Homemade Flexible aluminum OAK pipe/tube/duct

[Bob E]

I can't find anybody selling replacement pipe for my OAK to save my life. I've either went to or called every hardware store, farm store, stove store, and auto parts store that I know of within driving distance and nobody has anything close to the 2" flexible aluminum pipe that I need. I've been on ebay, amazon, and every hinkey fly by night web store that turns up in the first couple pages of several search engine's results. And still no luck. So last night, after waiting around all afternoon for the last local stove place to blow me off instead of calling back like they said they would I decided **** it, I'm going to try to make my own with foil tape and bailing wire.

It worked out really well. I figured I can't be the only guy who ran into this problem so I might as well throw together a little how I did it for anybody else having a hard time finding aluminum flex pipe.
I found a piece of 1 1/2" schedule 40 PVC that had about the right O.D. (1 7/8") to use as a form

First I hung the pvc pipe off the edge of the table and wrapped a layer of foil tape around it with the sticky side up. When you get yourself, the tape, and the pvc situated just right it's pretty easy going. Just twist the pipe with one hand and guide the tape on with the other, pausing to peel off the backing strip off the tape as necessary. Just let the tape roll on the floor. Try to overlap about half the width of the tape. Continue on until you reach you desired length of


Now get a couple strips of foil tape read to go

And let your bailing wire unravel into a rats nest on the floor.

Get a few wraps of bailing wire around the end and use one piece of foil tape to hold it in place and keep it from unraveling as you go.

Now wrap it just like the tape. Spin the pipe with one hand guide the wire with the other. I tried to maintain about a half inch space between the wire and that seems to have worked pretty good, doesn't have to be perfect just close enough. I think a smaller space would make your flex pipe more rigid and a wider space less rigid, but I haven't tested the theory. When you get to the end use the other piece of foil tape to hold the wire in place

Snip the end of the bailing wire.

Now flop your roll of foil tape around and wrap it with a second layer of tape sticky side down. Just like before twist the pipe with one hand and guide the tape on with the other, pausing to peel off the backing strip off the tape as necessary.



rollin' rollin' rollin' do-do do-do do-do .... It is kind of slow goin' especially when you have a long piece to make.
Stay tuned, I hit the picture limit for one message.

 

[Bob E]

When you're at the ends be careful not to get too much sticky side down on the pvc it will make it hard to remove your flex pipe.

The flex pipe should slip right off the pvc.

Trim the ends square with scissors and snips

Bingo! flex pipe!

 

[Dhosh]

I like your ingenuity! I used PVC, but didn't cover it with foil ... but I was informed the PVC pipe was a no-no as if you got a back fire, it can melt/burn the PVC putting of noxious gasses in your house. That's not so good. It would probably be somewhat negated by your aluminum foil wrap, though.

The 2" pipe appears to be available on ESW's site as a PU-OAK Outside Air Kit....

http://www.englanderstoves.com/manuals/PU-OAK_Info.pdf

PU-OAK Outside Air Kit for Pellet Units (3 lbs. each)
$60.58
This kit is manufactured by England's Stove Works. Provides outside fresh air that is mandatory for most pellet and multi-fuel installations (including all England's Stove Works models).
Complete, through-the-wall outside air installation kit for pellet and multi-fuel units includes: Aluminum Flex Hose (expands to 6'); Aluminum Screen; Inside Wall Plate; Outside Wall Plate; Weather Hood; Hose Clamps.
For 10-CDV, 25-PDVC, 49-SHC22, 55-SHP10, 55-SHP10L, 49-TRC22, 55-TRP10 and American Standard 1998 and newer.
For 25-PDV, 55-SHP22, 55-SHP22L, 55-TRP22 and American Heritage 2001 and newer.
Also for multi-fuel stoves (stoves with CPM in model number); for "Evolution Pellet" stoves (stoves with EP in model number); for Pellet Auxiliary Heaters (stoves with PAH in model number); and for "Imperial Pellet" stoves (stoves with IP in model number).
Will not work with old pellet add-on furnace models (25-PAF).
For more information on the PU-OAK Outside Air Kit

==============================

Granted, my eyes are getting bad .. but I had to look 3 times for it .. and finally noticed 2" in the description. It doesn't include an elbow for the bottom of mine ('96 25-PVDP) ... but should work grand for yours, as it looks like your intake tube feeds from straight out the back. Otherwise, a flexible muffler pipe might be able to be used for the bends. You could also get a 2" to 3" adapter (might actually be 2 or 3 step pieces!) .. then you can use off-the-shelf 3" flex pipe. I've see quite a bit of that .. or even 4". Both would require a bigger hole through your wall, though.

 

[Dhosh]

Oops ... forget bout the PVC thing ... I didn't read your post very well (told you my eyes were bad ....) ... I just noticed you only used the PVC pipe as a form.

Never mind ..... ;-)

 

[Bob E]

The O.D. for my homemade flex pipe turned out perfect for the hole in my thimble and wall, but the I.D. was a little tight for the pipe nipples on the stove. So, I made flared collars.
Measuring stuff around the house I found this can of air freshener that was the perfect size.

I cut 2 pieces of foil tape each long enough to wrap around the can once

I wrapped the first piece around the can sticky side out

I slid the tape so it was even with the end of the can. I held the end of the flex pipe up to the end of the can and wrapped the second piece of tape around them both, half on each sticky side down.

I cut tabs in the sticky side out tape that was left exposed and folded them over sticky side down.








I got a call back from the stove place today. They can order a whole outside intake kit for me for $60. I think they said it comes with 2' of flex pipe.

