Showing posts with label PVC. Show all posts
Showing posts with label PVC. Show all posts

PVC - PVC as a thermoplastic

It turns out, PVC isn't just my favourite product to work with, it's also a thermoplastic.

Who knew?

I should have remembered the thing I read back when I was making aquaponics grow tubes, but you don't know what I'm talking about, so there's probably no point in referencing it.

But on the up side, there is a point to this post.

And that's that PVC is even more excellent than I first thought.

It turns out (not my idea) that PVC can be heated, formed into a new shape, then cooled so it sets and stays with it's new shape.

You've gotta be happy with that.

PVC, but whatever shape you want!

I started by holding part of the delivery system from my demand fish feeder under a candle until it got a bit hot.

I'm always torn between the desire to keep a museum of the things I build as part of doing this "120 things in 20 years" caper, and grabbing a lump of kit from a previous project and reusing it at the expense of said project.

Oh well, I guess if it's worth building, it's worth building again.
The next step was to squish it a bit.

The steps after this include trying to make it fit the fillet knife I keep ominously lurking in my little tackle box.

That'sit there in blue.






I say ominously because when I'm fishing, it tends to be used to hack at somewhat suspect portions of slightly off bait sitting in the sun, then when I get home, I expect it to shed it's immuno-challenging persona with a quick wash n a soapy sink, and stop threatening to cut me and give me some hideous infection.

I also expect it to get suddenly sharp enough to fillet fish.

Sometimes I expect too much.

But this time it turns out I oddly expect around about what's reasonable to expect.

This is mainly due to my sudden understanding of how to make stuff sharp. I've been using a honing steel for the last 20 years to keep my kitchen knives useful, but for some reason, suddenly I now seem to be able to make them half again as sharp. (((see chunking) actually see the top of the chunking article because that makes more sense) or this if you want to skip the links...

If you learn Morse code, you learn it gradually for a bit, then suddenly instead of thinking of the word "and" as...

dot dash blah blah
blah blah blah
blah dash etc

you start to know it as a single entity in much the same way as you originally knew the individual letters. ie the group "and" becomes the 27th letter of the alphabet. The result is that the learning process is non-linear, and you tend to gain new ability in "chunks" rather than gradually.)

Why am I distractedly talking about chunking motor tasks?...

So...

Sharp is much better.

And oddly safer.

Anyway, the result is that now, more than ever, I need a sheath for the razor blade that rattles around in my tackle box and kitchen.

The knife in question is only an inexpensive thing, and it doesn't hold an edge for long, but it does readily allow itself to take on a scary sharpness. I guess there's a compromise between gaining an edge, and keeping an edge, and this inexpensive fillet knife has chosen as it's lot in life, to be way sharp. At least for a bit.

Quite useful for fish filleting really.

PVC is a thermoplastic!...

The "holding it over a flame" thing works a bit, but it's a little tricky softening the entire thing so you can bend the entire thing all at once.

But boiling water made that a whole heap easier.

If you don't have an enormous pot of boiling water, I recommend you send any kids safely away for the afternoon, and just dump boiling water all over the place in order to heat up your PVC.





It actually doesn't take that much.

I'm guessing a hair dryer would do it.

I used half a cutting board, and a sizzling steak hotplate holder to squish it flat after I heated it to bendy point.

You could also just step on it.

It's quite soft, and cures to it's new shape in only a few seconds.




The result was something that looked a lot like a folded flat length of PVC pipe.

Actually this is (obviously) the result of a different method, but both ended with a folded length of PVC tubing.

This one was done with the aid of two clamps, and pouring boiling water all over the house.




There are probably a dozen more ways to do it.

Heat it, then squish it flat.

This post has derailed a bit, so to re-cap, I'm making a knife sheath from PVC pipe by heating it and reforming it to shape.

Place your knife over the top of the flattened PVC envelope, and loosely trace around it with some kind of marking device leaving around a centimetre of excess white space around the blade.

I used a pen, but you could also use whatever marking method your culture enjoys.






Next I cut out the shape with tin snips, scissors, and a hacksaw to test as many methods I could find at hand. That's why this photo actually came before the last.

Yeah...

time can do that.


The result was the start of a pretty convincing knife sheath.










I drilled a few holes.











