Chagrin

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Re: Glueing/Laminating fir for "prop"
« Reply #4 on: September 01, 2005, 06:12:39 PM »
Both epoxy and Gorilla (polyurethane) glue are overkill. Titebond II (or III) is all you need. Just make sure you have a good joint when you laminate those boards together.
« Last Edit: September 01, 2005, 06:12:39 PM by Chagrin »

bob g

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fiberglass resin and mat?
« Reply #5 on: September 01, 2005, 07:11:59 PM »
what about the possibility of using fiberglass resin?


such that you sandwich the layers of wood with fiber resin and fiberglass matt between.


seems like it would make for an incredibly strong blade, with very high rigidity or resistance to bending.


of course carving would be complicated i guess, but perhaps in a jig cutter like some are using this could be overcome.


just a thought, possibly not worth the extra work if you have to machine/shape/carve the wood by hand


bob g

« Last Edit: September 01, 2005, 07:11:59 PM by bob g »
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Experimental

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Re: Glueing/Laminating
« Reply #6 on: September 02, 2005, 12:33:47 AM »
      STK, I really recommend West systems epoxy -- the longer cureing time, allows the epoxy to soak into the wood --There is also a thickning agent they recommend for filling all voids !!( available from marine supplys)

      I don,t recommend polyesters at all, as they cure to quickly, and don,t penetrate ( been there, done that -- won,t again!!)

      I also use west systems to coat the entire blade assy, before painting and use acrylic enamel, for top coat ..Have also used , several coats of west system and sanded with 220 paper, between coats -- then polished it to a glass like finish -- it has UV protection and it,s really pretty on mahogany props !!

      Incidentally -- mahogany works real good, and I have found it cheeper than vertical grain fur !!

      I don,t believe you can use, to good a glue -- it,s to much work, not to and laminated props are stiffer, resist bending !!

      Good luck on your project -- we,ll look foreward to pictures !!  Bill H....
« Last Edit: September 02, 2005, 12:33:47 AM by Experimental »

jmk

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Re: Glueing/Laminating fir for "prop"
« Reply #7 on: September 02, 2005, 06:39:15 PM »
  I use alot of tite bond II in my wood work. I used it on my 12' rotor. I like to spread it onto both mateing surfaces. Clamp it moderatly for about fifteen minutes than ease of a little. This leaves enough glue inbetween the boards to give a very strong bond! I like to test the scrap peices to see how stong they are. You can put your cut offs in a vice and smack them with a hammer and they break through the wood and not the glued joint. If you clamp it to tight you will squeeze to much glue out pluss stress the wood wich will try to acualy seperat the joint after you take the clamps off. When you hit scap like that it breaks at the glued joint in some places.  
« Last Edit: September 02, 2005, 06:39:15 PM by jmk »

rotornuts

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waterproof white
« Reply #8 on: September 02, 2005, 07:51:27 PM »
In my mind it comes to cash. If you can shell out for west system go ahead. I personally will continue to use the weldbond white I've always used after I got sick of spending untold amounts of cash for 8 oz of glue. Your glue only needs to be as strong as your wood. Your average carpenters glue will produce a joint parallel to the grain that will not yield before the wood does. That said other gles can only offer a couple things such as gap filling properties to accomodate sloppy joints or weather resistance. If Titebond and Weldbond are the same glue then in my opinion Titebond is a suitable glue intended for intermittent exposure to water without weakening. I firmly believe that if your wood is going to see long term exposure to water then the wood itself will likely fail ajacent to the joint before the glue does.  


Just make sure you keep on top of protecting the wood with an oil to prevent water/moisture from penetrating into the wood. Oil will require more frequent maintenance and a varnish will require periodic stripping and recoat.


Just my opinion but as long as the glue is designed for intermitent exposure to water(most waterproof glues) then it's up to your finish coat to do the rest or the wood will fail anyway.


Mike

« Last Edit: September 02, 2005, 07:51:27 PM by rotornuts »