 

[Bob E]

Oops ... forget bout the PVC thing ... I didn't read your post very well (told you my eyes were bad ....) ... I just noticed you only used the PVC pipe as a form.

Never mind ..... ;-)

Yup, besides the adhesive on the foil tape which is rated for 325 my flex pipe is nothing but metal

 

[zrtmatos]

Ingenious! Great job!

 

[Dhosh]

Bob E ... Good hob!
That 2' flex pipe expands to 6', I believe, as it's 'corrugated'.

 

[ttdberg]

Very inventive, I love it! I recently went through the same struggle trying to find 2" flex pipe. That Duravent kit is the only one I could find, but I didn't want to spend all that money when I don't need anything else from the kit. Mine is just going a few feet up an 8" SS flue along side the 4" pellet flue, not through the wall. I ended up buying a Walker 6 foot flexible exhaust pipe (part number 46973 for 2", 46975 for 2.5" which is what I bought, they have larger sizes as well if needed). In case the home build option doesn't work out for the long term, you may want to try this as an option? I also bought the Walker exhaust reducer 41999 to adapt my P68 outlet from 2.75" I.D. to 2.5" O.D to make attaching the flex pipe an exact fit. $26 on ebay for both parts, supposed to arrive later this week. Will post pics and an update.

 

[DMKNLD]

"Necessity, (and improvisation) is the mother of invention" - brilliant, Bob E ! Love the pics and the step-by-step tutorial, for those like me who are 'engineering challenged'. Thanks for the post !!

 

[mik_kane]

Here is a 2 inch metal flex pipe that should work for you, $23 and free shipping
http://www.jegs.com/i/Dynomax/289/46973/10002/-1?parentProductId=

 

[Bob E]

I don't know, that might work for somebody, but If you need to run it through your wall you have to keep an eye on the O.D. as well. The flexible exhaust pipe I've put on my car in the past was meant as kind of a shade tree repair and was slightly oversize so it could slipped over the existing rusted out exhaust pipe. And it was really heavy duty, a hose clamp wouldn't cut it, it had to literally be crimped in place with a u-bolt that also crimped the old exhaust pipe at the same time. I'm not confident it would bend as tightly as I needed it to, I didn't want to ream out the hole in my thimble/wall, and I didn't want to crimp the pipes on my stove...

 

[bags]

GET -R- DONE! Amazing what one can do with some heavy duty KY Chrome. Duct tape is utility KY Chrome or standard grade. LOL!

 

[2011 GT/CS]

I also saw you can get 2'' aluminum flex pipe at McMaster-Carr. I use them a lot in the machine shop I work at. But anyone can purchase with a credit card

 

[Bob E]

Dang! That is what I was looking for. The O.D. is about 3/16" too big, but I probably could have made it fit. I'm pretty happy with my homemade stuff, but I'm saving this link for future reference.
http://www.mcmaster.com/#flexible-duct-hose/=ujy55b
(scroll down to "Bend-and-Stay metal duct for fumes)

 

[Papelletman]

This is the one...

http://www.mcmaster.com/#flexible-duct-hose/=ujz17q

 

[Papelletman]

Or this one......(broken link removed to http://www.ducting.com/industrial-exhaust/semi-rigid-ducting/Aluminum-Flex-400.html)

 

[ian105]

Or this one......(broken link removed to http://www.ducting.com/industrial-exhaust/semi-rigid-ducting/Aluminum-Flex-400.html)

$55 for 5 feet? May as well buy the overpriced OAK kit.

I have a hard time believing that this stuff is that expensive in bulk. Even at 100% markup $5/foot in bulk...I doubt it. I Guess they can charge whatever they want since its so scarce

 

[LordmetalZ28]

Same thing happened to me. I ended up using electrical metal conduit and two pieces of pre heater hose from autozone.all 2in. Ended up spending 25$ after hose clamps. I figured the pre heater hose connects to exhaust manifolds it should be fine for a stove.

 

[ian105]

That pre heater hose looks way better than the exhaust flex option. Is it all metal? I didn't even know that stuff existed. To young for carburated daily drivers. Only experience with carbs is on small engines and muscle cars, so they don't see winter.

 

[Bob E]

I remember it being kind of a papery foil. Very similar to the remnants of the original hose that was left on my stove. 10 years ago I could walk into an auto parts store and grab it right off the shelf as a generic package, just pick whichever size you need, Now it seems to be a special order deal sized for a specific make and model. Their computer doesn't list the diameter or length, they couldnt tell me the size until I order it and they receive it...

 

[LordmetalZ28]

Im sorry it was advanced auto parts. Yes there where 4 of them laying in the help section when i went. They are metal they hook to exhaust manifolds. There very flexible and they expand out to 18in. I did notice a thin film of almost like cellafane. But it goes to an exhaust manifold so i didnt think it was that big an issue

 

[moey]

Huge markup for 2" pipe. You either improvise and build something yourself and spend close to $30 in some cases or buy a kit and spend $50. I gave in and bought a kit for about $50 after I priced out the alternatives and was always coming up with about $30 and some part of it that was a bit hooky.

 

[mik_kane]

You know that you will get condensation on that homemade OAK. I hope it holds up when it gets wet.

 

[Bob E]

I'm sure it will be fine. There is foil tape on the joints of the outside portion of my exhaust vent pipe. It has been there longer than I have lived here, I can only imagine it was put there when the stove was originally installed. Rain, snow, wind, and condensation don't seem to harm it. Worst case scenario I'm out a buck or two worth of tape and bailing wire.