How to fix a dent in your motorcycle’s gas tank that works every time

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The gas tank on a motorcycle is often the first thing that people see about it. It’s a great way for a rider to express his or her personality and is one of the best ways to customize a motorcycle.

But it can be an eye sore if there are any dents in the tank, even if they’re just small ones. As annoying as they are, motorcycles are especially susceptible dents in the tank because of where they’re normally stored: the corner of the garage.

Over a dozen bikes have been restored and all gas tanks, including dent repair, have been repainted. I’ve tried every possible method to remove dents. This article will describe the best way and exactly how to get them out so you’re not embarrassed to take your motorcycle for a ride.

Different Methods Of Removing A Dent

Every motorcycle I’ve owned had some sort of dent(s) in the tank when I bought them. This was mostly due to the fact that I purchased older bikes. It was only natural for them to have a few dents, especially because the paint was new and no one had ever looked at the tank before.

It’s important to remember that no matter how you attempt to repair a dent in a tank, you will need to completely remove the tank from the motorcycle and empty the gas inside. Drain the gas and add some rubbing alcohol. The cap should remain open to allow the residual gas to evaporate. Rubbing alcohol, which is soluble in gasoline, will aid in the process.

There are several methods out there that can help repair a dent that you’ve probably heard about. To pop out the dent, you can use an airbag.

The theory is that you can get some type of air bag, such as an inner tire tube or blood pressure cuff, and stuff it inside your tank behind the dent. As you slowly inflate the tube, the pressure should work against the dent and pop it back into it’s original position because of the memory of the metal.

Another possibility is to somehow get a hammer, or other similar tool, inside the tank and smash out the dent. This way can be a bit difficult because usually the only opening you can do this from is through the gas cap hole which isn’t very big.

You can also heat up the dent with a hairdryer or similar tool and spray it immediately with freeze spray. You want the extreme temperature change to make the dent disappear.

I have also tried to repair dents with dent repair tools. These have a mechanism that drills tiny holes in the metal or connects to the dent’s center with a very strong suction cup. These devices are designed to remove dents. These are available at any auto shop or online.

The last and final way I’ll discuss about how to repair a dent in a motorcycle gas tank is by simply using a body filler and repainting the tank. This is the way I suggest you use because it’s inexpensive and will ensure your tank is fully restored.

To remove dents, I tried every method mentioned. To be honest, I was surprised at how effective they were. I found that the best method was using body filler to paint the tank. The air bags that I used always burst, the hammer method always created more dents and was too difficult, the heat/freeze method never worked and the repair kits always caused additional damage.

This is my opinion. They may work for you if you’d like to try them. For me, I’ll always go with body filler and a new paint job and I can explain exactly how to do that.

How to Fix a Dent 100%

It may sound like a daunting task when you’re thinking about repairing a motorcycle gas tank by using a body filler and repainting it. But it’s actually a lot easier than you would think and it works 100% of the time if you take the right steps. You can actually make your tank look better than before.

I did my first motorcycle restoration. I had to paint the gas tank and fill the holes. I had no experience, but just went with it. It turned out to be quite amazing.

Here are the materials you’ll need:

  • Safety glasses
  • Respirator
  • Sandpaper, specifically 80-150, 220 and 300 grit
  • Sandpaper block
  • An old newspaper and/or sheet
  • Tow strap
  • Bondo and other body fillers
  • Bond Scraper
  • Green self-etching primer
  • 2-part clear coat catalyzed
  • Auto paint (the color you choose)
  • Painter’s tape

Be sure to have sufficient space for work. Also be sure that pets or small children don’t have access to your work space to ensure there won’t be any further damage to your tank while you’re working. Use the old sheets and newspaper to cover up anything around you that you don’t paint dust to get on.

First, you’ll need to sand down the entire tank until it’s all smooth. Unless certain areas require it, you don’t need to sand to bare metal. The only time I take the whole tank down to bare metal is when it’s peeling everywhere and has several thick layers of different paint. It doesn’t matter what the tank looks like after sanding.

