plastic lumber ???

MedicineMan

Filing Flight Plan
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MedicineMan
Quick and to the point .....

Has anyone used or seriously looked into the "plastic lumber" for builds in place of real wood ???

Like for a pietenpol.
 
You mean like plastic deck boards? Heavy, weak, very flexible. Not suitable for aircraft construction at all.
 
There is no plastic lumber that is suitable for aircraft construction. Works great for decks, docks, outdoor furniture, fences and house trim. It is heavy and very flexible. Not suitable for framing, or structural use.
 
I have used TREX (a brand of plastic lumber) for a number of home improvement products. Believe me, it's not suitable for a number of reasons:
1. It's HEAVIER than wood of the same size by almost TWICE. This is probably enough to disqualify it right there.
2. It's nowhere near as strong. TREX flexes more than wood. You have to have closer spacing on the joists to use it properly.
3. It's really only available in "deck board" sizes and really isn't designed to be cut/planed into smaller pieces.
 
I think there's a reason you don't see more materials used in aircraft structures. The ones you do see (wood, aluminum, steel tube, fiberglass, carbon fiber) seem to be the most efficient in terms of strength and rigidity to weight. Other materials like extruded plastic are either not as strong, too flexible or too heavy, or a combination of those three. Or really expensive, like titanium alloy.
 
Could be used for wheel chocks.

Not very good ones. To my knowledge it does not come anything thicker than standard "2x4" dimensions. There is no 4x4. So the chocks wouldn't be very tall and they would heavy. If somebody wants little plastic portable chocks, then the Air Gizmo ones would be much better.
 
I have used TREX (a brand of plastic lumber) for a number of home improvement products. Believe me, it's not suitable for a number of reasons:
1. It's HEAVIER than wood of the same size by almost TWICE. This is probably enough to disqualify it right there.
2. It's nowhere near as strong. TREX flexes more than wood. You have to have closer spacing on the joists to use it properly.
3. It's really only available in "deck board" sizes and really isn't designed to be cut/planed into smaller pieces.

To which I might add: Toxic as all hell if it catches fire.
 
I have used TREX (a brand of plastic lumber) for a number of home improvement products. Believe me, it's not suitable for a number of reasons:
1. It's HEAVIER than wood of the same size by almost TWICE. This is probably enough to disqualify it right there.
2. It's nowhere near as strong. TREX flexes more than wood. You have to have closer spacing on the joists to use it properly.
3. It's really only available in "deck board" sizes and really isn't designed to be cut/planed into smaller pieces.
Several years ago there was a "wooden" boardwalk (made from that plastic lumber). There were signs that it was an experiment to test a cheaper, longer lasting construction method. A few years later, I noticed that the experimental boardwalk was gone and was replaced with conventional lumber.
 
Is it any better at resisting termites?
 
Trex indeed has some problems in addition to it's advantages. The biggest issue is abrasion. If you're in a really gritty environment or you have someone willy nilly pressure washing it a lot, the outer layer will go (it's not homogenous like wood).
 
Is it any better at resisting termites?
Trex won't get termites or rot. Good pressure treated stuff won't have much of a problem (nor will some of the more resinous untreated species).
 
Trex and it's competitor, Timbertech aren't 100% plastic lumber. They are composites. The inner core is made from wood pulp with a polymer binding and then it is wrapped in polyethylene covering. This inner core has been problematic and caused mold and rot. It's also why you want to avoid ripping these boards. They make them this way to be cheaper.

True plastic lumber that is 100% plastic through and through can be found from Azek, a solid PVC product with bonded color cap made of some other plastic (probably polyethylene, but I don't really know) because you can't make dark colors in PVC, or Bear Board a solid Polyethylene product that comes in different colors with no need for the cap, or Homeland Vinyl's Gorilla Deck as well as Westech's Brock Deck offer solid PVC boards with no cap as long as you are OK with white, light grey, or very pale brown.

The advantage to PVC is it is the most UV resistant plastic known. Polyethylene offers colors. I've used both. My preference for Docks is the PVC products and also for decks if you can tolerate the pale colors. If you need darker, richer colors the Bear Board isn't bad and holds up pretty good too. It's also more recyclable. I prefer the solid, non capped products.
 
I am currently making plans to build the largest wooden plane ever made. Even bigger than the Spruce Goose. It will be built using mainly plywood.

