# trouble with shrinkage



## MrGus480 (May 25, 2018)

I have 2- 5H 2g WP boxes; 1 set on the east wall of a room, another on the west; holes are vertically oriented. I want to pull an 8" 90 on each end, then kick 8" at each end to transition to the North/South wall running between them, with the conduit entering the bottom of each box. I was never taught how to calculate shrink for kick bends and any help will be appreciated.


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## 99cents (Aug 20, 2012)

90's will take care of expansion/contraction.


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## MrGus480 (May 25, 2018)

I should clarify; I wanted to end up with 90.25" back to back. I decided to use mirrored 8" offsets instead.


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## Bird dog (Oct 27, 2015)

In the pamphlet below there is a shrinkage table for offsets. It might work for kicks also. 
If not, bend kicks the same & then cut and couple as needed. :biggrin: 
http://pdf.lowes.com/howtoguides/783250740345_how.pdf


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## emtnut (Mar 1, 2015)

Oh ! _That_ kind of shrinkage !

Sorry ... carry on :blush:


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## MechanicalDVR (Dec 29, 2007)

Welcome aboard @MrGus480.

Sounds like you worked it out.


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## MechanicalDVR (Dec 29, 2007)

emtnut said:


> Oh ! _That_ kind of shrinkage !
> 
> Sorry ... carry on :blush:


Yeah coldwater was my first thought as well.:vs_laugh:


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## emtnut (Mar 1, 2015)

MechanicalDVR said:


> Yeah coldwater was my first thought as well.:vs_laugh:


That seems so out of character for you Mech :no:

:laughing:


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## TGGT (Oct 28, 2012)

MrGus480 said:


> I have 2- 5H 2g WP boxes; 1 set on the east wall of a room, another on the west; holes are vertically oriented. I want to pull an 8" 90 on each end, then kick 8" at each end to transition to the North/South wall running between them, with the conduit entering the bottom of each box. I was never taught how to calculate shrink for kick bends and any help will be appreciated.


Shrink for a kick is the same as an offset.

Sent from my SM-G930T using Tapatalk


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## splatz (May 23, 2015)

My way would probably be to just do it with 90s around the corners rather than kicks, it will hug the wall tighter and pretty much math free. 

My second idea would be to make a mark before a measured rise method kick, and afterwards actually measure the shrink, then make marks to match. This would probably be a lot more reliable than me doing the math. 

My last resort would be, I think you'd just use the same number you use for offsets, for a 45 degree 8" kick, you'd use 3/8" per inch of offset, so 3" of shrink.


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## Bird dog (Oct 27, 2015)

splatz said:


> My last resort would be, I think you'd just use the same number you use for offsets, for a 45 degree 8" kick, you'd use 3/8" per inch of offset, so 3" of shrink.


I would just bend the kick, stick it in place to mark for my cut, saw it & mount it.


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## MrGus480 (May 25, 2018)

splatz said:


> My way would probably be to just do it with 90s around the corners rather than kicks, it will hug the wall tighter and pretty much math free.
> 
> My second idea would be to make a mark before a measured rise method kick, and afterwards actually measure the shrink, then make marks to match. This would probably be a lot more reliable than me doing the math.
> 
> My last resort would be, I think you'd just use the same number you use for offsets, for a 45 degree 8" kick, you'd use 3/8" per inch of offset, so 3" of shrink.


My only objection to using the additional 90s is max allowable bend; I prefer to stay away from 360° as much as I can. My run is close to the ceiling so the offset method worked ok in the end. I'll keep the "before and after measurement" idea in mind.


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## splatz (May 23, 2015)

TROOF, I'd be doing whichever of the above I thought of first. 

If I make it perfect on the first try I might just quit and go home early because I know it's all down hill from there. 

If my screw up can make it perfect with one coupling, that's business as usual, I'll give it one regretful sigh then move on with my day.


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## splatz (May 23, 2015)

MrGus480 said:


> My only objection to using the additional 90s is max allowable bend; I prefer to stay away from 360° as much as I can. My run is close to the ceiling so the offset method worked ok in the end. I'll keep the "before and after measurement" idea in mind.


I hear that, but in a one stick run I wouldin't worry about it


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## Bird dog (Oct 27, 2015)

MrGus480 said:


> My only objection to using the additional 90s is max allowable bend; I prefer to stay away from 360° as much as I can. My run is close to the ceiling so the offset method worked ok in the end. I'll keep the "before and after measurement" idea in mind.


True, if your kick almost turns into a 90, better off bending a back to back 90, or, 30 degree offsets then bend a 90. Worst case, set a box or LB (LB, LL, LR, LF)


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## MechanicalDVR (Dec 29, 2007)

emtnut said:


> That seems so out of character for you Mech :no:
> 
> :laughing:


Thinking about a guys 'item' yeah not my usual train of thought but it happens to us all!!!


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## JoeSparky (Mar 25, 2010)

Search google play for Conduit Bend Lite. Offsets and 3 points with shrink measurements. A 90 with a kick has the same shrink as an offset. Get the shrink for the size kick (offset) you need. Add that number to your 90 measurement and bend your 90 as usual. Stand the back side of the 90 up on a level surface and mark on the pipe the distance you got from the app. Bend that angle starting at that line back towards the beginning of the pipe.


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## TGGT (Oct 28, 2012)

JoeSparky said:


> Search google play for Conduit Bend Lite. Offsets and 3 points with shrink measurements. A 90 with a kick has the same shrink as an offset. Get the shrink for the size kick (offset) you need. Add that number to your 90 measurement and bend your 90 as usual. Stand the back side of the 90 up on a level surface and mark on the pipe the distance you got from the app. Bend that angle starting at that line back towards the beginning of the pipe.


To be the most accurate he will need to bend on center.

I mark my benders with 10, 15, 22, and 30 center lines. Anything in between can be guestimated.

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## lighterup (Jun 14, 2013)

shrinkage is actually a false representation of the facts
and that my friends is the trouble with shrinkage


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