Topic: Removing oil from parts before phosphate

[CharlesTurner]

Recently been fighting with a pair of hood hinges that won't take phosphate.  Blast and leave in the solution for 30 minutes and very splotchy and inconsistent appearance.  Did them again yesterday and hardly any phoshate took to the surface.  I've applied motor oil to these before, so I'm guessing it's still in the surface.  Does anyone have a recommendation of something to soak these in to get all the oil off?  Tried chrome mag cleaner, which is an acid, didn't make any difference.

Thanks

[carlite65]

what about a soak in lacquer thinner?? or maybe brake cleaner? i've run into the same problem but not to a great extent as yours seem to be.

[lancelot66]

I've been using Berryman Chem-Tool for a long time Charles, to get parts clean before doing pretty much any kind of re-finish. I've been using spray cans but It comes in gallons with the little soaking basket in there, so you'd have to pour it into a container that would be big enough to submerge the whole hinge. It might work for you though. Might want to use a pair of gloves along with it too if you go this route...
-Lance

[jwc66k]

I had a hood latch that didn't look right either after phosphating. I used paint thinner with a clean (for recycling back into the thinner can) oil changing pan and a couple of different size brushes to get inside the housing, a day or two of air drying and bead blasted again. I've also used spray can brake cleaner on hinges and latches for the penetrating power. All the small parts I do in bulk go into a gallon can of old carb cleaner for a week (to loosen paint accumulations). The carb cleaner is too contaminated to use on carbs but I save the old stuff in a five gallon bucket for large parts. A week in that mix hasn't failed yet. I rinse the carb cleaner off in a deep sink using the soapy water from my clothes washer, then air dry. The city has a recycling program for hazardous materials that I occasionally take advantage of. Another trick is to drain the remaining oil from WD-40 spray cans that have lost their gas and use that oil to flush pivot points clean (use an eye dropper) after phosphating. It takes a couple of days of applying oil a couple times a day.
Just a few things I've tried.
Jim

[Toploader]

Soldering and brazing requires chemically clean surfaces. To meet this flux is used. An array of flux is available for use in different applications. I've used a flux containing zinc chloride when I needed a clean metal surface (wasn't for phosphating, though).

On the same note pickling agents are used for cleaning steel chemically. Hydrochloric acid is widely used (clean with water after).

Aqueous cleaners are used in industrial part washers with better results than hydrocarbon cleaners in some cases. Maybe you could go down that road (I have no experiences with these, just a suggestion).

Remember most thinners are oil (based).

If blasting have been done on a greasy surface there is a possibility that contaminants have been hammered into the surface.

[CharlesTurner]

Thanks for the replies.  Yes, I'm afraid that blasting has possibly pushed the oil down farther into the pores of the metal.  Will try out some different things suggested.  It's really annoying as I have phosphated many hinges before with no problems.

[rockhouse66]

Muriatic acid - briefly.

[JKWilson]

One additional suggestion Charles, Heavy Duty Easy Off oven cleaner.

[CharlesTurner]

Thanks again, really appreciate the replies!
 

[aaatp]

I used acetone to degrease all my parts before phosphating. What's nice is that it dissolves oil and when it dries it leaves no residue whatsoever. All my parts turned out great.

John