waterproof void filler?

[Ca++]

I want to make a flood&drain system for seed trays.

I have the grey box. I want to reduce it's height to be just enough for 15 or 40 cell, and a little more head height for plumbing. The pics with the green line show my plumbing. It's just a case of shove in some hose, fill with some black unobtainium, and lop the hose off flush.

I can't decide what the black stuff should be. It's a couple of liters of something. Maybe resin. Maybe foam. Maybe I just forget the fill, and pop in some ice packs full of sand (to stop them floating). Boat buoyancy foam seems to rot it it actually gets wet. I could latex paint it. But it seems a bit short lived. Resin is a bit costly for a cheap project, and it's a big lump of landfill for the future. Gravel is a maybe. I really want something solid though. That space could hold a couple of liters, and my tank can't run below a couple of Liters to keep the pump happy. Say I have just two trays, it's 6L I need in my tank, before I have enough to wet their feet. I might need 9L in my tank, just to make it work, and really just want a bucket or bowl, so I have to use some unobtainium, to get 4L ahead.

My second design is a tank connector, into a central gully. If I use resin, I could make them two side have a tiny slope into the gully. Then, not shown in the pic, I could put a slope on the gully with some more fill. Resin is self leveling, so it's just a case of tipping the tray as it sets. I have built little walls with stick tape, to keep resin in containers as it sets. It's not like water, some tape can hold back the tide. Perhaps with a temporary wall supporting it.

Perhaps casting resin isn't so bad, or expensive? I use potting resin for projects, which is likely similar.
I tanked out a cellar with cement that has a lube in it to let it settle as a waterproof barrier. Perhaps that's an idea.

As I type, I'm things a load of stones, then my resin, so it's not pure resin. Plastic waste doesn't make me happy.

I did pause on the idea of a pipe fitting in the bottom. Like the hose idea, I could use a plastic tank connector. Fill with resin until the nut was covered. Then chop the excess threaded bit away. I could even sit the tray on a little slope as the resin leveled, so in use, the water would find the tank connector in a corner, giving a full drain out. I just don't fancy a fitting sticking out the bottom. It's a handling issue. It would be clumsy to store, or even set down. Maybe the tank connector could unscrew once the nut is held in the resin, but I'm not sure I can bank on that. It just seems a bit second rate.


I guess I could be giving this a bit more thought than needed, but I want to do it right. I need some decent filler options really, to settle my mind I'm doing the right thing. Before I do something really shit, like ice packs.

The resin would give a great finish. Proper kitchen draining board like. Be bussin, if it's not toxic?

 

[Ca++]

That's perhaps better. If the tub and fitting are both abs, they will solvent weld. If I use the tub slightly tipped, I can save some resin. Potting resin alone will hold that fitting though. It's the black stuff they pot electronics in. 24v to 12v DC convertors are commonly potted up, as are other modules such as cop ignition coils.

It seems a better plumbing solution. It's ready for a hose.

 

[Ca++]

That resin really is expensive.

Sometimes just talking out loud helps. The pics may of helped me to..

I have had great success, just drilling a hole, and cramming a hose in while warm. My tool of choice has become a step drill, as normal bits can bite and cut triangles, not circles. The step drill gives a pretty polished hole, and a quick run around with the deburring pick sorts it.

Using a hose crammed in, I can get about the lowest drain off point possible. Roughly the width of the holes wall, from the bottom. Lets call it 3mm.
The blue bits, could be 5mm thick sheet material. I know I can drain down below 5mm, though building in a bit more margin would be nice.
If I can get the water down to 3mm, with a bit of tipping perhaps, I think that might do. I won't need 2L just to get their feet wet. Maybe a 10th of that, making it non-consequential. I'm just left with that 3mm to think about, which is stood in some pretty small channels. Perhaps that is the time to start pouring resin, starting from the left, to let to run to the right. Having first covered the hose entry point, so it doesn't actually get stuck in. 1, so it can be changed, and 2, it answers my storage issue, if they can stack.


It's getting better...

