Repair Rust Spots and Dents on your Car
In this article I will be explaining how I personally repaired some rust spots on my MGB GT 1980 model and the problems I encountered. I say 'how I personally repaired' because whilst doing the preparing for the job I obtained advice from friends, manuals and club members and some was good advice and some opinions I discarded.
Firstly I will say it was not a simple job. Many factors need to be considered before even beginning to touch the effected areas. I began by checking my Haynes manual and buying the necessary equipment in order to undertake the job. The manual is very useful if you can obtain a copy because it has a double page centerfold and specific advice to your model car.
I managed to narrow it down into 3 sub catagories, preparatory products, filling products and finish/paint products.
The Preparatory products included wet and dry - sandpaper, wire brush, pliers for sharp bits of metal, rust eater, goggles, dust mask and protective gloves. Don't forget some old clothes or overalls!
The Filling products included Isopon p30 & p40, small trowel(usually comes with fillers), glassfibre resin + hardener, cloth because it can get quite messy!, fine wet and dry paper( 600-1200 grade), sanding block
The Finishing Products included specially mixed paint(must be exact match with code and oil-based), primer(i used grey but depends on lightness of top paint), 3 pack of masking tape, lots of newspaper, AutoGlym Paint Renovator, TurtleWax Original in tub, cloth and a garage
These are just a rough idea of the things you will need and I will go into more detail in the following paragraphs.
Before you can start there are a few important things you must plan, the main ones being how much time you will need, a schedule of when you will do each step and the conditions needed for a successful drying of the paint.
I decided to book a week off work when I originally painted mine, this was ideal for me because I spent all my money on my car rather than a vacation anyway. I also found this benefitial because I would probably be too tired and find it frustrating if I had to be in work whilst concentrating on something so important to me.
Next I was able to write a brief outline of how I was going to complete each task in the 9 days I was free and still have time to participate in my social activities. It went something like this:
- Saturday: clear away debris and sand 5 main spots affected by rust i.e areas either side under windscreen, tail wings and under left headlamp. (these being smallish bubbles where paint is begining to crack)
- Sunday: repeat process of clearing and sanding making sure all rust is removed and bare metal is showing. Depending on the condition of the car you have purchased there could be a lot of rust spreading, unless you want to go the full 9 yards on the job just remove what is necessary to make a satisfactory patch up. Apply Rust eater with small brush to areas.
- Monday: Now you have a nice clean surface readily prepared for you to start applying some Isapon P38 polyester filler. My one friend also has undertaken filling jobs, if you have a large hole you can always add a piece of small wire mesh to keep the filler from falling through.
- Tuesday: Repeat filling with P38 and make sure you have applied it nice and smoothly using trowel provided and even you fingers if need be. For larger holes Isopon P40 fibreglass mix may be more appropriate.
- Wednesday: Either filler dries fairly easily and can even be sanded wet, this is an important part and can be crucial to your end result. You want to use at least 2 grades of wet and dry, and avoid pits and grooves being as gentle as possible. Don't stress too much remembering if you wanted an expert job you'd be paying someone else.
- Thursday: You will probably want at least a second day for sanding, depending on how many spots and checking from different angles for a nice even edge.
- Friday: Now that the hardest parts are out of the way, you need to mask around the areas you have worked on. I left about 4-5 inches around the filler to avoid upsetting too much of the original paint job. Use plenty of newspaper to cover things such as chrome and windows. You are now ready to apply a coat of primer to each area, avoid using too much as it may show through when you come to use finished paint. So apply from a greater distance towards the edges of tape as it can leave a distinct line which is raised compared to old paint.
- Saturday: Now comes another important part, the final paint layer, your chosen colour! I had to search the internet for the code or my model, it was pretty easy on google it came straight up with a webpage. You will still need to test against something like the inside of your boot. My friend told me a great place near us which mixes paint in 30 mins and I gave the code. I have heard a number of techniques about achieve the end result:
- one was the feathering technique - I don't know how effective this is for other people or maybe I was doing it wrong, but from what I understood it involved folding the edges of you masking tape leaving the sticky side to catch particles of paint. Apparently this is supposed to give a more gradual fade into old paint.
- If your using an air brush there is a mixture you can buy which you add to the paint which dissolves into the old paint and blends it with the new.
- All these techniques are supposed to help avoid leaving a distinct line where you masking tape is, the method I used myself which I believe has created a satisfactory result for me was different. I decided that for the edges I would remove the masking tape and fade them with spraycan freehand and from a greater distance(maybe 30-35cm away)
- Sunday: Paint takes 30mins to dry so you have plenty of time for second coats. I now had time to clean up any edges with my favorite polish 'Autoglym Paint Renovator' or even a paste compound called G3(expensive) but gets rid of any marks or filler. Some people continue on to apply Lacquer but this Ive heard is very messy but could be a preventative measure for protection. I would say give your car a week or so before driving in wet weather or cold climates to ensure the paint doesn't react to the air, and apply lots of polish - prefferably Turtlewax.