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Author Topic: How would YOU put knee dents in this tank?  (Read 4234 times)

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Offline DaytonGuy

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How would YOU put knee dents in this tank?
« on: May 16, 2009, 10:27:34 AM »
This is an eBay tank I picked up for a pretty good price.  I would like to pound some knee dents into the side but that existing dent in the tank seems to me would cause some problems???  Do you think I could put the knee dents in it as is, or would I need to get that dent pulled out first?  Because of its location, I'm afraid of creasing the metal of otherwise ruining the tank.  Any thoughts?  I'd sat that dent is 1/4 inch deep or so.

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Offline Alan F.

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Re: How would YOU put knee dents in this tank?
« Reply #1 on: May 16, 2009, 11:34:57 AM »
I know someone will reference this other post, so here it is...  http://forums.sohc4.net/index.php?topic=51537.0
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Offline DaytonGuy

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Re: How would YOU put knee dents in this tank?
« Reply #2 on: May 16, 2009, 11:39:19 AM »
I had thought about using one of those dent popping kits but I didn't think I would have much success because the dent is relativly small and located on top of that curved portion of the tank.  If it were on a "flatter" portion of the tank....no problem.  Do you think I could pull this dent out with one of those given its location?
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Offline Alan F.

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Re: How would YOU put knee dents in this tank?
« Reply #3 on: May 16, 2009, 12:16:16 PM »
I dunno.  Honestly the first thing that came to mind was to bend some 14" round stock into the shape of the outline of the knee insert and tack-weld it into place on the tank, then tack some more, and tack some more until your tack-welds are say a half inch apart, going slowly so that nothing warps.  Then repeat on the other side.  When you've got your outline frames tacked on, you can start pounding your knee inserts in, I'd go with one side first, go slowly and get it the way you want it, then do the other side even more carefully to match.
Then you fill the edges in with a little body filler and sand smooth. 

That's how Indian Larry did this tank, I always thought it'd be the easiest way to add knee inserts with a cool flared edge.

That dent might not even matter if you go this route...
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Offline robe0531

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Re: How would YOU put knee dents in this tank?
« Reply #4 on: May 16, 2009, 12:36:29 PM »
i heard of guys cutting out section on tank turning it inside out and rewelding it and it gives then dents never done it  just heard of it
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Offline Alan F.

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Re: How would YOU put knee dents in this tank?
« Reply #5 on: May 16, 2009, 12:40:04 PM »
Yeah, I think that's the 'time honored' way of doing it.
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Offline Old Scrambler

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Re: How would YOU put knee dents in this tank?
« Reply #6 on: May 16, 2009, 02:05:29 PM »
A CB500T tank already has the knee relief and will fit on the 500.
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Offline mlinder

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Re: How would YOU put knee dents in this tank?
« Reply #7 on: May 16, 2009, 03:10:14 PM »
Paulages did a pretty nice job with a mallet.
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Offline B.O.X.N.I.F.E.

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Re: How would YOU put knee dents in this tank?
« Reply #8 on: May 16, 2009, 03:29:27 PM »
Personally, because you asked, I'd cut/flip/weld.
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Offline DaytonGuy

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Re: How would YOU put knee dents in this tank?
« Reply #9 on: May 16, 2009, 03:36:17 PM »
Thanks for all of the suggestions.  I think I know how to do the knee dents.  I guess my questions to you guys would be...would the existing dent in the tank, given its location, cause any concerns with any of you more seasons bike guys.

I have no welder, so I wanted to go with the mallet method.
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Offline WFO

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Re: How would YOU put knee dents in this tank?
« Reply #10 on: May 16, 2009, 04:03:02 PM »
Quote from: DaytonGuy on May 16, 2009, 03:36:17 PM
Thanks for all of the suggestions.  I think I know how to do the knee dents.  I guess my questions to you guys would be...would the existing dent in the tank, given its location, cause any concerns with any of you more seasons bike guys.

I have no welder, so I wanted to go with the mallet method.


Well just proceed slowly and mark out what you want pushed in with a marker to make sure it's uniform with the otherside buuuuuut this tank might end up being a trial and error learning experience hopefully you didn't pay alot for it.
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Offline DaytonGuy

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Re: How would YOU put knee dents in this tank?
« Reply #11 on: May 16, 2009, 05:29:27 PM »
That's what I'll do.  When I get to the area with the dent I'll go extra slow.  I guess I'll need to use a lot of body filler to raise the exiting dented area up to match the surrounding area.

I think I only paid $45 including shipping, so if I trash it I won't be too disapointed.  If I get it right, it's going on my 77 550K.
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Offline Steve F

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Re: How would YOU put knee dents in this tank?
« Reply #12 on: May 16, 2009, 05:49:59 PM »
I've never tried this, so take my suggestion with a grain of salt...perhaps you could take a 3/8 to 1/2" round steel bar and bend it to fit through the filler neck to reach the dented area, and use the end of the rod to tap the dent out from the inside?  IF it can reach that far back...  ???
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fuzzybutt

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Re: How would YOU put knee dents in this tank?
« Reply #13 on: May 16, 2009, 05:56:25 PM »
Quote from: Steve F on May 16, 2009, 05:49:59 PM
I've never tried this, so take my suggestion with a grain of salt...perhaps you could take a 3/8 to 1/2" round steel bar and bend it to fit through the filler neck to reach the dented area, and use the end of the rod to tap the dent out from the inside?  IF it can reach that far back...  ???

i used a tire iron bent up to hit the dent.
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Offline babyfood1217

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Re: How would YOU put knee dents in this tank?
« Reply #14 on: May 17, 2009, 05:50:26 AM »
Quote from: Steve F on May 16, 2009, 05:49:59 PM
I've never tried this, so take my suggestion with a grain of salt...perhaps you could take a 3/8 to 1/2" round steel bar and bend it to fit through the filler neck to reach the dented area, and use the end of the rod to tap the dent out from the inside?  IF it can reach that far back...  ???

In the metalsmithing/hollow-ware world, that's called a "snarling iron"  ;D

Forget cut flip welding it.  Unless you're good with a TIG or a #000 gas tip, you'll save alot of time carefully denting with a hammer.  Chances are the small dent that is there already won't really present a problem, and if it is still visible after your knee pockets are dented, a little body filler/body lead will finish it off nicely.  Lotsa threads on dent on this forum.  Search it up! :)  Keep up posted too  ;)

-Chris
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Offline DaytonGuy

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Re: How would YOU put knee dents in this tank?
« Reply #15 on: May 17, 2009, 07:46:19 AM »
Quote
Chances are the small dent that is there already won't really present a problem, and if it is still visible after your knee pockets are dented, a little body filler/body lead will finish it off nicely.

OK...that is what I was hoping to hear.  I'll take a few pics along the way.  I think I can take it nice and slow and get it where I want it.

Thanks for the help and suggestions.
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Offline swan

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Re: How would YOU put knee dents in this tank?
« Reply #16 on: May 17, 2009, 09:39:24 AM »
Do not re-invent the wheel. Others have done it and posted their results: http://dotheton.com/index.php?topic=2007.0
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