 

[Ca++]

Sheet of ply. Perhaps chip, but bathroom standard. The black bit is just a temporary wall, as over the board, goes the resin. The resin is tough, and just a mm of it is plenty. It's the edges that matter more, where the resin must pour in the gaps and attach to the grey box. It's epoxy, so has a good chance. Perhaps a bit of 'up side down' counter top is the best wood, as it can have the bottom waterproof. The resin would then reach down to this, encapsulating the board. So if it breaks free on the grey box, the worst it can do is float until I silicone the bugger back in.

This is a lot less resin. A lot less water before their feet get wet.


Anyone following, need only add an overflow pipe to get this working. The pump sends water in the green hose, it fills, and overflows back to the tank. The overflow need only be big enough to cope. Once the pump stops, the water drains back to the tank, through the pump. Do check you can blow back through your pump though, before setting off.
I use fancy pumps with high pressure, who's seals won't like any dirt draining back though them. I have a different plan.

 

[Brother Nature]

Aww, was kinda hoping this thread would be some existential, philosophical discussion about the ways we fill the cavernous spaces of existence....

Maybe it is...

 

[Ca++]

Have you tried the HID vs LED thread?

 

[Loc Dog]

Is there a reason you do not use 90 degree threaded connectot and piece of wood to raise a little. I used to use 36 inch cheap plastic window boxes. Then for feed black plastic tubing connected to pvc pipe holes for feed. You do not want light getting to reservoir water or algae.

 

[Ca++]

Is there a reason you do not use 90 degree threaded connectot and piece of wood to raise a little. I used to use 36 inch cheap plastic window boxes. Then for feed black plastic tubing connected to pvc pipe holes for feed. You do not want light getting to reservoir water or algae.

Mainly stacking when not in use. I'm not sure I can gain anything either. If I put a fitting through the bottom, there will be a nut inside my tray. Presenting the same drain problem as if I go in the side. I can actually go in the side, putting a hole within a hose wall's width of the bottom. Just 1.5mm, though I'm going to aim at 3mm to leave room for mistakes. A nut would be 5mm perhaps.
Also a hose in the side, is just that. A hose in the side. No fitting, and adapting to hose. No loss of height in my 1.2m enclosure. Which has about 90cm to give me. To split between plants and space from the lights. If I'm to have my tank below. So just 5cm lost, is 10% of my plant height

It will generally be tidier without bits of wood, and bits out the bottom that make stacking difficult.

I have given window boxes some thought. Some have feet, which would be very useful as somewhere to plumb to. It's not a standard size, for a typical cardboard box though. Or for typical seed trays, though they do come made to fit window trays. I once made some lights, about 80cm long for this 110x65 enclosure. Seemed a good idea, all air cooled as the heatsinks were within ducting. Nightmare to store though. I chopped then to 50cm and span them round. So much better.., not in use, but in storage.

I guess you need a few years under your belt, and a bit of the hoarding gene to really see my point. Everything I make or own, has it's own box, or will need one. My pro-ultra shades had their rivets swapped to screws, to get 4 in a box made for one. My F&D kit hasn't been used in 15 years, but it's buckets not coffins. I wouldn't have coffins. I have had 15x15x240 boxs made, to house bits of wood that make specific systems. Every thing must compact to store and move it. Trays with fittings out the bottom, that have to sit on bits of wood, just don't fit my bill. My last system was pots on paint trays, that all plumb together. Them trays had been stacked 8 years since their last run. Plants pots... don't get me started.
I need kit that packs like russian dolls. I won't use a load of resin then bin it. These trays should be with me a long time. They need to be right for that

 

[Loc Dog]

Mainly stacking when not in use. I'm not sure I can gain anything either. If I put a fitting through the bottom, there will be a nut inside my tray. Presenting the same drain problem as if I go in the side. I can actually go in the side, putting a hole within a hose wall's width of the bottom. Just 1.5mm, though I'm going to aim at 3mm to leave room for mistakes. A nut would be 5mm perhaps.
Also a hose in the side, is just that. A hose in the side. No fitting, and adapting to hose. No loss of height in my 1.2m enclosure. Which has about 90cm to give me. To split between plants and space from the lights. If I'm to have my tank below. So just 5cm lost, is 10% of my plant height

It will generally be tidier without bits of wood, and bits out the bottom that make stacking difficult.