I added a loop rubber band made from a slice of bicycle tyre inner tube (bicycle tyre inner tube rubber bands last around 25,000 years longer than normal rubber bands)









The loop will hook over the handle and act as the fail safe, and might allow me to wear it in a way that might be a little more practical than hanging it on a belt.










And a few more holes to snug it all up tight to the blade with some multi-strand artificial fibre twine and we are done.

I count this as a total success.

Much less dangerous.

And now probably safe enough to take on an epic adventure.



It will still need to be washed after using it to handle bait, but at the moment I cant see a way past that as a compromise.

If you try it yourself, make sure there is a bit of space between the PVC folds at the sharp end to allow water to pass through when you wash it, and also make sure the bindings pull the PVC together tight enough that the blade can never touch the binding twine. The easiest way to achieve this is to not take the bindings all the way to the tip of the sharp end. And to stick something in the end when you are heat-forming the sheath. However you do it, try to make sure you can see through the sheath when it's empty, to allow rinsing the sheath.

I found that after it was finished, heating the entire thing while the blade was removed, and bending it slightly from end to end, made the blade sit a bit tighter. Enough so that you could could hold the sheathed knife upside down and shake it, (without the safety rubber band) and the knife would not fall out of the sheath.

A total success, and definitely some tech that I will add to the ever growing grab bag of tricks that I might employ to solve something, somewhere, one day.




120 Things in 20 years just came back from a quick trip into the future, and found it's all made of PVC...

and there's some 3D printed concrete housing.

but the future's definitely made mostly of PVC.
























Electronics - Aquaponics - Demand fish feeder software


As far as I know, the software is all working on my demand fish feeder.

It's a bit of a mess, with a few goto statements and a few unused variables. I'll fix it in time, but for now I'm going to move onto getting a finished product up and running. As far as I can tell with the software simulator everything works, but the real world might be a completely different story. (the breadboard version also works)








A switch lever extends down into the water. If a light near the lever is lit, the fish can press the lever and feed is delivered. Feed can also be offered with an override button that sets the light on and the feed on if the fish hit the lever (so you can show people how it works)

Dawn detection seems to work. In the end I went with two startup options.

1. A human who holds down the FeedNow override button during startup, then taps out the approximate number of hours since dawn. This skips the code that searches for a new dawn.

2. An abnormal restart with no human. This stops all feeding (there might have been a blackout, and subsequent ammonia buildup) (note to self - add code that flashes some lights to indicate the device is in abnormal start mode so a human can reboot it if they desire). Feeding resumes after night time is detected, and a dawn is detected.

The user can select (via a screwdriver to resist little finger making their own adjustments) ...

 - the feed amount per day in tenths of a second of motor on - from 0 to 65 (I'm guessing I'll use 1/2 a second per feed event) The motor turns an auger under a hopper full of feed. So there is another adjustment available

- The number of feeds in a day that are offered (0 - 255 per day)

- The level of light at which dawn is detected. This allows for a system built in the glow of a streetlight or whatever. At dawn each day, all the numbers reset. This is a bit of a problem as far as reading how many feeds were delivered in a day, but for now I'll leave it as it is. My fish feed like crazy at dawn, so I want to give them the greatest opportunity to feed. Eventually I'll add a data logger, so it wont matter when it resets.


The system reports...

- the number of hours since dawn

- the number of feeds since dawn

- The number of false hits to the feed lever when the FeedIsAvailableLED is NOT lit (these will go down to near zero once the fish learn they can only get food when the light is on)


I ran out of feed a while back, and have been feeding my two big silvers on duckweed, lettuce, and worms, so I will need some pellet food before I can test it in the real world. (I still have the PVC device from the first version).

I'll also need a motor as my original one is no longer with us.

The feeding regimen isn't very intelligent at the moment, but I'll do a bit of research, and add some code that tries to deliver the maximum amount of feed in a day that the system can handle. This will probably involve allowing 3/4 of the feed to be dumped at will, with the rest being spaced out over the day ... or something. I haven't given it enough thought because I don't really know what the fish need. My experience in fishing for wild fish indicates that the feeding pattern is far from a constant grazing all day long. I'll work it out.

But...

It's going to work. In fact, it already does.


