Fixing dented tanks

Preparing to paint my bike. I have a good sized dent on the right
side of the tank from the previous owner of the bike. Suggestions on
how to pull this dent out myself without drilling any holes? I don't
have a epoxy puller and I think due to location the suction cup kind
won't form a good seal either. With the location being on the relative
top side of the tank would drilling a small hole to pull the dent
really matter if I patched afterward with fiberglass or the like?
I've also heard about folks putting an air hose up to the tank and
filling with compressed air inside to pop it back out but i'm not sure
how I would do that on the vf500 tank in a manner that would form a
good enough seal to build pressure. Suggestions anyone? Thanks.

 

I would take it to any decent auto body shop if you are going to paint it have them pull the dent and sand and prep the area for primer and paint. Most will do it for next to nothing.

 

dent puller

Here's a way to do it. Fill the tank with water (to avoid explosions) then weld a 1/8 " diameter welding rod to the dent. Now you can pull the dent out as far you can with a slide hammer. Grind it off and fill the rest with filler before painting. Probably not for amateurs.

As far as body work pricing goes I wouldn't expect a real shop would charge less than $100+ for prepping the tank like this. And other than a tech school I wouldn't take it to any shop willing to do it for 'peanuts'.

 

I once filled a tank with water and put it in the freezer for a few hours. Popped the dent right out. It is a little risky, though. Could split the seam along the bottom.

 

I've heard this same thing, cept they used nitrogen, that and depending on the dent, I've also heard something about dry ice and hot water??

 

The dry ice only works on dents with no creases and usually on the thin gauge metal used on car panels. I wouldn't think it would work for the heavier gauge and curved tanks.

 

Rough it up and fill the dent with body filler.
Cruising range slightly reduced, but problem solved without welding or drilling.
How big and deep is it?

 

I've done the freezer trick on aluminum auto parts before. It works good, but just need to pay attention to it. It will crack the tank if left in too long.

 

Ive also got a dent in my tank dahlbug, actually its the same bike as yours and same colors! Anyways just curious what you end up doing with it, if you figure it out let me know. I would appreciate that.

 

same here. i have 2 i need to get out.

 

oddly, I read you can fill it up with hot water, seal it up, and wait. The hot water pressure builds up and it slowly pushed it out. Some say if you add dish wash liquid it helps, I've also heard Coke in it and shake it up. I tried the hot soapy water thing on a sealed container, and it blew the top off. What can it hurt, at least the tank will be clean! I have one in the back of mine that I'll try this winter.

 

How would you go about getting detergent out after? I have a dent, but am nervous putting anything but gas in my tank.

 

Hmm I might have to try the hot water trick and if that doesn't work the freezer trick. As I have a small dent in my tank that doesn't have a crease.

 

So in preparation of doing the hot water trick (maybe the freezer trick if hot water didnt work) I pulled the tank and drained any gas that was left in it. Im thinking that it might be hard to push all the water / detergent out after considering that I was unable to get all the gas out. Theres still a little left sloshing around in there, Suggestions?

 

Just sit it out in the sun for a few hours with the cap off. It will evaporate right out. Same with water as well as gas. It'll just take a little longer for the water to evaporate.

 

i had a pretty nice dent in my tank. i had some luck with a crow bar through the top. then i pulled the level sensor in the bottom and had pretty good access to the dent from underneath. popped as much of it out from there that i could and glassed the rest. other than the less than perfect lines you can't tell there was anything there.

i emptied and used multiple cycles of water empty water empty...left it dry for overnight and used the shop vac to continually suck the air through for 5 minutes. took a torch to it without problems. may be overkill on prep? i dunno but my face is unharmed

 

I took a plastic syringe (get them at Tractor supply etc...) and attached a hose to the end. Was able to get down into the crevices and remove about 2 cups of water.

Then I took a spare section of PVC pipe I had and put one end on the gas cap hole and put a hair dryer on the other end. Tank was bone dry in about 10 minutes.

I used the 3-4' PVC pipe to keep the gas fumes from getting to the hair dryer.

 

Methyl ethyl ketone will absorb a lot of water.

 

Sorry I was gone for a while, but yeah, a hair drier on the bottom works. Leave the fuel sensor in until its evaporated. As for getting the detergent out, just put a hose in the fuel fill and let it cycle out. A little detergent won't hurt the fuel any. Hot water will evaporate quickly. I have a deep sink in the basement, so the hot water is right there. Fuel drier additive works for getting out the water, too.

So did the dent come out?

 

Thanks for the info. I haven't tried yet.