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Removing a dent using a dent puller – Auto body work 101

It happens to us when when we least expect it. A few months ago my wife was talking on her cell phone while driving. Next thing I know, she comes home with a nasty dent on her driver side door.

At first I considered replacing the whole door but this would cost several hundred dollars to do. Finally I decided that it was time to break out the old dent puller and get to work.

Dent is car doorMany people think that performing body work is a difficult task and is best left up to the professionals. This theory is supported when one sees that car with 3/4″ of Bondo slapped on the side. While it does require some skill to do, the average do it yourselfer can easily accomplish this task. The key to doing great body work is to take your time and carefully examine your approach before taking action.

How to do body work on your car

There are a few basic tools and products that you will need in order to get started. Harbor Freight is a great place to find most of the items that you need. Print this list out and take it shopping with you.

Items that you will need

  1. Dent puller. I used one similar to this one from Advance Auto Parts. Harbor Freight sells one that is a little heavier duty for $70 if you would like to spend the money. There are of course other options such as the weld on studs that do not require drilling but these can get expensive.
  2. Angle grinder. I picked up an angle grinder from Harbor Freight on sale for $12 and it works surprisingly well! You will also need a grinding disk  to go with it. They are the thicker disks, not the thinner ones used for cutting.
  3. Power drill and small drill bit. Most DYI people already have a power drill and drill bit set. The drill that I prefer is the Craftsman C3 cordless drill.
  4. Assorted stand paper. 80 grit is a must when it comes to sanding excess bondo. Also pick up some 200, 400,800 and steel wool.
  5. Rubber sanding block. These are really cheap and readily available.
  6. Bondo and Bondo cards. This is a must when it comes to getting that smooth surface.
  7. Red putty filler. Used to fill in any pin holes or small imperfections prior to priming.
  8. Primer. While most primers will work, I tend to reach for the mid range primers. $.99 primers are usually thin and spit when sprayed. Advance Auto sells a nice primer-filler with adjustable nozzle made by Duplicolor. While a bit pricey, this is a nice product to work with.

Shopping around will allow you to pick up all of these items for less than $100.

How to used a dent puller

Drilled holes for dent pullerDepending on how bad the dent is, you may or may not be able to use a dent puller. In some cases it is necessary or more time effecient to simply replace the entire panel. This is especially true if you have a badly dented door, hood, or fender. These items can usually be replaced by removing a few bolts and replaced with an aftermarket product that is ready to paint. In my case, a door would have been quite expensive so pulling the dent was the best option.

Keep in mind that not all dents need to be pulled with a conventional dent puller. Often times, a uniformly round dent can be pulled out with a suction cup puller or even a household plunger. It is always better to try this method first because it is least expensive and does not require painting. There are various products on the market that make this task a DYI project.

If you have decided to proceed with a slide hammer puller, you will want to drill several holes that are smaller than the screws that come with your puller. You will want to pull the dent out from several points so that matches the original contour of the car as closely as possible.

To use the dent puller, start from the outer edge of the dent and work your way to the middle. Use a screw driver to insert the screw into the pre-drilled holes. Grab a hold of the handle and apply moderate pressure away from the body panel. Use the slide to “pull” the dent out. Pull just a little from each hole until the dent has been pulled out. It helps to step back and take a look at the panel from various angles. When finished, your panel should be in the general shape it once was but will have several volcano shaped bumps where you pulled from. This is okay. The next step will help help to eliminate them.

Use angle grinder to remove protrusions

Grind down dent puller holesWith the dent pulled out, plug up your angle grinder and lightly hit each hole that you made. This will help to remove the “bumps” that you made by using the dent puller. Generally, just a light grinding for a few seconds will do the trick. If you do not have an angle grinder, a Dremmel should do the trick.

Grinding down the pull marks is an important step when it comes to reshaping the panel. If this is not done, you will likely see several areas where the dent was pulled out. Once completed, The surface should be much smoother but will still have some high and low spots. These spots should vary only a little (less than 1/8″). The surface differences will filled with a plastic filler and sanded smooth.

Use a plastic filler

Mix bondo fillerUsing a plastic filler is perhaps the most difficult part when it comes to doing body work. The only reason why this part is difficult is because once the hardener is added, you only have a couple minutes to work it before it hardens. It will quickly become too hard to spread and you will have a lot of sanding to do.

Sand the working area with 80 grit sand paper to remove the clear coat. Ensure that you hit all of the low spots so that the filler adheres.

