Results 1 to 11 of 11

Thread: Fuel Tank Dents

  1. #1

    Fuel Tank Dents

    I have a number of vintage motorcycles that have dents in the tanks. I would like to repair the dents before repainting, but I am unsure how to proceed. Does anyone have suggestions or direct experience with this kind of repair? Would appreciate some insight into this. Also, one of the tanks has rust issues and small (dime sized, or smaller) holes at the top rear. I am a competent welder (mig and gas), but would also appreciate ideas on this kind of repair.

  2. #2
    You have a couple of options for the dents. There are body shops that offer "paintless dent removal" which is a procedure using special mandrels to push the dents out. There are stud guns that arc weld a stud to the dent which allows you to pull the dent out. Then there are fillers. Holes can be welded, but you can get warping. Holes can also be soldered up, using fine brass screen as a backer. In some cases, the repair is cost effective; in other cases not.

  3. #3
    Sir Darby Darryl Cainey's Avatar
    Join Date
    Mar 2003
    Location
    Fenwick, Ontario Canada
    Posts
    2,581
    A friend took his tank into one of those places that fixes dents from the inside and was told the metal was too thick to get the dent out.
    Ambassador BMW MOA Ontario Canada
    President Niagara BMW Riders #298
    Knights of the Roundel #333
    1977 R100RS, (Retired) 1993 R100GS (just getting started)

  4. #4
    Registered User jagarra's Avatar
    Join Date
    Aug 2016
    Location
    Reno, NV
    Posts
    249
    When I bought my airhead I was talking to one of the guys that was in the garage and mentioned getting the dents out of the tank to him. He told me he filled the tanks with water and allowed them to freeze, the expanding ice would push the dent out.
    Now I am not saying this will work, but the concept makes you wonder if it will work and if it would cause other issues.


    I have one of those stud welder dent puller units if the thread author happens to live close by.
    1994 R1100RS-(5/93)-,1974 R90/6 built 9/73,--1964 Triumph T100--1986 Concours

  5. #5
    Liaison 20774's Avatar
    Join Date
    Sep 2005
    Location
    San Antonio, TX
    Posts
    18,215
    I would think on the ice freezing option you have little control over where the forces go and there's every possibility that the seams at the bottom would break.
    Kurt -- Forum Liaison ---> Resources and Links Thread <---
    '78 R100/7 & '69 R69S & '52 R25/2
    mine-ineye-deatheah-pielayah-jooa-kalayus. oolah-minane-hay-meeriah-kal-oyus-algay-a-thaykin', buddy!

  6. #6
    Aspiring Profligate Jeff488's Avatar
    Join Date
    Apr 2007
    Location
    Nacogdoches, TX
    Posts
    1,065
    Quote Originally Posted by 20774 View Post
    I would think on the ice freezing option you have little control over where the forces go and there's every possibility that the seams at the bottom would break.
    Yup, that's the first thing that came to my mind.
    I think it's a sure fire way to burst the seams.
    However, at that point you could pound out the dents from the inside and reassemble the tank.

    Not sure that's a very efficient method of repair, but it would give you something to do over the winter.
    '08 BMW R1200RT
    '08 Suzuki DL650 "Screaming Yellow Zonker"
    Looking for Ed Sanders' Truck Stop.

  7. #7
    Registered User
    Join Date
    Jul 2017
    Location
    Bunbury WA Australia
    Posts
    27
    I've heard one can put a couple of straps around the tank to stop it from spreading and use compressed air to pop dents out.
    Should be fairly easy to control, I would think.

    Steve

  8. #8
    Aspiring Profligate Jeff488's Avatar
    Join Date
    Apr 2007
    Location
    Nacogdoches, TX
    Posts
    1,065
    Quote Originally Posted by Darryl Cainey View Post
    A friend took his tank into one of those places that fixes dents from the inside and was told the metal was too thick to get the dent out.
    I tried this method on a '75 R75/6 tank and found that the metal is too thick to allow it to be moved with the amount of pressure that can be brought to bear on the inside of the dent.
    '08 BMW R1200RT
    '08 Suzuki DL650 "Screaming Yellow Zonker"
    Looking for Ed Sanders' Truck Stop.

  9. #9
    Aspiring Profligate Jeff488's Avatar
    Join Date
    Apr 2007
    Location
    Nacogdoches, TX
    Posts
    1,065
    Quote Originally Posted by sterob View Post
    I've heard one can put a couple of straps around the tank to stop it from spreading and use compressed air to pop dents out.
    Should be fairly easy to control, I would think.

    Steve
    Seems to me this is about the same as freezing water in the tank. You'd end up with split seams and perhaps a distorted tank.
    If these old tanks have a weak point, I'd guess it's at the seams.

    It might work with a large, shallow dent; but that's not what we normally see in tanks.
    '08 BMW R1200RT
    '08 Suzuki DL650 "Screaming Yellow Zonker"
    Looking for Ed Sanders' Truck Stop.

  10. #10
    Depending on how big & deep the dent is, you can under the right conditions, pull it out...now don't laugh...with a toilet plunger . Of course,I have NEVER dropped a bike, so I wouldn't know about this.
    Gail Thorne
    2017 F700GS

  11. #11
    Fortis Fortuna Adiuvat Omega Man's Avatar
    Join Date
    Jan 2010
    Location
    Mansfield,MA
    Posts
    11,898
    Some of the "paintless" dent removal companies use an adhesive based stud attachment system that allows a pull that works like a stud weld.
    They are pretty clever in "messaging" out the dent from the inside with some specially shaped tools.
    OM
    "You can do good or you can do well. Sooner or later they make you choose." MI5
    Mod Squad
    2009 F800GS 1994 TW200

Similar Threads

  1. Replies: 21
    Last Post: 10-12-2015, 08:21 AM
  2. R50/2 fuel tank
    By ripperfarms in forum Vintage
    Replies: 5
    Last Post: 07-28-2015, 05:27 PM
  3. Replies: 5
    Last Post: 05-31-2014, 05:21 PM
  4. fuel tank...what's this
    By 136388 in forum Oilheads
    Replies: 6
    Last Post: 10-14-2009, 03:13 AM
  5. How to repair gas tank dents?
    By 3moskvichi in forum Airheads
    Replies: 14
    Last Post: 07-14-2009, 01:24 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •