Author Topic: Gas Tank Dent Removal!!!  (Read 2341 times)

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Offline puppytrax

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Gas Tank Dent Removal!!!
« on: September 07, 2013, 10:44:14 PM »
I have a CB550 gas tank in very nice condition, except for one dent...

Is there a specialist who can remove the dent with minimal damage/repair [like welding a patch back over an access hole]?

Is there a 'How To' on doing it yourself?

A story...Many years ago, I got a gas tank for a Norton which had a small dent...I had the bright idea of stoppering all holes, installing a Schrader valve [tire valve] in the gas filler plug, and putting about 3-5 psi compressed air in the tank...And then heating the dent with a torch to pop the dent out...

Big mistake...No, no explosion (no gas fumes), but the superheated air billowed the sides of the tank outward like a set of waterwings...Ruined the tank...    :'(

So that doesn't work...    ::)

I'm not a body man, and I doubt my ability to weld sheet metal as thin as a gas tank bottom...And I don't have the body dollies to hammer the dent out anyway...

I do have one other tank...But that CB500 tank has three dents in it...    :-\

I've been watching these guys on cable TV "American Restorations", and I know it's possible...I just don't know how...(Or who)...   :|
« Last Edit: October 10, 2013, 11:40:44 AM by puppytrax »
...stock 1972 CB500 '500 Four' undergoing re-assembly...
...Stock 1972 CL450 'Scrambler' also being re-assembled...



Offline vrm

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Re: Gas Tank Dent Removal???
« Reply #1 on: September 08, 2013, 02:57:40 AM »
PDR

Paintless dent repair. They usually work with hail dents but by the looks of it what you have is right up their alley. Go to a big car lot in your area and ask them who they use.
Ride it like you stole it from your ex-wife's new husband.

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Offline RAF122S

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Re: Gas Tank Dent Removal???
« Reply #2 on: September 08, 2013, 07:13:03 AM »
That dent cannot be removed with paintless methods...the crease line is the problem.
Places that do tank restoration charge between $200-400 to open a tank, remove dents, close tank and resurface for primer coat. When you can find people who know what they are doing.
David M
Blountville, TN
my current collection of bikes:
'65 Honda CA95 Benly Touring 150 (running awaiting restoration-storage) 
'70 Honda S90 Sport 90 (yes it is a Nov 1969 production, labeled as a 1969 US market bike, in storage)
'74 Honda CB550K0  (refreshing, returning to street after 25 yrs...working on it)     
'78 Honda CX500 (plastic maggot, plated & licensed - not riding)         
'81 Honda C70 Passport (plated & licensed, storage)



Offline puppytrax

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Re: Gas Tank Dent Removal???
« Reply #3 on: September 08, 2013, 08:45:05 AM »
I've found references in other cycle forums for Dent Dynamics in Sonoma California. I'm thinking of them as a kind of last resort (or Rick Dale!  :D )

I'm not too worried about the paint itself; I don't like this color anyway (I like the Garnet Brown color offered in 1971 by Honda).   ;)
...stock 1972 CB500 '500 Four' undergoing re-assembly...
...Stock 1972 CL450 'Scrambler' also being re-assembled...



Offline wvshooter

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Re: Gas Tank Dent Removal???
« Reply #4 on: September 08, 2013, 12:50:48 PM »
A story...Many years ago, I got a gas tank for a Norton which had a small dent...I had the bright idea of stoppering all holes, installing a Schrader valve [tire valve] in the gas filler plug, and putting about 3-5 psi compressed air in the tank...And then heating the dent with a torch to pop the dent out...

Big mistake...No, no explosion (no gas fumes), but the superheated air billowed the sides of the tank outward like a set of waterwings...Ruined the tank...    :'(

So that doesn't work...    ::)

I tried that with my Honda tank. Wish I had known what was going to happen. Made me sick. I beat around on it trying to get back to a normal shape and probably got to within 90%. Lesson learned. Don't pump air into a gas tank.



Offline Stev-o

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Re: Gas Tank Dent Removal???
« Reply #5 on: September 08, 2013, 01:57:12 PM »
PDR

Paintless dent repair.

I've called three places but each has told me they don't work on bike tanks. The metal is much thicker than what is used on modern cars.  Still looking.....
'74 Honda 750K [836]   '77 Honda 750K project    76 Honda 550K cafe      plus plus plus



Offline calj737

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Re: Gas Tank Dent Removal???
« Reply #6 on: September 08, 2013, 02:04:34 PM »
That dent cannot be removed with paintless methods...the crease line is the problem.
Places that do tank restoration charge between $200-400 to open a tank, remove dents, close tank and resurface for primer coat. When you can find people who know what they are doing.

Rafster is probably right, though, if you find someone very experienced in PDR he could try 2 tricks; a rod specially bent to run inside the tank and push outward. This will not put it back to 100% but it might get it close. The other, is weld on a few pull rivets and draw it back. Light heating of the metal first will help.

Either method will damage your paint and require some fillet, but may save you some bucks on the repair work.

