The future of Wood.

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ToddK

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It’s a well known fact that the Sitka supply chain is having problems. Wicks no longer sells it, ACS turn around time is stretching out weeks to over a month depending on what you need. My guy buys right from a guy who sells direct to other kit manufacturers and the lead time was six weeks. Why? The Japanese are buying it in huge quantities for musical instruments.

None of this is good for a builder. Waiting a bit might not be a big deal for most of us, and it’s not like the supply is just going to disappear over night. But, given the situation maybe now would be a good time to start collectively pushing an alternative, even better if it’s inspected but uncertified.

Western Hemlock and Doug Fur seem like the best candidates. Anything much heavier is a non starter in my view. A vendor who can sell it in large boards with strait clean grain to be cut down by the builder via table saw or band saw, or for an extra fee mill it down to specific sizes would be ideal. I think finding someone in the business already, who ships, and then working together to come up with a product line would be the best bet.

Any know of such a company?
 

Aerowerx

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Marion, Ohio
Any know of such a company?
Keim Lumber in Charm, OH. The heart of Ohio Amish Country.

I got some 16 foot lengths of Douglas Fir about 6 years ago. 1 inch by 12 inch rough cut. Perfect grain. They also have shorter lengths.

Free delivery within 150 miles.

I don't know about Western Hemlock, but the only Sitka they had was small pieces for guitars.

Farther away? If you are really set on building with Douglas Fir, it might be worth the trip for you.

I'm sure they are not the only large old-fashioned lumber yard left in the country. Any type of wood you want they have. Or can get it for you!
 

cluttonfred

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I agree that the future of aircraft-grade Sitka spruce is questionable. If I were creating a new wood design from scratch today I would focus on Finnish birch plywood from sustainable forests, which presumably should remain available for a long time. The spar and longeron stock is a harder question.

This supplier offers lumber and pre-cut kits for various wooden aircraft in white ash. No weight figures are given, but presumably you'd be looking at a substantial increase in empty weight without recalculating the whole structure to allow smaller sizes.

I wish I know of a readily-available source for aircraft quality Douglas fir, noble fir, Port Orford cedar, or any other good substitute for Sitka spruce, but I have only ever heard of folks finding a source of quality lumber and then hand-picking boards to meet aircraft wood guidelines.
 

Hot Wings

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Any know of such a company?
Wish I did. There was a member here a few months ago promoting his Ash wood but I haven't seen him post lately.

The plane rights I bought from Falconair also requires lots of wood so I understand your motivation in finding a good source.

Edit: C*fred posted the link I was thinking about.
 

Turd Ferguson

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The airplane market is small potatoes. Japanese have been buying up all the spruce for decades. They use if for everything and they pay a premium for it. They get the best timber because they buy the crap timber as well. It's loaded onto a boat at a NW US port then while the boat is under sail the wood is processed so when they get to port in Japan, it's milled, stacked, bundled and cataloged ready to be sold. The Japanese are smart. If you were in the timber business, who would you want to work with? A customer that buys large even quantities of the premium and other cuts or a nit-picky customer that wants tiny quantities of only the premium timber leaving you with more crap that is hard to get rid of?
 

Victor Bravo

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Well, this forum does have reasonable access to one of the very top wooden aircraft structures experts in the US. Pete can verify or de-bunk what I'm about to say here, and definitely take his word over mine, but:

It is my understanding that you can use a milled or shaped piece of Douglas Fir as a replacement for Spruce, for a monolithic (solid plank) spar. The reason as I understand it is that the little bit of extra strength of Doug Fir allows the wood to be removed from the milled areas (between the upper and lower edges... "caps") without any net loss of strength. So you wind up with something halfway between an I-bean and a rectangular plank, at the same strength and weight overall. The price you pay for this is the cost/effort of machining out the "shaped" spar as opposed to a slab-sided plank.

