Rust

If there is one thing that an older bike restorer comes across, it's RUST! The curse of living on a wet planet with lots of oxygen. Rust will occur just about anywhere there is metal so I will break it down into the different areas of the bike where it occurs and how to handle it. Let me first say that the highest quality of restoration comes from the cleaning and rechroming of damaged parts.... BUT, most of us can not afford to have parts rechromed and thus this article provides an avenue for us less well off restorers.

THE FUEL TANK: By its design the fuel tank just asks for rust. If you live in an area with just about any moisture in the air and with fairly large temperature changes throughout the year, you will see rust. The air chamber above the fuel within the tank provides a supply of moisture that will condense when temperatures drop, adding unwanted rust producing water to your tank.

There are 3 things that you can do to a rusted tank and still ride the bike:

I tend to follow the second method and thus I will describe that here. Try this at your own risk to the tank and yourself, if you are a minor you need adult supervision!

  1. Remove the tank from the bike and remove the fuel. I find that lawn mowers can tolerate quite old gasoline!
  2. Remove the fuel petcock from underneath the tank. The petcock will need cleaning but since it is made from aluminum the acid will harm it.
  3. Stopper up the petcock hole with a rubber stopper. (better hardware stores will carry them). I would also clean the outside of the tank and put on a thick coat of automobile paste wax for protection. (leaking acid can cause damage)
  4. Get yourself a pair of good rubber dishwashing gloves, goggles and perhaps even a rubber apron. While buying this protective gear, purchase a gallon of muriatic acid (really it is hydrochloric acid but this old name is what it is sold under) Also buy a large plastic drain tub that is bigger than your tank.
  5. Find 2-4 cups of old nuts, bolts and screws!!? Pour the metal into the tank and then close the fuel fill cap and petcock hole. Now make like Ricky Ricardo and shake rattle and roll the tank. This will dislodge a lot of the rust and make the work of the acid easier.
  6. Shake out the loose metal and save for the next tank. Pea gravel will also work but the sharp edges of the metal is more efficient. Flush the tank with water to remove any loose rust.
  7. With the stopper in place, half fill the tank with water and place the tank in your plastic drain tub.CAUTION! Now pour in about one half gallon of acid. CAUTION This acid is hot stuff and you better protect yourself and the surroundings. Now fill up the rest of the tank with water. Don't let the acid run over the surface of the tank.
  8. Let the tank stand with the fill cap open and check every 15 minutes on the progress of the acid. You will see that the rust will start to disappear and the gray metal beneath start to show. I have had tanks take from 1 to 4 hours depending on the level of rust.
  9. When the job looks done, carefully remove the petcock stopper and drain into your plastic tub. Refill the tank with water and discard normally since the level of acid in this wash is very low.
  10. Shake out as much of the water as you can and then pour in 1 - 2 cups of acetone. This will absorb any water and leave the tank when poured out.(place the acetone in a bowl and allow to evaporate)
  11. Mix motor oil with gasoline, CAUTION, and rinse out the tank. A newly etched tank will rust super fast so a slight coat of oil will stop this action.
  12. To neutralize the acid, pour into the tub marble chips that you can buy in a gardening store until the fizzing stops. Harmless carbon dioxide gas is given off.

Well, nobody said it would be easy! The commercial products work in the same manner but end with a coat of plastic.

Again, watch the acid, acetone and gasoline!
Applying wax afterwards (except on the mufflers) will inhibit rust.

SHOCKS: Most older bikes have chromed shocks and they tend to rust. I would remove them from the bike and dismantle them. Using 000 or 0000 steel wool start to rub. This level of wool will not scratch the metal. If some of the rust refuses to be removed with this grade of steel wool, try 0 or perhaps higher but watch the pressure since higher numbers can scratch. As a last resort try a brass brush wheel on a bench grinder. Some pitting may remain if severely rusted.


WHEEL RIMS: Follow the same procedure as for the shocks. DO NOT CLEAN ALUMINUM WHEELS IN THIS MANNER! The spokes can be individually cleaned for best results.

HANDLE BARS AND FENDERS: Use only 000 and 0000 on these items since they can scratch easily. Fenders tend to pit if left out in the rain for years!

TURN SIGNALS AND TAILLIGHT HOUSING: These parts have the thinnest coating of chrome that can be found on a bike so go easy! The underside of the taillight is normally a bad customer. Bolts and nuts usually need help here.

INDIVIDUAL BOLTS AND NUTS: These can be very bad at times and can require the brass wheel to clean. You will be surprised on how they will improve the look of the bike once cleaned.

EXHAUST PIPES: Good luck! Although this is the area of thickest chrome, the heat really weakens the metal and rust will abound. These will almost surly require a wire brush wheel. Use 000 to polish up afterwards.

ENGINE: Although the engine block does not appear to rust it can have a very uneven finish! The news is that it is rusting but in a fashion that aluminum does, uneven white patches. A further problem is that Honda painted all of their older bike engines with silver aluminum paint. If you go rubbing too much you will go through the paint and hit shiny bare aluminum. Patches of bare aluminum and old paint looks bad! Either take 0000 steel wool and very carefully go over the engine removing the white aluminum oxide or go to bare aluminum and repaint!

OTHER ALUMINUM AREAS: (lower forks, wheel hubs) Treat this just like the engine block.
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