12MM Stainless pipe

[DannyH]

Hi guys,

I'm looking to make a set of custom stainless lily pipes.

Due to the size of the tank (45x 30 x 27) I'm looking to keep the pipes as minimal as possible.

My question therefore is peoples thoughts on using 12mm external diameter pipe with 12/16 hosing?

It might seem obvious to go slightly bigger but 12mm seems a common size for pipe benders etc and id be using clamps/ jubilee clips to secure.

Thanks for any thoughts,

Danny

 

[Greenfinger2]

Hi Danny, Stainless Steel piping is really hard to bend with out kinking and spoiling the look 🙁

This link explains it well

http://www.ukaps.org/forum/threads/diy-stainless-steel-filter-intake-outflow.39657/

 

[zozo]

12mm is possible to bend with a heavy dutty version of a tool like this 🙂 But you will need to put in in a vise and eat some spinach regular pipe is 1,5 mm wall thicknes a thinner wall will surely kink. You might need an extension too, get some leverage on the bending tool.. The other thing is, the radius of the tool is preset, i'm not 100% sure if i'm corect with 12mm but in general the radius is 3.5 x pipe diameter, that would be 7x12 for a 180° bend at least 8.4 cm. Could be more for 12mm. I did bend a lot of that stuff building laboratory instalations back in the days i worked in that industry. We used 10mm stainles steel pipe for transporting corrosive fluids etc.. And with short pieces of pipe you can't use the pipe itself to create leverage, man that stuff is tough to bend. Also it is though to saw, you can't do it with a regular sawblade or regular pipe cutter this will be dull and ready for the trashbin after the first cut, you need special suitable tools for that and not the stuff you use for copper and regular steel. That industrial stainles pipe also aint polished nor brushed, this you need to do yourself, brushed is the most beautifull everything you buy in the lfs is brushed as well. Also need a special brush for stainles steel a regular steel brush will wear off before you are done.. So al added and if you have to buy all the special tools for a one time job, it probably will not be cheaper nor more beatiful then what can buy at hinterfeld (sponsor).

 

[tmiravent]

Not a perfection but you can check mine 12mm tubes!
Not easy to bend but will last for life!
Stainless steel is not cheap here, remember to use AISI316...
The main advantage is that you can make the size and bend that fit's you most.
Cheers!

 

[DannyH]

Hi guys,

Thanks for getting back to me.

12mm is possible to bend with a heavy dutty version of a tool like this 🙂 But you will need to put in in a vise and eat some spinach regular pipe is 1,5 mm wall thicknes a thinner wall will surely kink. You might need an extension too, get some leverage on the bending tool.. The other thing is, the radius of the tool is preset, i'm not 100% sure if i'm corect with 12mm but in general the radius is 3.5 x pipe diameter, that would be 7x12 for a 180° bend at least 8.4 cm. Could be more for 12mm. I did bend a lot of that stuff building laboratory instalations back in the days i worked in that industry. We used 10mm stainles steel pipe for transporting corrosive fluids etc.. And with short pieces of pipe you can't use the pipe itself to create leverage, man that stuff is tough to bend. Also it is though to saw, you can't do it with a regular sawblade or regular pipe cutter this will be dull and ready for the trashbin after the first cut, you need special suitable tools for that and not the stuff you use for copper and regular steel. That industrial stainles pipe also aint polished nor brushed, this you need to do yourself, brushed is the most beautifull everything you buy in the lfs is brushed as well. Also need a special brush for stainles steel a regular steel brush will wear off before you are done.. So al added and if you have to buy all the special tools for a one time job, it probably will not be cheaper nor more beatiful then what can buy at hinterfeld (sponsor).

Great to hear of your experience! I'm actually not creating my own pipes to cut costs though, more just to get exactly what I want. I'm going to require a sprayer design to reduce the velocity at which my filtered water re-enters the tank, as well as a matching light bracket. Its a very good point you make regarding brushed finishes/ cutting etc requiring further specialist tools, hadn't thought of that 🙁 The tool I'm using will be a 'RIGID' 12mm stainless bender and a bending spring. I've checked out the radius (38mm) and it should work as in my following model if all goes well Can you for see any particular flaws with the design? (I'd be grateful if you'd cast an eye over it as i've never bend stainless before!)

