Roger Our eastern Hemlock is close to the specific gravity (weight) of Sitka Spruce. The western hemlocks are about 8-10 percent heavier. We use the hemlock here in Vermont for barn construction. The disadvantages of hemlock might be 1- the lower elastic strenght, about 25% lower which means the wood will split instead of flex. 2- It doesn't laminate (take to glue)as readily as Spruce and 3-the diffuculty in finding nice straight grained stock which can lead to twisting, distorting etc. before the pieces are locked in. As an example, cut 2 pieces of Hemlock 5/8"thick x 2" wide x 4'Long. Let them sit about the shop for 2 weeks and you will find that they are no longer equally straight. That is not good if they are stabilizer or wing spars. Having said this, hemlock will work, it will not dry rot as readily as spruce. I did make a gear spring as you describe, 55 layers in all of Bid and uni, came out to 7/8" thick and weighed in 20% heavier than the cessna spring I was copying and was not as stiff. I was surprised. Perhaps I used too much resin. I also put it on a press to see how easily I could break it. It did split along the layers...but not fatally Pat R ----- Original Message ----- From: "Rodger Nicolls" <bandenok...@gmail.com> To: <kr...@mylist.net> Sent: Wednesday, August 03, 2011 1:05 PM Subject: Re: KR> Flap and belly board combination.
> Phil and Larry, > Thank you for the replies. I am looking at dropping the stall/landing > speed, > increasing the visibility, and contending with a heavier empty weight > (using > hemlock, 10% heavier than spruce, with extended fuselage). I have moved > the > controls in front of the rear spar and plan to use the entire area behind > the spar for the flaps. > On anther note: I completed building my gear legs: 50 layers S-glass-BID > and > 38 layers S-glass-UNI, with a total compressed/cured thickness of .80". > Now > I just need to get the mount welded. > >