Using a piece of cardboard or similar material, remove a golf ball size piece of the putty. A wooden popsicle stick or paint stick works well. Squeeze an inch long line of hardener and mix well with the Bondo. This stuff will set up fast so get ready to spread it on the body panel.

First application of body fillerOnce mixed to a consistent color, spread the filler all around the work area while attempting to create a feathered edge on the ends. If this is your first time using bondo don’t worry if you don’t get this right. After sanding for a while you will quickly learn an application technique. Depending on how much hardener you added, you will need to wait 30 mins to an hour before proceeding to the next step.

Sand and shape filler

This is the part where most people go wrong. It only takes a few seconds to apply 1/2″ too much bondo but properly removing it will take several minutes. The idea here is to feather out the edges of the filler when it meets the metal. In addition, you will want to hit all of the high spots inside the repaired area. Try not to sand too much of the filler away and if you find a low spot, leave it. This area will be filled in using the next application of filler.

Sand the area using 80 grit sand paper until you get a nice rough shape that is similar to the original contour. The first application is not going to be perfect so fear not.

Repeat filling & sanding

Sanded Bondo With your first coat sanded and the dust blown off, apply a second coat as instructed above. Right now is a good time to use a large Bondo card to fill in the low spots uniformly. Use your finger tips as a guide to find high and low spots.

Using your sense of touch is the key to great results. Remember, if you can feel it, you will be able to see it – no doubt about it. When you think you are getting close close your eyes and feel the surface for waves, bumps, pits, inconsistencies, etc. At this point you should be getting very close to achieving the original shape.

Use glazing putty

Glazing putyGlazing putty is one of the last things that you should do when performing body work. It is a fine red putty that is applied on top of your finished bondo work. The purpose of this product is to fill in minor imperfections, creating a nice smooth surface that is ready for primer. For less then $8 a tube, this step is crucial if you to achieve a professional finish.



sanding before primingSimply apply by squeezing the tube and working over the entire area with a bondo spreading card. Spread an extremely thin layer over your work area and allow to dry. They trying time on this product is much longer because its not used with an activator. Dry time can be anywhere from 30 mins in hot, dry conditions to over an hour in cooler humid conditions. Allow to dry and stand with 400 grit or finer sandpaper to a smooth finish.


primed doorNow that the hard part is done, its time to prime. Primer provides a solid surface for paint to stick to and it can also cover any remaining perfections. In addition, it can be a great way to protect your metal from rust until you get around to painting it.

When doing body work, you should anticipate putting the top coat on within a few weeks, not months. Driving around with primer on your car for a long period of time not only looks silly but will eventually introduce water to the bare metal surface.

To prime, use a quality masking tape to mask off areas where you do not want paint to adhere. It is much easier to tape it off than to remove over spray afterwards. Don’t forget to also tape off all glass if nearby.

Shake the can vigriously and apply paint in a sweeping motion. Apply several coats, allowing several minutes to dry between coats. It may be a good idea to hit the area with steel wool in between coats and then remove the sanding dust that it leaves.

primed door side viewWhen finished, carefully remove the masking tape.

Paint as soon as possible. The painting process takes a little bit if effort but you can also do this. Stay tuned for an article on painting using a 2 stage base coat – clear coat finish.


The other day I was searching for my jumper cables in the trunk well in my car. Lo and behold I had a swimming pool where my spare tire sat. Luckily, I caught this before it caused any rust or odor.

Others are not as fortunate. Throughout the years, I have seen several cars with damp floorboards or a pool of water in the trunk. This problem is often ignored by most but can be an annoyance for others.

Have you ever got into someones car and took a deep breath of the wet towel funk? If you have smelled this before then you know what I am talking about. A musty, moldy, stale smell usually means one thing and one thing only – you have a water problem. Perhaps the car that you are thinking about is yours. There are a few tell-tale signs that you have a water problem:

  • Your car smells of wet dirty socks
  • Mold spores tend to form, causing allergic reaction for some
  • After a heavy rain your window are soaked on the inside with condensation
  • Interior of vehicle is damp
  • Metal components inside your car begin to rust

Dealing with a water issue is not as difficult as you may think. The source of water is usually easy to identify and correct. In fact, the majority of times it is simply a worn weather stripping or deteriorated caulking. Fixing this issue begins by first identifying the underlying cause.

