Cleaning a '36-64 Oil Tank

[Plumber]

The interior was blasted with aluminum oxide, or silicon carbide. Rock hard media, that has to be completely removed
I poured a 1/4 cup of simple green into the tank and filled with with almost boiling water and 40 nuts of various sizes, then used rubber palm gloves the shake the tank for about 2 minutes.
Dumped the soap-water into the bucket and got plenty of grit laying at the bottom. The brushes are used on airless paint sprayers. Available.
Media grit gets stuck in ALL the treads of the caps and nipples. Where the larger softer brush is good for ports, the smaller hard-bristle brushes knock grit out of the threads the best.
Rinsed and shook the tank about 20 more times. The grit diminished to a few flecks left at the bottom, but each rinse still produced media-flecks.
I filled the tank with water last night and will pour the contents through 3-layers of paint filters to see what's left. If I find any grit at all, I'll rinse them again. Any media that finds it's way out of the sump will travel directly to the oil pump.
If you use copper lines with the nuts for sealing, be sure to make the copper flare wide, because if you wrench the nuts down, they'll reduce the width of the flare to where the nuts won't completely tighten. Don't force a fit.

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I was getting media-grit with every rinse, so I've opened all ports and have 120 psi of water pressure directed at every angle a nozzle will reach. There were a few bright metal winding fragments before, so I'm getting down to the jurassic layers.
And with these findings, I'll need to re-think the gas tank cleaning for por-15.

[panacea]

I shook my oil tank with a couple cup fulls of 5 1/16" hex heads and some orange smelling solvent till my arms gave out. After about three days trying to clean all the crap out, they finally rinsed clean. Next time I'll rent a paint shaker!...Mike

[Sarge]

If I ever clean out my oil tank I don't think, after reading what you wrote, that I'll use rock hard media grit that could in itself ruin a running engine, to the tune of $thousands, if not removed to the last, single, microscopic speck. But tha's jus' me.

[Plumber]

My biggest weapon is the full water pressure behind a brass twist-nozzle. I put the noz in the oil fill hole and hang the back edge of the tank on the plywood and fan, then a slow reduction to a full stream, until the tank backfills to the top. I let it sit, full to the top, and then empty it into the gallon bucket and look for grit.
I had close to none last time.
If your oil line nuts would spin-on before you started cleaning the tank, then anytime the nuts bind, you've got what? Grit. Only a stiff brush knocks it out.
This media is the devil to remove completely. You have to smash the media with a hammer to shatter it, not like spark-plug media that is designed to crush on a valve margin without galling the surface(s).
My neck hurts. This is an initiation I didn't sign-on for.

[Rubone]

The only way I have ever cleaned an oil tank is chemically, in a hot dip tank. Any kind of blasting media is not just dangerous in that application, it's plain bad practice What prompted you to try it Plumber?
IMHO
Robbie

[cane]

The interior seam will expand with heat and vibration; trap and release grit into circulation. It will be cheaper to either replace or open, clean and repaint the contaminated tank than to flush it and still need to repair your engine. If your engine fails as a result of circulated abrasive you'll have to pull the bearing races, bushings and galley plugs.

Good luck.

[2vls]

I remember when the guys at the British magazine (as I recall) Motorcycle Mechanics blew the rebuild of a Honda CBX 1000 six cylinder back in the 1990s. Seems their mechanic had cleaned up the inside of the cases with glass bead which (surprise!) got loose when they restarted the motor. Trashed the cam bearings and basically ruined the motor.

Ever since I have kept blast media away from my engine bits. I don't even like the idea, which one builder suggested to me recently, of using a low pressure cleaning with fresh (round) glass beads to freshen up the sand cast finish on the outside of the engine cases. I'm thinking wow, if I didn't get the thing totally sealed and properly clean after the blasting, I could wreck my rebuild.

Maybe soda blasting if you ABSOLUTELY MUST treat the motor inside. Even walnut shells would be better than glass or other hard media

Walt
32V4191

[Plumber]

Here's what left after another standing-boiling water rinse.
The water:


The grit.
I emptied all the water, replaced the plugs and sprayed about 1/4 can of WD-40 and spun it to disperse water. Remove the plugs and set the tanks at a tilt towards the drain hole; long-folded a sturdy Costco paper towel and twisted into the hole to wick water and WD out of the tank overnight. I'll part-fill the tank with kerosene and do another couple of drain and strains, and re-use the kerosene.
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Made pick-up sticks using a glue gun. Removed the stick first try.

The twice, almost boiling standing-water (with simple green) soaks helped tremendously on expanding any inner seams, as Cane mentioned.

This is the first kerosene rinse. Nada grit.

The rust/brown gobs are leftover water. No grit at the bottom of settled kerosene.
I left the tank soaking with kero. I'll strain it through (3) PPG paint strainers and post the results.
Note: PPG's paper filters have a tiny mesh. House paint paper filters aren't fine enough.
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If you keep the ports capped, then you can remove the drain plug and slowly open the fill cap to control how fast the kerosene empties into a bucket.
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Ay-caramba! My red stick fell out of the end of a WD-40 (white) nozzle and into the oil tank. I have it position in 1" of kerosene directly under the fill hole. I'm trying thin chopsticks.
But, I ordered these. Have a problem, buy a tool.
http://www.amazon.com/Tweezers-Jewel...ecc_rvi_cart_1
$9.13 shipped.
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I made pick-up sticks using a glue gun. Snip the end of the popsicle sticks. File the square ends of the stick at an angle to allow glue to cantilever the end so a hook can be created.

drop glue on the ends that are on a removable surface (like this Bondo spreader). Your making hooks.



After cutting the glued stick away from the spreader, hooks can be carved.
There's the nabbed red stick.

This is the overnight residue from a kerosene soak. No grit at all. Still some brown water flecks, but tank is now clean. At anytime during the procedure, if you feel threads binding, it's blast media. You have to remove the fitting and stiff brush the cap and nipple.
The oil tank and the gas tanks are the biggest hurdle. Once done the rest is nuts and bolts.

[Plumber]

Left the tank 1/2 filled with kerosene overnight and poured it off, after the black tank set in the sun for (4) hrs.
I ran out of PPG paper filters, so I used a thick Costco paper towel folded quarterly. Worked better than the PPG ones actually.
First shaken-pour and "Look Ma, no grit".

Cleaning the oil tank was the most intensive M/C work of the whole project.
The gas tank will be easier.