use of caustic soda to remove old oil paint
chablisa
An old cupboard made on softwood was given to me. It is coloured with
oil paint. My aim is to remove this painting. It was told to me that
caustic soda is a possibility. Has anyone experience with caustic
soda? Or does anyone knows other ways? Any idea on this is very
appreciated.
Best regards,
Chablisa
Charlie Self
Does caustic soda=lye? I think it does. Best avoided if possible. Modern paint
removers do a decent job, with less hazard. I've always had good luck with ZAR
Paint & Varnish Remover.
Charlie Self
"Did you know that the White House drug test is multiple choice?" Rush Limbaugh
George
strippers are formulated to stick to the piece so it doesn't have to be
immersed. Not all strippers work against all paints, though the nastiest,
methylene chloride, seems the most effective.
Lots of caution even with the "environmentally friendly" types advised.
Goggles, gloves, and disposable clothes.
"Charlie Self" <charl...@aol.comnotforme> wrote in message
news:20040729035256...@mb-m29.aol.com...
Wes Stewart
Caustic soda---lye---Sodium Hydroxide will strip paint. In my youth,
I worked in an automotive machine shop and we used a heated tank full
of the stuff to remove the crud from cast iron engine blocks, heads,
etc. In my later life in the missile business we used brief immersion
to clean aluminum parts before chemically treating them.
I believe some commercial paint stripping operations use something
similar.
The problem is that it can damage the wood to some extent and should
be neutralization with weak acid afterwards. All of this water will
raise the grain of the wood and glue joints don't much care for this
insult either.
Some commercially available strippers are lye-based (no pun intended)
and include thickeners to make them stay on the work surface while
they do their thing. I've heard of homemade versions of these using
things like cornstarch for thickeners.
If your project is to be repainted, doesn't have glue joints and you
have a method for safely applying this stuff, than it might be
appropriate. Otherwise a commercial stripper, also handled with the
appropriate cautions, is your best bet.
Larry Fox
> oil paint. My aim is to remove this painting. It was told to me that
> caustic soda is a possibility.
I have some experience here and I wil provide what I have. I have and
have been working on an old house for some years now so paint
stripping is one of life's constants for me. Couple of observations I
have made (personal opinions and experience only so please keep the
flame-throwers in check)
1) Chemical strippers are frought with issues. The best chemical
stripper I have used is Peel-Away 1. It strips paint like nobody's
business but the watch word here is MESSY. The process is that you
smear it on, put a "special" paper on it, wait a while, peel off the
paper and the paint. You have to "neutralize it" after you are done
and you basically need to repaint as it stains the wood. Peel Away 7
is supposed to not require neutrilization and not stain wood but I
have never used it. The company says that it is perfectly safe but
you can hear it working. For my money, if I can hear a chemical
working then I am giving it it's distance and applying all sorts of
safety measures regardless of what the manufacturer tells me. There
are others, that are of varying degrees of effectiveness, mess,
hazard. MC-based ones seem really dangerous. Peel Away 6 doesn't
work worth a crap in my opinion.
2) Heat gun. If you are SURE the paint is oil-based and NOT
lead-based (this goes for all layers of paint) then a heat gun might
just be your best bet (assuming you are repainting). You just need a
good scraper, lots of time, and lots of patience. Watch for fire
though, especially if the cabinet is not free-standing and there is a
substrate behind it.
3) Sanding / mechanical removal. This is tough-love and I don't
recommend it for things with any appreciable amount of surface area.
4) There is a product call the SilentPaintRemover that is quite good.
I have one and am quite familiar with it's operation and can answer
questions if you have them. Web site is www.silentpaintremover.com.
I am unafiliated with the company but have only had positive
interaction with the product and the company.
This topic is discussed to death in old house forums, you might also
want to try there for more information.
George
Launched many a hydrogen-filled balloon as a kid after generating same with
NaOH and Aluminum.
"Wes Stewart" <n7ws_@_yahoo.com> wrote in message
news:tpvhg09l394nlgtdi...@4ax.com...
Kevin
some acid.
FWIW, we used to dehorn calves using caustic soda. Quite common practice but
nowadays with all the polled varities not necessary.
"chablisa" <chab...@gmx.de> wrote in message
news:bcceb1ec.0407...@posting.google.com...
Bill Rogers
wrote:
>On 29 Jul 2004 00:42:30 -0700, chab...@gmx.de (chablisa) wrote:
>
>|Hi!
>|An old cupboard made on softwood was given to me. It is coloured with
>|oil paint. My aim is to remove this painting. It was told to me that
>|caustic soda is a possibility. Has anyone experience with caustic
>|soda? Or does anyone knows other ways? Any idea on this is very
>|appreciated.
>|Best regards,
>|Chablisa
Sorry. I missed the OP.
NaOH (Caustic Soda, Lye ..) is the direct oppposite of a strong acid.
SO, imagine how you'd do if working with a strong acid like Sulphuric
[sulfuric] or Hydrochloric. Chemicals such as this euire extrreme
caution; well, at least not an entire lack of caution. I.E. rubber
gloves, goggles even an apron if protecting clothes.
