How to remove a dent from a closed tank

[Devil's Toupe]

Did search and found the topic covered for a tank bike where they could remove the sides separate. But this is on a fake tank that is complete and round and the only openings are at the bottom where the machine screws thread in. There is a small dent on one side and I would like to take care of it before I paint the tank. Since painting the tank signifies "done for now" I sure don't want to do the work just to have that dent glaring back at me. So does anyone have any suggestions? Without access to the back I would guess dry ice is about my only chance on a small dent. I don't have access to a stud welder and a slide hammer is probably big for this. The picture sucks and makes the tank look like it has been rolled down a gravel road. It really is pretty smooth except this one dent. I would like to think that one day I will convert this to a motored bike and use the tank so I would prefer to not just bondo over it but figured I would let others give suggestions. I have seen an interesting video of a guy pushing out a gas tank dent from the inside using what looked like a hay hook but I would have to live with the dent for who knows how long before converting the tank to fluid capable.

If I can :
Order my bars next month,
Work on white walling the tires this weekend,
Get rid of the dent and paint the tank,
then I can call it good enough till next spring. Any input is appreciated.

http://i15.photobucket.com/albums/a386/ ... ketank.jpg

 

[scrumblero]

dry ice works for big dents but i dont know if sticks good enough to pull that one out, its pretty small.. hot glue and suction are other options, but require a tool purchase..

 

[fatkid]

When I used to work in the paint industry, some motorcycle guys would fill tanks with water and freeze em to pop the dents out. I guess it works if you don't overfill it and split it. :shock:

 

[KJV]

heat & wet towel.

 

[longshort]

well u can tack weld a welding rod to it then u can use a dent puller . basically like the dent remover with hot glue , but better . then just sand the tack weld off.

 

[Devil's Toupe]

I guess the welding rod would be cheapest, better than trying to find a stud welder to use. I would love to buy one but can't justify it for one simple project. I guess I was hoping for a "miracle" way like dry ice or heat. The freezing water could work except it's closed. And since I don't have a welder right now it is just going to have to wait. I decided the tank isn't ready to be painted yet anyway (bike is not close enough to "done"). I will either wait until I open the tank to convert it to useable and push it out from the inside with a hook OR I will finally give in and "cave it and pave it" with bondo. I hate to think of that but we'll see what develops. Maybe I'll meet a body guy and trade something for it. Maybe keeping the dent and flat black is just how I will keep it "rat."

After looking at videos of dry ice and the heat gun/canned air method I don't think this dent is a candidate with it's crease.

 

[longshort]

ok , if u were to go ahead and cut hole for gas cap and then use this whole to remove the dent from inside. then just put cap of some sort on it whether is actually for gas are not . u can use some type of self tapping screw and screw into tank , use screw to pull .but then the small has to be welded back of course. and if all else fails i have one i could sell u with no dents in it ready for paint. But if u seriously are planning on using this as a real gas tank the dent is the least of the problems , i would go ahead and starteing welding in all the places of the tank that are not welded including the four wholes in the bottom that mount it. then start pressure testing the tank because it isnt easy , i know this from expierence . hope this helps.

 

[Devil's Toupe]

The self tapping screw is a good idea. But of course requires welding for finishing. Looks like most of the good methods will require welding to some degree so wait it is, until I am better equipped. Some days the dent just bothers me a lot, others I don't care. When I say that I am going to fix it and make it a useable tank that means I still have to come up with a full motor kit and figure out custom mounting. Things I would like to do someday but at my pace it may just never happen. For now I have many good methods to contemplate.

At least I got the whitewalls done. One more thing to detract from the dent.

 

[ozzmonaut]

Or use very small screws to pull the dent, like with a dent puller, then fill those with some jb weld putty. It would be like the compromise between pulling and welding or just bondoing over.