# Straightening stainless coil



## pirateagenda (21/11/17)

I have cut up my 1/2" stainless immersion chiller and slid 10m of hose onto it *absolute prick of a job btw) to convert it to a counterflow chiller. now i've hit a stump... the fittings i have to connect the hose and seal it off don't fit because of the curve of the coil. 

so far have tried:
- grabbing it with vice grips and bending (hulk might have success with this)
- camping to a table and trying to use a screwdriver as a lever bar (screwdriver bent)
- hammering it on a flat metal surface (no straightening but pipe started to flatten)

any ideas? can't really heat it now because its wrapped in rubber hose.


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## Lionman (21/11/17)

remove the rubber and use heat? Use a bigger screw driver? 

Use the hole in the handle of a larger adjustable spanner or a large ring spanner? You should be able to stick the tubing through the spanner and use it like a lever to straighten it.

If you use a ring spanner, you can extend its length and so gain more leverage by using and open ended spanner hooked into the in the ring on the other end. Wear gloves, watch your knuckles.

Stainless is difficult to work with, especially without the right tools.

I'm surprised the hose was that hard to get over the pipe, although I havent ever tried this. What is the ID of the hose compared to the OD of the pipe? There is enough room for water flow yeah?


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## Dave70 (22/11/17)

Depending on the grade, stainless will work harden -i.e, the more you bend it , the tougher it gets - as you've probably discovered. If you're lucky enough to have 300 series, this can be reversed by annealing. But you cant.
You may be able to hire a flaring tool from a local plumbers supply (or buy a cheap one) and go with flared fittings. The mechanical seal and clamping force of the fitting itself can pull the material into place even if the flare itself is slightly out of round. And I doubt you will ever get it back if its gone slightly oval. 
Stainless is a brutal mistress, and for all the difference it makes, a plain old copper immersion chiller is more than adequate, at least at a homebrew level. (Personal opinion)


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## Pnutapper (22/11/17)

You could try making a straightener in a vice like this (Door rollers bolted in to rectangular steel tube):






Pulling it through is quite a chore though, mechanical assistance may be required.


EDIT TO ADD: Sorry, I misread your post. This won't work for you.


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## pirateagenda (23/11/17)

haha thanks guys. i'm leaning towards making a copper parallel counterflow chiller and re tasking this as a pre chiller. 

I should have just sold the immersion chiller before hacking it up and gone this route from the start


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## Pnutapper (23/11/17)

Are you able to post a pic of where you have gotten to so far?


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## MHB (23/11/17)

Find a piece of round bar that will fit inside the 1/2" SS, grind the end to a blunt round or if it's very close fit a bit of a taper, work it into the end of the coil.
You can use a soft or raw hide hammer to gently persuade the pipe as you work the mandrel, can even tap on the tail of the bar to move it along.
Mark


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## pcqypcqy (23/11/17)

Can you just go ghetto and clamp some silicon hose over the end and use a hose clamp to provide the seal?

Not sure how you're doing the take off though to get the chilling water in/out though, so this may not work.


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