Technical Cleaning a machined block

The machine shop that we use at work still has and uses the old style caustic hot tank. They dipped and old Qjet SBC intake for me about six months ago and it came out clean. This is not the machine shop I use for my stuff, he has a jet washer, it does ok, but not the same as a hot tank. When I was in Tech School from 1992-94, the College had a hot tank and it was awesome, I dipped everything I could and it took paint and everything off. Today, being older and somewhat wiser than when I was 18, I wonder what was in that hot tank solution.

 

Caustic soda,,,,or Lye as most people know it .
Extremely corrosive,,,,,,and will burn you,, (flesh ),,,badly .
It will eat aluminum or pot metal like it is melting ,,,,it will degrease iron or steel very well .
But it really won’t take away the rust from an iron block,,,,maybe somewhat,,,,,,but it’s not really a de rusting agent .
But it will get rid of oil , grease,and paint .

Tommy

 

I filled the water chambers with CLR, diluted 5 to 1 with water. I foamed up overnight but when I drained the block it came out pretty clean so it probably didn't do much. It still had a bite when some of it splashed on me.

I have the block completely disassembled and have the casting plugs out. I was going to degrease it and pressure wash it this afternoon but ran out of time before some pretty nasty weather came through. I'll be doing it tomorrow.

 

We still have a caustic hot tank at the college, works great, and yes it’s sodium hydroxide (Lye). No it won’t hurt machined surfaces.

 

If you have a pressure washer, use the red tip in the gun, it's the pin point nozzle. You can get in the oil passages much easier with a lot more force. https://www.amazon.com/5-Pack-Press...hvlocphy=&hvtargid=pla-4583657839905715&psc=1

 

Gave the block a bath today and cleaned the head.

 

Scrub with dawn , every hole with rifle cleaning brushes , including crank . Do it 2x , blow it dry , hose it down with Gibbs

 

I tell our students when we make them scrub blocks after honing, when you think it’s done clean it twice more!

 

Aircraft paint remover to remove the sludge and external grease worked in the past, followed by a lot of handwork. Now I pay my machinest and clean it till I bleed

 

Pretty much all good info has been suggested. When I was fresh out of Hogh School I worked at a machine shop /Racing Engine Builder shop. I ran the hot tanks and cleaned up everything before and after machining. It’s very surprising how much dirt is still in them after they look clean even a finish honed cylinder. I used Powdered Tide soap and a plastic brush to clean cylinders up then wiped them down with WD 40 or a light oil. My only advice is when you think you have it clean, clean it again! If it’s really funky you can rent the steam pressure washers they will clean it properly.

 

I understand the hot water and tide clean.. But if I blow dry it surface rust haze appears before I can get the WD-40 to it, especially on the machined surfaces, especially cylinders. Maybe its my well water or I am just slow? Years ago I bought a kit that had some special anti rust rinse but it didn't work for me. So rinse, attack with WD-40 then blow the water off?

 

WD means water dispersant, just spray it down and the water should run right off, wd40 will dry out after a while so you’ll need to keep an eye on it if you plan to store for a long period.

 

I put together my 355, I used what was supposed to be "lint free" Scott shop towels along the way. After it was ran a while, I had a valve cover off it (small leak) and saw evidence of lint suspended in the oil.

 

I recall one shop with a hot tank close to the front counter, they always had it going for cylinder heads mostly. I would go home after buying parts and still smell the solvent on my clothes. I cannot believe that working there 40 hours a week was good for you. Plus now with all the regulations and waste disposal, they are a thing of the past.

 

I still have one for my own use. It will eat up almost anything but iron and steel.

 

We've still got one where I work, but not for the public. Procedure is to clean an engine block in caustic, wash, then put it in inhibited acid, which removes all the rust. Then back to the caustic tank to make sure there's no residual acid present. This is a really top notch cleaning procedure, no sediment or rust left in water jackets etc.

We also still have a vapour degreaser, I think, but sadly they don't like looky-loos hanging around anymore.