i bought a used intake from the east coast and am now at a point where i need to clean it.

i already rebuilt my 2 barrel carter, took the intake to a machine shop, got some suggestions to use muriatic acid. he told me he could bead blast it, i didnt want the possibility of beads remaining in my manifold. so i bought some acid from a pool supply store.

question is how long do i soak the intake. i've done a few different internet searches, cant seem to find any info on how long.

thank you

Dario

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Is it an aluminum or a cast iron manifold?
DD

thanks, i forgot to mention it is a cast iron intake.

also my main problem is rust. specifically inside directly under the carb mounts.

just trying to get her prettier. also, what do you guys do for prep and paint/powder. what can i use to smooth out the metal

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There's nothing the matter with bead blasting. This is a very "open" casting; there really aren't any pockets where beads could hide, and that would be your easiest, safest, and least hazardous method of cleaning it. However, if you're determined to do it chemically, muriatic acid will work. You'll wind up with hazardous waste to dispose of (what fun!). You can neutralise the acid after you're done, with a great deal of baking soda, but you'll still have a bunch of sludge to get rid of. I tend to use oven cleaner (the regular Easy-Off kind, not the "no fume" stuff). It is lye, and will clean the manifold very nicely, with the same hot-water rinse you'll need to use after muriatic acid.

With whatever method, paint the manifold right away or it'll rust.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

i understand that time may vary, but how long should i soak the intake.
i probably will opt for bead blasting.
thank you

dario

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Dilute the acid down a bit with some H20. It is too hot out of the jug.
I'd go with a 70 %MA/30H20 to start.

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Super Six Conversion Stromberg

I am not sure of this but it was quoted on a boat engine review site i visit. I took note since i use this acid on my pool and have tried it on various other surfaces..

The cast iron manifold of one engine had very heavy rust scale on it, while the other three, which apparently were Barr Marine replacements did not. So why was the paint blistering all over the engines? Well, we can guess that these engines had been cleaned with muriatic acid, and when you put muriatic acid on cast iron it never stops reacting chemically. Muriatic acid DESTROYS cast iron. We learned that the hard way as kids cleaning our hot rod engines with the stuff.

that acid does not do any harm to cast iron if you know how to use it

1) clean all the grease off acid will not do anything to grease or paint.

2) before you even open the bottle make sure you HAVE PROPER VENTILATION,(ONLY OUTDOORS NOT NEAR THE HOUSE OR ANYWHERE ANYONE ELSE IS) AND A CHARGED GARDEN HOSE NEXT TO YOU

3) get a PLASTIC OR STAINLESS STEEL container to soak the manifold (if you use metal the acid will eat threw the metal also if you use stainless steel it will put a cloudy haze on the it)

4) put the manifold in the container first then pour in the acid DO NOT BREATH IN THE FUMES THEY CAN KNOCK YOU OUT (the reason you put the manifold in first is so you don't splash yourself with acid it does burn)

5) you don't need to soak it for to long you will be able to see the rust melting before you eyes

6) when all the rust is gone pull it out (either with water tight gloves or you can tie a coat hanger around it to pull it up)

7) then spray it down with water (water will neutralize the acid)

8 ) then I spray it down with g.p. cleaner (that will keep the rust from coming back cuz if you don't as fast as the rust melted off it will come back)

9) then let it dry really good and paint after that I usually spray a little WD-40 in the manifold to keep the inside from rusting out

with the used acid I spray as much water in the container as it will hold the water will neutralize it then pour it out (I pour it onto the gravel driveway then spray it down with water really good)

RR7169, you left out step number 0: Safety gear. Clear plastic full-face shield (the kind that attaches to your head with an adjustable plastic headband — they're not costly at all) and long chemical-resistant rubber gloves. It's best to have a big rubber smock and/or other resistant clothing, but if you're going to skip that, I recommend wearing short pants and shirt, because that way if acid does splash on you, you can rinse it away immediately; it won't be held in contact with your skin by the clothing it has soaked.

This is mandatory, not optional. Skipping it is foolhardy; you can lose your eyesight and/or suffer other grievous injury in a matter of seconds when working with this stuff.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

well some things go without saying its all in common sense.

Be careful where you dump this "rusty red" water, it stains clothing and concrete.
DD

Water will dilute acid. It will not neutralise it. To neutralise an acid, you need a base (alkali) such as washing soda or baking soda.

Also, never add water to acid. Always only ever add acid to water.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Oven cleaner works great for cleaning greasy cast iron.

So you mean when they use it to clean out a pool they coat the entire pool with baking soda. And then what would they do to get the baking soda out of the pool if they cant add water to it. It just does not add up to me

when you fill a pool you add a lot of PH plus which is similar to baking soda. I think one is corbonate and one is bicorbonate. If you do not you can ruin the pipes for the filter and get scaling which damages the concrete.