I will call it the Plywood Pelican.....
 
There is no plastic lumber that is suitable for aircraft construction. Works great for decks, docks, outdoor furniture, fences and house trim. It is heavy and very flexible. Not suitable for framing, or structural use.

Not really,

I've been drawing up my dock/beach setup for a while, debated on using the low profile snap together floating docks where you just add decking, but with the synthetic decking instead of wood, that lasted about 3 conversations with local boat and home owners, way too bendy, heavy and expensive, plus face it, it's fake wood and looks like it, compared to pressure treated/marine grade it just sucks.

Same in for siding, once you get close, it's a coke bottle trying to look like a tree, and with our winters, if you even look at it cross, it cracks. If fema got out of trailers and started to build houses, they'd have plastic siding.

Same with outdoor chairs, all the plastic stuff doesn't last in our winters, but through a rock and you'll hit a real wood Adirondack chair that's probably older than I am.

Closest I'll get is a lvl beam

For me, it's wood, stone or metal.
 
Early Trex also had a problem that it simply didn't last very long under heavy foot traffic, snow removal, etc. The outer layer wasn't very thick, and once you wore through it, it had to be replaced. A friend went through that process and tried to do it under their early warranty but they wiggled out of it via "not used as intended" type verbiage. He was pretty mad about it in the end and built a nice redwood replacement deck and forgot about laminates forever.

Another oddity a different friend ran into was (unknown manufacturer) one laminate that was nicely finished on the outside but just slightly below the surface the company had used larger chunks of "stuff" or their process didn't give the same density to the laminate all the way through and as the outer "smooth" surface eroded slowly over time, the "sharp edges" of something different underneath came out. Of course sanding and smoothing was possible but it also removed a layer of the exterior, lowering the lifespan of the deck significantly. Another "happy" customer frustrated who eventually went back to real wood.

I hear the manufacturers have generally fixed these and other problems with Trex and Trex-style materials, but I'd be cautious and want to see the exact material that's going to be used and know the installer real well and that they'd do it correctly. Otherwise, most any decking company or even one man band, can usually get a wooden deck correct as long as they use proper footings and hangers and drainage is done properly.
 
Just an opinion, but the only time any of these materials should even be considered, is if they are specifically engineered for aviation use. Will those materials withstand scrutiny in an aviation court of law?

Dude, we're talking about experimental aircraft (see the "like a pietenpol" in the first post?). Much of what goes into them isn't specifically engineered for aviation use. Hell, WOOD isn't engineered at all, though there are standards for it and its use. What on earth is an "aviation court of law?" Must be some segment of the judiciary I've missed.

If you had some new material that was as light and strong as spruce, it would be fair game. As pointed out that most of the plastic lumber isn't going to meet it because of the technical qualities as I pointed out in the first post. It's heavier than wood by a substantial margin and in most cases, more flexible which for most structural uses is going to be problematic. Even going to mahogany (great for boats) or maple is going to be a substantial weight penalty over spruce.
 
Sorry WmIOnce, the "dude" was purely for emphasis. Your opinion was over the top, and frankly incorrect. I didn't say there wasn't aviation law. What there is NOT an aviation court, and there are no aviation specific judges in a real court. There are some administrative law judges on the FAA (not really the judiciary), but again, nobody is going to get hauled into an FAA enforcement because they experimented with new materials in a homebuilt. If they get sued over civil liability issues, it will not be in an "aviation court", and it will not be in front of a judge who has any aviation credentials (in fact, most likely one party or the other will insist on recusal if the judge coincidentally happens to have any).

That's my opinion and I am as entitle as you are, dude, to have one.
It's also fact.
 
I find it disrespectful to call me "dude." Did you really mean it that way?

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Come on guys!! Got to keep this thing light! The Balsa Big Bird, of course it can only be painted yellow. Of course if it needs to be lighter, maybe Balsa Budgie.
 
The plan needs to be spruced up. You can pine for the old days, and spar about the idea, but I wooden count on structural integrity. The fabric of the plan is full of holes so don't be a dope.

This thread has me in stitches.
 
Just use lignum vitae for the spar, and you should be alright. 3/4" plywood formers and wing ribs. You'll need solid stock formate leading edge to protect the edge of the plywood--you don't want bug splats to separate the layers. Build it like a really big RC model! :D
 
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