Reinforced PVC tube and perfect PVC cutting tools

I found out that to reinforce long PVC tubes I can just inert a 1/2" EMT conduit into a 3/4" PVC tube.  The combined price is still less than a 2" by 4" piece of wood with the same length.

But why?

A PVC pipe is quite flexible if you look at a 3/4" piece with a length of over 6'.  You can break it up into sections, adding supports in the middle.  But those fittings are also the weak points.  Sometimes you just need a straight long piece of pipe.  Fittings are more expensive (stronger) than the pipes.  You can go thicker but the price of pipe and fittings increase exponentially.

EMT conduit is much stronger and cheaper.  However, there's no easy and neat and cheap way to fit them together.  So I get best of both world by inserting a EMT into a PVC.  For example, a reinforced 3/4" pipe can support an adult bicycle, while you can just put together such a shelf with only PVC fittings.  Also you can add fancy couplings along the pipe without weakening the reinforced pipe.

The advantage of EMT pipe is that it can be cut easily.  Saws are a pain, especially if you have a hand-held jigsaw.  It dawn on me that there may be EMT pipe cutters that is specialized for the job.  There are.  They are the roller blade types for copper pipes.  I use my copper pipe cutter on EMT pipes and it's good.

It dawned on me that why don't I use the copper pipe cutter on PVC pipes.  Excellent.  The shear types is convenient but it's increasing hard for thicker types.  The edge will never be perfect - always at some angles to the pipe length rather than perpendicular.

Someone uses table saws for PVC, which is a mistake.  Saws will generate heat, which will melt the plastic that is a environment concern.  Pipe cutters have no saw dust to breathe in, and they are the most precise among saws and shears.

The last shower bath tub caddy you will ever need

I always hesitated to drill holes on my bathroom tiles to mount anything.  I tried many alternatives with suction hooks and springs but nothing worked.  I hate to drill because all caddies doesn't meet all my needs.

I have to drill for body wash and shampoo holders.  I have to drill for wash towel hangers, sponge holders.  I have to drill for shaving accessories.  And I have to drill for a shower head set for kids.

Finally I designed the ultimate shower / bathroom caddy.  The basic frame is a T-shaped thing made of PVC pipes and fittings.  You can add anything to it at the end points, or branch out at the tee fittings already built-in.  All you need are 3 drill points for fixing the end points of the big T.

The main thing is the horizontal bar for hanging towels, lots of them.  Each hook is made from a short section of PVC pipe, with part of it cut out leaving a finger like extrusion.  The uncut section of the pipe sits into a tee coupling.  I cut PVC using a cheap oscillator tool, which cuts like butter.

On the right is a platform for soap made from tee couplings.  The inside of the tubes can also hold things, like a grout cleaning brush here.  The gap between the pipes and the tile can also hold things like a razor.

The kid's shower head holder is an after thought.  I cut a gap along the length of a tee coupling for the shower head tubing.  It's not adjustable but a 45 deg bend is sufficient.  Adults can also shower without wetting their hair.

At the drill points, screws hold flat PVC plugs in place.  Tee couplings near the big frame are then pushed into the plugs with the help of a rubber mullet.

As the mounting was surprisingly perfect, I accidentally discovered the law of triangle mount.  Thou shall not mount with 2 holes, not 4 holes or more, but 3 and only 3 holes.  You first assemble the whole frame and trace the tee openings on the tiles where the plugs should go.  Drill at the centre of the openings and also at the centre of the plugs.

Now, if you ever drilled on tiles before even with a tile bit, it's not possible to be precise.  I would have thought 3 points will be a disaster.  But it turns out to be perfect.  Absolutely no wobbling.  My theory is that the holes in the tiles, holes in the plug, and the plastic frame itself, all can give at least a little.  Or you can say a little play.  But ... once you can gently hammer the frame in place, there will be no wobbling, as if the drilled holes were in the perfect position.  Say if one side of the triangle is too long for the holes, the other two side will help to fix that side in place.  Only if you are too far off, you just need to replace some of the plugs with holes in better positions, until you can push the frame in.

I don't even need to seal the screw holes.  The screw is covered by the PVC frame.  The plugs act as seals.  Water can get into the pipes and reach the screws.  But the water level cannot rise high enough.

Also, if you cannot add enough things to this gadget, you can always pull the whole thing out from the plugs and do a complete redesign using the same 3 screws.  There's absolutely no glues and other screws used.  The whole thing is totally reusable and recyclable.

