De-greasing delicate aluminum?

Carmine

Old Man with a Hat
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I'm repairing a non-C body after a minor wreck last fall...

I lucked into finding a non-rusty 79 Chrysler 300 in a local pic-a-part and scored a lot of parts, including an a/c condenser. I grabbed this one because the only oily area was at the connection/seal, thus indicating that was a leak the last time the a/c worked. I would like to clean this oil buildup, but my normal "go-to" for heavy grease (Oven Cleaner) is a no-no for aluminum (I think?). Keep in mind, heavy mechanical motion isn't an option because of the delicate nature of the fins. Any ideas on how to clean this part? The part that looks like it's made from volcanic ash is supposed to look like the fins to the right.

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I think the spray on engine cleaner is OK with aluminum parts. Something like Gunk or one of those brands.

Soak it, hit it with a hose.
 
nu brite coil cleaner made by Calgon # 4891-08 is the best coil cleaner available. hvac guys should have it in stock or in their truck if they are any good at their trade. be careful though mix it 50/50 with water put it in a spray bottle or garden sprayer and be careful and don't inhale the fumes. it also eats paint so don't use it around painted surfaces or if its windy out. the foaming cleaning action will make you think you are watching a horror movie. this **** works. rinse it off thoroughly after it has done its job.
 
Light application of heat - (hair dryer) to soften the buildup, scrape the main part of it away with a plastic scraper. Use Castrol Super Clean or something similar to remove the residue, and you should be able to get it off. Good old lacquer thinners will get the rest.
 
that stuff is for kids. listen. you don't want your condenser or evaporator to just look clean. you want it to be clean inside. clean means proper heat transfer whether it be a condenser or an evaporator. the original post from carmine was looking for a way to clean the area beside the condenser. we need to go a step further. the condenser is filthy inside as well as outside. the **** I am recommending is the best **** available period. the fin spacing on automotive condensers is no different than a central air conditioner. the fins are spaced so closely together that they plug up incredibly fast. if you want it to look shiny paint it silver. if you want it to dissipate heat and cool properly than use the **** I recommend.
 
I'm repairing a non-C body after a minor wreck last fall...

I lucked into finding a non-rusty 79 Chrysler 300 in a local pic-a-part and scored a lot of parts, including an a/c condenser. I grabbed this one because the only oily area was at the connection/seal, thus indicating that was a leak the last time the a/c worked. I would like to clean this oil buildup, but my normal "go-to" for heavy grease (Oven Cleaner) is a no-no for aluminum (I think?). Keep in mind, heavy mechanical motion isn't an option because of the delicate nature of the fins. Any ideas on how to clean this part? The part that looks like it's made from volcanic ash is supposed to look like the fins to the right.

View attachment 375844

Any chance you know/have the VIN for the
'79 300 parts car? Some folks over at FBBO are logging every '79 300 VIN they can find:
1979 Chrysler 300 Registry

Thank you for any help you can provide.

Back to the topic at hand. I use simple green for a lot of things, but that Calgon coil cleaner sounds like the way to go for coils
 
As dried as that accumulation appears to be, I concur with the plastic scraper. Or, even a flat-blade screwdriver used carefully and gently. Then probably a shot of cleaner for the residual stuff. Once clean, then a light polish with steel wool or light green ScotchBrite, followed by some clear battery protector spray (clear paint) for preservation (on the exposed tubing only).

Use an alcohol flush solution for the innards, similar to the old "A/C line flush fluid" we used to be able to get, back in the 1990s.

Keep us posted on your progress,
CBODY67
 
Put some good dish soap in a spray bottle and thin it with just enough water that it will spray. Then soak it down over a couple of days. No harsh chemicals to worry about.

That new dish washing spray soap that flows grease out of that pan, looks like it might make some decent degreaser?
 
nu brite coil cleaner made by Calgon # 4891-08 is the best coil cleaner available. hvac guys should have it in stock or in their truck if they are any good at their trade. be careful though mix it 50/50 with water put it in a spray bottle or garden sprayer and be careful and don't inhale the fumes. it also eats paint so don't use it around painted surfaces or if its windy out. the foaming cleaning action will make you think you are watching a horror movie. this **** works. rinse it off thoroughly after it has done its job.


This stuff?

https://www.amazon.com/Nu-Calgon-Inc-429108-Nu-Brite-1-Gallon/dp/B00ECV4D38
 
that is the stuff Monaco. you wont be sorry you bought it. believe it or not it even works on a/c condensers what it was intended for. lol
 
I used the idea of applying some heat and a light scrape on the no-fin areas.. Then I put the hottest water I assumed wouldn't melt a thick trash bag + some "purple power". I let that sit in the sun. It stayed hot for a long time. Removed from bag and used a moderate brush. It came out pretty well I think.

Opening the system revealed that it was very, very dry. However, it will be a long time before I care too much about getting the air going. Frankly I wish it didn't even have a/c, but I don't want a "kludge" of half/half parts.

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Keep in mind, this part was originally painted black. I'll touch it up as necessary. The impact bent the lines a little more than I expected. I might just seek out new hard lines since the AC isn't a priority. I actually have both ends covered in aluminum tape.

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Here are some before/durings

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NAPA carries an Aluminum Brightner that has Phosphoric and Sulfuric acid in it the gallon jug is #1478 and the spray bottle is #1458. It is for use on all machine finished open pore cast aluminum so you might have to be a little careful with it but it might work if you dilute it with water.
 
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