# Polyurethane Failure w/ isopropyl



## jprefect (Mar 4, 2015)

Hi Everybody,

I haven't been around much lately, but I've got a question. This actually happened in my own house: 










When I redid my floors about a year and a half ago, I had some old poly and not terribly expensive brand anyway, which I used upstairs, as a kind of experiment (and because I'm terminally cheap sometimes). I sanded, and sealed it with a coat of Amber Shellac (to match color) and two topcoats of that cheap oil-based poly. 

A couple of weeks ago my wife spilled some 91% isopropyl alcohol on it, and it immediately fogged out white. I've never seen poly react to alcohol like that. 

My inclination is to scrub it off with a greenie pad. Unless someone has a solvent-based solution to this? Your thoughts are appreciated. 

- Jeff


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## jprefect (Mar 4, 2015)

here's the image that didn't load above:


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## pacific paint (Nov 21, 2015)

Try some Lemon oil first before drastic actions. Just might work.


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## Gurnoe (Sep 5, 2015)

That is odd. Did you already try wiping it with mineral spirits? I'm curious to hear solutions from others in case I ever encounter something similar.


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## jprefect (Mar 4, 2015)

Gurnoe said:


> That is odd. Did you already try wiping it with mineral spirits? I'm curious to hear solutions from others in case I ever encounter something similar.


I have not touched it with anything. It was weird enough that I wanted a colleague's opinion first. Luckily, I only use experimental crap material on my own house.


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## stelzerpaintinginc. (May 9, 2012)

What was the exact product you applied?


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## Damon T (Nov 22, 2008)

My guess is the alcohol got past the poly and is causing blushing with the shellac. 
Not sure how to fix. With rings on tables etc you can wipe with alcohol I believe , but obviously alcohol didn't work to well here!


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## Wolfgang (Nov 16, 2008)

Try removing it using different grades of steelwool. Either way you're probably going to have to hit it with the shellac to tone it again and re-poly.


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## jprefect (Mar 4, 2015)

stelzerpaintinginc. said:


> What was the exact product you applied?


Rust-Oleum Parks 5-gal. Clear Gloss 350 VOC Oil-Based Interior Polyurethane

BUT it had been on clearance because it was old stock, and then it sat in my basement another 6 months or more. 

I definitely think it got past the poly. Not sure why. I will notice that, when the floor gets a ding, instead of good adhesion where the poly hugs the dented wood, you see chipping. I don't know what happens to expired poly that causes it to fail, ergo I don't know exactly how to fix it. 

I will try wiping it with lemon oil before I try mechanical abrasion. Then yeah, it's time for greenie pads and/or steel wool. Polish it, if it's only on the surface. Worst case scenario (which I susupect) I have to scrape the poly off and fix the shellac


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## jennifertemple (Oct 30, 2011)

Are you sure that Poly was oil based?


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## jprefect (Mar 4, 2015)

jennifertemple said:


> Are you sure that Poly was oil based?


Oh yeah. Stunk to high heaven, took forever to dry.


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## jacob33 (Jun 2, 2009)

I spilled some rubbing alcohol on a coffee table one time in my house and it did that same thing. I did not know the finish but I took some howards feed and wax and buffed it with 0000 steel wool and its like nothing happened even years latter you can not tell.


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## Crackshot (Dec 29, 2015)

i think its hit the bottom of the poly and met the shellac


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## Ric (Oct 26, 2011)

jprefect said:


> Hi Everybody,
> 
> I haven't been around much lately, but I've got a question. This actually happened in my own house:
> 
> ...


Parks Poly is not usually a very cheap product, and is actually a pretty good oil modified polyurethane finish. Most polys are somewhat resistant to alcohols (incidental exposure) and the finish may be un-affected if spills are cleaned up immediately (not allowed to stand on surface). I think you've got some good advice on how to repair affected areas (Howards Feed & Wax, or Lemon Oil). I would try lightly sanding affected areas first with a very fine grit paper before applying a thin film of oil (or even re-applying a thin app of Parks), then the damage should be un-noticeable...

But - it should also be pointed out that most oil polys are not recommended for use in conjunction with shellac as a sealer or undercoat, and the reasons are based primarily on risk avoidance...In many applications, there will be no reaction or consequences - but if a problem does present itself, it can impact the curing process of the poly, and affect the hardness, abrasion and solvent resistance of the finish film. In the future, use only the de-waxed shellac (BIN Seal Coat) beneath poly and avoid the possibility of a reaction.


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