OT: Plastic Tube Materials

But wood warps with changes in humidity. The problem here was the plastic elements bending from heat. It seems unlikely that having them bend from a little rain would be an improvement. d8-)

-- Ed Huntress

To a greater or lesser degree, like most other materials. Without knowing the application it's all speculation. And that's what we like best. Have a look at the ipe boardwalks the next time you're down here in paradise.

Kevin Gallimore

Carbon fiber tubing has a lower coefficient of thermal expansion than anything else you're going to find out there:

Dunno about pricing on this stuff. Might not be doable for the $$$ but worth a look.

And it's freaking gorgeous!

-Frank

Great stuff. But it's electrically conductive.

-- Ed Huntress

"Ed Huntress" wrote in news:4a7a1b27$0$22547 $ snipped-for-privacy@cv.net:

A number of unfortunate souls discovered this the hard way. A friend of mine took a flyfishing class in Scotland about 30 years ago when graphite fishing rods were just coming out. A lot of the best stream fishing in Scotland is in fairly flat areas, and they started losing several fishermen a month due to lightning strikes. Standing in water waving a 9 foot conductive rod over your head when a storm is brewing is NOT a good idea.

Doug White

When there's lightning around, I lay the rod on the ground and get away from it. I don't like flycasting with a lightning rod.

-- Ed Huntress

On Wed, 05 Aug 2009 18:46:31 -0400, the infamous axolotl scrawled the following:

What about them, Kev? (Inquiring minds want to know.)

-- "It was difficult for the three of us to write a book titled _The End of Prosperity_."

"We're not doom and gloom people; we're natural optimists. And we're not part of the trendy set of intellectuals who like to trash our nation, blame America first for all the world's problems, or worst of all, predict with glee America's downfall as some kind of punishment for our alleged past environmental crimes, racism, financial mismanagement, greed, overconsumption, imperialism, or whatever the latest chic attack on the United States is." --page one, by Arthur B. Laffer, Stephen Moore, & Peter Tanous

Hi Dave, can you provide additional information? Application; what kind of finish is required; size; cost limitations?

Structural fiberglass components are available in a number of shapes. Catalog sez it's UV resistant:

Large diameter fiberglass is available from the guys who make high-power rockets. Expensive.

Hope this helps -- Terry

Thanks for all the help and info guys... Fiberglass is probably the way to go. It's just a hard pill to swallow when it's a much bigger pain to work with and about 6 times more money. Except for the bending issue, I've actually found PVC to be otherwise very dependable if you get the right kind. I just happen to stumble across some of the UV treated conduit kind in the desert the other day, which is what we use and also the furniture grade... Two foot pieces of 1" sticking up out of concrete. If I had to guess, I'd say they've been sitting there in the sun at least 10 years. I kicked the top as hard as I could with my heel and it didn't do jack. So with the right stuff, it can be pretty darn tough. But the expansion factor is just a problem sometimes. Strangely enough, I went and looked at a few of our installations yesterday and in 100 degree bright sun, all were perfectly straight. So I don't know why some curve and others don't seem to have a problem.

Sch. 40 vs. Sch. 80?

Good Luck! Rich

Most of the large surfaces are laminated. Plywood that is a better grade than Home Depot. And a kiln dried 2x4 or round stock does not warp much with water exposure.

Going along with the thread drift... you guys may find this bridge interesting from Michigan's Upper:

"M-26: Eagle River Timber Bridge (1991) A rather interesting and, for Michigan's state trunkline highway system, unique bridge sits on M-26 and spans the scenic Eagle River in the community of the same name in Keweenaw County, at the top of the Upper Peninsula. The following two articles have been reproduced from an internal Michigan Department of Transportation newsletter from the early 1990s..."

A slightly different photo here:

I've stopped and taken photos too, but mine aren't in any digital format right now suitable for posting...

That's a cool bridge, Leon. I've been all over that area, but it was around

1969 - 1972, so I missed it.

-- Ed Huntress

Very nice. My grandfather built wooden trestles in the Rockies in the early

1900's. They seemed to work very well for a long time for railroad traffic. I guess it is a curse of the engineering schools that the old is relegated to the not working category.

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Here's an example of old-not-relegated -- a Bailey Bridge in temporary use across the Yellowstone ... I have some closeups of the underside, and the little clamps that hold the bridge parts together, should there be interest.

Bailey bridges are great. They used one near Ft. Ross in Hiway 1, Coast of California a few years ago when a flash flood down a gully took out a large section of the road. We used that bridge for a couple years until they rebuilt the culverts and roadway.

As a member of a reserve army engineer unit, we had access to a training resource scale model training set. Quite an interesting "toy". At that time I was employed in a highway materials quality control lab which happened to be co located with the maintenance and storage yard for the regional Bailey Bridge Depot, so I did get to know a bit about how they went together. Gerry :-)} London, Canada

I thought Bailey Bridges floated, either on boats or other type of floats. Are there more than one kind?

Thank You, Randy

Remove 333 from email address to reply.

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Bailey Bridges use support girders, not floats. MLSB and MGB bridges that may look similar have floating variants --