Chemical removal of rusty spark plug
knut pedersn
Thanks for all suggestion on how to remove a rusty spark plug from an
aluminium top. After a week soaking with penetrating oils, I started to test
chemical methods. First I put a iron screw and a piece of aluminium in a
saturated solution of aluminium sulphate, temp. 40 C degree after one week the
screw is still in perfect order.
Then I started test with nitric acid. Concentrated acid is 65% sp. weight
1,4.
In the test glass vials with 10 ml mix acid and water were used. In each vial
I put one 1/8" screw ½" long of iron and an aluminium rivet of same size. The
weight of screw and rivet were determinated with an analytical balance.
One part acid and one part water, typical exothermic reaction temperature
raise to 60 C degree. After 10 min. the screw had almost dissolved.
start weight end weight
screw 0,6489 g 0,0031 g
rivet 0,3294 g 0,3282 g
One part acid and four parts of water, temperature did not raise. After one
hour the screw were reduced to a tiny needle.
start weight end weight
screw 0,6563 g 0,1657 g
rivet 0,3448 g 0,3432 g
One part acid and nine parts of water, temperature did not raise. After four
hour the screw were reduced to the half.
start weight end weight
screw 0,6582 g 0,3384 g
rivet 0,3447 g 0,3430 g
My chemical book says that nitric acid is an oxydative acid, in reaction with
aluminium the natural oxid layer will increase and so protect the aluminium.
Then to the honda engine. I took off the top removed some of the insulation
and started to add the one to one mix into the hole in the plug. It was a
heavy reaction with gassing, hydrogen and some nitrogendioxid. After a few
minutes reaction stopped, the old brown mix were removed and new mix added.
Same process again and again every five minutes. I used a syringe to handle
the acid. Be careful it is a nasty stuff. After four hour the wall thickness
was reduced to 0,5 mm. I tried a wrench and the plug went in two pieces. One
hour later with acid treatment, a tap was easily run through the hole and the
job was finished. No damage to the aluminium at all.
I beg you pardon for using so many words on a rusty spark plug. Hoping it may
bee to help for someone who want to remove iron from aluminium.
Knut
Bergen Norway
mull...@advinc.com
ni...@imp.imp.uib.no (knut pedersn) wrote:
> Then to the honda engine. I took off the top removed some of the
> insulation and started to add the one to one mix into the hole in the
> plug.
Glad it worked out. Was the head on, or off the engine? From
your descriptions above it seems you had the head on the bench
and were adding the solution into the underside of the plug.
Or had you broken out the ceramic first?
Thanks - Jim
Sent via Deja.com http://www.deja.com/
Before you buy.
Susan Hill
had always assumed the nitric acid would dissolve aluminium alloy more
quickly than the steel or iton but your experiment (which I must say was
incredibly WELL documented) demonstrates that many of our assumptions are
just plain WRONG.
Thanks
Brook Hill
knut pedersn wrote in message <89fsfu$jmn$1...@toralf.uib.no>...
>Chemical removal of rusty spark plug.<snip>
After a week soaking with penetrating oils, I started to test
>chemical methods.
<snip>
>One part acid and one part water, typical exothermic reaction temperature
>raise to 60 C degree. After 10 min. the screw had almost dissolved.
> start weight end weight
>screw 0,6489 g 0,0031 g
>rivet 0,3294 g 0,3282 g
<snip>
Doug Goncz
was some way to make the potential of the two parts different.
What happened to the piece of aluminum that was put into the aluminum sulphate
solution?
You get an A. See me after class...
Yours,
Doug Goncz
Experimental Machinist, Replikon Research ( USA 22044-0394 )
Home Page: http://members.aol.com/DGoncz/index.html
"The great enemy of clear language is insincerity."--Orwell
Dan Caster
the best idea. I hadn't ever tried it, but it sounded good when I
read it.
The big problem with nitric acid is finding a place to get it. At
least that is my first problem. The second is of course using it
safely.