I recall reading this on some kind of an ancient stone tablet (ANC-18, or the older version of the 43:13 ???)
 

manna

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Here in Australia, we are using Hoop Pine which was an approved substitute for Spruce during the war. Hoop pine is a plantation timber source and is easily accessible through multiple sources. Slightly heavier than spruce but also stronger. I am building a GP4 and the estimated extra weight of 20 lbs over the finished aircraft as advised by the designer when I discussed it with him.
Hoop plywood is also available and is an alternative to Finnish Birch. This is a nice cheap alternative to Spruce in Australia.
 

Chris Matheny

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I bought a bunch of rough cut white ash off the gentleman that cluttonfred linked to. This will be for my KR2S and from my calculations add 13-15lbs total to my plane. This plane design is a lot of foam and fiberglass also so it doesn't add as much as an all wood plane would add.
 

TFF

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Length and spar is the main issue for spruce or any other nice quality wood. Usually 8 ft and under is usually available. 10 ft a little harder. 15 ft is getting hard to find. Wide and thick and long, OMG. Shipping anything is going to hurt when shipping 8 ft or longer. Wood, aluminum, 4130, carbon rods.

If I had to give up on Sitka Spruce, I would put my energy into Douglas Fir. It does not really matter the species at airplane quality. It will be expensive to buy and expensive to ship. Unless you live next door, shipping will be equal to material cost. Might as well spend shipping on a family road trip to pick them up if within 600 miles; adventure and spars for the same cost. At least for spars if I had to give up Doug Fir, I would be probably going aluminum spar extrusion if open rib, fabric covered. If it was something like a Tailwind, I think I would build a composite spar. More likely would be a composite wing.

I bought a 4x4 post of Doug Fir from Home Depot. It’s not spar quality. Of the times I have looked, I only found maybe 4 other candidates over a year so I jumped on this one. It will probably be used for a home furniture project but I would not feel bad if it was turned into ribs. I think the clear pine at home d is imported Hoop Pine.

Substitute is going to be entirely on what you are trying to build. Something like a Legal Eagle or Mini Max the performance of the material is weight. Light weight is high performance in that manner. You really need a minimum of nice wood. Something like a small continental powered parasol, it would probably be better to have an aluminum extruded spar. Enjoy the rest in wood. If it was going to be something like a Falco, I would be beating up old ladies to get the wood I needed( not really). But you get the point.

You have to love the design first, then figure out how to build it. No material is easier. No material cost less to build in. You just build differently. Love has to conquer all. Kum ba yah.
 

Aviacs

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Oct 21, 2019
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Noble fir or Pacific silver fir weigh the same or less than Sitka spruce & have same or greater values.
I get the impression both are widely cut for house framing lumber, but seldom if ever segregated?
I'm on the east coast.

I used to find spar quality wood at LOWES in the 2 x 12 x 16 footers not all that rarely. log center cuts with QS down both sides of the pith; sometimes one or both sides clear for 12 ft or even the whole length. I would cruise the piles when in the store, and pick out likely candidates to take home to throw up in the loft. Eventually they would get used for millwork. The species that show up here no longer seem to include Doug fir anymore, though.

Tulip Poplar is widely commented on as being similar in all properties to Sitka spruce. Maybe a lb. or 2 heavier per ft^3 perhaps as much a 1% less stiff, very similar strength, better hardness and crushing strength. Cheapest clear hardwood on the east coast (well, before the ash started dying); but no one ever actually uses it. A friend built some hollow masts and spars out of it for a largish sail boat (rather than paying for Sitka or clear Doug fir). That sort of scares me because poplar has no rot resistance. The green colored heartwood might have a little.

smt
 

JohnBouyea

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Nov 10, 2019
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Hillsboro, Oregon
Has anyone looked into what is being called Hemlock Fir or "Hem-Fir?" I've seen some nice looking board selections in the "Appearance Boards" section at the Big Box stores. What I've researched says it is actually a mix of Hemlock and/or (Douglas) Fir.
 

Aviacs

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Oct 21, 2019
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Keep in mind that Dougals Fir is not a true fir.
The fir i have seen in HF (Hemlock Fir mix) , or SPF (Spruce Pine Fir mix) has -not- been Douglas "Fir" around here. East coast, upstate NY.

