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DIY Spraybar for Eheim Tubing

If the silicon cord is not the correct diameter (smaller) you'll have a air pocket in the pipe, when you warm it up and bend it there is risks the pipe will wrinkle in the inside bend..

If you can't get the proper diameter cord you could also do it the old fashion way with 2 plugs and fine dry sand. Note "DRY" sand, this means completely dry, so warm the sand up first or put it on the heating for a night, so all moist is completely out. Put a plug in the pipe, like cork, rubber, wood, doesn't matter as long as the fit is tight. Fill the pipe with the sand and tap it and see the sand go down, keep tapping it till it doesn't sink in anymore. If it is full leaf space for the other plug at the other end. Make sure there is no air pocket beneat the plug.. 🙂

Heat the pipe and bend it. If the sand isn't dry, the moist in the sand will evaporate and pressure will build up and the plug will probably pop off or you get an air pocket again and wrinkles..

Succes. 🙂
 
Thanks Manu,
Amazing bends!
So, are you recommending 12-13mm cord for 14/18mm acrylic tube and 14mm for the 16/20 or is the 14mm cord for the 14/18 tube? I notice that the tolerance is ±1mm so I assume that the exact diameter may be too tight.

I also found that the same company does a 15mm Silicone Sponge cord 😵. Is that OK too or are they completely different properties?

Steve.
 
Hi Steve,

Zozo is right, you don't want too much "play" as you won't get a neat finish but you can't use a silicone cord that will be the same size than the inside diameter of your tube. When I did mine, I ordered a 10mm cord for a 10/14 tube and I couldn't get it in inside at first. I had to use a potato peeler to reduce the diameter 🙂 And then, I put a small screw at one end of the silicone cord, attached some cooking thread or string and pulled the silicone instead of pushing it. Pushing the cord make it expand and blocks it, pulling it make it stretch and it slides better. Be sure your screw is small enough but also well fixed to the cord.
In your case I would go for a 13mm cord and a 15mm. Sorry, I can't comment on the silicone sponge cord, I'm that of an expert 🙂
If not, order a small piece of tube and try Zozo's method with the salt. It will be much cheaper!

Cheers,
Manu


Sent from my D5803 using Tapatalk
 
Silicone sponge cord should be able to withstand 200C.. I believe it's used in surgical sealing for high temps
 
Thanks for the great advice Manu and Zozo.

Thinking about it again I reckon that I can probably get away with a (almost) straight connection with a short length of Eheim flexible hose to the Eheim 3000 pump anyway. Speaking of which, does anyone make clear flexible tubing for Eheim kit rather than that green stuff?

Steve.
 
Use some silicone spray or teflon spray, than it probably will slide in perfectly without much trouble. Spray it inside the tube and not on the cord.. Try not get to much on your hands or they will becomme to slippery as well to get grip. A little bit of dishwashing soap can do too.. 🙂
I'm an old fashion pipe fitter/plummer. Bending tubes and getting tight fits together is a daily propperty in that bussines.. 🙂

I would go for the sand option.. But thats just me. Because im experienced with it.. 😉
 
Hi again!
Almost there. I've got the tubing (from here since they were the only place I could find that supplies 2 metre lengths), silicone cord (£2 from eBay), clear end caps (eBay again) and a heat gun (Screwfix). Before I start bending and drilling a couple more questions though:

- Recommended diameter of holes?
- Quantity of holes in the spraybar from the Eheim: the same number as on the original Eheim spraybar (nine), but spaced out over the 1m or so length?
- Angle of holes? Horizontal (across water surface back to front), 20-30 degrees down, 45 degrees down, other? I was thinking of something like about 25 degrees for the majority, with 3-4 horizontal holes to give good surface movement.

Cheers, Steve.
 
I note on drilling acrylic, you might ask the seller first what your dealing with.. Casted GS Acrylic or Extruded XT Acrylic.. The last one is not particularly fond of drilling and cutting and easily to crack in the proces. If you drill holes, no matter which version start as small as pissible and go bigger is steps no larger then 2 mm at a time. DO not apply force just guide the drill use the weight of the machine. Make sure the drill doesn't get to hot, pause or cool the drill after each hole. The drill always gets hot after 3 holes you might melt acrylic instead of cutting it and you''l get a acrylic film on the drill, which could be sticky while drilling or hard while cooled. 🙂

Best results you will get with looping the spraybar, so connect each end and both hoses to the T should have smae lenght and route.. :thumbup: If only connected to one and pump pressure is more of an issue.. 🙂
 
Coys said:
It's extruded! :grumpy:
Click to expand...