120 Things in 20 years That's all. Just 120 Things in 20 years.


Aquaponics - PVC Tube tomatoes

My PVC tube tomato now seems to be growing at full speed.

There's stacks of new growth every day, and the first of the tomato flowers are just starting to form.

That should really read "the first of the tomato flowers since I cut all the existing flowers and leaves off, so that I could jam it into a PVC tube, are just starting to form".






The entire point of the exercise was to get the tomatoes outside where it could grow as big as it wanted without taking up all the space inside, but it looks like the entire system is about to be outside.

The grow house isn't UV stable, and as a result is turning to dust every time I so much as look at it.

Even a sly sideways glance from a distance sees yet more daylight induced destruction.

The hardware chain I bought it from will probably replace it, but this is my third one from them and I'm starting to wonder if they really care about the percentage of my life I spend dealing with a product that really shouldn't give any problems.

Any % of life spent at a returns counter, is too much %.




Aquaponics - PVC Tube tomato

My PVC tube tomato seems to have found it's feet.

It took a while after I removed all but four or so leaves on each of the four plants that make up this particular experiment.

 It's probably back to around what it looked like four weeks ago.

By my standards, that actually constitutes success.





On a side note, the foliage in the background is the grow bed that I emptied and flooded around five weeks ago (flooded to get any slugs out).

That's lettuce you can see, and we've been cutting a salad a day from just that right hand side. The left hand side was Bok Choy, but that all went to seed, and has since been fed to my worms.

When I put the seedlings in (bought from a shop) I also sprinkled some mixed lettuce seeds around.











It looks like this five weeks later.

We've been harvesting from the front, and you can see some of the seedlings from the seeds are looking a little weak because they have been struggling for light, but now they have some, they will spring to life.








In summer, and harvesting a light lunch size salad each day, (in Adelaide South Australia at least) we found you need around half a blue barrel worth of growbed real estate, as long as you seed every week.

I like coz lettuce because it can be harvested as it grows (ie just cutting off leaves rather than pulling up the plant) , but these loose leaf varieties are proving to be quick growing, and can also be repeat harvested. if you drop seeds in around the seedlings when the seedlings are around the size you buy them at, the seeds are seedlings when the lettuce has been repeat harvested as much as it can, and finally gets pulled out.  I just read that again, and I think all that means something. 

The leaves get bitter toward the end of the lettuce life cycle as they are about to go to seed. The leaves  also grow further apart. So once they start growing from a stalk rather than from a central point at the base, it's time to pull the plant up, and let the light in to the little ones, that are by this time the size of the store bought seedlings.

I don't think I've ever grown the iceberg style lettuce that grows like a cabbage, so I don't know if you can repeat harvest that, but I suspect not. 

I used to take a lot of care with growing lettuce seedlings, and transplanting them, but now all I do is put a stack of different seeds into a jar, and sprinkle a pinch of them around directly into the growbed. 

I suspect the clay balls are better than scoria when you direct seed. I think the seed (especially small seeds like lettuce) fall down until they stick to the side of the media once it's deep enough that the media is damp. 

I suspect that's just right as far ar growing goes. 

Perhaps with scoria, the seeds catch in the holes in the media before they get to the correct depth. 

Or it could just be luck, but I'm seeing much better germination rates in the clay ball media. 

But it's also a constant flood grow bed, so perhaps that's got something to do with it as well. 




120 Things in 20 years - Results, but no science to back it. Oh, and also PVC Aquaponics tomatoes.






Aquaponics - Tomato in PVC

It's been a while since I used PVC in a novel way, so I thought I'd cut all the leaves off my tomato and ram the stems and roots into a PVC pipe.

It seems to have worked.

I like to think of it as a solution.

I started with four tomato plants that have been happily growing with their roots just dangling in my fish tank.

That's them after I fulled them from their comfortable home and lay them on top of the fish tank. They are around a metre long from root tip to top.

They look healthy, and have a stack of clusters of flowers and little fruit forming all over the place.



They were a bit bushy to fit them into a PVC tube with a 90 degree angle and it was going to be way too difficult to jam all that foliage through the pipe, so I trimmed some of it away.


Trimmed.













Now it fit easily into the pipe so that the tips were peeking out of one end, and the roots hanging out of the other.











The only thing now is to see if my aquaponics system will be a nice enough place for it to live that it bounces back from my cutty mistreatment.