Dan
Don Wilkins
wrote:
>,;I was the one that suggested aluminum sulphate. Guess that was not
>,;the best idea. I hadn't ever tried it, but it sounded good when I
>,;read it.
Aluminum sulfate wouldn't be useful for dissolving aluminum. There is
nothing there to drive a reaction.
Concentrated nitric acid is known (to chemists) to be a poor solvent
for aluminum. More dilute nitric acid however will dissolve aluminum
rapidly with the evolution of hydrogen gas.
>,;
>,;The big problem with nitric acid is finding a place to get it. At
>,;least that is my first problem. The second is of course using it
>,;safely.
If you store concentrated nitric acid you should keep it out of the
light (particularly sunlight).
Bob Unitt
HISdw...@means.net> writes
<SNIP>
>
>If you store concentrated nitric acid you should keep it out of the
>light (particularly sunlight).
Why ?
Just curious...
--
Bob Unitt (UK)
Gary Coffman
>In article <38bf21ec...@news.wcta.net>, Don Wilkins <REMOVE_T
>HISdw...@means.net> writes
><SNIP>
>>
>>If you store concentrated nitric acid you should keep it out of the
>>light (particularly sunlight).
>
>Why ?
Light causes it to decompose. You get red fumes which are
nitric oxide (I think it is nitric rather than nitrous).
Gary
Gary Coffman KE4ZV | You make it |mail to ke...@bellsouth.net
534 Shannon Way | We break it |
Lawrenceville, GA | Guaranteed |
Don Wilkins
<ju...@bobunitt.demon.co.uk> wrote:
>,;In article <38bf21ec...@news.wcta.net>, Don Wilkins <REMOVE_T
>,;HISdw...@means.net> writes
>,;<SNIP>
>,;>
>,;>If you store concentrated nitric acid you should keep it out of the
>,;>light (particularly sunlight).
>,;
>,;Why ?
>,;
>,;Just curious...
Curiosity killed the cat but cats can't type very well so...... your
curiosity should be harmless.
In the presence of sunlight concentrated nitric acid decomposes to
oxides of nitrogen which are gases. This results in a brown color
instead of the colorless product you had before you did such
dastardly and abusive treatment of your pristine and pure nitric acid.
In many cases this isn't going to make a whole lot of difference in
the way the nitric acid will behave when you apply it to do its thing
on whatever.
The problem can arise when you leave it on the shelf in a sealed
bottle. Those gaseous products of decomposition would like to get out
of the bottle and do their thing. Unfortunately there is that damn
cork or worse a tight screw cap preventing their escape.
So they wait patiently until the pressure in the bottle becomes large
enough to rupture the container. AHAH now they are free.
Once it blows you probably would prefer to be elsewhere.
Ted Edwards
> Once it blows you probably would prefer to be elsewhere.
Believe it!
Ted
Knut Pedersen
>On Wed, 01 Mar 2000 03:27:15 GMT, Dan Caster <dca...@my-deja.com>
>wrote:
>for aluminum. More dilute nitric acid however will dissolve aluminum
>rapidly with the evolution of hydrogen gas.
Knut
Don Wilkins
Pedersen) wrote:
>,;In article <38bf21ec...@news.wcta.net>, REMOVE_TH...@means.net (Don Wilkins) wrote:
>,;>On Wed, 01 Mar 2000 03:27:15 GMT, Dan Caster <dca...@my-deja.com>
>,;>wrote:
>,;>>Concentrated nitric acid is known (to chemists) to be a poor solvent
>,;>for aluminum. More dilute nitric acid however will dissolve aluminum
>,;>rapidly with the evolution of hydrogen gas.
>,;This is not according to my learning, that is what the book says about iron.
>,;Knut
What "the book" says about iron doesn't have a whole lot to do with
what happens with aluminum.
If you would give a clear and concise statement about what your
learning has been perhaps I can correct your misconceptions.
I will stand by my original note. What I stated is rather elementary
chemistry (to chemists).