Not impossible, just more difficult, i made the internal deviders from my sump out of 2mm XT sheet and drilled about a 100 holes and only 8 cracks. Just be verry gentle and carefull, up 3 mm drill goes relatively good don't apply to much pressuse with any form of cutting. If you use force it definitely will crack easily.

From the technical point of view, so you know why.. XT is heated acrylic pressed and pulled through a mold (like steamrollers) during production, than when it cures the moleculair structure isn't alined there it has areas with internal tensions thats why it cracks so easily. GS is heated to a almost liquid pourable state and casted, then the moleculair structure is more alined and therefor stronger and less internal tensions..

Good luck.. 🙂
 
I made and installed the spraybars about two months ago and thought an update was due. Drilling and bending went well apart from some surface bubbling (any advice how to avoid in future?).

Flow is now amazing, even with the Eheim 3000 pump on minimum flow; the fish seemed a bit confused at first and avoided the current but soon got used to it and now swim freely through it. One big advantage appears to be the almost total lack of visible fish waste on the bottom, which I used to hoover up in vast quantities during water changes; I can only assume that the improved circular current now pushes it towards the filter intake and into the filter, which clearly wasn't happening before.

The only issues I've had is that the clear tubes very quickly became opaque with a buildup of dirt and that the holes can get clogged with small pieces of plant material. During today's water change I fixed that by sawing off the ends (which I had permanently sealed with acrylic disks), cleaning the tubes with a long flexible cleaning brush and finally replacing the glued disks with rubber bungs sourced cheaply from eBay.
 
Coys said:
bending went well apart from some surface bubbling (any advice how to avoid in future?).
Click to expand...

Means it was to hot.. 🙂 I do not remember the excact number but the temperatur acrylic is rather low, a bit over 100°C.. Look it up and put the pipe in an (electrical) oven set to the correct temperatur so it can't overheat. If you use that silicone inner tube to prevent kinks this material has a far hihger melting point so it can be in there while in the oven.

If that's not an option the tube could be to long for the oven and you need to use a heating gun or torch then just don't heat to long at one point.

First mark the area of the bend, usualy to get a rather nice short radius with bending tubes with heat. Then mark the lenght desired and count from that point 2 x tube diameter backward and mark it, and again count 1x tube diamter forward from the lenght mark.

Example - If you have 16mm tubing and need 30cm lengt mark the tube at 30cm.. Now count 2x16=32mm back and mark it.. Go back to first 30cm mark and count 16mm forward and mark it.. Now you have an area of 48mm lenght marked which is the radius of the bend.. Now place the tube an the table with tath area sticking over the edge, now you can roll the pipe back and fort over its complete diameter with a flat hand on the pipe.

Heat only the 48mm marked area while rolling the tube back and fort with swinging the heater or flame over the tube withing the marks.. Not overheating it is a matter of experience and practice, the shorter the heater or flame is at the tube the hoter it gets. So keep the correct distance and keep a swinging motion and rolling the tube all the time, never stop at one place. If you do this long enough the marked area will be evenly heated all around over the proper lenght.. Once this is the case you will see the tube bend by the force of gravity, since that part stick over the tables edge and the angle of the bend stays the same while rolling it. At that point you can stop heating and bend the tube in the desired angle and wait for it to cool. Of you made a 90° bend and you did all correct you will have excact 30cm from tubes edge to centre tube diameter of the 90° bend.

I wish i could make a video for you, but i can't.. So this is the best i can do (explain).. 🙂

Happy bending and succes next time.. :thumbup: I guess it will take a few bends and burned pipes before you get a hang of it. I haven't done it in years and probably will screw up a few before i got it again.
.
 
zozo said:
Means it was to hot.. 🙂
Click to expand...

Yeah, I assumed that was the case; I think that the heatgun was more like a deathray and would probably have melted lead 😱. Oh well, it was a good first attempt thanks to all of the help on this forum :thumbup:.

I'll probably have another go later in the year to neaten it up, but in the meantime it's fine.
 
Using such a little butane pencil gass torch is actualy much more easy.. Give it a go next time.. Just keep it swinging.. DO it while listening a chubby checker track. 🙂
 
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