Sources for 6” Flexible Ducting that’s not crazy tight on metal fittings

[Alan Lightstone]

I’m being driven crazy by the 25’ of 6” clear flexible ducting that’s inside diameter is so tight, that I need to take needle nose pliars, a screwdriver, and a lot of time / force to pull the tubing around my Nordfab metal duct connectors. (Yes, I’m using the right adapters).

I have some black flexible ducting I just ran out of, that slips on fairly easily, which I then put metal clamps on. But this clear stuff is torture to install.

Anyone know some good vendors to find 6” clear flexible ducting that isn’t so tight?

[Charles P. Wright]

I bought my regular pipe and 6" clear flex tube from Oneida and don't recall any problems hooking it up.

[Steve Eure]

Have you tried to heat the flex tube with a heat gun or hair dryer. It will soften it up enough to help stretch it. I would try that before wasting more money on new tubing.

[Marc Jeske]

Can you slightly reduce the OD of your male connectors like this ?

In a pinch I have done it using two needlenose pliers.

Marc Edit - Looked at Norfab duct.. looks like the have rolled ring ends... so I dunno.

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[Alan Lightstone]

Unfortunately can’t with the Nordfab.

[John K Jordan]

I had the same problem fitting high quality clear flex to PVC. I did it like this:


Cut the spring steel wire through the tough flex material and pulled out about a turn of the wire. (Required good cutters)
Lubricated the inside of the flex with a tiny smear of silicone grease.
Heated the end of the flex with a heat gun to soften it, then grabbed and pulled the end over the PVC with pliers.


Have no idea if this would work with your metal ductwork. Getting it started with the wire removed let me easily pull it that part over the end which then guided the part with the wire intact. I may have twisted the flex a bit in the "uncoiling" direction while pulling, I don't remember since it's been several years and I am elderly and feeble-memoried.

If that didn't work I'd probably cut a piece of metal or PVC that would fit inside the metal duct and fit easily inside the flex. I made lots of adapter rings like this for various places in my DC installation to make flanges, adapt to blast gates, etc. It's easy with PVC to make any size adapter ring by cutting a gap out of the circumference. I hold such things together with glue and/or sheet metal screws.

JKJ

[Marc Jeske]

No offence John, but that silicone grease in the shop scares the the helloutame.

Marc :eek:

[John K Jordan]

No offence John, but that silicone grease in the shop scares the the helloutame.


Certainly no offense taken, but just curious, what is it that frightens you? Perhaps getting it on wood and doing something to a finish some day? My shop is multi-use. I use silicone grease and silicone spray in the shop and around the farm. I've found nothing better for lubricating the big neoprene o-rings on poultry waterers.

Could use soapy water instead. Or maybe WD40.

Or even KY jelly. (I keep tubes of that and nitrile gloves for getting fecal samples from llamas. If anyone wants to help stop by.)

JKJ

[Alan Lightstone]

John, it's been a goal of mine to one day respond to a post about getting fecal samples from llamas.

My bucket list is now complete. :)

I tried the heat gun, without removing the wire. Didn't help. It's interesting how one brand of black rubber tubing (or some polymer) is slightly larger and goes on quite easily, but the clear stuff is torture.

[Jeff Bartley]

Alan,
I was also going to suggest a heat gun, I did that the last time but in the end I had to make linear cuts into the pvc around the end of the tube. Where did this tubing come from?
Jeff

[James Biddle]

Are you having an issue putting the hose onto a Norfab hose adapter or their pipe?

[Alan Lightstone]

It was from Oneida. It’s 6”clear flexible duct.

The black duct I got years ago (wish I remembered where) fits easily.

[John K Jordan]

It was from Oneida. It’s 6”clear flexible duct.


I got mine from ClearVue. Maybe they will send you a short sample to test.

JKJ

[James Biddle]

It was from Oneida. It’s 6”clear flexible duct.

The black duct I got years ago (wish I remembered where) fits easily.

But what are you trying to stick the flexible hose onto? Norfab makes a hose adapter...is that what you're using or are you trying to shove the hose onto a section of pipe or a fitting?

[Jim Becker]

But what are you trying to stick the flexible hose onto? Norfab makes a hose adapter...is that what you're using or are you trying to shove the hose onto a section of pipe or a fitting?
That's what I used for the two quick disconnects I have (Nordfab) and the hose slips right on and tightens down nicely with a clamp without any crimping. My hoses were ordered from Amazon.

[Jim Andrew]

I have spiral pipe, but on one fitting, could not get the flex over the fitting, so used a coupling to slide the hose onto, and just stick the coupling into the pipe above.

[Alan Lightstone]

Are you having an issue putting the hose onto a Norfab hose adapter or their pipe?

The hose adapter

[Ben Rivel]

Have you tried using a little soapy water to lubricate the hose a bit. I had to do that a couple times for some of my hand crimped pipe to hose connections.

[Marc Jeske]

I have not used these fittings - But thinking.. could a person cut 3 or 4 kerfs w a fine hacksaw, small cutting wheel, etc and then ever so slightly bend in the tabs to reduce the OD at the end of the nipple and slightly taper it ?

Marc

[Jim Finn]

What I did : Using some sheet metal, I made a 6" long piece of pipe, small enough to fit inside the metal pipe and inside the flex pipe, and then caulk and clamp the three together.

[Alan Lightstone]

Have you tried using a little soapy water to lubricate the hose a bit. I had to do that a couple times for some of my hand crimped pipe to hose connections.

I tried with water, but not with any soap or other lubricant. I'll have to give this a try for the next hose fittings.

I found some 6" black rubber hose that I think will fit easier than the vinyl, but it's crazy expensive.

[Marc Jeske]

I have not used these fittings - But thinking.. could a person cut 3 or 4 kerfs w a fine hacksaw, small cutting wheel, etc and then ever so slightly bend in the tabs to reduce the OD at the end of the nipple and slightly taper it ?

Marc

So why not this ?

Make the cuts like 2" or so long.

Marc