That said, there are a number of Firs that should be reasonable options. Some lighter and close or exceed same strength as DF & SS. Noble Fir and Pacific Silver Fir as mentioned post 11. Others are very close. But they aren't sorted, and absent positive ID and perhaps rudimentary stress & strength tests, a bit difficult to sort out of a rack and commit for structural wood.

Usually what is grouped in "Hem - Fir" construction lumber is white fir, which is lighter than DF, but also slightly more than 84% of the elastic modulus. Interestingly, though, it is about 81% of the weight (26 lbs ft^3). Unfortunately, crushing strength and modulus of rupture are not as close or favorable.

East coast Red Spruce compares favorably across the board (no pun intended) with Sitka spruce. Only a percent or 3 down in most values which is a little more than an averaging error, board to board in a real world comparison of material. But not easy to find knot free. It is another construction lumber type.

https://www.wood-database.com/red-spruce/

smt
 

MadProfessor8138

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So that brings up a point of interest that I found out while looking through the wood at several box stores.......
They label wood as being one thing and when you look at it you can clearly see that it's a totally different species than advertised.

Kevin
 

fly2kads

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Justin, TX
Cypress seems to be another reasonable alternative. It's mechanical properties are very similar to Sitka spruce, but there would be a slight weight penalty...about the same as Douglas fir.
 

Aviacs

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Oct 21, 2019
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Be sure you can ID the sapwood in cypress, and don't use it.
Shrinkage & expansion of the sapwood are awful, it takes a compression set, and will mold & rot if it gets damp.

That said, i used to occasionally use a lot of cypress for millwork. Recently cut some of my last 8/4 x 10" x 16' boards for stringers & bulkheads for a hovercraft our EAA is using for a group project so "everyone" can work on it. (navy says hovercraft are aircraft :) ) The good thing about cypress is it is available in long, thick clear boards. It does move around when re-sawn. And even the heartwood does not have the rot resistance old growth was famed for in the past.

smt
 

lr27

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Nov 3, 2007
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If there's any question of wood species, it may be a good idea to test stiffness and density. Even if you get the species wrong, you'll be better off if the stiffness is sufficient, and I suspect there's a strong correlation of stiffness and strength. Anyone know how much stiffness varies within other species? In balsa, it can vary something like +/-30 percent, even at the same density. And, of course, in balsa density varies wildly. I've seen usable balsa from 3.5 to 24 lbs/ft3.
 

dog

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Dec 29, 2019
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Out on the wet coast there has been a problem of log jacking,and for a long time it was very difficult to prove that a log on a truck matched a given stump.Turns out that the genetic variability in trees
is very high compared to humans,making a test
quick and cheap.
This has resulted in enough prosecutions to realy help protect some of the last stands in some areas.
Where that is relavent to this thread is that a highly
diverse genetic makeup is very likely going to express itself in physical characteristics.
Ever see the work done on growing square trees?
Yup,paint growth hormones on 4 "corners" of a seedling,keep at it untill it gets square, and then the
tree will maintain the shape.
Suposed to be a whole test forest somewhere.
 

Dana

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Around here (CT) 2x4s are usually S-P-F, and 2X6 or larger is usually GDF (green douglas fir).

The problem is that real spar grade stuff comes from old growth spruce, and those are dwindling fast.

Back in the 1970s for awhile there was a panic in the R/C world about short supplies of balsa wood. Seems the Japanese (again) were buying vast quantities to insulate tanker ships. It worked itself out. Of course balsa grows fast, and modelers weren't looking for really long straight planks.

Fun fact: As soft as it is, balsa is technically a hardwood.
 

lr27

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Nov 3, 2007
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If they were making tankers with balsa insulation that long ago, some of those ships must have been broken up by now. I wonder where the balsa went. Or maybe we are about to be inundated. Imagine carving a full scale airplane from huge balsa blocks!
 
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