I have given window boxes some thought. Some have feet, which would be very useful as somewhere to plumb to. It's not a standard size, for a typical cardboard box though. Or for typical seed trays, though they do come made to fit window trays. I once made some lights, about 80cm long for this 110x65 enclosure. Seemed a good idea, all air cooled as the heatsinks were within ducting. Nightmare to store though. I chopped then to 50cm and span them round. So much better.., not in use, but in storage.

I guess you need a few years under your belt, and a bit of the hoarding gene to really see my point. Everything I make or own, has it's own box, or will need one. My pro-ultra shades had their rivets swapped to screws, to get 4 in a box made for one. My F&D kit hasn't been used in 15 years, but it's buckets not coffins. I wouldn't have coffins. I have had 15x15x240 boxs made, to house bits of wood that make specific systems. Every thing must compact to store and move it. Trays with fittings out the bottom, that have to sit on bits of wood, just don't fit my bill. My last system was pots on paint trays, that all plumb together. Them trays had been stacked 8 years since their last run. Plants pots... don't get me started.
I need kit that packs like russian dolls. I won't use a load of resin then bin it. These trays should be with me a long time. They need to be right for that

Late and going to bed. Make sure resins do not leach toxins when exposed to water. I drilled perfect size hole t screw threaded fitting into bottom of tray and sealed outside with silicone. Tray needs slight tilt to drain well. Did a lot of DIY hydro before going to coco in smart pots. Problem is if it goes bad, they all go bad. Their is live (heisenberg tea) or sterile, adding a little bleach, like a couple of drops per gallon.

 

[troutman]

Fill it with clay pellets to the level you need.

 

[Ca++]

Clay would offer some height, but displaces little water, and has an unwanted side effect. My roots would grow out the seed tray, into the stones. I use air pruning at this stage. Roots that can grow out the cells, are often lost at transplant. It's a complication best avoided.

I'm looking at chopping boards now. 12mm thick, food safe, and about a tenner. Typically 30x45 which makes two slabs that couldn't fit much better.

A tray with a hole, and a chopping board, offers few complications. I'm not sure sealing it in is the idea, when it could come out and go in the dishwasher. I would rather give all the surface water chance to leave, but I have used plenty of systems that leave a dribble, day to day. I will trim the insert tray a row, to allow airflow, not constant crazy RH. Also, it allows me to get a hold of it.

Thank you for the ideas.
Watching what plastics I use has been gnawing away at me. Many pours are fish safe, but in stating that, the product jumps 4 fold in price (same prodict, different sellers). Checking the data sheets is a bit time consuming though. I may use an aquatics silicone around the chopping board. So I can pop a shim under one end for a 1 in 40 fall. Without making a cavity for bacteria.

 

[Timj]

You could just make a plywood box with the desired pitch and use a pond liner to waterproof it. Your fitting should not leak against the rubber pond liner if you use a threaded one. It's the way most larger DTW tables are made.

 

[Hiddenjems]

View attachment 18871868
That's perhaps better. If the tub and fitting are both abs, they will solvent weld. If I use the tub slightly tipped, I can save some resin. Potting resin alone will hold that fitting though. It's the black stuff they pot electronics in. 24v to 12v DC convertors are commonly potted up, as are other modules such as cop ignition coils.

It seems a better plumbing solution. It's ready for a hose.

Do you use ign1a coils, or a specific car model coil?

I’ve seen aftermarket ecu’s filled up before as well.

 

[Ca++]

I have done dtw that way myself. I have made I beams, used on their sides (so H beams?) with plastic lining to. I have seriously considered tanking out a room, finding the low point (usually the middle) and fitting a sink/shower waste. Like a ghetto wet room. I do construct frames with wood on every occasion, but I'm not sure about this one. I want total drainage of the F&D units, with little compromise. Few tank connectors I know of, offer a low drainage point. Even bolted in the bottom leaves a puddle that might last the day. I would really like a dry out, for hygiene reasons. I could certainly knock them up in wood, and would probably use a polyurethane varnish to keep to the paint roller tray shape I can see working. Not a scale model of a roller tray, you understand. Just a draining platform, and much smaller well area to draw the water out from.

