[Green Hornet]

I want to clean some old cast iron intakes I have on the shelf...

They are as removed....with grease,old paint and rust......and some have some rust in the plenum under the carb mounting flange....

Just exploring my options....speed vs cost.....vs quality of job....

Electrolysis.......muriatic acid...media blasting.....Evaporust soak?

Done the wire wheel \ wire brush route before.....

Looking for some input.....Thanks

[i82much]

wife.

[phil400]

I did this about 5 years ago, but I cleaned up a 72 intake with a wire wheel then soaked in plain ole white vinegar for a few days maybe a week then knocked off the loose stuff with a wire wheel after soaking, intake came out alright but my stuff idmsnt high dollar builds, included some before and after pics

[phil400]

More pics, afterI was done I used brake clean the coated it with WD till I was ready to paint

[phil400]

Another pic

[phil400]

Here it is painted, sorry for all the posts, was years ago had to go searching through my phone for the pics,I also painted the exhaust crossover with several andI mean several coats of high header paint to slow the engine paint burning off and rusting, several years some discoloration but no rust

[1968GTO421]

When I was in AACA years ago, one of the guys used electrolysis, putting the part in a large tub with leads from a battery. One lead went to a clamp on the part and another to the metal tub (if I remember correctly). His technique worker great on some really funky parts. I really like Phil400's method as it does not involve electrical stuff and possible shocks to curious kids and others. Thanks, Phil.

[Skip Fix]

The exhaust crossover junk is something to be sure is all gone and not just loosened up to be blown into the ports on the other side regardless of what you use.

[mgarblik]

If you have a machine shop in your area with a thermal cleaning process, that is simple and easy. They will look like new manifolds when they come out, inside and out. A shop around here would probably charge $50.00-75.00 to run a load. Our drum would hold maybe 6 intakes. So per manifold, pretty reasonable.

[Green Hornet]

Originally Posted by mgarblik

If you have a machine shop in your area with a thermal cleaning process, that is simple and easy. They will look like new manifolds when they come out, inside and out. A shop around here would probably charge $50.00-75.00 to run a load. Our drum would hold maybe 6 intakes. So per manifold, pretty reasonable.

I local guy here quoted me $300...to run a load/batch....so I crossed that off my list.....

Does that process remove rust...or just paint/grease?

[Green Hornet]

Originally Posted by 1968GTO421

When I was in AACA years ago, one of the guys used electrolysis, putting the part in a large tub with leads from a battery. One lead went to a clamp on the part and another to the metal tub (if I remember correctly). His technique worker great on some really funky parts. I really like Phil400's method as it does not involve electrical stuff and possible shocks to curious kids and others. Thanks, Phil.

I'm just setting up to experiment with electrolysis......and also muriatic acid soaking.....

[Green Hornet]

Originally Posted by phil400

I did this about 5 years ago, but I cleaned up a 72 intake with a wire wheel then soaked in plain ole white vinegar for a few days maybe a week then knocked off the loose stuff with a wire wheel after soaking, intake came out alright but my stuff idmsnt high dollar builds, included some before and after pics

Thanks for posting all the pics/info....

I also have a 78 Ta that I've owned for a long time...

[Green Hornet]

Apparently....Muriatic acid....will potentially damage intake if left too long in the soak...
Phosphoric acid would be a better choice..

[mgarblik]

Originally Posted by Green Hornet

I local guy here quoted me $300...to run a load/batch....so I crossed that off my list.....

Does that process remove rust...or just paint/grease?

That is a very high price. $300.00 worth of thermal cleaning here would do an entire engine. Block, heads, crankshaft, manifolds, and sheet metal. Typically 3 full loads. So maybe $100.00 a load now.

Parts come out like new castings from the foundry. No rust, paint or anything else, inside and out. We bake iron in a slow rotating drum at about 650 degrees F for an hour. Then it goes directly into a stainless steel shot machine with .030" tiny steel wire shot for 45 minutes.

Where are you located?

[unruhjonny]

honestly, if you put a little bit of effort into it before worrying about the rust, your time invested will be well worth it.

Take them to a pressure washer to get the grease and oil off;
Then a soak in evaporust(ect) will prove astonishing results.

[Green Hornet]

Originally Posted by mgarblik

That is a very high price. $300.00 worth of thermal cleaning here would do an entire engine. Block, heads, crankshaft, manifolds, and sheet metal. Typically 3 full loads. So maybe $100.00 a load now.

Parts come out like new castings from the foundry. No rust, paint or anything else, inside and out. We bake iron in a slow rotating drum at about 650 degrees F for an hour. Then it goes directly into a stainless steel shot machine with .030" tiny steel wire shot for 45 minutes.

Where are you located?

I have no concept...of what anything costs anymore.....

Figured if that what the price was....I would find an alternate method...

I'm north of Seattle...about 150 miles...

[Half-Inch Stud]

An electrolysis, lemon juice, oxalic acid, snd such may be woryh it for 3 or more manifolds.

[mgarblik]

Originally Posted by Green Hornet

I have no concept...of what anything costs anymore.....

Figured if that what the price was....I would find an alternate method...

I'm north of Seattle...about 150 miles...

I understand. It's hard to keep up with the escalating costs of everything. WA is a long way from OH! You might want to shop around some more or try one of the other methods mentioned. Hot tank won't work. Does not remove rust. If having the parts commercially cleaned, thermal is the way to go. Works great on aluminum too at a much lower temperature. We bake aluminum at around 300 degrees for 1 to 1 1/2 hours depending on the amount of sludge and carbon. Then blast. The blasting darkens the aluminum slightly, but still produces an "as cast" look.

[lust4speed]

1967 intake manifold media blasted with #7 glass bead and an early hub/balancer assembly.

[Drag Star Le Mans]

Originally Posted by Green Hornet

I have no concept...of what anything costs anymore.....

Figured if that what the price was....I would find an alternate method...

I'm north of Seattle...about 150 miles...

So you must be in Canada or just hiding your location? Nothing a trip to local machine shop and a hot tank clean up can't handle. They have always been cheap for me? Just a thought.