Not a perfection but you can check mine 12mm tubes!
Not easy to bend but will last for life!
Stainless steel is not cheap here, remember to use AISI316...
The main advantage is that you can make the size and bend that fit's you most.
Cheers!

Nice pipes! Thanks for the heads up on the grade of steel required! Can I assume you are using the 12mm stainless tubes with 12/16 hosing? How does this work for you?

 

[tmiravent]

Nice pipes! Thanks for the heads up on the grade of steel required! Can I assume you are using the 12mm stainless tubes with 12/16 hosing? How does this work for you?

Yes i'm using 12mm pipes with 1mm thickness.
I got to the last design with a few experiments.
Some things that i improved:
- no suction needed, the pipes don't touch the glass!
- they are attached to the cabinet with clips, easy to clip in and out. (very useful when cleaning)
- i can easily adjust the height of the pipes, more or less surface agitation (also very useful)
- i can direct anywhere (almost 180º)! Useful when doing water change (to not mess recent planted stuff) normally i turn the pipe against the glass.
- i also made a 'special' Co2 and electrolys pipe. The pipe inserts the gases in the middle level o f the tank.

cheers

 

[zozo]

Can you for see any particular flaws with the design? (I'd be grateful if you'd cast an eye over it as i've never bend stainless before!)

The drawing looks pretty cool.. Very progressive desing for a first time job.. If you never bended stainles steel before, brace yourself.. 😉 It's tough, you need quite some muscle power and most likely some extra leverage on the RIGID bender, they are pretty short and don't have much of it. And you probably wont be able to bent it like that without using a rather sturdy workbench and a strong vice.. If you need a vise, i do not know maybe you're a Arnold Schwartzenegger type, but with 180 degree bends the vice might prevent you to go a fully 180° if you clamp one leg of the bender in the vise. Then you wont be able to close the bender fully because the vise is in the way and can't go further than a 160°. I still have my old 10mm bender somewhere in the shed, it has a steel angular profile welded to it, so it can be clamped on top of the vise and make the full 180° turn. I'll see if i can find it back tomorow and shoot a pic of it, so you see what i mean. 🙂

Also the 180° bend and then go offset 90° to the right or left will be a nice challenge.. Because it's so tough and you need a lot of power, you wont easily notice you turn the bender a few degrees up or down. Then done bending you might have a correct 90° vertical bend, but horizontal it might be a few degrees off pointing away from or towards the tank. With copper and regular steel it's peanuts to correct this, with stainless it's Walnuts. It's just very tough to correct it a millimeter if you need so much power.. But again maybe i'm just babling and you are realy Arnold Schwarzenegger. In industrial installations a few milimeter are not an issue, all is hidden away in shafts and behind workspaces nobody will notice. In your case it's in view and i guess you like it rather to be perfect..

Good luck can't wait to see it when your done.. I will take off my hat for you and bow if you pull this off as a first timer..

 

[tmiravent]

With this images (sorry for the phone pic's) you can have an idea of the imperfections...






cheers

 

[zozo]

I would realy search for prefab bends and find a welder.. 😉

 

[zozo]

With this images (sorry for the phone pic's) you can have an idea of the imperfections...






cheers

See @DannyH that's a 50mm radius and already kinking and deforming, yours is 38mm? It will be more difficult with a smaller radius to prevent that with such a thin wall of 1mm. The moment you start bending it needs to go with one even force all the way throug.. The moment you start pulling and jerking the bender it's more likely to kink.

 

[ian_m]

To bend pipe, especially stainless, without kinking you really need a proper pipe bender. These clamp the pipe and prevent the pipe kinking and rippling during the bend.