Identifying the source of water coming inside car

Wet trunk spare tire wellFinding the water source is usually pretty easy but can sometimes be difficult. This is especially true if the source is coming from the firewall area high above the dash board. In most cases you can identify the source of water by using the following steps:

Remove paneling or carpet and dry out

The best way to start is to remove moisture all around the area. Snap off all plastic panels and pull back the carpet around the wet areas. This usually takes a phillips screwdriver and or some type of prying device. If you know where the fasteners are at, you can sometimes pull panels off with your bare hands.

In most trunk compartments and some floorboards a rubber plug can be pulled out or pushed through to release any pooling water. I find it easier to push them through and then retrieve from underneath the car.

remove tire well drain plugUse a towel or paper towels to dry up the area. This should be done on a sunny day with the windows down or doors open. You can also use a water extractor/ carpet shampooer. Running the heat on the floorboards with the windows down is also a good idea if you are working in the floor board. While cleaning up, take note of the color of the water. This is especially important if you are working on the floorboard of the car. If the liquid that is being extracted is green, there is a good chance that it is antifreeze and a component such as your heater core is leaking.

Powder the area with baby powder

Powder used for water detectionPowdered trunkOnce everything is good and dry, grab some baby powder, line chalk, foot powder, whatever you have around the house will work. If possible, chose a color that contrast the color of your car. Just a light layer will help to identify the trail that the water makes when entering your car. As a bonus, if the powder is scented it will make your car smell better. Well, better than mildew. Choose your weapon carefully as some products such as powdered sugar or flour may not be the best option.

Simulate rain conditions with a water hose

rain simulationClose all doors, windows and the trunk lid. Simulate a rainfall with your garden hose. It is perhaps better to use a shower nozzle for this. Spray around all channels and even places that you would never suspect water to get in. It is surprising the places that water finds its way in. When creating rainfall, remember that rain falls straight down and sometimes a little sideways. A 45 degree angle around each body panel should be more than enough. A car is not water proof, only water resistant so you do not want to force water into areas where rainfall would not naturally reach.

Allow the vehicle to dry off

Allowing your car to properly dry is good for two reasons. First, immediately opening the trunk or doors may introduce water into the car that can be mistaken for a leak. The second reason is that it gives time for even the smallest leak to find its way into the car. Give it a good 30 minutes or so depending on weather conditions.

Slowly open panels and look for leaks

Water intrusionWater entering cabinIn most cases, the issue will clearly present itself whenever you open the windows or doors. Slowly open each and closely inspect the area for water trails. The first place to start is usually the rubberized weather stripping around the edge. This is typically the first thing to get torn or dry rot. The water trail will usually point directly to the source. Having a flashlight handy is a good idea.

After identifying the source, determine the proper corrective action. Do you need to replace torn or rotted weather stripping, Does your rain catch sill need to be caulked? Are your drain channels clogged, causing a backup in your car? There are a number of reasons why water can enter your car.

Fix your leak

Rain water puddling in trunkOnce you have determined the source of the leak, fixing it is the most obvious step to take next. Fixing the problem is best accomplished using a common sense approach. If its cracked, chipped or broken replace or repair it. I have used 100% silicone to repair a tare in weather stripping before but this usually only works for a short period of time.

In the case of my vehicle, the culprit was unexpected. You may have read my recent post about replacing the lift arms on a hatchback lift gate. Although the replacement shocks work well, they may be a hair too long, preventing the trunk lid from closing all the way. After removing the lift supports and testing the theory, most of the water stayed out.

There was one spot where water was barely getting by. This is probably not enough to amount to much of anything but I will soon replace the entire weather stripping in order to achieve a tight seal.


I’ll have to admit, for years I have used Blue Rhino tank exchanges for my propane needs. It wasn’t until I begun homebrewing that I started to question what I was really paying for liquid propane. While brewing beer with my 55,000 BTU burner, I begun to use more gas that ever before.

Now, I have always heard that refilling your own tank is much less expensive than doing the exchange but never really investigated it until now…

Exchanging a propane tank vs using a filling station

The price of Propane (LP) per gallon and tank exchanges can vary greatly from one area to another. That being said, you should still get the general idea by reading this even if you live in a different part of the country. Lets begin by discussing exactly what you are getting with a Blue Rhino swap.

The Blue Rhino exchange tanks

Blue Rhino Propane tankThese days, it is rare to visit a Walmart, Lowes, Walgreen’s, or any major supermarket and not notice the steel cages containing BBQ propane tanks. But what are you really buying. The simple answer to this question is that you are purchasing convenience. Simply bring your old empty tank to the retailer, pay at the register, and an employee will come out to unlock the cage so that you can fetch a refurbished filled tank. So whats in the tank?


