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View Full Version : Rust Repair on Mazda 3 GT 2004



Highlander
10-08-2012, 11:53 PM
Purchased my Mazda 3 GT 2004 from a private owner for $5,600 (CAN) had 95,000 km on it. It had some cosmetic rust on it, mainly above the wheel wells. My mechanic estimated rust repair for $350 per wheel, so about $1,400 for the complete job (I'm sure they would charge even more at a dealership or some other body shops). I spent on all the materials about $200 so you can save a lot of money this way. I've decided to repair the rust myself as I had lots of free time. I spent about 2-3 weeks working every day for 3-6 hours. Here are some tips that you can use if you decide to repair the rust yourself. There are plenty of YouTube videos and websites that you can learn from before starting the job. This was my first rust repair so I can't guarantee that I did everything perfect. However, in the end it looks quite decent. You can see some pictures at the bottom of my finished job.
It is a good idea to wash the car thoroughly with soap before starting the rust repair because you don't want any grease or dirt to interfere with the new paint application. My head lamp with extension cord came in very handy as I was working in the garage and some areas need more light even in the day time.

Materials I purchased: primer spray, base coat color spray, clear coat spray. https://www.automotivetouchup.com/ Note: to find the exact body color look inside the driver's door for the correct color code. Mine is Y29 for Titanium Gray Color. I've purchased my spray paints online which better matched the colors as compared to retail stores. I purchased one of each spray cans but later I ran out of them as I did rust repair on the lower panels underneath the car doors. You don't have to get the paint and primers from the online store as they're a bit pricey. You can try finding them in the local body shop supplies stores as well. Another useful component is the rust converter: a clear spray that can be purchased from any auto retail store. It converts rust into paintable primer. Like this one: http://www.canadiantire.ca/AST/browse/4/Auto/AutoBodyRepair1/AutoBodyRustControl/PRDOVR~0477965P/Rust+Check+Rust+Converter.jsp?locale=en The rust converter takes quite a bit of time to work properly - about 24 hours for best results. The best one is the rust converter clear spray which doesn't effect your base coat color. If you sprayed accidentally on the painted area you should wipe it off as it can react with the paint. The rusted brown areas turn black after the application.
I used drill and metal grinder with various disks to grind off the rust and paint to bare metal. I purchased all the disks at Walmart and Canadian Tire. You have to wear a dust mask and safety glasses as the grinding procedure creates a lot of fine dust. It is also a good idea to keep all the doors and windows closed when you grind off the rust spots. Good gloves are very useful for the job as well.
I also used a metal scraper to scrape off initial paint and rust. http://t1.gstatic.com/images?q=tbn:ANd9GcSf87aUOTBO-YmgzGjbRE1sSLE8-HlcRTI9Og9LhxYkmzA6NB1sOfvHRHzwPgThis was probably the most important tool. You can sharpen it with a metal grinder when it gets dull but its absolutely important for the rust repair. Anywhere where you see the bubbles in the paint the rust is right underneath so you have to remove the paint. I scraped the rust and paint above it first and then I applied the metal grinder and the drill. Usually at the end of the work day I've applied the rust converter to work overnight. It is a good idea to finish the work day with some kind of paint application as it requires some time to dry.
I haven't taken the pictures of the rusted areas on my car, so I used some from the internet that look similar: http://s1.bild.me/bilder/160512/8757683Rust_1.jpg (http://www.bild.me), http://s1.bild.me/bilder/160512/4807046Rust_2.jpg (http://www.bild.me).
Another material I've used is fiberglass with fiberglass special cloth for the areas where rust ate through the metal and left holes in the body. Fiberglass material is used to fill up the holes as it gets rock solid when dry and doesn't rust. It adheres to metal quite well. I used the reinforced fiberglass which should be a bit stronger than regular. I've watched quite a few videos on how to use the fiberglass and cloth to repair the holes in the body.
http://www.youtube.com/watch?v=g_FDYbWs5eY&feature=related
You can search more videos and helpful websites to prepare yourself better when it comes to the actual job. Here's some: http://www.instructables.com/id/How-to-Fix-Rust-Spots-On-a-Car/,
http://www.youtube.com/watch?v=aCMeAze56AQ,
http://www.youtube.com/watch?v=VMhoRnBIEE8
You also need some tools in order to remove the bumper sides or plastic panels within the wheel wells to get a better access to the rust. Some parts are attached using plastic clips, which are hard to remove. I've removed most of them but 1-2 got broken. It is alright as you can buy them at an auto shops. The grinder is really strong and you have to be careful using it as it can easily grind right through metal and even damage the skin on your hands.
I was working on each spot one by one. I've purchased a torque wrench to remove the wheels to get a better access to the rust spots. The one that comes with the car is too short. I recommend using a torque wrench. I lifted up the car using the existing jack (found in the trunk).
Keep in mind that all the areas prior to painting should be grease free, otherwise the paint won't adhere very well. There are a bunch of degreasers you can purchase. I recommend using clear ones like acetone or alcohol based.
The area that needs to be painted should be properly masked off, using masking tape, plastic or newspaper. The spray may affect your existing color when gets over existing car paint; and it's hard to remove later. I had some trouble with my primer because it was a very light gray color and I got some of it on the car's painted areas. I've purchased the masking tape and clear plastic film with masking take online together with the paint sprays.
The sand paper I barely used - mostly on wheel rotors and when finishing up with fiberglass. Fiberglass I only used to repair major holes where rust ate right through the metal. Keep in mind that fiberglass takes very little time to work with after you've mixed it with the hardener - approximately 5 minutes or less. I've purchased a plastic board and a plastic scraper for the fiberglass. You should clean the board and scraper thoroughly after each use.
Follow the instructions on each paint can on how long you should leave it for until you can apply the next layer. I usually gave it an hour or so. After the paint job was done I removed the masking tape and plastic and noticed the edges. You can smoothen them out with a sharp knife and then reapply the clear coat so there are no gaps in between the old and the new paint.
So finally here are some pictures of my finished work:
http://s1.bild.me/bilder/160512/9172697Above_the_Rare_Right_Wheel.JPG (http://www.bild.me)
http://s1.bild.me/bilder/160512/8722514Back_Trunk.JPG (http://www.bild.me)
http://s1.bild.me/bilder/160512/2297625Door_Spots.JPG (http://www.bild.me)
http://s1.bild.me/bilder/160512/8935472Front_Hood_Rust_Repaired_Spot.JPG (http://www.bild.me)
http://s1.bild.me/bilder/160512/9783159Front_Left_Wheel_Lower_Side.JPG (http://www.bild.me)
http://s1.bild.me/bilder/160512/5233661Front_Left_Wheel_Upper_Side.JPG (http://www.bild.me)
http://s1.bild.me/bilder/160512/7379681Front_Right_Wheel.JPG (http://www.bild.me)
http://s1.bild.me/bilder/160512/8072746Rare_Left_Wheel.JPG (http://www.bild.me)
And you don't notice it too much from the distance:
http://s1.bild.me/bilder/160512/98602164.JPG (http://www.bild.me)