To use on softwood is not a good idea. I easily stripped old brown
varnish from the woodwork of my older home. I removed the wood, and
took it outside. There, I brushed vigorously with a stubby-bristled,
cut-down old paintbrush using TSP (Tri Sodium Phosphate.) It removed
the varnish easily, but paint would be more stubborn, just requiring a
bit more patience. When scrubbed to my satisfaction, I simply hosed
off the gunk. All the mess was outside, which is where you should do
your work.
You said "an old cupboard", so if self-standing, take it outside. If
kitchen cupboards, it is still worth removing them, finishing, then
replacing to avoid all the other work.
Bill.
Bob Bonn
have also suffered through my share of this!)
It's probably worth adding that lead paint would also be an issue with
sanding. You don't want to kick up any lead dust. I seem to recall
that heat guns were actually somewhat safer in this regard, compared
to sanding. There may be more recent research on this, though.
Either way, it's worth paying attention to possible lead content. If
the piece was painted before 1950 or thereabouts, there's a good
possibility that one or more coats contained lead.
lf...@dca.net (Larry Fox) wrote in message news:<4e94af14.04072...@posting.google.com>...
Barry Lennox
I have used caustic soda quite a bit as a paint stripper, it seems to
give mixed results, but always works better when hot.
It is nasty stuff, though and you must wear gloves and goggles. It
also is a bit rough on the wood, but it cleans up well enough.
Do it well outdoors, in an area you can hose down the whole mess when
done.
I have been meaning to do a small trial mixing caustic soda with
wallpaper paste to make a "caustic gell" Most of the paint strippers
are a gell, so as to hold the stripper against the wood for a longer
period.
Barry Lennox
Eric Ryder
worthless as a stripper on Helmsman exterior polyurethane.
"Barry Lennox" <rianz.1...@neverbox.com> wrote in message
news:92sig0l6m6dev0dln...@4ax.com...
Dan Cullimore
(personal opinions and experience only so please keep the
> flame-throwers in check)
If you are SURE the paint is oil-based and NOT
> lead-based
Not a flame, but a mere correction: lead was (and is still, just not
for residential purposes) used as a pigment in paint. It is not a
"base". The base would be some kind of oil, an alkyd (think synthetic
oil), or, in the case of latex paints, water. The "base" is the
carrier or solvent in which the other ingredients are suspended,
dissolved or otherwise distributed. The "base" evaporates and leaves
behind the pigments, bonding agents, and a multitude of other things
that make the paint flow, stick, resist the sun and (acid) rain, etc.
Lead is wonderful as a pigment because it stays put and is tough as
metal (this last is kinda obvious), but it sure plays havoc with
living systems (nerves, blood, bones, kidneys...it has an affinity for
red blood cells, and thinks nothing of taking the place of iron in
hemoglobin) so we don't use it in homes any longer (thank you, gov't
regulation). However, it's still used in industrial paints, highway
paint, etc.
The point of all this is that if the cabinet in question was painted
before 1980 (and even later--how many cans of paint are in your
basement and how long have they been there?), the paint probably has
lead in it. In addition to using appropriate precautions for whatever
method you use to strip it (chemical, mechanical) be aware of the
potential lead poisoning hazard. Anything you do to take the old
paint off can pollute the area in which you work so be careful, keep
the kids away, wear proper clothing and gear, etc. Lead poisoning is
no joke.
The EPA has information about safe treatment of lead bearing paint
which you can probably find on their website (www.epa.gov/lead). Or
look for EPA publication 747-B-99-003, "Lead In Your Home: A Parent's
Reference Guide", among others.
Good luck, and strip safely.
Dan
Dan Cullimore
> This is an excellent summation. (I'm a fellow old-house owner, and
> have also suffered through my share of this!)
>
> It's probably worth adding that lead paint would also be an issue with
> sanding. You don't want to kick up any lead dust. I seem to recall
> that heat guns were actually somewhat safer in this regard, compared
> to sanding. There may be more recent research on this, though.
> Either way, it's worth paying attention to possible lead content.
DO NOT (shout intended as hazard eminent) EVER use a heat gun,
especially one with an open flame. The heat can release the lead as a
toxic, readily inhaled vapor. The safest methods for removal will be
mechanical--wet sanding and scraping, with the significant word being
"wet". Lead dust is less easily inhaled because it is too heavy to
stay suspended in the air (it is lead, after all) unless there is a
lot of dust and the air constantly disturbed, as in heavy demolition.
Chemical stripping would be a distant (because of compounded
toxicities) second choice. Heat guns should never be an option.
> If
> the piece was painted before 1950 or thereabouts, there's a good
> possibility that one or more coats contained lead.
>
Lead bearing paint was manufactured for the U.S. consumer market until
1978. Given that inventories probably stayed on the shelves for a
while after that, it is wise to consider anything painted before 1980
to have at least one coat of lead bearing paint; given how long some
cans of paint survive neglected in basements, it might be wiser to add
a even more years.