I'm willing to bet this experiment will work quite well.

One potential problem I can see is that it will still try to make foliage in the pipe, and as a result, the conditions in the Tube will be damp and still, and that might lead to disease.

If that looks like being the case, I can always simply cut the PVC away with scissors.

It only has to last long enough for the tomatoes to reach outside and concentrate their growing out there.

Once there is enough foliage outside, and if I do have to cut the PVC away, it should be easy enough to keep the stems inside the grow house free of new growth.




120 Things in 20 years - only time will tell if my aquaponics PVC tomato works. It should be just a few weeks before I know.

Aquaponics - My algae farm

My algae farm is working better than I expected.

Unfortunately I expected no algae at all, and got plenty.

But it seems there is a cure.

It turns out algae, like pretty much everything else, needs light and nutrient.

The nutrient I cant do much about, but I can definitely cut off it's light supply. It turns out the fish prefer to feel safer in semi darkness as well, so all I need to do is cover my fish tank.

I chose blue.

All that junk on the ground is the inevitable result of  letting me near PVC with a saw.

I think if I cover the top half of the blue bit where it's visible, and just leave a blue skirt, it might even look ok.





It's a very necessary thing to do as my water now looks like this.

That faint dark smudge on the bottom left is the bottom. It's only 1 metre away and you cant really see it.

That's not so good.

My big concern now is that when all that algae dies, there is going to be a huge spike in ammonia and nitrite as it breaks down, so I've stopped feeding.

On the up side, I have my new grow bed available to take up some of the workload in processing the waste, so I might be ok. I also bought some more media so I can get the second new grow bed online hopefully before the ammonia starts being produced.


My 120 things is 20 years sometimes turns an aquaponics system into an algae farm.

Aquaponics - System build - media screen

My first PVC screen I made to keep the media out was full of round holes.

To keep clay balls out. Round balls (like balls tend to be).

It didn't work so well.

So I thought I'd better make a new one.

I started by cutting a length of PVC lengthways so I could mount it against the end of the blue barrel, to surround the stand pipe.

It's difficult to tell, but the good bit is the bigger bit on the right.







The blue barrel has a curved face where the bung is, so I had to distort the base of my media guard to fit.










I drilled a couple of holes so I could get a jigsaw blade in there.











The plan being to cut long slits rather than my original holes. The slits should be able to be blocked, and should actually work.










The final result looks like this.

Neat isn't it.

It wont matter because it wont be visible.








Then just to be sure, I thought I'd stick some gutter guard on as well. Gutter guard is just a plastic mesh you can buy in a roll to keep leaves out of your house gutters.









I tied it on with some rubber bands to hold it in place.











The forced some silicon into the gaps.

The gutter guard seems to be made of the same stuff as black poly pipe. If that's the case, silicon wont stick to it, but I'm hoping that the silicone surrounding it should hold it well enough.

Only time will tell.









Doing 120 Things in 20 years, working on my new aquaponics system build, and making a media screen out of yet more PVC, you may feel I'm developing a PVC addiction. But it's always reassuring to know I have a long way to go. Take Theo Jansen for example. He's got it bad.

Aquaponics - System build

I made a bit of an improvement to my aquaponics system.

It went like this...

I started with one of these.

It's commonly called an IBC or International Bulk Container/Carrier.

They are used to freight liquid stuff all over the world, and there are a lot of them.

If you don't normally, wander down to your local dockyard or industrial/freight area, and you will be particularly amazed by two main things. First that we realy burn a lot of fuel in a lot of trucks, ship, planes,  and trains, and second, we use a lot of containers to move all the stuff that we burn all the fuel for.

Many containers are used only once.

Mine brought honey from somewhere, and even has a heating element under it.

I bought them ages ago in a previous life on a farm.

It's a strange and disturbing thing to discover that we humans make single use containers with mains power cords protruding from them.

It's a little bit wrong me thinks.

But anyway, reusing one for an aquaponics system has got to be a good thing, and a lot of people have done so.

That thing leaning against it is my SLO or solids lifting overflow. Or at least that's what it will look like when I make it.

The point of it is to move the solid fish waste from the fish tank(where the fish don't want it any more because it smells and tastes bad), to the grow beds (where the plants would quite like it). A SLO is another thing that a lot of people have used.

