bks84

iTrader: (9)

i used a 3" vibrant vband on this downpipe, I ended up warping the thing. im curious what ways there are to straighten it out, or am i fucked and have to start over?

i wasnt advised to clamp all the pieces of the vband to prevent warping, this is my first significant project of this nature.

CRMB

If its a flat faced vband, you can typically resurface them. If it's a male/female setup, it's done for.

bks84

iTrader: (9)

yea, its one with a lip so I assume its M/F.

thats crappy news, but something I suspected. so I need to just cut it off, and start with a new one? or would cutting it off allow it to "spring" back into position, maybe... possibly?

Luserkid

How warped are you talking about? Sometimes to fix warping you could do heat passes to pull the flange back to where you need it.

bks84

iTrader: (9)

Im not really sure how badly its warped. If I lay it on a flat surface Id say theres less than a 1/8 gap on the top side

Luserkid

1/8" is quit a bit of a pull. Can you take a picture? Is the warp even or in random places. If it's even its doable. Random different areas your best bet would be to scrap it if it's that much off.

bks84

iTrader: (9)

It may be less, like 3/32 or something and it's only on one side, the top. I'll snap a picture tomorrow.

I ordered a new vibrant vband assembly already. Just in case but I'm leary of cutting off the current band.

I'm guessing I need to clamp the flange as an assembly completely before welding it next time

Luserkid

That helps but not always needed. Warping usually happens when you stop a weld and let it cool then start again. With anything round once you start welding don't stop.

bks84

iTrader: (9)

All the reading I've done regarding vband flanges basically tells me to make 8 tacks evenly spaced then weld em in between the tacks skipping around similar to lug nut tightening sequence...

Now you're telling me something different.

Luserkid

Yes I am. For tacking your part you want to do it that way. Tack one side jump to the other then cross then cross again. But for the actual welding part you typically want to start and keep the heat going until you finish the weld. Jumping around with your weld could cause warping (like you seem to be experiencing). I say could because the technique you did might work for some people but in most fields you don't do it that way. Here is a video of how we weld most of our flanges, granted this is on thick pipping but this works on thin as weld (I weld .040"-.125"). Notice how he starts one place and goes around until finished. And of course clamping will help more then not having your part clamped.

weiRtech

welding a 1" thick flange to some schedule 80 pipe is quite different from welding a v-band to 16g tube. i'd be very surprised if something that thick warped significantly. doing a complete weld in a single pass on tube/pipe isn't always easy and i wouldn't expect to be able to do so on most exhaust applications without a spin fixture. properly placed tack welds is a good start.

in an ideal scenario, to prevent your vibrant v-band from warping you should clamp it to a thick heat sink and allow it to cool completely before un-clamping it. i have a few different size aluminum heat sinks that i've made on a lathe that i use for welding v-bands. if you have a v-band on your turbine housing, that is a good alternative for clamping it to during the weld process. currently, Vibrant is taking steps toward possibly improving the design of our v-bands to include a longer neck which will help with preventing warping as well as making them easier to weld by moving the joint further away from the clamp.

thank you for choosing Vibrant,

aaron

Luserkid

I was using the video to show how the start and stop go. One continuious weld not jumping around. That's all the video was for. Doing it this way we never have a problem with warping unless we stop somewhere and let it cool and start again. Again we weld .040"-.125" material

bks84

iTrader: (9)

thanks aaron, there is a v-band on the turbine housing, Ill remove it from the manifold and clamp it up when i repair it. i dont really have access to the methods, etc you do so getting or making a heat sink seems impossible since for whatever the reason scrap yards in my area wont sell their stuff.

Will my welding table work as a heat sink? I believe the top plate is 5/16 or 3/8 mild steel? I understand AL would be best, or at least better though.

bks84

iTrader: (9)

anyone ever these style v-band, they seem to have a larger lip than the vibrant ones...

CODE4

Go to mcmaster.com or online metals, or metalsdepot and pick up a block of aluminum.

bks84

iTrader: (9)

Thanks man ill check it out tomorrow