Zinsser paint and varnish stripper - did not work very well

[Doug Hortvet]

All,

My first use of a chemical stripper was Zinsser's paint and varnish stripper on the exterior face of a mahogany entry door - whose finish is old and mostly deteriorated.

Not sure if the stuff I got was old or what - can advised it was a paste - suitable for vertical surfaces, which fits my application..

This stuff is like the blob - definitely a non-Newtonian fluid - and not a real liquid - more like thick slime.

Is this normal?

Bottom line - after leaving in place for longer that the suggested 30 min. and then scrubbing with a stiff nylon bristle brush - very little of the finish came off.

Product is labeled to remove latex and oil-base paint, varnish, polyurethane, milk paint and more - up to 3 layers of finish in one application.

Temperature Application Range is 65 - 85 deg.F.

In Houston this evening was pushing the upper limit of the range when applied.

Per the MSDS the product is ~ 25% methlyene chloride - with the balance being methanol, acetone and toluene. I would have expected a strong smell with this composition

- which was not present.

Either the product was old and lost effectiveness or what is left of the old finish is very resilient.

Will review MSDS documents of other products for one with a greater % of methlyene chloride.

Thanks in advance for any comments / suggestions for a more aggressive chemical stripper product.

Regards,

Doug

[dadiOH]

Yes.

How much did you put on? Had it dried some when you scrubbed? You need to put on a *THICK* coat and scrape/scrub before it dies out. Once it dries some the finish it softened sort of reconstitutes. After putting it on, poke/scrape at the paint once in a while with something like a toothpick to see if the finish is softening. You can also see the finish wrinkling/cracking.

[Sonny]

I would seriously doubt any general stripper will remove milk paint, as you say that Zinsser labeling indicated.

Mahogany door! Take the door off the jam and work on it flat. Don't skimp on the repair of that quality of door. Working on it, with it vertical, to me, is doing a non-quality job.

KleanStrip has 60% methylene Chloride, which is the main active ingredient for general stripping. I think you (or someone) had earlier mentioned rinsing/cleanup with some sort of alcohol. *Note: From the KleanStrip website.

Data - Methylene chloride: Alcohol may enhance the toxic effects.

Should you try the KleanStrip, rinse or clean up with mineral spirits (preferred) or soapy water, not with an alcohol product. After all is stripped and cleaned, then, I suppose, an alcohol wipe-down is okay.

Sonny

[Michael Karas]

My experience of stripping old finish is that it may be necessary to go at it with multiple applications of the stripper. If the door has panel type features it may be necessary to work the stripper into the panel corners and edges using a pad of steel wool. Steel wool with stripper requires careful selection of the correct grade of the stuff. Too fine and the pad will just completely plug up and not be useful. Also it is necessary to make sure that you have the best hands protection you can get.

Your nylon brush idea may be a workable replacement for the steel wool but having not tried that I cannot comment.

I've had good luck with JASCO paint stripper. This discussion has some additional tips.

[Larry Jaques]

Is that rated for poly finishes? Not all strippers are, and those which aren't won't cut it, at all!

Yeah, they're usually like jello.

Uh, try a putty knife/scraper. If it still doesn't come off, refer to my first question. (Is it poly rated?)

If it dried up on you, it was too warm. Was it still a gel when you brushed at it? If not, the solvents evaporated and it dried up on you. That's a bad thing. Rewet it and catch it when it's still wet the next time.

OK, the methylene chloride was the poly killer, so it should have worked.

The gels usually don't lose effectiveness because they're gelled. Did it reek pretty good? If not, maybe it was bad.

Surprisingly, some of the citrus strippers are poly-rated.

One other thing to try: Take the door off, lay it down, gel it up, and cover that with plastic for 45 minutes. Now try to scrape the finish off. Did that help?

-- Truth loves to go naked. --Dr. Thomas Fuller, Gnomologia, 1732

[Pat Barber]

Since you "do not know" what finish you are trying to remove, various strippers might not work very well. Factory finished doors could have one of "many" very tough finishes.

Poly is an example of very tough to strip. Spar Varnish is also tough to strip.

Klean-Strip makes "several" strippers, all for different finishes.

Go here and do a little reading:

is NO single stripper that will work well on all finishes, you need to find the one for your door.

