Heat bending sand filled PVC

[wooden_reefer]

If you fill a PVC pipe with dry sand (no moisture) and cap it temperally, you can use a heat gun to bend a PVC pipe. Due to the sand, it won't pinch.

Do many people use this method to reduce the fittings and reduce friction due to sharp turns?

 

[der_wille_zur_macht]

Out of curiosity, what would be the advantage to doing this as opposed to flex PVC?

 

[wooden_reefer]

Out of curiosity, what would be the advantage to doing this as opposed to flex PVC?

Cheaper, no? What is the price of flexible PVC? Possible the wall is much thinner.

In addition, don't you think sometimes once-flexible but ridgid later may be better than always flexible. More durable may be because flexiblity is not the result of thinnest of the wall?

 

[Acrylics]

If you fill a PVC pipe with dry sand (no moisture) and cap it temperally, you can use a heat gun to bend a PVC pipe. Due to the sand, it won't pinch.

Do many people use this method to reduce the fittings and reduce friction due to sharp turns?

It's done but not sure how common it is on the hobby side of the industry. I've mode smallish ovens using ni-chrome wire to heat the pipe up and bend it. IME heat guns don't work well unless it's small diameter pipe. For me, it's always been 2" (or larger) pipe and heat guns were not the way to go.

HTH,
James

 

[wooden_reefer]

It's done but not sure how common it is on the hobby side of the industry. I've mode smallish ovens using ni-chrome wire to heat the pipe up and bend it. IME heat guns don't work well unless it's small diameter pipe. For me, it's always been 2" (or larger) pipe and heat guns were not the way to go.

HTH,
James

What do you regard as small? Is 1" or 1.5" PVC pipe be small to you?

 

[Qwiv]

I can bend 3/4" that way, but once you get into the 1"+, it is a lot more difficult. Most of my plumbing is 1 1/2 - 2" so the method is of no use to me. Anything that only requires 3/4" typically gets a hose in my tanks.

 

[suthrnmn]

ive seen electricians bend "gray pipe" used in running wires with a heated pad that has a spring that they put around the pipe to help with the pinching issue....wonder if this would work on pvc...that would be really cool! And flex pvc really aint all that flexy!!
This could be interesting...calling all electricians.

 

[wooden_reefer]

Some people say heat the sand first, but doing so might bend at the wrong places.

May be for larger diameter and thicker wall, one can heat the sand first so that the heat gun has a better chance.

For small diameter, do not heat the sand first.

 

[phuochai]

Never try yes. but I will in future. thank

 

[birddog486]

I've done this several times with all sizes up to 4" using a handheld propane torch instead of the heat gun. a steady motion so you dont burn the pipe and heating 6" either side of where you want the bend and your good to go.

I've put burn marks on a couple pipes but it hasn't caused any problems in our low pressure setups, and it's way cheaper than buying flex pipe.

BTW i've never put sand in the pipe. just take your time and use even heat/rotate the pipe constantly.

 

[Acrylics]

What do you regard as small? Is 1" or 1.5" PVC pipe be small to you?

Yeah, I'd say 1" would be on the small side.

 

[fishingdude]

very interesting... it should work fine...

 

[BeanAnimal]

Cheaper, no? What is the price of flexible PVC? Possible the wall is much thinner.

In addition, don't you think sometimes once-flexible but ridgid later may be better than always flexible. More durable may be because flexiblity is not the result of thinnest of the wall?

Cheaper... but IMHO not worth the trouble. It is not like we have to purchase hundreds of feet of flex. Also, the flex is certainly not "thin wall" or weak by any means, especially with regard to the parameters we operate it under.

 

[BeanAnimal]

ive seen electricians bend "gray pipe" used in running wires with a heated pad that has a spring that they put around the pipe to help with the pinching issue....wonder if this would work on pvc...that would be really cool! And flex pvc really aint all that flexy!!
This could be interesting...calling all electricians.

PVC conduit is ... PVC


As for flex-pvc not being flexy... it is when you heat it mildly. So if you are going to take the time to heat something, it is easier to heat a product that is already flexible and does not need a mechanical means to prevent pinching

 

[coralnut99]

Cheaper... but IMHO not worth the trouble. It is not like we have to purchase hundreds of feet of flex. Also, the flex is certainly not "thin wall" or weak by any means, especially with regard to the parameters we operate it under.

+1 on all the points Bean makes.

I saw video of guy doing it. It certainly can be done, but honestly I hate being in the same room as PVC cement. The thought of heating PVC pipe to bend it isn't appealling at all. The stuff wasn't made to be heated to those temps. so I wouldn't want to be in the same room with it.

 

[der_wille_zur_macht]

And flex pvc really aint all that flexy!!

I really hope this doesn't come across as mean, but does anyone else see the irony here? We have a thread about using heat to bend rigid PVC pipe, and people are complaining that flexible PVC pipe isn't flexy enough! :lol:

To each his own though. I suppose if I was somehow "stuck" in a bind where I HAD to bend some pipe, this would be a neat trick to know, but IMHO I'd rather just use products as designed where possible. I'll happily spend the extra few cents per foot for flex PVC vs. fussing with a hot stinky sandy mess to bend rigid pipe.

 

[KafudaFish]

I have seen the video as well and the guy had a heating blanket that cost more than the amount of flex length needed.

Also I have taken a heat gun for paint and bent pipe to make some DIY rock. Several times I got pin size holes in the PVC so it may not be a good idea all around. I did not care but you might.

 

[TheFishMan65]

Just for the record, PVC does not need a lot of heat. Put it in boiling water and it becomes flexible. Kind of hard with a long lenght I admit, but I have done it with short pieces.

 

[suthrnmn]

der willy...no not mean at all....just typical. ; )

 

[captain7359]

Out of curiosity, what would be the advantage to doing this as opposed to flex PVC?

stress on the fittings/bulkheads and it looks cool!!!

in our club puter did some nice work bending pvc with heat and sand iirc.

it makes nice custom fittings when you need a funky angle or a bend around something that would take 13 fittings, plus you can cut your friction losses down with a couple smooth long radius bends compared to short fixed length fittings.


Here's the real deal electrical conduit heater

Just go slow with whatever heat source you are using to keep it from browning/charring and you'll be fine once it becomes pliable.

or go to hd/lowes and get this.