This one supports 12mm pipe.
http://www.screwfix.com/p/irwin-hilmor-glm-pipe-bender/63880

Don't bother with a bending spring, you will just end up getting it stuck and throwing away the pipe and spring !!!!

 

[zozo]

Don't bother with a bending spring, you will just end up getting it stuck and throwing away the pipe and spring !!!!

Yup, most likely to happen.. Rather use sand, but it wont make it easier to bend it rather more dificult..

This is nostalgia.. 🙂 My old tube 10mm bender haven't seen this thing in 25 years.. This also is a Ridgid tube bender.. We bended up to10mm, larger diameters were welded.

Note the custom alteration made to the bender. The strip to clamp it on top of the vise, because if the vise is larger than the radius you wont be able to fully close the 180° turn. 🙂 At the end of the radius arm, a T profile so the pipe stayes in place, it was not possible to hold the pipe stadey to the arm by hand. Maybe for 1 or 2 bends for the strongest man contestents but then even they were to tired to go on. When you bend a full lenght or lets say you have a 3 feet pipe sticking out, then this is you leverage and pull the pipe too. Without that extra 3 feet of lenght we needed to put an extra piece of steel pipe to the bending arm of the bender. If you didn't maybe 2 bends and then you were exhausted. That's the reason for the custom alterations, without them you needed to keep all in place with your hands and bend it from the hip. But the pipe is so tough and all the power need you lost all control and instinctive feelings and some gass..


This little 10mm bender has a 25mm radius, then indeed your 38mm for 12mm tube would be corect.. But the shorter radius the harder it is to bend.
The more force you need, the less control you have.

The hardest part of your design to bend by hand is the offset bend where you go from 180° vertical to a 90° horizontal. Keeping the tube straight in the bender and the bender straight on the tube while using a lot of force. This requires a very strong fellow with quite some bending experience.. Not that i want to discourage you, just a heads up for a brace yourself.. Paper is easy and very patient, but putting whats on paper in practice is the hardest part.

This is al very nostalgic for me, thanks for the flashbacks in time.. 🙂

 

[zozo]

Although he makes it look darn easy..

I wish we had a bender like that back then... Jes.. i'm old fashion...
Still i think this is for thick wall tube..

This might be for thin wall tube.

 

[ian_m]

£170 those 12mm stainless benders from Ridgid. Nice. Perfect job.

 

[zozo]

Haha yes seeing what i had to do with back then, which is a Ridgid also, we needed some biceps, but Ridgid sure came up with some improvements. Still the guy say a nightmare to bend, so you probably need some practice before you can do what he does.. Also what the guy in the second video states, seamless pipe which is the thick wall is easier, thin wall is probably welded and has a seam, you might think on the contrary the thin wall is easier, but it isn't..

But thinking of it and looking at the glass lily pipes, they are also quite thick in the wall and nobody complains about that.. So why choose for thin wall stainles while the glass version filter in and outlets reduce it as much flow whit the same thicknes. I never measured the inside of my 16/12 glass lily pipe, but don't believe they ar more than 9 mm.. 🙂

 

[DannyH]

With this images (sorry for the phone pic's) you can have an idea of the imperfections...

Thanks for the pics! I've had a look on your journals and they certainly look the part in the tank!

Don't bother with a bending spring, you will just end up getting it stuck and throwing away the pipe and spring !!!!

Consider the spring idea ditched 😉

I would realy search for prefab bends and find a welder..

I haven't ruled this out worst case scenario, I'm just concerned that the weld might impede on the internal diameter of the tube

£170 those 12mm stainless benders from Ridgid. Nice. Perfect job.

They look super smooth. I couldn't justify that particular set but went for the 400 range below. Hopefully I won't live to regret it 😵

Not that i want to discourage you, just a heads up for a brace yourself.. Paper is easy and very patient, but putting whats on paper in practice is the hardest part.