20 lb propane tankThe 20 lb tank

You may have heard your BBQ tank referred to as a 20 lb tank but are you really getting 20 lbs? Several years ago, gas exchange companies such as Blue Rhino started filling their tanks with 17 lbs instead of 20 lbs, as the price of propane rose. The companies cited the rising cost of fuel as the reason for getting less gas. In an effort to keep prices the same with rising costs, they decided to reduce the amount of fuel that goes into each tank, anticipating that the average consumer would not notice or simply did not care enough to do something about it. This same tactic has been used by many food and beverage makers. Look at the “20 oz Pepsi”, half gallon of Bryer’s ice cream, or that box of general mills cereal. In order to maintain strong profits in times where inflation is going crazy, they do these things and most consumers do not notice.

At first, Blue Rhino landed in some hot water as they failed to disclose this on their labeling. In the end, they ended up paying up $7.50 for every tank purchased between 2005 and 2011 as a result of a class action lawsuit. Consumers could file a claim and receive up to $150 in refunds (20 tanks) if they have a proof of purchase. Those without proof of purchase one can receive one refund for $7.50. Needless to say, the propane contents are clearly labeled on every tank today.

Fast forward a few years and the 20 lb propane tank is now being filled with 15 pounds, not 17 and defiantly not 20. Perhaps this was caused by BR paying millions of dollars out due to the lawsuit in addition to higher operation costs? I can only speculate.

Now, the once “20 lb tank”, as they are commonly referred to as, contains 15 lbs of actual propane. It is clearly labeled on the plastic wrapper surrounding the bottle so if you read the label you will not be deceived.

How much can the Blue Rhino tank hold?

Although the exchange tanks are now (January 2013) filled with 15 lbs of propane, this does not necessarly mean that this all they will hold.

While researching the topic of the maximum capacity of a 20lb tank, I ran across quite a bit of misinformation that actually led me to believe that these tanks are only capable of safely holding 16 lbs. Where did this number come from?

The statement on the label reads that the tank should only be filled to 80% capacity for safety reasons. The 20% void is left for gas expansion as the weather changes.  The general consensus by the masses was simple:

80% of a 20 lb tank is 16lbs. Blue Rhino fills their tanks to 15 lbs so what the big deal? Its just a pound short?

Upon further investigation, I learned that this is far from the truth. A 20 lb tank holds just a hair under 20 lbs or roughly 4.5 gallons of propane. Where did I come up with this number? Here is the math.

Water Capacity

Water Capacity of 20 lb propane tankTake a look at the handle of your propane tank. You will notice several numbers on here. One number that you will see is the water capacity or “WC”. My particular tank shows “WC 47.6 LBS”.

What this means is that you can figuratively speaking, fill the tank to the very top, leaving no void space and the weight of the water added will be 47.6 lbs.

Water weighs 8.35 lbs per gallon so 47.6 lbs is roughly 5.7 gallons. My particular tank will hold 5.7 gallons of liquid at maximum capacity. However, you can’t fill these tanks to the top. Remember, a maximum of 80% propane?

80% of 5.7 gallons is 4.56 gallons. In terms of weight (4.27 lbs per gallon), this is approx 19.5 lbs, a far cry from 16 lbs.

The water capacity will give you a good idea of how much LP your tank can safely hold.

Overfill Prevention Device

overflow prevention device OPDDon’t concern yourself with overfilling your tank and it exploding. New style tanks with the triangle valve handle have an Overfill Prevention Device or OPD. If overfilled, propane will spew out the release hole. Overfilling tanks is a thing of the past when this device is used. All tanks between 4 lbs and 40 lbs are required by law to have this device before they can be filled. In fact, many filling stations do not use a scale or meter. They just fill the tank until it spews and charge a flat rate. These stations rely on the built in OPD safety device to cut the flow of gas. Not the smartest move in my opinion.

Having your Blue Rhino tank filled locally vs exchanged – a cost comparison

Now that it has been established that the exchange tanks have 15 lbs in them although they are capable of holding 20 lbs, lets compare the price of these tanks compared to bringing your gas bottle to the filling station.

In all fairness, lets compare the 15lbs that you receive from Blue Rhino to 15 lbs filled at your local filling station. Here in North Carolina, the current going rate for a gallon of propane is $3.00. The going rate for a exchange tank is $17.82. Here’s what we get with a side-by-side comparison:

15 lbs of Blue Rhino gas : $17.82

15 lbs of filling station gas: $10.54

Difference of $7.28 or 69% more! 

