Author Topic: My deer tank  (Read 2385 times)

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Offline 70CB750

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My deer tank
« on: November 10, 2012, 08:29:19 AM »
What are my options? Pull it back and filler? I guess there is no other way, is there?
We had a puller back in the shop, but dont have one, should i outsorce it? 
Share your experience, please.
Prokop
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Offline Stev-o

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Re: My deer tank
« Reply #1 on: November 10, 2012, 08:46:06 AM »
I bought another tank. (hit by car, not deer). 
'74 "Big Bang" Honda 750K [836].....'76 Honda 550F.....K3 Park Racer!......and a Bomber!............plus plus plus.........

Offline Mo

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Re: My deer tank
« Reply #2 on: November 10, 2012, 08:47:14 AM »
You could try, with caution, to blow compressed air into it until it pops out. Never tried it, but I feel like it could work?

Offline Killer Canary

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Re: My deer tank
« Reply #3 on: November 10, 2012, 08:59:04 AM »
The compressed air stunt works but won't make it as good as new. From the looks of it, there's some previous damage to fix. As long as it isn't rusted out, Bondo and high build primer will see to it.
If it's worth doing at all it's worth over-doing.
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Offline camelman

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Re: My deer tank
« Reply #4 on: November 10, 2012, 09:17:00 AM »
Call paintless dent repair shops and ask for a motorcycle expert. They can do amazing things just reaching through the filler port.
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Offline 754

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Re: My deer tank
« Reply #5 on: November 10, 2012, 09:33:17 AM »
 Don't use the  air, bad results..
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Offline Killer Canary

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Re: My deer tank
« Reply #6 on: November 10, 2012, 09:37:03 AM »
How so?
If it's worth doing at all it's worth over-doing.
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bollingball

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Re: My deer tank
« Reply #7 on: November 10, 2012, 09:47:14 AM »
Good chance of blowing out the bottom seams.
Ken

Offline BeSeeingYou

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Re: My deer tank
« Reply #8 on: November 10, 2012, 10:40:08 AM »
Epoxy a bolt or bolts to it and use them to pull out the dent.  Heating the epoxy with a heat gun/torch will soften it for bolt removal.

Offline Mo

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Offline TwoTired

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Re: My deer tank
« Reply #10 on: November 10, 2012, 10:57:13 AM »
Don't use the  air, bad results..
+1
Same goes for freezing water inside.

Why?  The pressures built up inside don't confine the force to the dent area only.  So, enough pressure to push out the dent will push out the metal everywhere from inside out.

There is also a "work hardening" factor.  Deformed metal actually becomes harder to bend (unless annealed).  So, the dented area will resist deformation before all the un-dented areas will.

There are very good reasons why the air pressure and water freezing recommendations generally come from those who have never tried it. 
 
imo.

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Offline 754

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Re: My deer tank
« Reply #11 on: November 10, 2012, 01:16:34 PM »
 The first think air will do is WIDEN your tank, now it won't fit right anymore..and it takes very little air to do that..
Maker of the WELDLESS 750 Frame Kit
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Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline crazypj

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Re: My deer tank
« Reply #12 on: November 10, 2012, 02:36:31 PM »
Yep, tank tried to open up like  birds wings.
I tried it once in 1978, never again   :-[
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Offline wvshooter

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Re: My deer tank
« Reply #13 on: November 10, 2012, 03:31:05 PM »
Quote
You could try, with caution, to blow compressed air into it until it pops out. Never tried it, but I feel like it could work?


I tried the compressed air thing. BIG MISTAKE. As others have said, the tank was deformed. What happens is the top of the tank cannot widen but the lower part of the tank can, and does. Not only that, but the bottom of the tank will deform downward. So you'll have a tank with the bottom pushed down and the lower sides bulged outward. Ugly.

One of the best fixes is to run a stiff bar through the filler opening and use the filler edge as a fulcrum to push the dent back out from the inside. Search "motorcycle tank repair" on Youtube. Of course, the bar has to have the correct bends to allow it to reach the dented area.

Offline TwoTired

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Re: My deer tank
« Reply #14 on: November 10, 2012, 04:01:06 PM »
Probably the best way to fix a dented tank is to spot weld studs to the dented area with a stud gun, and then pull on the studs while tap hammering the surrounding high spots to raise the dent.