To your health,
Dan
Bill Rogers
wrote:
>DO NOT (shout intended as hazard eminent) EVER use a heat gun,
>especially one with an open flame. The heat can release the lead as a
>toxic, readily inhaled vapor. The safest methods for removal will be
>mechanical--wet sanding and scraping, with the significant word being
>"wet". Lead dust is less easily inhaled because it is too heavy to
>stay suspended in the air (it is lead, after all) unless there is a
>lot of dust and the air constantly disturbed, as in heavy demolition.
It also depends on the fineness of the dust, which will remain
suspended for some time. It will also coat other items. I.E. Wear a
mask, even if wetted.
One common key throughout all of this is to take outside if feasible.
Bill.
Robert Galloway
cornea. OTOH, it doesn't insinuate itself into your blood stream and
lead to cancer, liver disease and the other nice things associated with
meth chloride. Much kinder to the environment and used by our
grandmothers without fatal result for a long time making soap. I think
I saw a recipe somewhere using corn starch with lye to make a paste
remover which clings to the wood long enough for it to do the job.
(Don't hold me to this, it was some common kitchen item used as a
thickener.) IIRC, meth chloride has a particularly hard time with milk
paint. I've applied a fair amount of it (milk paint) but haven't had to
strip any yet.
Bob G.
Bill Rogers
<Robe...@comcast.net> wrote:
>Methylene chloride - Lye.
Since when? Am I reading you wrong?
Bill.
J. Clarke
> Methylene chloride - Lye.
= lie.
Lye is sodium hydroxide, not methylene chloride. Whatever gave you the idea
that it was methylene chloride?
--
--John
Reply to jclarke at ae tee tee global dot net
(was jclarke at eye bee em dot net)
George
You might have read that wrong.
"Bill Rogers" <willr...@aol.com> wrote in message
news:lq5ng0l84368jq796...@4ax.com...
Baron
damage the wood if you don't know what you are doing.
You don't say how large the cupboard is but I will assume that it is
small enough that you can handle and turn it on a large suitable surface.
You don't indicate how old it is. I realize you have said "oil paint"
but I do not know how you determined this. If it is very old, you may have
milk paint. There are specialized removers for this that are safer than
caustic. If it is indeed oil paint, there may be lead in it so don't go for
sanding or a heat gun. All but the milk paint can be removed with standard
methylene chloride containing strippers although there are removers made
specifically for paint. BIX makes one that is a powder you mix with water.
The best thing you can do is to buy a small quantity of a methylene
chloride based stripper and try it out over a small area. If it works, you
have just saved yourself quite a bit of time spent on specialized safety
precautions.
One of the most difficult aspects of stripping paint is if the paint was
applied to the raw wood. It is MUCH easier to strip paint from something
that had a clear coat finish and was then painted over. Paint tends to
lodge in all the pores, splits, and cracks so well that a fair amount of
time spent in getting it out.
Good Luck.
"chablisa" <chab...@gmx.de> wrote in message
news:bcceb1ec.0407...@posting.google.com...
nosp...@vcoms.net
paint from pores. No experience.
On Sat, 31 Jul 2004 14:39:48 -0400, "Baron" <pfi...@voNGicenet.com>
wrote:
Robert Galloway
chloride = lye and that's not what I intended to say. I meant to imply
meth chloride on one hand, lye on the other or meth chloride versus lye.
My following explanation of the hazards of each makes it plain that I
have no confusion about the two chemicals.
Bob G.
J. Clarke
> Wish you'd come across with a valid e-mail address.
The email address in my sig is perfectly valid. But I am curious as to what
you have to say to me that you don't want to put in an open forum.
> I didn't write meth
> chloride = lye and that's not what I intended to say. I meant to imply
> meth chloride on one hand, lye on the other or meth chloride versus lye.
> My following explanation of the hazards of each makes it plain that I
> have no confusion about the two chemicals.
Well, actually, it doesn't. And regardless of _your_ confusion your
"following explanation" is likely to confuse anybody else who comes in not
knowing the difference.
--
Robert Galloway
think what we've exchanged is of little interest to the whole group and
just wastes some folks time in the downloading.
J. Clarke wrote:
> Robert Galloway wrote:
>
>
>>Wish you'd come across with a valid e-mail address.
>
>
> The email address in my sig is perfectly valid. But I am curious as to what
> you have to say to me that you don't want to put in an open forum.
>
It bounced for me the first time I tried "Reply to Sender Only" I'll
try again.
Robert Galloway
think what we've exchanged is of little interest to the whole group and
just wastes some folks time in the downloading.
J. Clarke wrote:
> Robert Galloway wrote:
>
>
>>Wish you'd come across with a valid e-mail address.
>
>
> The email address in my sig is perfectly valid. But I am curious as to what
> you have to say to me that you don't want to put in an open forum.
>
It bounced for me the first time I tried "Reply to Sender Only" I'll
try again.
>
Baron
is really just forcing you to do a second complete stripping. If you do a
good, thorough job the first time with good quality chemicals, equipment,
and technique, any paint in the pores will either come out or will require a
brass brush, pick, etc. The shellac won't help.
<nosp...@vcoms.net> wrote in message
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