I've got a very good friend who does this for a living and he did a 360 tank for me. My crease was not too dissimilar as the bike hit the trailer top rail on the way to shop. Argh! He used both methods described above and got it pretty dang close. After paint, perfect result.



Offline puppytrax

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Re: Gas Tank Dent Removal???
« Reply #7 on: September 08, 2013, 03:02:33 PM »
I've got a very good friend who does this for a living...and got it pretty dang close. After paint, perfect result.

Would he be willing to give my tank a try???   :)

I tried that with my Honda tank. ..Lesson learned. Don't pump air into a gas tank.

Yep...I don't remember where I read that 'trick' (it was long before the Internet/PCs), but it was one of those 'urban myths' that go around every ten years or so, like putting moth balls in your gas tank to raise the octane...   ::)

It's one of those mistakes you only make once...   ;)
...stock 1972 CB500 '500 Four' undergoing re-assembly...
...Stock 1972 CL450 'Scrambler' also being re-assembled...



Offline calj737

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Re: Gas Tank Dent Removal???
« Reply #8 on: September 12, 2013, 02:45:37 PM »
Just sent you a PM



Offline vames

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Re: Gas Tank Dent Removal???
« Reply #9 on: September 12, 2013, 04:39:20 PM »
That's a pretty small dent. If you're going to repaint, can't you just do some filler or some lead solder?



Online Greggo

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Re: Gas Tank Dent Removal???
« Reply #10 on: September 12, 2013, 04:47:07 PM »
I've found references in other cycle forums for Dent Dynamics in Sonoma California. I'm thinking of them as a kind of last resort (or Rick Dale!  :D )

I'm not too worried about the paint itself; I don't like this color anyway (I like the Garnet Brown color offered in 1971 by Honda).   ;)

Dent Dynamics!!  The guy works friggin miracles, and he's done it with more than one of my tanks.  He's fixed doors on my cars, and I can't recommend him enough.  If you choose to send him your tank, please tell him who sent you.




Online Greggo

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Re: Gas Tank Dent Removal???
« Reply #11 on: September 12, 2013, 04:55:47 PM »
I don't have an after pic, but he fixed every little ding in this NOS tank, and I was able to sell it for a small fortune.




Offline puppytrax

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Re: Gas Tank Dent Removal???
« Reply #12 on: September 12, 2013, 05:07:30 PM »
That's a pretty small dent. If you're going to repaint, can't you just do some filler or some lead solder?

It's about 1 3/4" top to bottom, along the sharp crease. The problem with this dent is that the ends of that crease have raised it above the level of the adjoining metal. If it was filled, it would bulge at each end. It needs to be popped out and [hopefully] hammered flat, then filled. It is probably within my skill level to cut out a 2" hole in the bottom of the tank, make up a rough wood buck to place the dent against and carefully hammer out the dent from the inside, using a long rounded mandrel. But I no longer have the welding equipment to weld a patch over my hole. It's still thin metal, and it's been years/decades since I've welded. Actually, the last time I painted a car/truck/motorcycle was in the '80's, so it's a crap shoot for me to even paint it. I'm hoping my Binks spray guns still work - they've sat unused for 25 years...   ::)

Using a welded-on screw to try popping it out is outside my experience. I doubt if a glue or vacuum dent-popper will pop this one out. I used to do body work back in my youth and I hated it. Painting is OK; bodywork sucks.

I asked around here in my small town and I was not impressed with the answers I got or the samples I was shown. Dent Dynamics sounds like a good deal.
...stock 1972 CB500 '500 Four' undergoing re-assembly...
...Stock 1972 CL450 'Scrambler' also being re-assembled...



Offline Xnavylfr

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Re: Gas Tank Dent Removal???
« Reply #13 on: September 13, 2013, 02:40:21 PM »
Try this trick first!!
Take a hair dryer and heat the dent area so hot you can't hold your finger to it then put a piece of DRY ICE on the dent.
The HEAT anneals(softens) the metal and the DRY ICE causes a RAPID shrinking . I've used this method to take hail dents out of Aircraft skins.


Xnavylfr(CHUCK)



fendersrule

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Re: Gas Tank Dent Removal???
« Reply #14 on: September 13, 2013, 02:52:35 PM »
If you sent that tank to me, I would strip that area and then fix it with a stud welder and a pick hammer to lower the high spots. It would probably take me 2-3 hours, max. You will still have to use a minimal amount of filler (no more than an 1/8") to optimize the body line, and you would then be forced to repaint the tank. What are you goals with the bike/tank?

Understand the concept of a dent first. Yes, what you see is a low spot. But around that low spot is a ridge (high spot). Both have to be solved.
« Last Edit: September 13, 2013, 02:57:31 PM by fendersrule »



Offline puppytrax

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Re: Gas Tank Dent Removal???
« Reply #15 on: September 13, 2013, 05:46:32 PM »
Understand the concept of a dent first. Yes, what you see is a low spot. But around that low spot is a ridge (high spot).

