pvc melt/ bend temp- odd pvc shapes

[matt the fiddler]

the search has been down for 3 days every time i check... so i apologize if this is over asked here.. I live over in the sps forms.

BUT if I am going to melt pvc [ 1.5 inch, schedule 40 to the bending and streching point..

what temp should an oven be set,
how long will it take on a slow bake,

is this bad to do in a standard WELL VENTELATED room and gas oven/ [note well vented gas oven] ?

will this kill me with fumes or risk igniting something?

I am planning on expanding a section of pvc over a glass bottleneck to get a more parabolic funnel for a skimmer's top

[xtrstangx]

We had to bend some PVC electrical conduit for a project at church. We filled up the tube with sand (to prevent collapsing) then taped off the end. Got our little propane torch and slowly heated where we wanted the bend to be. Make sure you don't concentrate it on 1 area otherwise you'll just burn it. Make sweeping motions over a 1' area around the bend. Then just get someone to hold one side of the bend and one person to bend it to whatever angle you want.

HTH

[matt the fiddler]

i am putting it in an oven it for equal heating... i am trying to get a cone shaped end.. i know people who have bent it [i have before in boiling water] but i am talking some pretty major streching over a pretty long duration.. [long and just barly the right temp so no bubbling or .. smoking occurs.. and i can do it slow and steady...

[tekknoschtev]

350 for an hour. Wait, that's for the brownies, er um, cookies, er um... I forget. I'm in my dorm right now, so no more making cookies :( Anyways, I'd say anywhere between 250 and 300 would be fine. Just let it get warm. I see what you are saying for the cone shape, and depending on how much of a flare you want to get you might have to do it in successive passes. Do you have a form for the tapered cone shape? If so, then this is a piece of cake. Just heat the PVC initially laying on its side.

Test it until it is soft, but not melty, and then place on the form. Then I'd leave it on the form in the oven, but turn the oven off, and just let it cool. That way the form will stay.

If not, and doing it semi-freehand, then I think several passes will be needed. As in do a little, heat it up, do a little heat it up. Sort of like working with metal.

[DEA_MT]

no!!!...i am a plumber by trade and i know for a fact that pvc vapor is very harmful...aka poly vinyl chloride particles when heated can be dispersed into the air and this as a lot of people know has been known to cause cancer. if you really want to bend it i would recommend boiling it maybe

[Abyss]

that's right, boiling it! with water or hot corn/vegetable oil. Just becareful when you do it with hot corn/vegetable oil, you probably need a heat resistance hand glove.

[jjac]

You can do it with a heat gun. Just keep turning the pipe so that it won't burn. I have also made odd shapes before.

[KevinM]

jjac has it right. Use a heat-gun and do it right on your form.
That way, you can heat it outside and lessen the chance of harmful vapors building up.

Kev

[matt the fiddler]

i am worried about charring the outside of the pipe with the heat gun... my black and decker acrylic paint remover gets reallly hot.. i have used it on acrylic bends, and i have yet to get a "perfect" non cracked/ bubbled bend on anythign over 4".. though i haven't done acrylic bending too much...

[ziac]

well plz listen to the advise of the other plumber on here i too am a plumber and been on volunteer fire deptment and the fumes from pvc pipe can kill you expecily mixxed with water they give of a aicd fumes that can eat up your lungs make use you do not get it too hot to cause it to give of fumes or burn and outside would be the best place to do it

[jjac]

All you have to do is wave the heat gun back and forth while turning the pipe. It will not burn if you do it that way. What size of pipe are you trying to shape?

[Silencer]

You do realize that they make funnel shaped pvc adapaters used to convert from one size of pipe to the other, right?