Is Blue Rhino a rip off?

Those who have this knowledge may accuse Blue Rhino of being a rip off. Is this true?

On the surface, it is easy to say YES! They are charging 69% more than the local guys.

My personal opinion is that they are practicing business as usual. Think about it from a business standpoint. Blue Rhino has to pay additional expense that the local guy doesn’t. These prices include but are not limited to

  • Retailers discount so that they can profitably sell the exchanges
  • Supplying and maintaining the large steel cages that sit in front of the store
  • Vehicle fuel and maintenance for every gas delivery truck on the road
  • Costly insurance for these trucks. I can’t imagine how much it cost to insure a truck full of flammable propane.
  • Truck drivers salary
  • Cost to strip, paint, and relabel their exchanged tanks
  • Cost to replace bad tanks and have old tanks re-certified
  • re-certification of old tanks and replacing parts
  • Class action lawsuit payouts. Ferrell gas (Blue Rhino) has paid out $25,000,000 in lawsuit settlements.
  • Cost of several more staff members
  • Too many more to name

One can imagine the overall cost of operation. In the end, they are likely profiting, as they should.

As mentioned at the beginning, you are paying for the convenience. All of these additional expenses paid out by Blue Rhino are passed down to the consumer in the form of a convenience charge.

Advantages and disadvantages of both

 Blue Rhino


  • Convenience – can be found at several locations around town, more common than filling stations
  • No need to “re-certify” your own tank when it reaches 12 years of age
  • Always a clean, nice looking tank
  • You can get a tank any day, any time at many retailers such as Wal-Mart


  • Costly – nearly 70% more than filling your own
  • Potential to lose gas if you are not able to completely empty your tank prior to exchange
  • Hard to tell how much gas they are actually filled with at time of purchase
Propane filling stations


  • Cost effective – nearly 70% less than exchanging 
  • You can get a full 20 lbs, less trips to the store to fill up
  • You can see the tanks being filled so you know whats in them
  • In most cases, you can pay by the pound or gallon, no need to completely empty tank


  • Sometimes more difficult to locate in comparison to picking up an exchange at the supermarket 
  • Tank must be re-certified after 12 years in order to be legally filled. ( Use a service such as Blue Rhino to dump your old tanks to avoid this)
  • You have to clean and maintain your own tank
  • Most filling stations are going to have limited hours. If you run out of gas on a Sunday night you will likely be out of luck.

You are the only one that can determine which one will work best for you. For most people, refilling would be the most cost effective approach assuming there is a filling station near by and they are open when you need gas.

How to determine how much gas is left in my propane tank

Perhaps after reading this you decide that exchanging your tank is going to be the best option. The problem is, you only own one tank. This makes it very difficult to strike a balance between removing as much gas out of your tank while not running out while cooking that T-bone steak. What does one do to determine how much gas is left in a propane tank?

Unlike a gasoline can, you can not open the lid and take a look inside. This presents a challenge when you need to find out what’s left in your tank. There are actually three methods that you can use to determine what you have left.

Good – Pour hot water down side of tank

How to check propane levelsAn old time trick to determine the level of liquid in your tank is to take a glass of piping hot water and slowly pour it down the side of the tank. Use your sense of touch to feel along the side where the tank turns from warm to cold. The transition to the colder area marks where the propane level is. The difference if fairly obvious. This will give you general idea where you stand.

Better – Buy an inline propane gauge

Pick up an inline propane gauge. These are available online for $10 to $20 and can give you an idea of how much gas is left in your tank. Although they are not completely 100% dead on accurate, this may be sufficient and certainly better than taking a wild guess.

Best – Weigh it

Tare weight

Tare weight propane tankWeight of empty 20 lb propane tankThe first thing that you need to understand is the “tare weigh”. The tare weight or “TW” should be clearly marked on the tank handle. On my tank it is  stamped 16.6 LBS – yours will likely vary. This simply means that when completely empty, the tank should weigh 16.6 LBS.

Now that you have determined the tare weigh, put the tank on a scale and weight it. I use a postal scale but if that is not available a good bathroom scale will work.  Lets say this particular tank weighs 26.6 lbs. Simply subtract the actual weight from the tare weigh and you get 10lbs of gas remaining. A 15 lb (considered full by Blue Rhino) should weigh in around 31 – 32 lbs.


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