Food grade instant insect killers for flying and crawling bugs

It is well known that diluted soapy solution kills ants instantly.  It works well for other crawling insects.  Spiders can't run away when it is slippery all around them.  When bugs can't escape, it's up to you how to kill them.  There are organic liquid soaps too so you can use food grade insecticides around food, pets and people.

I would think soapy solution works well for flying insects.  But no.  The first hit will slow down a fly a bit.  You need a few more hits to ground them.  They can recover once dried.  So you have to kill them using other chemicals.  70% Rubbing alcohol is very effective.  Just a drop or two you can see their body twisted into a mess in seconds.  So a food grade killer will be Vodka.  It doesn't smell like vinegar.  It's easier to find than citric acid powders.  No residue.  It is actually a cleaner.  It is also not new, just that I haven't come across it because I wasn't looking.  I haven't yet find out how much dilution is still effective.

So for flying insects, I now use rubbing alcohol while not in the kitchen and Vodka otherwise.  Also for spiders.  Just one hit and you can kill them.

I used to spray lawn insect killers.  Brain washed.  There are no insects that eat grass that much.  And if there are, they are most welcomed since I do not need to mow the grass that often.  Ants don't live on lawns as long as it is regularly watered.  They also don't get across lawns if there are no reasons to.  Every year ants from the hills and neighbours all come to feast on the palm fruits/seeds.  I don't bother anymore as I don't need them.  If I remember I will cut and discard the fruits/seeds first.

They also come for the fruit trees.  But my fruits are so big and the tree so tall I don't eat all of them.  Some rots and some birds got them.  Ants really don't consume that much in comparison.  I don't even notice.

Fill cracks and voids with whatever you got, sand, lime, soil, glue, proper repair compounds.  It is much more sensible than spraying.  Anything that can be sprayed outdoors and claimed to be remaining effective outdoors for months are biochemical warfare that I won't touch.  Even worse if the claims are indoors where I live.

Trash bag adapter Mark IV

Mark III is the same using Crius clips only.  It's not bad but without target for the trash bag to clip on to.  This one adds 4 tees just as marks for the 4 corners of the trash bag.  And since they are tee's, the bag can be securely held on position with a small section of pipe plugging into the tee.

Because the field modified dimensions last time wasn't updated on the spreadsheet, I was wrong by two inches.  I find it useful to clip the trash bag onto the frame at two more locations, forming a hexagon.  The new shape is better, if only there's less length for the trash bag to slack.  So, there will be mark V with the clips replaced by tee's.

Defeating the Flushmaster patent: automatic toilet bowl cleaner

You really never have to brush the toilet bowl again for less than $1.  You only need to open the toilet tank maybe once every 6 month and drop some super cheap household chemicals in it.

My previous improved version of the Flushmaster split the water from the fill tube into 2 paths, but still using the Flushmaster.  It was a temporary fix for prove of concept.  Once the concept is proven, using the Flushmaster is totally unnecessary, overly complicated, inconvenient, and unreliable.

Since my new design is patentable, I look up the patents reluctantly.  Reluctantly because there's not much money to be made because everybody can build it for less than $1.  But still, many people will still want to just buy and drop one in the tank and forget about it.  Fortunately, Flushmaster has already patented the concepts in 2007, so I can disclose my findings immediately and not spend my time in the toilet business.

The current Flushmaster gadget is patented about 2001.  Why they don't give you products with the new 2007 patent? Money!  Now the refill cartridge sells for $7 (?) and last for about a month for a large family with older high flow toilets.  That's totally not bad if you don't have a cleaner/house keeper.  That's a steady revenue stream that the new produce will decimate.  And if you see the new thing, probably you want to copy it for less than $1.

Overflow tubes are 1" pipes slightly narrower than standard PVC 1" pipes.  So the whole thing is based on 1" pipes and fittings.  In this final assembly, the Tee on the right just slides onto the overflow tube.  Nothing is needed to modify permanently any existing fittings.

For this design, the chamber on the left stands on the tank bottom.  This is not necessary.  To secure the assembly in place all you need to do is to glue a 1" coupler to the Tee on right.  That will hold anything securely in place using the overflow tube itself.

The whole assembly need to be water tight so the chemicals don't leak a lot into the tank.   Since the assembly is not under any pressure, you can just use PVC glue to put them together without worries.

Water from the fill tube is split into two branches.  The main branch goes into the top of the Tee on right, via a 1/4" hole, drilled with a plastic drill tip so it doesn't slip during drilling.

