There are many ways to restore your cooling tins as you can probably imagine. Let’s face it. When it comes down to it they are just pieces of metal that get painted.
Ask yourself what you want in a finished product. Perfect show quality restoration? Serviceable and clean? It is really all up to what your desired outcome is.
Many driveway amateurs do not have access to media blasters, paint sprayers, clean rooms/booths, etc. This includes myself.
So. What do I do to try to do optimal restoration on a budget and with things commonly found in my garage and at my local automotive store?
Why basic manual tin restoration!
Manual Tin Restoration (On A Budget)
What you need?
- Paper Towels
- Wire Brushes (Plastic/Steel/Brass bristle) – Harbor Freight cheap ones work fine,
- Large Plastic Bin (to use as a parts bath)
- Outdoor Hose (to rinse parts)
- Purple Power/Simply Green (or other soapy degreaser)
- Handheld Orbital Sander (with a variety of grit sheets) – great for large flat surfaces
- Dremel (with sanding bits) – if you really want to get detailed
- Steel Wool (to scrub parts) – it sometimes works a lot better than brushes
- Appropriate high-temperature automotive primer, paint, and clear top coat – something to stand up to say 500°F (260°C) at the most
- Sunlight – it helps
- Fan (can help evaporate water quicker)
- Acetone (final cleaning of parts and moisture evaporator)
- Rubber gloves
This does not cover any repairs to your ins. It assumes your tins are in good shape with the exception of some surface corrosion that may be present. Repairs to screw mounting points, cancerous rust, or other damage repair is outside of the scope of this and requires basic welding or even metal fab.
Step 1 – Tin Removal
Remove all of your VWAC engine tins from your engine. I hope you have a full range of tins, and do not just have a haphazard setup as missing tins can reduce the cooling efficiency of your motor. And in the air-cooled world, cooling is key.
- Consider your tin screws at this time. If you are still dealing with originals, perhaps you should preserve and reuse them. I personally like the larger pan head screws and washers I took off my original 70’s engines. Much nicer than the aftermarket kinds that are available.
Step 2 – Manual Debris Removal
The goal of this step is to just get rid of the large “crap” that may have accumulated on your tins. . Get some paper towels and a basic spray cleaner. Clean up the major crud. This is especially found on the heat exchanger tins, the undersides of the cylinder tins, and the 2 bottom tins at Cylinders 2 and 4.
It wouldn’t hurt to go over all of your tins at this step.
Step 3 – Degreaser Bath #1
Fill up your bin with hot water with the degreaser soap/detergent of your choice. I prefer Purple Power and Simple Green, but I’ve used Dawn Dish Detergent as well when others were not on hand.
Drop your tins in and let them soak a bit.
After 10 minutes or so, begin to scrub them up with the brushes and steel wool, making sure to get into the folds and metal creases. Keep pulling them out of the water to inspect them and keep working all debris off.
- Change your water frequently. It can quickly become dirty and the detergent’s power will be diminished.
Step 4 – Rinse
Rinse the parts off with clean water. I prefer my garden hose. Shake as much water off as you can and lay them out to dry. I typically do this in the sun on a hot concrete driveway. You want the water to evaporate as quickly as possible.
Step 5 – Inspection – Grease gone?
Once dried, take a look at the surfaces. You are looking for any sheens of oils or greases that may still be on them. Don’t mind any surface corrosion at this stage.
If they appear oily, or feel oily, repeat Step 3 and 5 until they are as oil-free as possible.
Step 6 – Inspection – Plan your attack!
Pick up each tin and inspect them. Note the areas of each piece you’ll need to remove corrosion on.
I find it best to sort tins by “needs most work” and “needs least amount of work” as you can quickly crank out the easy ones and get them on to other steps.
Step 7 – Sanding (This can take some time)
Using either wire brushes, sand paper, or an orbital sander, sand off the top layers of surface corrosion (if present). You may need to get meticulous here and creative with how you can get your abrasives into the crevices and any folds in the metal
The orbital sander is exceptionally good at long flat surface areas. Rough up the existing paint.
Continue going over each tin in detail until you are satisfied with the work you’ve done. You can spent as long or as little time on this step, but the more corrosion you remove, as well as the more paint you lightly scuff, will make for a better surface.
You can also try using a Dremel tool to sand down small and fine areas. That’s up to you and your goals for your tin.
Step 8 – Degreaser Bath #2
Fill up your bin with hot water with the degreaser soap/detergent and wash all your parts again, getting any grit or rust off them. The cleaner the parts the better.
Step 9 – Rinse #2
Rinse the parts off with clean water. Shake as much water off as you can and lay them out to dry.
Step 10 – Inspection – Yes! Again!
Go over each of your tins, feeling areas you sanded and determine which ones may need more work, or if they are good to go. The level of effort done earlier will show here. You want to have as much surface corrosion removed as possible.
Repeat steps 6-9 as long as you have to, or until you are happy.
- This is a good time to bend any misshapen tins back to something resembling normal. The cylinder tins fan shroud openings often get bent up and distorted.
Step 11 – Acetone wash – This is critical!
Wearing gloves, dip paper towels into acetone and wash up the surface of all of the tins. This will clean up any additional residues that may have gotten on them.
Try to get into every crevice. The cleaner the surface, the longer lasting your work will be.
Repeat this on each tin until the paper towels are clean. The beauty of acetone is that it displaces water and evaporates quickly.
Warning! Do not touch your tins again with bare hands. Always were rubber, powder-free latex, or nitrile gloves from now on to keep the surface contaminant free.
- I am sure other solvents will work. However, the goal here is to remove every last vestige of contaminants on the metal surface. I found acetone to be the best to work with and it doesn’t leave any residue behind when it evaporates. Mineral spirits often does.
Step 12 – Primer
Following the instruction on your primer, apply clean coats in a well-ventilated area.
When dry, look at the primer coat. You may need to remove specks here and there from the can nozzle’s spray. It is inevitable.
Step 13 – Painting
Following the instruction on your paint, apply clean coats in a well-ventilated area. The number of coats you want will determine your effort here.
When dry, look at the paint coat. You may need to remove specks here and there from the can nozzle’s spray. It is inevitable.
Repeat coats per the instructions of your paint.
Step 14 – Clear Cover
Following the instruction on your paint, apply clean coats in a well-ventilated area. The number of coats you want to apply will determine your effort here.
Repeat coats per the instructions of your paint.
Note: Some paints require some roughing up paint coats prior to another coat. Make sure you first coat if fully dried and cured before doing this or you will have a bad time, and some really bad sanding paper!
Step 15 – Admire your work.
When all of your paint is dried and fully cured, admire your work.
- The inner parts of the fan shroud will be all but impossible to clean. Do your best to get as much oil and grime off of them. You won’t be able to spray much inside, but what you do spray you want to adhere for years to come.
Top Engine Tins (visible from engine bay)
- Let’s face it. Your fan shroud and the tops of your cylinder tins, pulley tin, and front tin (where your preheat hoses go) is what makes your engine bay your jewel box. These are the areas you should really pay attention to when painting and top coating. While it is important to make sure that the surfaces under your cylinder tins, and under your engine, are coated to prevent future corrosion, the amount of time and effort you choose to spend will determine how long all of this takes. Personally, if you are already doing this manually, spend the time on ensuring the visible stuff is flawless. Manage your time well.