In the end when your paint is absolutely dry - takes maybe 24-48 hours depending on the paint itself you can apply some buffer or wax for the car to look shiny. I didn't actually do it yet. There are some creams you can purchase and electric buffers which are a bit expensive.
Well, I hope this will be helpful for you if you decide to repair the rust yourself.

aris
10-09-2012, 03:15 PM
nice work...but i it will be back

coriolis
10-09-2012, 03:17 PM
nice work...but i it will be back

Yeap, unfortunately. I have the same problem on mines, same colour and I've just given up. Spent too much time, money and hassle trying to fix it, but it always comes back. Interestingly enough, it comes back faster and faster every time I try to hide the rust.

Highlander
10-09-2012, 09:46 PM
Oh yeah. It will probably come back, but how soon? Like in a year? I actually did a rust proof on the car ($250). They sprayed the bottom with black rocker guard paint and applied the grease all around it.
I can see why the rust would come back. The rust is removed mostly from the outside surface of the panels but it actually still on the inside surface where it's hard to get to it. And that's where it starts up - from the inside and underneath.

silverstarmazda
10-09-2012, 10:57 PM
you didnt blend the paint, but very nice work considering its diy. i still need to paint my fender....but so much other mazda problems lol

Canadmos
10-15-2012, 07:24 PM
Oh yeah. It will probably come back, but how soon? Like in a year? I actually did a rust proof on the car ($250). They sprayed the bottom with black rocker guard paint and applied the grease all around it.
I can see why the rust would come back. The rust is removed mostly from the outside surface of the panels but it actually still on the inside surface where it's hard to get to it. And that's where it starts up - from the inside and underneath.

Last winter/spring, my car was backed into while parked. Buddy did some damage to the front and at the time I was working for a body shop. While repairing the front bumper, we also repaired all of the rust, similar to what you did. We didn't cut out any metal.

The paint was bubbling within two weeks and the bottoms of my doors are right back to where they were. Trying to fix those spots hardly did a thing. It sucks. Everytime I look at this car, there is more rust.

Highlander
10-20-2012, 02:54 PM
Yeah, I was trying to find how to do it, but couldn't find anything. Yeah, after the paint dried off I took off the masking tape and the edgy white lines were there (I assume from the primer as it was light gray color). I wiped off the area (after it's dry) and then reapplied the clear coat over the edges.

mazdasteve
03-13-2013, 11:38 PM
nice work...but i it will be back

i just bought my mazda 3 months ago, and it had rust when i bought it, there is nothing you can do to contain the rust other than wash it oftenly and keep it in a rust free environment when your not driving.
the only when to permanently eliminate the rust, and some shops oftenly wont even go this far, is to manually grind the rust out untell youre at bare metal, if there is rust, there is a source, and it will always spead. remove it all, and fabricate with sheet metal, or simply replace the fender, when you consider the time and effort and money in parts put into doing these jobs, a fender of any type really ranges from only 1-400$. and most oftenly you can find one like new with a couple phonecalls to scrapyards. dont waste youre time with bondo, and other " quick and easy to fix methods". doing nothing but causing yourself more work.