# Steam Box - 150MM UNPERFORATED TWINWALL PIPE



## Aden30mm (11 Dec 2017)

I am planning to make a steambox 5 ft, I have considered most of the possibilities of using ply and wood construction.

I had discounted the use of plastic pipe due to heat sag. However, I never thought about twin-wall underground drainage pipe. So the question to the forum is, have anyone used this pipeline for steambox construction, or any possible downsides to its use?

Any other input surrounding this subject would be most welcome.

Pipe info: http://www.polypipe.com/civils-and-infr ... rated-pipe

Rgs

Aden


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## NazNomad (11 Dec 2017)

It's HDPE. I reckon it'll sag with steam.

Even using that pipe, you've still got to frig about sealing the ends and connecting a pipe to it.

Also, supporting the timber that you're steaming is a good idea. hard to accomplish with that pipe, maybe?



It's seriously easy to make one from wood.

I used an old pressure cooker (on a portable propane ring), a washing machine hose and a few plumbing fittings for mine. Worked perfectly.







(and yes, I know what that means)


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## Aden30mm (11 Dec 2017)

Yep you may be right bout the sag issue. 

I have no issues with sealing the ends (a bit of turning will solve that issue) and connecting a pipe ( plan is to put a gallery vented pipe into the steambox), or even installing a rack to support the wood.

So I may have to revert to plan b, and go the wood option, post a chat with the twinpipe manufactures.

Thanks for the info

Rgs

Aden


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## El Barto (11 Dec 2017)

Here are a couple of excerpts from Peter Galbert's book Chairmaker's Notebook that might be helpful.


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## Yojevol (11 Dec 2017)

My 4" plastic pipe insulated and housed in a wooden case has never given any problems. I use an electric wallpaper steamer to generate the steam.


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## El Barto (5 Jan 2018)

Sorry to drag up an old topic but OP what did you go for in the end? I'm currently exploring ideas for different steam boxes. I had quite liked the idea of using thick PVC pipe too...


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## Aden30mm (7 Jan 2018)

I picked up some larch and started to put it together yesterday and today. In conversations with a plastic pipeline specialist he indicated that temperatures from steam would deform the pipe. So I chickened out and went for the wood option.


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## El Barto (7 Jan 2018)

Thanks bud. While I’ll probably build a wooden one too, I did think about using stainless pipe. Ideally I’ll cut a hole in my shed wall and have the steamer sticking out to reduce the footprint in the workshop. It’d be durable and practical (but expensive and hot).


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## NazNomad (8 Jan 2018)

El Barto":8os33d7c said:


> Ideally I’ll cut a hole in my shed wall and have the steamer sticking out to reduce the footprint in the workshop.



I'd worry about the steam condensing on everything metal as soon as I opened the steam-box door.


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## El Barto (8 Jan 2018)

NazNomad":3ngcy3l6 said:


> El Barto":3ngcy3l6 said:
> 
> 
> > Ideally I’ll cut a hole in my shed wall and have the steamer sticking out to reduce the footprint in the workshop.
> ...



Hm interesting, that might be a good point. Thanks for foiling my plan Naz! :evil: 

Anyway, I'm going to try some Class E PVC. I will report back my findings and possible sag issues.


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## NazNomad (8 Jan 2018)

El Barto":1ysbfis7 said:


> Thanks for foiling my plan Naz! :evil:



I didn't want you to cut a hole in your workshop and regret it. :-D


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## Sheffield Tony (8 Jan 2018)

My various attempts have included 4" PVC waste pipe, which worked a few times but did deform quite a bit. With some support it might last a good few uses. Currently using 4" aluminium tube, wrapped in an old fleece blanket for insulation. 

But I do wonder, what about stainless steel twinwall flue pipe intended for woodburners ? Inner diameter ~150mm, surrounded by 30mm rockwool insulation and an outer stainless layer. Available in up to 1m push together lengths. I presume a cheaper brand would be OK for this. Anyone tried it ?


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## El Barto (8 Jan 2018)

I also considered using twin wall flue. I'm sure it'd work. I like the idea of plastic because it doesn't require any further insulation, it seems to be about as simple as it gets.


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## NazNomad (8 Jan 2018)

I should add a few notes about the photo of mine from above...






Inside is a copper t-piece with lengths of copper pipe about 1ft long, drilled with little holes along the top surface.

I assumed this would displace the steam more quickly and evenly around the wooden box. Now, when you open the box, it's pretty damn foggy in there, but I honestly have no idea if the pipework inside makes it better/quicker/easier or not, I never tried a 'before' test without it.

In the sides, along the joint of the two pieces of wood, I banged a row of 3'' nails (one row on either side) to support the wood during the steaming process.

Worth noting that where the wood rested on the nails, it did mark the timber I was steaming (not a problem for me as the marks almost sanded out and were inside an instrument with a tiny soundhole anyway, never to be seen again).