The 2nd branch fills the chemical chamber, via a dripper or flow restricter or narrower tube or you don't even need a 1st branch.  When the chamber overflows, the cleaning solution goes into the flow tube.

Since the overflow tube and the 1" Tee is only loose fit, I put some plumber's pudding on the edge of the flow tube to seal, so chemicals can't leak into the tank.  I don't think you need it because instead of NOT allowing drop-in-tank cleaner manufacturers to destroy flippers and gaskets, the new standard seems to require everything in the tank to withstand cleaner chemicals.  I spend time for this new design because chlorine destroys drippers for gardening drip irrigation.  It only lasted for a couple of months though it is dirt cheap.

If your fill valve ever malfunctions, water goes into the overflow tube horizontally via the Tee on right.  The "critical fill level" changed a little but you can adjust it.  I think this is or can be plumbing code compliance.  A simpler gadget will be based on 3/4" pipes and fittings.  A 3/4" tube goes nicely and tightly into the overflow tube.  There is no possibility of leaks.  But the effective overflow tube size is reduced to 3/4".

1" chlorine tablets simply drops into the chamber.  But I am experimenting with something better.  Let's see this in the tank. (The old Flushmaster is there totally unused.)

Recap: standard 1/4" pipes, for fridge icemaker or gardening drip irrigation goes straight into the white fill tube.  Pick the slighter tougher ones and you can insert it far into the fill tube, forming a water tight joint.  You also need a 1/4" tee and a dripper.  I'm experimenting with the flow rate but currently I have a 2 GPH dripper.

I have an older version that uses 1" chlorine tablets.

To reduce the swimming pool smell, you can make the tank lid reasonably air tight, or you can use a standard 1" plug to cover the Tee at the chamber opening.  The dripper is inside the plug so it will not hinder the chlorine tablets when taken out with the plug.  I rotated the chamber so it is lower profile to fit into the tank with the plug half in.

Chlorine tablets can go through standard 1" pipes, tees and caps, but NOT plugs.  So you have to allow enough space if you use plugs instead of caps.

I do not recommend expensive 1/4 tee's.  It's easy to take the tubes out but only when not inside the tank for months.  Drip irrigation tee's are much cheaper.  If you ever need to disconnect the tubes, cut the tubes, discard the tee and the tubes.

To really reduce the chlorine smell, like any drain you can add a u-trap at the open tee.  It's clumsy for 1" fittings but there's should be enough space for that.  The u-trap should be refilled with fresh water every flush.  The top level of the u-trap should be slight higher than the overflow tube so water will go into it rather than the tank.

Again, there's nothing wrong with the Flushmaster, but you can be environmentally friendlier.  First, they use a lot more chemical than required.  Their new patent sort of admitting that, or, you do not need to buy expensive slow dissolving tablets to avoid refilling too often.  They design the rubber seal so flimsy that you cannot refill it yourself with chlorine tablets. You can at most reuse the o-ring a few times.  I have yet to find o-ring in hardware store to fit without using pliers to twist the cartridge out.  My design works at low pressure and you don't need any seals.

As for the new chemical, I can hint that it is very cheap and easy to find.  If your tank is larger you can fit in a few chambers and you might not need to refill in a year's time.  I have calculated the solubility of chemicals and nothing seem to last a week  unless you make some large crystals so they dissolve much slower.  But this is barking the wrong tree totally.  You'll see.

Miracle liner for pet cage and anything else

The miracle liner is polyester film such as Duralar.  It's like a sheet of paper but made of clear plastic instead.

The miracle?  It's easier to work with than paper.  It is tear and scratch resistance.  It stays flat, better than non-slip.  It's heat resistance and chemical resistance.  It's low cost.

Even if you brought a huge roll, it stay flat when you unroll it.  I know because I used it to cover the whole dinning table.  It's clear and you can write on it.  You can put it on a table or on the floor with a grid pattern on it.  It's extremely easy to align and measure the exact size.  Or you can trace the outline of the cage, or you can just cut freehand until the sheet fits the cage.
 
The sheet is slightly too thick for a paper cutter.  But it's extremely easy to cut with scissors.  It's easy to cut while following a straight line.  It's easy to make a smooth cut whether you cut is straight or slightly curved in multiple parts.  And since it's clear plaster, it's hard to notice that the cut is not perfect.