To remove any dust, clean the tank with a wet cloth after it has been sanded. After it dries you can apply Bondo or any other body filler and then use the scraper to fill in the dent. It is best to use a large amount of it so that you have plenty of workable material when it dries. It is important to note that body filler should not be more than 1/4 inch thick

Allow the body filler time to dry as directed. It is possible to sand too quickly, which could lead to large clumps being removed. Use the sanding block (not your hands) to sand down the body filler until it’s smooth. You can start with 80 grit and then work your way up to 400 grit. Continue the process by adding more body filler, if necessary. You may notice some other small dents on your tank while you’re doing this, so this is a perfect time to fill those as well.

Once the filler has been sanded down, smoothed out with a rag, you can wipe it down using a wet cloth to remove dust. Tape off anything on the tank you don’t want paint on such as the gas cap. Now you’re ready to prime the tank. Because I have full access to the tank, I prefer to use a strap to attach it to the ceiling. Click here for my recommendation of upgrades.

Make sure to apply primer several times to the tank. You can practice on a piece or other disposable material if necessary.

After primer has dried, you should inspect the tank. You’ll probably notice some parts that aren’t as smooth as you thought or that you didn’t quite get the body filler shaped how you wanted. This is normal and why primer should be applied.

Sand any areas that are still in need of attention. Repeat the steps until it looks perfect. Continue these steps until it looks exactly how you want it when it’s primed.

After priming the entire tank and you have waited for it to dry, you’ll need to wet sand the entire tank using water and 400 grit sand paper. This ensures any rough particles are sanded off and make the tank extremely smooth which will give it an incredible shine when you’re done.

Now you’re ready for your new coat of body paint. You can also click here to read my article on the best body paint for motorcycle gas tanks.

Do this slowly. You can also practice applying the body paint to something disposable. Paint the tank in several layers and don’t try to rush covering the whole tank in paint in one go. Make sure you have your respirator on any time you’re painting.

After you’ve painted about 3-4 coats, wait for the paint to dry according to the directions on the back of the paint can. Once that is dry, you’ll need to clear coat the entire tank. This ensures that gasoline or other chemicals don’t eat through the paint. Click here to view my recommended clear coat. Clear coat is extremely potent so make sure you have your respirator on.

Here are some tanks that I have restored. These tanks had dents which I was able fix with this method.

A complete video series on how to fix and restore a motorcycle has been produced. You will find detailed videos showing how to paint and fix a motorcycle gas tank. You’ll see tips and tricks you won’t find anywhere else online. Click here for more information if you’re interested in restoring or building your dream motorcycle!

What about Deep Dents?

As I have already mentioned, you should not use body filler more than 1/4 inch in depth. Anything beyond that can cause waves or chipping. Body filler should not be used on deep dents. What can you do to fix those deep dents?

Depending on the position of the dent you can try to hammer it out from inside. If that fails, then proceed with the above steps. That way you won’t be filling in a huge dent with thick body filler.

Some dents can be difficult to reach with a hammer, or any other tool. If this is the case, you’ll simply need to get a new tank altogether or have a professional take care of it for you (though it’s likely less expensive to simply get a new tank).

The Cost To Replace Motorcycle Tank Dents

My experience is that fixing dents in motorcycle gas tanks is much cheaper than hiring a professional. I have never paid more than $100 to repair a motorcycle tank.

A body shop will probably charge you around $200 to repair the dents. They may have some special tools that can help get the dents out without needing to repaint the tank, but those methods usually aren’t 100% and there will still be some scratches and warps.

A new motorcycle gas tank usually costs between $150 and $200. You can get one for about $100 that is down to bare metal that you’ll need to paint yourself.

It is possible to paint a tank by yourself, even if you are not a skilled craftsman. Although there are other options, I believe this method works the best.

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