Total Motorcycle Community Forums

What do you guys suggest for repairing dents on gas tanks on older bikes?

I have a larger dent on my tank and would love to repair it without messing with its structural integrity and without spending hundreds of dollars. This is why I am hesitant to drill holes and bang out the dent:

http://tinyurl.com/e4qnb

May I use Bondo to simply fill in the dent? Then I could sand down the gas tank myself and take it to a pro to have it nicely repainted to a color close to my bike’s original color?

I bondo'd a small dent in my tank and it seems to be holding fine. Don't think I'd want to use it on large dents though.

You'll probably get better response in the appropriate forum.

http://totalmotorcycle.com/BBS/index.php?c=3

Joe Mc wrote:I bondo'd a small dent in my tank and it seems to be holding fine. Don't think I'd want to use it on large dents though.

You'll probably get better response in the appropriate forum.

http://totalmotorcycle.com/BBS/index.php?c=3

my apologies. i always seem to screw up and not post in the right forum. sorry guys.


but before i go... would you say mine is a small or large dent? in other words, would you use bondo on it?

I would just bondo it in layers.

I wouldn't recommend using Bondo on it. Bondo wasn't designed to fill that large of a hole. I'd use some fiberglass to fill the dent, get it in the ballpark of true and then use Bondo to fill in the large surface irregularites the fiberglass will have.

It'll look better and last longer.

i'd buy a POS $10 tank or two at the yard or on ebay, then i'd experiment on them by cutting out the dent, cutting out a good section from another tank that has similiar contours, then weld that in. Then I'd just use bondo to fill in any irregular surfaces. Then i'd sand it a lot. If it worked out ok i'd try it again on the tank on the bike.

And after all that, i'd probably decide that it looked like crap, scrap the entire thing, and pay way too much for a new tank.

But hey, it would have been worth a try.

Plus its always good to have an excuse to weld something.

The fiberglass idea should work fine. Make sure the paint is off first, all the way to metal, and sand with 40 or 60 grit to roughen the surface. Use a fiberglass filler with chopped long-strand fiberglass if the dent is really big. Otherwise, short-strand will be okay, like the Bondo marine repair kit. For a shallow dent, use the fiberglass jelly. Finish with bondo or preferably a polyester filler (bondo makes one, called Premium, I think). Fill above the level of the surrounding surface and sand down to match so you don't leave a depression. Then do a search for painting threads right here and paint it yourself. You will save many, many dollars!