If the cage floor is reasonably fitted with a sheet from wall to wall, it's very difficult to take the sheet off because it stays flat from edge to edge, corner to corner.  My bunny toss everything and attack steel wires but he couldn't do anything to the sheets.  If the cage has some sort of "wall", it's better than non-slip liners.  It just couldn't slip pass the walls.

The sheets are extremely easy to clean.  I used rigid sheets before such as acrylic.  I have to soak them in acid to get the rabbit poop off.  It's a lot harder to cling onto flexible plastic sheets.  When the poop are dry, they will almost fall off by themselves.  Chemical free.  I suspect that there is something to do with it's diet and the strong sun.  In any case, this material is the most easy to clean stuff I ever used.  It will return to it's flawless clear state after cleaning.

Because it is cheap, I stack several of them.  It's non-slip even when stacked together.  When the top one gets dirty, I just lift it off and expose the 2nd sheet.  Then I dry the dirty sheet in the sun.  If you want to wash it clean immediately, you need some acid such as vinegar and citric acid.  Or, you can wipe the poop off with tissue paper whenever you see them.  It's almost perfectly clear again once you wipe it.

The sheets are slippery so the naughtiness of the bunny is reduced a little.

My cage floor is made with perfectly pre-cut to size wood pieces.  Polyester sheets are the perfect liner for that.

PVC pipe gadget techniques — no glue no screw

In building PVC pipe furniture and gadgets, glue or screws are often used.  I doubt it is necessary, and arguably weaken the structures.

If you insert a standard PVC pipe into a standard PVC tee, all the way in with a rubber hammer, it's almost impossible to pull it out, even for the thinnest 1/2" CPVC pipes.  To pull the pipe out, you have to have a clamp securely holding on to the pipe, and then twist the tee with hand or tools.  You have to twist clockwise and anticlockwise until the joint come loose, and then the pipe can be taken out.

So, in your end structure, if you can't twist the pipe against the coupling by hand, and there's no direct force to pull the pipe straight from the coupling, you don't need any glue.  This is easy to design and usually very natural thing to do.  For example, if you have one pipe jointing with two tees at each end, and they are of different orientation, you can't twist the pipe against anything else since the tees are fixed in space in the end structure.

The only way you can twist the pipe is to use a clamp directly on the pipe.  Even so, the force needed is great and don't do much damage since the pipe is still in the same position.

The disadvantage of glue is that it is usually toxic or at least contains some undesirable volatile compounds.  It takes time to apply and dry.  And the coupling cannot be reused.  If you don't use any glue, when you change your mind about the design, you just need to cut the pipe and twist it out with pliers.  All parts are reusable.

Some people drill through the coupling part and use bolt and nuts to prevent the joint from coming apart.  Any drilling will weaken the coupling and the pipe.  The nut and bolt will only be effective when the joint already come loose.  They don't come loose if designed properly.  In my roof top rack, a Christmas tree carrier, I don't even use glue or bolts.

Tips for plans.  To be glueless, the plan has to be precise.  I always use spread sheets to calculate the dimensions.  You need the dimension of your structure modified by the dimensions of the couplings.  For example, the top bar of the T character is about 2.5", the height of the vertical bar is about 11/16".  The extra pipe length to insert into the tee socket is 3/4".

I always use standard tee's and occasionally 90 deg turns.  They are much cheaper than the couplings designed for PVC furniture with more variety.  Arguably the standard ones are better too.  You can use two standard tee's to replace a 4 way coupling on the same plane, or a 3 way coupling in the x,y and z axis.  Even though a standard tee joints everything on one plane only, if your dimensions are reasonably accurate, you can put together a cube quite nicely and squarely.  You just hammer the pieces together with a rubber hammer and the pieces will fall in shape.

Tips for the ugly markings on the pipes.  I don't know why but the cpvc markings can be easily removed with sand paper or steel wool.  But it's almost impossible to remove the markings on white PVC pipes.  Solvents will remove the markings but stain the white pipe with whatever colour the ink is.  Most of my gadgets are by the wall and stationary.  So I just need to turn the markings furthermost from the usual line of sight.  It's almost totally hidden unless you go squarely at the back, which is impossible if the gadget is by the wall.

Tips for reusability and flexible joints.  If the joint depth is 0.75", and you want to joint two tee's back to back together, the best pipe length is twice that at 1.5".  If that part does not need to be structural and you want it to be taken apart with reasonable force, make the pipe length 1 1/4".  If the joint is for the purpose of a "lock", that you may take it apart occasionally, make the pipe length 1", and insert the pipe all the way into the stationary coupling first.  In this case, you can also make a hinge.