Windshield Urethane Adhesive Removal

You could try chlorinated brake cleaner. Acetone may have an effect, if not methylene chloride definitely will. But work fast, either will attack the paint if left on too long! Worse case, you may have to remove it mechanically (sanding) and then buff out the paint.

Given the potential for damage from the methylene chloride, I would definitely recommend sanding and buffing.

I would try MEK but work fast it cleans very well and does effect polyurethane coating buy leaving a haze that is buffable

apply petroleum jelly to the area immediate to the adhesive to protect the finish the use MEK judiciously

Do not use methylene chloride (the main solvent used in automotive paint stripper) or MEK. Methylene chloride will remove your paint to bare metal in seconds, MEK will cause it to blister and fail over a very short period of time.

I think your screwed. Try with surgeon precision to shave the excess off with a razor. Keep the blade lubricated to slide through the urethane. Maybe fabricate a guide to keep the blade from getting to close to the paint.

If you want to remove more, try masking off the paint and carefully sand down the urethane. Make sure to go really slow, and plan to spend many hours.

I work with urethanes regularly and have found that NMP works very well as a solvent for urethane. I have also used products called Dynasolve from Dynaloy. Check out their products at http://www.dynaloy.com/. Careful using these on a surface with a urethane coating since it will desolve the finish as well.

Good luck.

Guest,

Normally poly urethane resins are mixed with organic solvents like acetone, ethyl methyl ketone, butyl / ethyl acetate solvents which dry up allowing the hardened resin.

The following means can be tried.

1] Gently scratch the hardened resin part by steel knife edge.

2] You place an absorbent pad or cotton cloth paste it over the hard resin, inject any one of the above solvents and cover with a polythene sheet [to avoid solvent evaporation] give sufficient soaking time for the resin to get solublized and scratch it away after soaking.

3] The other option could be using a grinding stone.

Try the hot knife tip on your soldering gun. It should work fast enough not to affect the paint if you do it in a cool place or in the shade.

Maybe 3M has a contact website?

use SIKA next time...you would not have had the problem...

Sika is used by most auto OEM's

In my business we use urethane daily, which I am sure would be a different chemistry but probably similar in principle. When we had clean aluminum molds that were NOT spayed with mold release (Silicone) and urethane potted in the mold. The result was not good for that set of molds. Our urethane manufacturer laughed and said urethane is designed to stick and especially to medals. We found even after soaking in solvents we had no luck. Scraping with knifes caused damage to molds. We couldn't burn out since temp to burn urethane was about the same as melt point of aluminum. We finally found a process that may work for you.

We heated up the urethane and mold to approximately 180 degree F and cooled immediately. Urethane and our metal had different expansion right and loosened the bond. We were able to remove without damage. It worked for us, you may want to try a similar method. Good luck let me know what works. We are always open to learning new approaches.

Good Luck, Matt at FilterDeal@yahoo.com

You are going to have to scrape it off carefully with a razor knife, then clean the remainder with lacquer thinner if the clear coat is fully cured, or wax and grease remover if the paint is somewhat fresh ). Then buff out the clear coat to restore the original luster. Good luck.

I have no idea if this will help at all, but if it were me, before trying any harsh chemicals that might damage the paint, I would pour a little vegetable oil around it and pick at the urethane with a fingernail to try to get the oil to creep under it. That can't hurt and who knows.