How do you remove heavy rust and scale from engine cooling fins?

[ebinmaine 62,952]

We are working on the K341 that is going in the C160.

The engine is going to be painted a light color.

Navajo white to match the wheels and other parts.

 

I can't use a sandblaster because the engine is all assembled.

 

We've tried 1/4" diameter wire brushes on a drill and they seem to work okay but literally last about 1/4 of one fin. That's a lot of wire brushes to purchase!

 

What other suggestions do you have?

 

 

 

[oliver2-44 8,834]

Vinegar is a good rust remover. I'm just beginning to use it more.  @jabelman might jump in here as I've read of him using it.  I have soaked some rusty items in a 5 gallon bucket, took about 4 days with very good results.  I also has some old monkey wrenches I wanted to clean, but not immerse the wood handles.  I wrapped the metal part in several layers of old towel that I had dipped in vinegar, then wrapped them in plastic wrap tightly to keep the vinegar from evaporating.  It did a fair job.

 

I wonder if you cut strips of cloth that you could loosely pack into the fins, then put some plastic wrap around it?

As I type this I just realized I haven't used vinegar near/on aluminum (head) or brass (governor shaft nut) so hold this idea.  Hopefully someone can comment on the effects vinegar would have on those metals! 

 

I've found at the grocery store, the name brand vinegar ($3.95 gal.)is 4-5% acetic acid and the less expensive ($2.95 gal.) store brand is 9% acetic acid.  So I of course used the 9% acetic acid vinegar. 

 

Edited December 31, 2018 by oliver2-44

[Ed Kennell 35,602]

I have used  6" dia. wire wheels and scotch brite pads on a 4.5" angle grinder to clean fins.     Make sure you have good protection as the wires break and fly off and if the pads get caught, they explode.   My barber found a wire stuck in my ear lobe during a haircut a few years back.

[squonk 38,844]

Needle scaler 

[953 nut 51,499]

All good ideas!                   The one thing you don't want to do is grind/sand the fins smooth. The roughness of a cast fin is added surface area and breaks up laminar flow allowing the turbulent air movement  to provide better cooling.

[ebinmaine 62,952]

8 minutes ago, 953 nut said:

provide better cooling

My concern is really about getting the paint to stick long term.

We've removed some of the rust from the fins and there's still a solid layer.

I know we won't get it to bare metal but how much is enough?

 

Perhaps we need to use a rust converter chemical like Naval Jelly or similar?

Perhaps we should just not worry about it?

 

[AMC RULES 36,941]

Old school baby!

[WHNJ701 4,164]

I have a bench top grinder I ripped all the guards and safety junk off and mounted 2 wire wheels on it, I then mounted the grinder to a 2x6 which then gets clamped to a set of saw horses outside.  I prep alot of parts that way

the cooling fins shouldn't be painted they should be cleaned of debris and junk for proper cooling,   however I do I paint the heads with a real Thin aluminum paint.

are you taking the head off?, I would assume you are since you would want to decarbon, check the gasket etc..

happy new year!

Edited December 31, 2018 by jabelman

[ebinmaine 62,952]

1 minute ago, jabelman said:

are you taking the head off, I would assume you are since you would want to decarbon, check the gasket etc..

That's part of the issue.

 

I did all that over a year ago and won't be removing the head to repaint.

I don't want to damage the aluminum either.

 

[WHNJ701 4,164]

Looks like old school would be the way to go then

[pfrederi 17,125]

Paint is actually a bit of an insulator They make special thin black paints for radiators as regular paint interferes with heat transfer...why paint it

[AMC RULES 36,941]

  Wire brush, no paint.  

[Digger 66 3,476]

21 minutes ago, pfrederi said:

Paint is actually a bit of an insulator

why paint it

 

Was wondering that myself ^ 

Scrape / pick off as much as you can and leave it natural .

[JoeM 7,608]

[ebinmaine 62,952]

Here's the engine as it sits on the bench for us to work on it

 

 

 

I'll get some more of it ... during process.

[wallfish 15,905]

14 hours ago, Ed Kennell said:

My barber found a wire stuck in my ear lobe during a haircut a few years back.

You're killing me Ed. Can only imagine what the Proctologist found

[Ed Kennell 35,602]

1 minute ago, wallfish said:

You're killing me Ed. Can only imagine what the Proctologist found

 

Now John,  no hitting below the belt.

The  barber that found the wire was a young lady that had just started working for my 80 year old long time barber.

She was trimming the hair on my left  ear when the wire stalled the clippers.

She freaked out and refused to finish the haircut.

The old timer got a needle nose pliers from his tool box and yanked it out...then finished cutting my hair.

 

BTW,  as you know, I have very little hair so the barber only charges me $2 bucks for the haircut.

Then he adds on $2 for each eyebrow and each ear for a total of $10.

 

Sorry for the  Eric, @ebinmaine,  but it's John's fault.

[wallfish 15,905]

3 minutes ago, Ed Kennell said:

The old timer got a needle nose pliers from his tool box and yanked it out

Your barber needs a toolbox to cut your hair. Again, you're kill'n me Ed.

Sorry for the  Eric, it's Ed's fault for continuing to TEE them up!

[953 nut 51,499]

13 minutes ago, Ed Kennell said:

as you know, I have very little hair so the barber only charges me $2 bucks for the haircut.

              Lucky he doesn't charge a "Finder's Fee".                

[ebinmaine 62,952]

57 minutes ago, Ed Kennell said:

Sorry for the  Eric, @ebinmaine,  but it's John's fault.

 

49 minutes ago, wallfish said:

Sorry for the  Eric, it's Ed's fault

 

 

Boys, Never apologize or be concerned about being off topic in one of my threads.

I really do enjoy the amazing friendly banter we all have.

And today I have learned to inspect my ears more carefully after using a wire brush.

 

[squonk 38,844]

Get the needle scaler. It will take you longer to hook up an air hose to it and turn the compressor on than it will to get the rust off the cylinder.  Plus they are great for stripping paint off the tractor frame! 

[ebinmaine 62,952]

3 minutes ago, squonk said:

Get the needle scaler. It will take you longer to hook up an air hose to it and turn the compressor on than it will to get the rust off the cylinder.  Plus they are great for stripping paint off the tractor frame! 

Mike I've been thinking about buying one of them for a little while anyway.

Is there a way to use that for the area in between the cooling fins?

I'm sure they make many many different kinds of these but the only ones I've ever seen where at least a half inch or more in diameter.....

[squonk 38,844]

Just stuff it in there. Force some needles between the fins. Each needle moves independent of the others. Buy spare needles when you get the scaler. HF has them.

[ohiofarmer 3,156]

https://www.harborfreight.com/4-inch-150-grit-shaft-mounted-wheel-brush-91372.html

 

https://www.harborfreight.com/3-in-80-Grit-Nylon-Abrasive-Wheel-with-14-in-Shank-60324.html

 

 Worth a try.. These wheels don't get caught as easily as steel ones. I use them a lot to get those last bits of paint from tight areas

[The Tuul Crib 7,332]

 Well Eric you know my technique which I just started doing is the electrolysis method. Of course  you don't put aluminum in the mix but cast-iron would clean up like a breeze.