Shaping Small Parts from PVC

With a Pyrex measuring cup, a little water, a piece of PVC, and a microwave you can shape plastic pieces that enable you to do and make useful things.

WARNING: Our PYREX cups are several decades old and work well with high heat.  I just learned PYREX was sold to a company off-shore that uses a different composition for the glass, and it is prone to exploding violently under heat stresses that were no problem for the original PYREX.  It sometimes explodes as you are removing it from an oven.  (October 12, 2009)

Step 1 From round to flat

Pictured is a half-round piece of PVC I had left over from another project. The flat square was made by cutting a piece from the half-round and heating it while the water in the Pyrex cup boiled in the microwave for two to three minutes. I removed the cup from the microwave and used the tongs to pull the PVC piece from the very hot water. The tongs also helped to unroll the softened PVC so I could place the piece of wood over it and hold it flat against the countertop until cooled and firm. In the absence of a good supply of Plexiglass, some PVC flattened with the aid of a microwave and some hot water offers some impromptu versatility.

Comments

[juiceman74]

Phil, Thank you so much for the interesting post (as usual).

Can you first expand the idea behind the Dremel holder?
I'm looking into creating my own Dremel press. Would you recommend any technique?

Also, I was just wondering, about the GPS ball; Wouldn't it make more sense to form a mold from the original, and then cast a new shape from that?

Keep it up,
God bless - O>

[b1u3f0x]

You do understand PVC has lead in it right?

[Phil B]

I was not. Since you mentioned it, I see lead is used to stabilize PVC. I could not find anything about conditions under which lead in PVC might be released. Some items noted we use PVC for lines carrying drinking water, but seemed to let it drop there. What do you know for certain?

[MaddMann]

Newer PVC (Poly Vinyl Chloride) is lead free, look for ROHS compliant materials. Typically PVC is only harmful if it burns up. Warming it, as you did, in water shouldn't cause any harmful vapors or smoke which is where the real danger is. Lead free or not, PVC smoke is very harmful! I have spent the past 30 years working in environments where PVC is heated to melting point and extruded into various shapes. Don't take my word though, do some research on ROHS compliance, and MSDS sheets for various types of PVC from manufacturers of it.

Be safe, and keep the nice instructables coming!

[Phil B]

Thank you.

[stayputnik]

Actually, PVC is typically only used to carry waste water *out* of the home (ABS is only used for this purpose too). Any lines that carry potable water will be made of copper (unless the plumbing is very old, in which case galvanized steel used to be used a long time ago). For lines that carry drinking water into appliances (like to feed your ice maker), those will be made of PEX (cross-linked polyethylene). Cool tip though... I'm going to try this out (using an old pan filled with water).

[jj.inc]

I live out of town and we have our own well, it is newer and every drop of water in our house passes through PVC from the well to our blast tanks.

[MaddMann]

Your summation of residential piping is not entirely accurate. PVC piping is routinely used for carrying potable water as well as DWV piping; the latter is typically "Schedule 40" piping. PEX tubing is also used for potable water, heating systems, and - thanks to its flexibilty - in under-floor radiant heat sytems (Which ROCK!). Older homes also used copper supply (usually with lead solder) and cast iron for DWV. REALLY older homes used cast iron for everything, some used lead for DWV.

[Goodluck]

Another wonderful tip. I'm not yet sure what I'll use this for, but I'm sure I'll use it.

By the way, I'm sure you're familiar with the "burrs" that saw cutting pvc leaves behind. An excellent way to get rid of those is a rag dipped in acetone (finger nail polish remover). They wipe right off.

[Phil B]

Thanks.  I usually removed the burrs with a file or sandpaper.  I will have to try acetone.

[covey12]

yea, burning pvc emits a harmful gasses, not sure about melting itthough

[Seppuko]

Phil, This is a great Instructable. I stumbled upon it for other reasons, but it suits the needs of a different project I had in mind but hadn't figured out how to do. Thanks for posting it. Out of curiosity, why do you microwave instead of using a pot of boiling water?

[Phil B]

Thanks. I am glad it is useful. The microwave was more a matter of personal preference. I felt I would not need to wait so long for the water to reach a boil and I would not need to wrestle a hot metal pot. Since doing this I came into some birthday money that I spent on a heat gun, like a big hair dryer. It makes shaping PVC even easier.

[northie]

Not to be a devil's advocate but, isn't there a chemical in PVC that you would be exposing yourself to if you heat it?

[Phil B]

I did not notice any vapors or smells when heating the PVC with hot water. If I thought that is a problem, I would be sure to work in a well-ventilated area. I have a stick welder and there are noxious fumes. I try not to weld in closed areas and try not to breathe the fumes.

[northie]

Just be careful. You get mixed stories online. Some say it's safe, others say heavy metals leach out when heated and the vapors are have been linked to lung cancer. It might not be from being heated underwater though.

[ycc2106]

Great tip! I'll definitely use it. Thanks!

[Phil B]

Thanks for your comment. With a little imagination you will find even better ways to make use of it.

[Davetech]

This will similarly work with ABS black plastic pipe, although I heat it up in a toaster oven. I keep a close eye on it and check the material's temperature often with my infrared thermometer. It seems that 260 degrees F is when the ABS goes soft and pliable.

[Davetech]

The 4" ABS pipe I used has 1/4" thick walls, so if you flatten it, you will have a very sturdy, weatherproof platform to mount projects on or whatever. Gorilla glue does a good job of joining ABS pieces but I have not tried it on PVC. It seems like PVC cement would do a good job in joining the squares to create your sphere.

[Phil B]

Thanks. See my response to colinlewis. I do not buy PVC cement unless I have a job that very much requires it. The stuff always turns to sludge before I can use much of even the smallest can of it.

[Phil B]

ABS would work. I have not tried it.

[colinlewis]

Very useful technique with some practical applications. I have used PVC in a variety of uses, but never heat formed it. Regarding the epoxy, I would bet that a thin layer of the glue used to connect PVC pipe to its fittings would work well, I believe it dissolves part of the PVC itself forming a strong connection between the two pieces.

[Phil B]

I think you are correct about the real PVC glue holding better through dissolving the surfaces together. I have some of the PVC cleaner solution, but the glue always dries out before I can use much of it. I no longer have the glue and this job was too small to run out and buy another can. I also should have waited longer for the epoxy to cure before messing around with the pieces. But, the threads I cut are holding very, very well. PVC is easy to form and heating it with water is almost foolproof. Thanks for your comment.

[Phil B]

Thanks. Rimar. I hope you can use it.

[rimar2000]

Great, Phil!