A lot of people are very clever.

I know some of them.

I even call some of them friends.

I'm friends with clever people.

Which is nice.

So...

the plan was to squeeze a one and a bit cubic metre fish tank into a 1.8 cubic metre grow house, and still have a stack of room left over for growing stuff.

In fact the ultimate goal was to squeeze a one and a bit cubic meter fish tank into a 1.8 cubic metre grow house, and still have 1.8 cubic metres of space left over to grow stuff in.

Tricky.




But by bending space and using a roof for a wall, I nearly managed it.

All I need now is something to wrap the bottom of the new fish tank in and nobody will be the wiser.

I think it looks better than the original, but that could be a dehydration issue.

It's really hot.

Or at least it's really hot in a growhouse when you are trying to fit big things into small spaces.

One of the problems with using a honey freighting container is that it's difficult to get the honey out.

That's why you need a heater.

Heat makes honey runny.

Heat makes fish runny as well, but it doesn't taste so good afterwards.

So to make it so I could get the fish in and out, I drew a rectangle.


The best thing about drawing rectangles is that, once done, you can use the drawing as a guide to get a power saw involved.

But the close cousin to the power saw is the hole saw.

I cut a hole as a thing to put your thumb in to act as a handle.

This rectangle is going to be a door soon.








I also drilled another hole along the line so I could put a jigsaw blade in to start the cut.












And then a few more holes to allow me to tie some fishing net mending line through to form a hinge.











See the tape and stainless steel wire holding the entire thing together.

I did that.

It nearly cuts straight!

Nearly.






I've had this jigsaw for longer than anything really long.

And it still works.

But it's really loud, and shakes a lot.

Some would say the bearings are shot, but I say the name says it all.

It's meant to jig, and jig it does.



After a few hours of jigging, it started to look like this.












It turns out IBCs are made of slightly sterner stuff than I first thought.

Not much sterner, but slightly.

The plastic is thicker than I thought, and less brittle.

It needed a little support to keep the jig saw from creating a friction fire, but it was easily dealt with by the addition of a trusty stick.

I choose a milled quarter round stick.


After what seemed like hours, the hatch was finally cut.

I suspect it seemed like hours because it actually was hours.

Apparently, after 20 years or so of frequent use, it seems it's best practice to buy a new blade.

Who knew.

Luckily, as mentioned previously, I strive for second best practice.

Here's a photo that doesn't really contribute in any way.

Oh hang on, yes it does.

It shows the newly revealed inside of the fish tank with the hatch sitting on the top.







A 30 second scrape with a file smoothed all the rough edges.

One of the best things about working with plastics is how well all your tools work.

Even sand paper is satisfyingly productive to use.







I found myself walking on the leftover cut outs from months ago when I cut the NFT holes, so thought I'd use one as a latch to stop the lid from falling though into the fish tank when I close it.

String.








Now it looks like this when the lid is closed.

The point of the lid, is partly to give me some control over evaporation, but mainly so that I dont need to fish about with a net all day whenever I decide to foolishly use the top of the IBC as a work bench.

When I try to use the top of the IBC to put stuff on, the lid will force me to close it in order to get to the nice flat space behind it. The lid sits at 90 degrees, when open, because it rests against the frame of the grow house.

That's the frame just under the brand name.

The 90mm PVC pipe with the elbows on each end are to gently introduce the grow house fabric to it's new shape.



I used cable ties to connect the PVC directly to the IBC frame.

That should give a ton of security to the growhouse in windy weather.

It took an hour and twenty minutes to fill from the tap, and looks really inviting.

Which is lucky, because the first of my errors was to fail to put any kind of screen over the outlet at the bottom.

The result is that I might need to go for a swim.






The next step involved not going to the hardware and plumbing stores any more to return, and re-buy everything.

Luckily I found this solution to deal with the transition between PVC and black poly pipe.

I tried all kinds of arrangements and only reluctantly remembered from my earlier solar hot water heater experiments that silicone doesn't stick to poly pipe.

These saved the day.


They didn't actually fit the rest of the design or anything convenient like that, so I needed to file them down a bit.












And then had to file down the PVC linkage.













Until the adaptor nearly fit inside the PVC

And then had to bash it with the flat side of a hammer.