Next time I use it, I'll replace the nails with small dowels or bamboo skewers.

Again, I assumed raising my piece of timber off the bottom of the steam box would be ''more better'' and I had to do it anyway because of the copper pipe I'd installed in there.


My steam generator: Nothing I would improve or change there, it worked perfectly. Gas burner / pressure cooker with the valve removed / washing machine hose.

There's a washing machine tap visible, I installed it to keep the steam out of the box until it was properly mental boiling, Again, I have no idea if it's necessary.


Just a few notes from having been there, done that. Albeit infrequently.


Try it, if it ain't working then try summat else, it's all a laugh, innit?


Oooh, important addendum: Don't write 'THAT' on it if you have children that use the internet. 8)


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## Claymore (8 Jan 2018)

.....


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## El Barto (8 Jan 2018)

NazNomad":2objlg1s said:


> I should add a few notes about the photo of mine from above...
> 
> 
> 
> ...



Nice. Thanks for the info. How long is the box?


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## NazNomad (8 Jan 2018)

El Barto":1249rzfb said:


> Nice. Thanks for the info. How long is the box?



As long as a pallet... I have no shame.


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## NazNomad (8 Jan 2018)

Claymore":87or5pt2 said:


> ... what did you bend the wood for?



Amongst other, smaller things, I bent the side for this Langspil.






I suspect most people have never heard of a Langspil (I hadn't, until I had?)- https://en.wikipedia.org/wiki/Langspil


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## Aden30mm (8 Jan 2018)

Installing a steam ledge, I've used 10mm dowels along the sides. So I've got two dowel ramps allowing me to place up to 2 inch stock thickness, on two levels.

I thought about a pipework gallery to distribute the steam, but will we how I go when I first raise some steam.

As I have the same space issue in my workshop, when not in use, it will be kept wrapped up behind my shed. As I've used latch its a pretty durable material.


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## NazNomad (8 Jan 2018)

Don't forget some decent gloves, that wood get frikkin' hot in there. :-D


... and make sure you are all set up and ''ready to bend'' as soon as it comes out of the steamer.


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## Hot stuff (9 Jan 2018)

What's the pressure cooker capacity versus steaming time required ratio like? I know the wall paper steamers fairly chew through water but they switch off automatically when they run dry. 
I presume you need to rely on the noise the cooker is making? 
This is all fascinating as it's on the to do list of experiments for this year.


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## Aden30mm (10 Jan 2018)

Test steam today, some small mods to do but its worked well and sustains 100 degrees steam. Thanks for all the feedback. See some photos[attachment below


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## Claymore (10 Jan 2018)

.......


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## Aden30mm (10 Jan 2018)

Condensate diverter (with silicone) and barbecue thermometer, idea from web.


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## El Barto (10 Jan 2018)

Awesome! What were you bending


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## Aden30mm (11 Jan 2018)

Blackthorn, hazel, hawthorne and ash.


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## El Barto (12 Jan 2018)

Post pics!


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## NazNomad (12 Jan 2018)

Good idea with the condensate diverter, mine just pished out through all the gaps :-D

... and as above, pics of what you're making would top it off nicely.


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## Sheffield Tony (12 Jan 2018)

+1 for pictures (or even better a WIP)


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## Aden30mm (18 Jan 2018)

Have to wait a bit, timber and sticks air drying/cutting. Currently manufacturing bending/straightening jigs.

I'll post info when I'm raising steam.


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## MARK.B. (15 Feb 2018)

Sheffield Tony":xsmdejlh said:


> My various attempts have included 4" PVC waste pipe, which worked a few times but did deform quite a bit. With some support it might last a good few uses. Currently using 4" aluminium tube, wrapped in an old fleece blanket for insulation.
> 
> But I do wonder, what about stainless steel twinwall flue pipe intended for woodburners ? Inner diameter ~150mm, surrounded by 30mm rockwool insulation and an outer stainless layer. Available in up to 1m push together lengths. I presume a cheaper brand would be OK for this. Anyone tried it ?



Having just recently installed a wood burner in my workshop using twinwall i have to say the price per metre of decent pipe makes your eyes water.


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## Lazurus (15 Feb 2018)

For straightening walking stick blanks I used a stainless steel tube, turned caps for the ends and a plastic connector for attaching to the wall paper steamer, works a treat with many shanks going in at the same time, all be it gets very hot so I tend to use it outside. I guess it is small for some projects but does the job for me.


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## Robbo3 (16 Feb 2018)

MARK.B.":s8pleirj said:


> Having just recently installed a wood burner in my workshop using twinwall i have to say the price per metre of decent pipe makes your eyes water.


Off topic, but why use twinwall? All the heat from the flue is going outside rather than helping to heat the workshop.


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