I'm in two minds here. I was going to use wood in my boxes, but I'm happy to be using plastic for cleaning reasons. The idea of using very little plastic is obviously appealing though. If I were to make that well very small, then we are just talking teaspoons of water left. Perhaps then it would be resin time, or simply silicone, to fill that well, up to the tank connectors water channel.

I guess it's a case of making my draining board the full size on my box. Then at the well end, it can stand on some 2x2, properly bonded, as if my draining board was just thicker. In to this, I can plunge a 15mm router bit to make my well. HDPE tank connectors tend to have the nut inside, not outside. So It only need be a small well. Maybe 30mm deep, and 50mm long.
Lets see how that looks, using UK 2x2, which is just off square at about 48x50

The real issue with that, is I drew the wrong tank connector lol (you couldn't fit the external nut type)
The burgundy is resin or sealant. I guess if I varnish before the connector goes in, the seal would be okay. The HDPE won't take paint, but a smear of silicone over the top, should give a second water barrier.

I think I like it, but there are some issues. It won't stack away well. The connectors not cheap, and needs a bit more to adapt to hose. I don't have any varnish, which isn't cheap. I'm not sure I have any ply or 2x2. As a vision in my mind, I can't quite see it in my space. Perhaps with a lot of varnish, but still, I will be switching the number about, as I switch plant spacing (an issue hidden from this thread) so I really want that stacking bit to work. I have a 110x65x120 tent, with a shelf for these to be used on, or stored under.

I don't really want to be leaving this space to fetch and carry, what could just stay here. My tank must also go under there. Along with props, lids, jugs, stuff that shouldn't really be there, stuff I wish wasn't.

I like the wood idea, but as I need 4, I'm mocking up two, to look at repeatability. If it's just a container, a hole, a chopping board and a jigsaw, I could scale this idea, and easily share it. One concern when I make things, is how easy it is to copy. In all honestly, I don't look for reasons to get my router out. I save up such jobs, and trash the house with dust and blood in one go.

 

[Ca++]

Do you use ign1a coils, or a specific car model coil?

I’ve seen aftermarket ecu’s filled up before as well.

I was just trying to think of places people would see potting resin used. That kinda glossy looking fill, that fills you with loathing, when you open up something to fix it lol

I have not seen that specific coil before. It looks quite a beast. I expect it can allow a big gap for low rpm behaviour, while having the strength to keep that long spark from being blown out in high demand situations.
I think I'm running an ngk7 on stock coilpack, having doubled the power. While a stock plug is 8 or 9. I really don't have any issues, with just a pack on my wing running batch/wasted. The ECU I put in won't do sequential anyway, but I'm close to needing a cop setup, if I swap my rods to get a bit more. I will just dive into the manufacturers parts bin though. It's easy to look on enthusiast forums and see the limits of peoples stock systems. I don't think a coil for 250bhp per pot, is quite what I need. Though do let me think about that for a bit. I could change my mind

 

[Ca++]

My trays base (or storage container, about to be chopped) measured roughly 22x32 iirc.
20x30 is a standard tile size. First cheap trade ones I saw, were 7.5mm thick. So thick enough, and just a cm short on each side. That almost seems like a drainage channel. Or a good bead of silicone.
Perhaps some floor tiles will be a bit more solid, and water resistant on all sides.

A tray, a hole, a tile and some squidge. That's quite a boiled down idea, and we can't say I just did the first thing I thought of. Or that it's some over thought technical marvel (that's another project). I'm not sure I can make this any easier. The chopping board was nice, but £7 a unit. A tile is about £1 and fits.


EDIT: Yes, I'm already thinking about the cec. LECA seems to work fine. I don't think it will be a problem, if I don't use sealant in a trial

 

[Ca++]

I bought some tiles. Bit bigger than needed, but my attempts to scratch them and jump on the damn things paid off. You could park on these things. I was literally jumping on them.

Just got my level control together. This is what plumbs to the trays the plants go in. It has a couple of level floats. 12vdc jack to power it. Timer to the second, and a cable for the flood pump, and one for the drain. My pumps also use dc jacks, but oddly, you can't get a 5.5mm male for panel mounting. So the wires had to stick out, where I can screw the males on