But then it fit perfectly.













Then I had to trim it.













So it would fit into my 50mm PVC "T" junctions without taking up too much of distance between the fish tank, and the rear wall. I needed to add three taps so I could control the distribution of water throughout the system.

The taps will be 25mm poly taps, and that's the point of this PVC to poly adapter.












See.













The plan is to send some water to the original grow bed with one tap, to the two new constant flood grow beds with the second tap, and to the half inside, half outside tomato/mellon/pumpkin grow bed/duckweed tank with the last tap.

I included a bit of space so if needs be I could add another tap down the line by splicing it between the fish tank and the first tap.





It looks like this inside.

I tried to minimise the potential traps where solid fish waste might collect.










Each join has silicone jammed in all over the place.

I'm told the blue glue that you normally use on PVC plumbing is a better option, because you can unstick your work with the application of a bit of heat.

I went with the ever confident silicone.

I'm all about commitment.





I stuck a stack more on the outside as well.

I really don't want to have any more leaks.

Fish hate leaks.









The final product looked like this.










Next up was to deal with the internals of the new grow bed.

I used a lot of silicone.

This is another transition point between whatever the blue barrel lid plastic is, and poly pipe.

Poly pipe doesn't like silicone, but there was an existing screw thread in the lid that only needed puncturing, and a poly pipe screw thread 25mm elbow fitting fit perfectly. I siliconed it a lot anyway.


And then did the same to the outside.













And then plumbed the barrel back to the old fish tank, now the sump.












Next up was to create a media screen so the clay ball growing media in the grow bed doesn't try to escape into the plumbing.

After sawing and filing and sawing and sanding and bracing the half cut screen with a crazy arrangement of clamps, I discovered you can just cut 90mm PVC storm water pipe with scissors.

There's a hot tip.

Scissors.


Then I drilled some holes in the media screen to let the water through, but keep the media out.

Round holes.

To keep the clay balls out but let the water through.

Round balls.






And then placed the media screen over the drain hole, and started excitedly adding the clay balls.

A few fell through, but that was to be expected.

But for some reason, I didn't expect the round balls to sit in the round holes.

And block those holes.





Perfectly.

Oh well that was error three.

Error three appeared just before error two, but I wasn't aware of error two at this stage.








So I made this.

I made it out of something that looked almost identical to this before I started.

Only slightly longer.

Originally this was some back room shelving from a now defunct Adelaide department store called John Martin's. I got a very large quantity of it at auction for free.

Which is odd.

The upright brace of the old shelving, coupled with two laundry baskets made a reasonable roost for half the new grow space.

The other half is yet to be made.









I also have a tip.

If you want to really crank up the pressure on your ratchet clamps that seal your poly pipe to your poly elbows, you can squeeze with everything you've got...









but if you are as feeble as me, you can use the handles of a pair of pliers to get that one last click out of them.

My pliers failed to be just quite large enough to get their jaws around the clips used for 25mm poly.

But the handles worked a treat.






And the final result looked like this.

The wire you can see is one of two stainless steel wires I wrapped around the grow bed to stop it spreading.









And error number two was brought to light at 4am when I sat upright in bed and realised that ever after planing for just the right angle that the taps should depart the SLO to maintain an equal distribution of water to all three taps, for some crazy reason at the last minute, just after applying silicon, and just before going to bed, I thought I'd forget the plan, and tilt the tap "T" junctions down at an angle that would mean all the water would be biased toward the first tap.

The original plan called for this.

Almost, but not quite flat.

Not quite, so fish solids wouldn't get trapped, but almost, so all taps would see similar flow.








But for some reason I made this.

This would mean that I'd need to close the first tap right down, and make the path through it a perfect trap for fish solids.

I think.







So at 4am, I suddenly sat up and ran outside to twist everything back into the correct angles.

The silicone seemed forgiving at the time, but only time will tell.

It shouldn't be an issue, because there's no pressure involved. If it leaks, I can just seal it from the outside with yet more silicone, but I think there is some kind of lesson to be learned about plans, and sticking to them.



I still don't know what that lesson might be, but I'm pretty sure it's there somewhere.





120 things in 20 years, where sometimes you can make a stack more room in your brain by posting all the accumulated stuff to do with an Aquaponics - System build

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