Yes, the high spot at each end of the crease is my primary concern. This is an unused dealers NOS tank that had something dropped on it. Inside is rust free. I hate the purple color, so it will be repainted, some type of rootbeer brown metallic (similar to the OEM Garnet Brown metallic). I hope to replicate the black side panel, and add either a painted stripe or decal (if they're available).
« Last Edit: September 13, 2013, 05:48:05 PM by puppytrax »
...stock 1972 CB500 '500 Four' undergoing re-assembly...
...Stock 1972 CL450 'Scrambler' also being re-assembled...



Offline puppytrax

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Re: Gas Tank Dent Removal???
« Reply #16 on: September 13, 2013, 10:17:59 PM »
Try this trick first!!
Take a hair dryer and heat the dent area so hot you can't hold your finger to it then put a piece of DRY ICE on the dent.
The HEAT anneals(softens) the metal and the DRY ICE causes a RAPID shrinking . I've used this method to take hail dents out of Aircraft skins.


Xnavylfr(CHUCK)

Interesting...I have no idea where to find dry ice...(or a hair dryer either, for that matter)...   ;D

I asked my insurance agent about shops in the area that specialize in hailstorm repair...they gave me one name, but when I stopped by, no one was there...   :(
...stock 1972 CB500 '500 Four' undergoing re-assembly...
...Stock 1972 CL450 'Scrambler' also being re-assembled...



Offline RAF122S

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Re: Gas Tank Dent Removal???
« Reply #17 on: September 13, 2013, 11:40:31 PM »
If you have a harbor freight tools nearby then buy a heat gun and use it on low, high can help remove some paints. (1500 degrees F)

Dry ice is sometimes carried by grocery stores, otherwise start calling around to ice and compressed gas suppliers. Dry ice is CO2 in solid form. Need to use heavy gloves to handle or other tools like tongs. It is very cold stuff and will burn exposed skin on contact (severe frost bite). It creates a CO2 fog gas when placed in water as it "melts"

A can of compressed air inverted can sometimes substitute for dry ice if you spray the heated spot with a thick coating.  Dry ice will be cheaper for a very small block.
David M
Blountville, TN
my current collection of bikes:
'65 Honda CA95 Benly Touring 150 (running awaiting restoration-storage) 
'70 Honda S90 Sport 90 (yes it is a Nov 1969 production, labeled as a 1969 US market bike, in storage)
'74 Honda CB550K0  (refreshing, returning to street after 25 yrs...working on it)     
'78 Honda CX500 (plastic maggot, plated & licensed - not riding)         
'81 Honda C70 Passport (plated & licensed, storage)



Offline nancy

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Re: Gas Tank Dent Removal???
« Reply #18 on: September 14, 2013, 01:23:42 AM »
Sheesh...stop worrying about perfection...fill it and paint it.
See my B4 and after pics. A lot of damage was under my paint job when I had it blasted. Never knew. Re-bogged it and repainted it. Looked just right ....or I could have gotten an expert to deal to and spent another $600.



Offline thirsty 1

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Re: Gas Tank Dent Removal???
« Reply #19 on: September 14, 2013, 01:40:04 AM »
Sheesh...stop worrying about perfection...fill it and paint it.
See my B4 and after pics. A lot of damage was under my paint job when I had it blasted. Never knew. Re-bogged it and repainted it. Looked just right ....or I could have gotten an expert to deal to and spent another $600.

WOW!



Offline PeWe

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Re: Gas Tank Dent Removal???
« Reply #20 on: September 14, 2013, 04:46:24 AM »
really nice paint job compared with before.
Like some women and their makeup! Works the other way too in that case.... like waking up in the morning in another bedroom the day after a party when I was a bachelor... ::)

Soft dents are possible to repair by using tools from inside . The very sharp dent that is seen here might be difficult to straight out without thick layer of 2k plaster.

I could not resist to search on Youtube where plenty of DIY's can be found.
4 ways to pop a dent from a motorcycle gas tank
« Last Edit: September 14, 2013, 05:01:33 AM by PeWe »
CB750 K6-76 with modified engine.



Offline PeWe

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Re: Gas Tank Dent Removal???
« Reply #21 on: September 14, 2013, 04:57:00 AM »
Another one among many....
Paintless Dent or PDR tools: Kawasaki Motorcycle Tank
CB750 K6-76 with modified engine.



Offline PeWe

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Re: Gas Tank Dent Removal???
« Reply #22 on: September 14, 2013, 05:37:32 AM »
CB750 K6-76 with modified engine.



Offline PeWe

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Re: Gas Tank Dent Removal???
« Reply #23 on: September 14, 2013, 05:58:00 AM »
another video :-)
Motorcycle Dent Removal - Paintless Dent Repair (Sarasota)
CB750 K6-76 with modified engine.



Online Greggo

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Re: Gas Tank Dent Removal???
« Reply #24 on: September 14, 2013, 01:52:29 PM »
Before and after pics of my wrinkle tank after Dent Dynamics took care of it.


Before: 3 major dings


After: No more dings

« Last Edit: September 14, 2013, 04:52:20 PM by Greggo »