November 14, 2009
Cleaned up and repaired the oil tank and the tool cover, and got them mounted.
Click pictures for a better view.
The tank looked to be in decent shape. It had cracked and been repaired once many years ago. You can see the brazed repair under the paint at the base of the forward top mounting bracket.
Here's where I started to get a little more concerned. This is the "Oil Tank Filter", and is supposed to have a mesh screen (the filter) on it. I later found what was left of the screen embedded in the sludge in the tank. Note the goo. It's the consistency of gritty jam.
Inspection of the inside of the tank with a flashlight showed a lot of thick black stuff on the bottom. My regimen to clean the tank was:
1. Load half a pound of pea gravel with solvent (used paint thinner). Plug orifaces and shake for a while. Empty out the solvent and gravel. This gets out most of the remaining oil.
2. Repeat 1 until solvent comes out fairly clean. There was still evidence of a black material at the bottom of the tank.
3. Load half a pound of pea gravel with hot soapy water. Plug orifaces and shake for a while. Empty out the water and gravel. Still some sludgy stuff.
4. Load half a pound of pea gravel with hot caustic (sodium hydroxide) solution. Plug orifaces and shake for a while. empty out the caustic and gravel. This should attack any thick oil sludge. After this stage, I could see mostly bare metal inside the tank, but there were patches of what appeared to be rust.
5. Load half a pound of pea gravel with a strong solution of phosphoric acid. Plug the orifaces and shake for a while. Empty acid and gravel. This should eat the rust and provide a protective phosphate coating on the bare metal.
After all this, the inside of the tank looked clean. I did notice while shaking in step 5 that the liquid was leaking out of the tank. After checking my plugs, i realized that the leaks were from some tiny pin holes on the top of the tank. They were probably bridged by rust during cleaning with the other fluids, but the phosphoric acid dissolved the rust. The holes wer barely visible. The picture shows how big I could make them with an awl. I dimpled each of them slightly and soldered over the area to cover them.
In parallel with the oil tank I was also working on the tool cover of similar shape that goes on the other side of the bike. There is no earthly way to do a good job stripping, cleaning, or painting inside the tool compartment in the cover. It appears that the factory spot welded the tool shelf onto the cover after painting. I ground off the spot welds so I could do a proper job of prep and paint.
Tank and cover, ready for paint. Filled a few minor dings, and gave the units a phosphate treatment.
I painted the tool shelf and the back side of the cover, then put the two together. I have a spot welder, but in this case chose to attach the shelf to the cover with a metal filled epoxy (OK, it's JB Weld). The bond will be plenty strong if the metal surfaces are free of paint, grease or oil.
The exposed sides of the tank and cover were painted with about six coats each of black and clear lacquer, hand rubbed after each three coats. This series shows the progression of the final finishing of the tool cover. The tank is used for comparison in all the photos.
After last coat of clear lacquer has dried for a few days, (1) rub down with wet 600 grit, (2) wet 1500 grit, (3) Automotive rubbing compound, (4) automotive polishing compound. You can see that although the tank looks pretty shiny, the reflections in the rubbed cover are more distinct.
Finally some anti-swirl compound and some wax finish the job. Picture on right shows difference between rubbed and unrubbed.
Pop rivet the re-plated detent spring onto the cover.
The tank is mounted on rubber cushions at three points--one at the bottom of the tank, and two at the top. The battery carrier is also rubber mounted to the frame on one side and to brackets on the oil tank on the other. Here are all the pieces to the tank and the battery carrier. All the rubber parts except the battery mat are new.
There is apparently some confusion on the correct dimensions for the tank and cover mounting grommets. The two sizes in the picture were both supplied under the same part number. The larger ones seem to be the correct ones.
On cleaning up the old tank filter fitting, there was this pretty severe corrosion damage on the flare fitting and on the tubing. A new filter is a fairly pricy part, but I got one anyway. The feed pipe is a short piece of 5/16 steel tube with a double flare. It doesn't seem to be available from any of my usual sources, so I made one from a piece of pre-flared steel brake line.
Tank looks pretty shiney...
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