Thanks very much for the comprehensive write up, much appreciated🙂 I've ordered myself a set of 12mm RIGID benders and also a sample of 316 12mm OD 1.5mm walled tube (As you say the 9mm clearance should be sufficient when all considered). As you mention the 180 degree followed by an immediate 90 will be the trickiest, I suppose I could incorporate a small straight section between if it proved impossible. I'll put the bender in a vice anyhow as long as I can get the 180, and if push comes to shove I have access to a welder so can mock myself up a setup inspired by yours I'll give it a shot within the next couple of weeks and post images of the prototype outcome on here. If the bending goes well, you never know, I might even have a zavvy surface skimmer design to share with you guys 😉

 

[zozo]

I'm just concerned that the weld might impede on the internal diameter of the tube

No it wont, at least not with a good welder, this is also something considered not to happen with in technical installations. Only thing is you'll need a grinder to grind the seams smooth and finish with brush/polish.. Then this is a rather precise job to get this nice an tidy. But good luck with the bender. 🙂 Realy curious how you're going to pull it off. Looks like the same type bender i stil have.. And i know i come over a bit sceptic but realy would love to see you succeed. Because i know what difficult job it is with stainless..

As you mention the 180 degree followed by an immediate 90 will be the trickiest, I suppose I could incorporate a small straight section between if it proved impossible.

You can make it as short as the bender allows you to, you would need an extra pair of hands and eyes.. One should put the bender in place close it tight and hold it tight, the other should straight it out with a carpenters square and a very straight eye.. This needs to be straight in 2 dimensions, because the tank is probably in perfectly straight angles.

So these are the options to end up with.. Red as should be, pink and orange as could be.. 🙂


Bending from the hip is something i never seen anybody pull off, not with such a baby bender. What could help a lot is put a set of longer steel pipes on the benders arms, to get some leverage. So the one giving directions looking from a distance should have a very good eye. If the tube is clamped in the vise you have at least one angle fixed, but then you need to bend from the hip so to say. If the bender is in the vise, the tube can redirect in all 2 dimensions. Now when the one looking says OK everything is straight "Start bending!", then the one bending needs to turn green, start to curse and swear and put all the juice in he has left, here you might loose 1 degree without notice. Depending on the lengt of the tube we all know one degree can end up in millimeters off set at the end. On a straight tank this will look awfull..

The thing is, look at the bender, this tool, you can not use to correct all such errors, you might be able to bend it a bit more in, but bending out is out of the question. If not perfectly straight from the beginning you're left with a vise and pliers and pieces of pipe to fit over and pull it, resulting in damage, cross contamination and probably even more crooked bends. Without heating the tube at the right spot to correct this is nearly impossible, heating the tube will cause decoloration which could be permanent. The guy in the video above also mentions cross contamination.. Thise means all the gripping and sliding of 2 different metals over and into eachother will leave non stainless metal parts on the tube which eventualy will rust in a moist invironment.

 

[DannyH]

As promised folks, photos of the prototype bend.

All in all it went well, the rigid benders arrived, they're a top not piece of kit. They had been machined with two flat sides so they fit into a vice nicely.
I greased them up prior to use so as to try and avoid as much resistance/ cross contamination as possible. My intention was to bend the 180 turn followed by the 90 but the sample piece was too short. It will be possible though. The piece was also un brushed/ polished and so I used a wire brush to clean up after. the process went as follows:

and after finishing:

The section squashed slightly as the bender fell of the end of the sample, however in the 'real deal' this won't happen as the bends aren't near the ends of the pieces. The stainless is 316 grade so should retain its appearance well. I'll be using levels/ set squares to ensure the finished things are aligned properly, then putting on a pillar drill to make the spray bar element. Now just to wait for the 3m length required for the light bracket to arrive in the post!

 

[zozo]

Looks realy nice.. 🙂 Just make sure you use a stainless steel wire brush, or else that will give cross contamination.. Good luck with the real deal.. Looks promesing..

 

[DannyH]

Good luck with the real deal

Thanks Zozo. I'll be using a stainless brush so hopefully I can eliminate cross contamination. I'm now just trying to source some 316 grade stainless end caps. It's proving a tad difficult, i might have to get a set turned