You will have to neutralize the gas inside the tank first, though.
Lloyd... (SOHC4 #11 Original Mail List)
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Those that learn from history are doomed to repeat it by those that don't learn from history.

Offline Killer Canary

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Re: My deer tank
« Reply #15 on: November 10, 2012, 04:14:18 PM »
I'm the only one who thought of chucking the bottom of the tank in a workmate bench so it can't spread and then threading  in a  schrader valve to allow air to be injected in small, controllable  amounts? Here I've been thinking I'm an idiot all these years ;D
If it's worth doing at all it's worth over-doing.
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Offline geminimotors

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Re: My deer tank
« Reply #16 on: November 10, 2012, 05:54:44 PM »
+1 on the stud gun. I bought an inexpensive one, as it sees only occasional use. Paid for itself in about two dents. Theres a technique, and the best way I can describe it is to expect baby steps, working from the outward edge to the middle area of the dent. A little heat can help sometimes.

Offline Cabilao

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Re: My deer tank
« Reply #17 on: November 10, 2012, 06:00:03 PM »
+1 on wvshooter. works fine with me.
before:
Kreidler RMC(50cc)
CB400N(first bike)
RD350LC(more than one)
XS850(great bike)
CB900F(wish i still have it)
FZR1000(too fast)
Rickman CR900(sold for a good price)
now:
Rusi 125
CB 125 CL(just for fun)
Yamaha XTZ 125
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Offline 754

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Re: My deer tank
« Reply #18 on: November 10, 2012, 07:11:05 PM »
Prokop, do you have a good pic of the leather tank strap?
Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline crazypj

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Re: My deer tank
« Reply #19 on: November 10, 2012, 11:17:21 PM »
I'm the only one who thought of chucking the bottom of the tank in a workmate bench so it can't spread and then threading  in a  schrader valve to allow air to be injected in small, controllable  amounts? Here I've been thinking I'm an idiot all these years ;D

 Don't think workmate was available in '78?
Anyway, I didn't have one but I did try to prevent tank from moving, almost worked
I fake being smart pretty good
'you can take my word for it or argue until you find out I'm right'

Offline Killer Canary

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Re: My deer tank
« Reply #20 on: November 11, 2012, 07:09:35 AM »
On a humourous note, years ago I brought a tank to a local ::) shop to have a small dent pulled, and they turned
a beginner loose on it. The tank exploded, but the funny thing was that the tank looked flattened, kind of like a crab.
If it's worth doing at all it's worth over-doing.
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Kawi GPz900, H1

Offline 754

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Re: My deer tank
« Reply #21 on: November 11, 2012, 08:03:27 AM »
We got a workmates in the yard that looks like from the 70,s.
 But20 psi over 20 or 40 or more square inches, can be considerable force.. Could hurt yourself.
Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline Killer Canary

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Re: My deer tank
« Reply #22 on: November 11, 2012, 08:07:11 AM »
You have to be careful, just like anything else. See above.
If it's worth doing at all it's worth over-doing.
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Offline crazypj

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Re: My deer tank
« Reply #23 on: November 11, 2012, 10:34:18 AM »
On a humorous note, years ago I brought a tank to a local ::) shop to have a small dent pulled, and they turned
a beginner loose on it. The tank exploded, but the funny thing was that the tank looked flattened, kind of like a crab.

LOL
Yep, did it to a scrap tank once to show owner why it wouldn't work (worked at a bike 'junkyard' at the time)
I fake being smart pretty good
'you can take my word for it or argue until you find out I'm right'

Offline Killer Canary

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Re: My deer tank
« Reply #24 on: November 11, 2012, 11:41:21 AM »
I've known about flushing fuel tanks with carbon monoxide since I was 10. We used several different methods for repairing tanks in the grain trucks with no loss of life :). You just have to be smart about it.
The dude had zero common sense and shouldn't have been allowed anywhere near a spot welder.
« Last Edit: November 11, 2012, 11:45:54 AM by Killer Canary »
If it's worth doing at all it's worth over-doing.
Honda MT250, CB400F, CB450K, CB550, GL500, CBR929
Kawi GPz900, H1