inner tubes

[Bruce Seidner]

I am trying to connect up the main trunks of a dust collection system and will have to cut and plastic-weld some custom fittings.

In the meantime I would like to use flexible duct to connect the straight runs while I figure out the angles for the fittings. I tried to keep it lined up in standard angles and on the same plane, 45 degrees, etc., but it has not worked out that way. Go figure.

I am using 8" SD-35 pipe and figure i could use 6" to 12" lengths of flexible duct to connect the straights and continue tweaking the setup.

I believe I have read of people, Alan comes to mind, who have used inner tubes for this intermediate mock up project. I hate to think I would be butchering a newly purchased 10' length of new duct for this purpose. I have lots of experience with bicycle inner tubes but am unsure where to begin looking for inner tubes that would fit over 8" PVC pipe. I will start calling around in the morning to figure this out but thought a quick note to Y'all might end run the process. I am guessing trucks still use inner tubes, dunno.

Thanks in advance.

Bruce

[Jim Andrew]

I'm sure you can buy new ones, most tires are tubeless, but some add tubes when tires get many tiny holes. My service station closed, the guy used to keep tubes to fit all sizes of tires. Mostly farm use. Over the road trucks are tubeless.

[ray hampton]

inner tubes do have other uses beside tires, inner tubes make nice boats, riding lawn mower also use inner tubes , wheel barrow also use inner tubes in their tires, I hope that this helps

[Bruce Seidner]

wheel barrels, lawn tractors, and trailers, oh my. wheel barrels, lawn tractors, and trailers, oh my.

The Northern Tools on-line catalog shows a number of promising suspects in 8" or so tubes. My habits are to re-use, re-cycle, re-purpose, etc. But I can cut up a $9 boat trailer inner tube for a short connector a lot easier than a $90 flexible duct.

[Bill Edwards(2)]

wheel barrels, lawn tractors, and trailers, oh my. wheel barrels, lawn tractors, and trailers, oh my.

The Northern Tools on-line catalog shows a number of promising suspects in 8" or so tubes. My habits are to re-use, re-cycle, re-purpose, etc. But I can cut up a $9 boat trailer inner tube for a short connector a lot easier than a $90 flexible duct.

How about tractor tires? Seems the bigger you get the tougher it would be to go
tubeless.

I'd call a truck garage that might also do farm equipment. They could at least tell
if you're on a fool's errand.

[Ole Anderson]

I would think that an inner tube would collapse at least part way into the duct as it has very little rigidity. Kind of like sucking on a balloon.

Ah, one advantage of steel, easily available cheap adjustable bends.

[ian maybury]

3D geometry is indeed treacherous and deceiving territory. I'd be cautious about a tube getting sucked in too - it's no accident that flex hose has a wire spiral. It'd by definition have a bend in it. Maybe over a short gap?

Might it be as easy as not to bite the bullet and use some flex hose Bruce? Especially if the gaps to be bridged are short?

ian

[Bruce Seidner]

Gentlemen, all points well taken. Thank you.

My concept is to use short lengths of the 8" PVC that currently do not line up and are not mitered to the correct angles yet and have the "flex" created/allowed by the inner tube that would go over the PVC tubes and extend about 6" on either side of the tube. This would stand in while I figured out the actual angles I needed to cut.

I had purchased some adjustable sheet metal 45 degree fittings but these have been a pain to work with so far. Maybe if I lubricated them, but they bind and are hard to crimp and fit inside the pipe. Hence, the use of flexible inner tubes that will not cut me and resist me. The plan is for not more than a .25" or maybe 1.0" of exposed inner tube between the PVC that will eventually be mitered to fit and then be welded in place. The tubing will just fill in for the as yet uncut angles. Maybe if this stuff were not so heavy and difficult to move around I would do it differently.

Houses are like that kids game of Telephone where you whisper a word in the first kid's ear and they whisper and transfer it down the line. At the end it is hardly recognizable. There is nothing that I can find in my garage that is square to another plane. There is no plane that does not resemble a topographical map of the Himalayan mountains. I have a friend who is a finish carpenter and he just laughs when I ask about using a level or these laser beam contraptions. When he is in a house to install the cabinetry, molding, etc., it is always Bizzaro world. He "makes it look right" after all the incremental errors add up to the cluster fest he is left with.

In keeping my 8" pipe in the upper corner of the wall/joist juncture I am faced with finding a golden mean of "level" and then negotiating what should be a corner using store bought fittings that then throw everything akimbo. So, I am making the long straights stay where they should and out of the way in a variable 8' to joist basement/garage and then trying to figure out how to connect these runs between the walls and corners that are anything but square. This weekend I will take a short length of pipe around and find a tube that will work. I had spoken with the fine folks at Wynn Environmental and they scoured the place for discarded short lengths of duct and we came up with nothing. They can not sell less than a 10' section and I am unwilling to butcher an expensive 8" - 10' duct for this experiment. My machine runs off the 8" line will all be 6" and then it will be appropriate to buy some length of 6" duct from them.

[Scott T Smith]

Bruce, I work with inner tubes here on the farm all of the time. Typically your best sources for them are farm/ranch/industrial tire dealers, or commercial (ie not autozone) auto parts houses.

You need to select a tire size that is small enough so that the collapsed tube is smaller than your 8" pipe, yet not so small that you can't stretch it over the end of the pipe. Probably anything for a 13" car tire would work, or a small farm tractor such as a 12.00 / 6.

Bill, surprisingly enough, large construction equipment uses tubeless tires. My farm equipment is a mix - the older stuff (80's and prior) uses tubes, the newer ones are tubeless. However I think that the reasons that the older ones used tubes in the larger tires is because the tires are frequently filled with a salt-water solution to add weight to the rear of the tractor, and it would corrode out the wheels unless contained in a tube.

[Bruce Seidner]

I forgot to thank you. Your tips helped a lot.

[Alan Schaffter]

Sorry, I'm a little late to the show- yes, I'm the one who used an inner tube to connect the main duct to my DC intake (vibration isolation) and cyclone outlet to filter box (a 9" flexible connector). I got an old (ruptured) truck tire inner tube for free from a local front end alignment/tire shop- he had lots.

I used band clamps, though they really aren't needed since the intake side of the system is under slight SP vacuum and discharge side is near zero or slight positive SP. Unless you try to span a long gap, the SP of your system will not collapse the inner tube.

It is a win-win situation- really inexpensive (maybe free), many lengths from a single inner tube, available at tire and truck stores (the dump?), will join large, mismatched, odd size, misaligned, etc. pipes.

[Bruce Seidner]

That's the ticket!

And, as you know, imitation is the most sincere form of flattery.

Thanx.

Bruce