[Baron]

There are a few things you did not mention so I will assume you did not do them.

1) Purchase a finish / paint stripper containing the most methylene chloride you can. A rough guideline is to buy the one that weighs the most. Methylene chloride is the heaviest component of the strippers and the can that weighs the most probably has the highest concentration of methylene chloride. There are stronger stripers available. They are usually called aircraft stripper grade and usually contain lye. They not something you should need. 2) Take the door off the hinges so you can work on it laid flat. This will keep the stripper in contact with the surface longer. 3) Before you apply stripper, clean the door. Dirt can actually block the stripper from reaching the finish. First use warm water at one gallon of water to one capful of dishwashing detergent. The idea is to get the door wet enough to do the work but not so wet that it becomes saturated. To rinse the door, use a fresh cloth and fresh water. Follow up with fresh cloth to dry the door. Wash down again with mineral spirits to remove any remaining oil soluble dirt. There is no rinse in this case, just use a fresh cloth to both remove the contaminated mineral spirits and dry the door. 4) Apply the stripper in a thick layer and do not continue to move it about the surface once you have applied it. You want the wax in the stripper to keep the methylene chloride from evaporating. Continuously moving it on the surface will not allow a wax "crust" to form and the methylene chloride will evaporate. 5) Once the stripper has sat for the time suggested on the stripper container, remove it and apply a fresh coat of stripper. There is no need to do an extensive job of removing the first coat but get as much as you can by scraping it off. Let the second coat sit as long as the first. Now you can do a thorough job of removing the stripper followed by a wipedown with either lacquer thinner or a solution of toluene, methanol, and acetone. Either should keep any residual finish from redepositing as you remove the stripper.

There are a few finishes that require the surface to be roughened to the wood surface before applying stripper but I doubt you will encounter these.

Good Luck.

[Doug Miller]

Doug Hortvet wrote in news:265dv79p1a0eihjk05bbcibdunkub8kfoe@

4ax.com:

Per the MSDS the product is *less than* 25% methylene chloride... They don't say how much less.

[Doug Miller]

Doug Hortvet wrote in news: [e-mail]:

Totally normal.

Also totally normal. Sounds like you left it on too long, and it dried up. You need to remove it while the stuff is still wet and slimy.

Did you shake the can thoroughly first?

You have less time in hot weather. Try again, but don't leave it on so long next time. [...]

Well, I recommended ZipStrip...

[Father Haskell]

Zip Strip. The grade sold for stripping boats is the fastest.

Lye will strip almost anything, although it's not terribly kind to wood or skin.

Is the door flat, with minimal joinery or panels and crossbucks? Card scraper is the fastest "stripper." Sharpen with a file, forget the burnisher, a hooked edge won't last three strokes on old paint. Save the Zip Strip for cleaning out the detailed spots.

[Doug Hortvet]

Thanks to everyone for the very helpful and informative comments.

Following additional info I did not include the first time:

1. The product has a very weak odor - tube plastic modelers cement or Ambroid tube glue has a stronger odor.

1. The can was vigorously shaken each time product was removed for use.

2. Noting the initial application appeared to have dried out in several areas, additional stripper was applied. While the first application was a bit thin - after the second application the total film thickness was ~ 1/8".

1. The finish never appeared to wrinkle / crack - this after the second application.

2. Sanding was completed before application of the stripper - mostly on the flat surfaces, and to a lesser degree on the curved surfaces.

1. The product tech bulletin advises the max. application temp is 85F - was likely very close to that during use. May have to do this just before dawn to ensure the ambient temp is at minimum for the day :)

2. Will get KleanStrip or Zip Strip this morning and go at it again, making sure the product is applied in a thick layer and removed before drying - this aspect of the procedure was most likely where I fell short of proper execution.

Thanks again to all for the benefit of your experience - much appreciated!

Regards,

Doug

Doug Hortvet wrote:

[DanG]

additional

flat surfaces,

ambient temp

real liquid -

milk paint

composition - which

chemical stripper

Granddaughter had someone else paint a crib and dresser with latex enamel. Asked me to fix it. I foolishly said, no problem. I tried quite a few different strippers and never did find one that was effective on the latex. The best performance was straight lacquer thinner with a 3M type pad. Very slow, but came out well. Great granddaughter turned out cute, smart, pretty, popular, etc, etc.