Crius cross, Crius square

See what I've done? For PVC structures the Tee is the expensive part and the most restrictive part. Now I can get rid of it in many circumstances.

Say if you want to pack a lot of pipes close together to form a raft like structure. It's not possible with Tee's because of the minimum distance between two pipes. Now you can pack two pipes side by side close to about two PVC pipe wall thickness.

Say if you build a pet cage out of pure PVC pipes. Now you just need a outer frame with rigid Tee's. The "walls" of the cage can be lined with pipes secured by Crius crosses.

Unlike Tee's, now it is not limited to PVC. You can use EMT or PEX for environmental friendliness. And since they are designed to be incompatible with different diameters, so for us there's always something to clip it secure.

Sometimes one clip is not secure enough for the pipe diameter, especially using the Crius cross. You can use concentric Crius clips - the Crius square.

By varying the arc length, it can be very hard to take off the clip unless slipping it sideways. On the other hand, using two clips side by side make it harder to slip sideways.

And if you apply some glue, it's not possible to take them out in many cases.

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.

Crius clips - attaching anything thin or flexible to any pipes securely and economically

This is my new awesome "invention" - Crius clips.

You can secure a thin or thick gauge steel wire to any pipe securely without slipping.  There's no slipping.

You can attach a towel or a plastic sheet on to a length of pipe for shelter or projects.  Not even high winds can detach it.

Say if your pipe is 1/2" PVC, pick the next size PVC pipe, which is 3/4".   Use a pipe cutter to cut out about 1/4" length of pipe.  From this O-ring, cut out about 90 deg, or a corner.  The remaining PVC pipe is a Crius clip.

Place the C opening on the pipe you want to clip on.  Push the clip on with your finger and it will go in easily.  It takes two hands to take it back out.

The clip itself is always PVC pipe.  The pipe to be clipped on to is not limited to any material.  For example, for galvanized steel 1/2" EMT pipes, the best clip is to be made from 1/2" PVC pipes (the OD is slightly larger than the EMT pipes).

If you want to clip thick power supply cable or a thick carpet, use two size larger PVC pipes.

I'm into PVC and EMT gadgets and found numerous uses for this Crius clip.

Environment issues: The manufacturing and recycling of PVC involve toxic materials.  PVC itself is stable and harmless as used in drinking water.

PVC and CPVC are supposed to replace expansive copper pipes.  There's no going back to copper as I myself witness micro pores that can form on copper pipes.  This is a nightmare as a leak can develop in any length of pipe.  The leaking can continue for a long period undiscovered.  The reason is still unknown.

The newer PEX are superior in many ways.  But I heard that rats like them too?

PVC will be around for a while.  They are also used to replace metal and wood window frames for energy efficiency.  They are not that environmentally friendly but they last a long long time.  They can be recycled too.

I can't find anything to replace PVC furniture.  Metal couplings cost 10 times more, and they are bulky.

PVC produces toxic fumes when burned.  Ironically PVC window frames and very popular.

There are ways to reduce PVC in furniture though.  For pipes that don't need to be tight fit, you can use steel EMT pipes that is about the same price.  You can still use PVC couplings but they won't exactly fit.  You can use loose pipes, for example, for the horizontal support of beds.  Or for vertical grids to keep things in.