Expensive lessons, don’t clean tail lights with denatured alcohol
12-30-2021, 07:34 PM
#1
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Expensive lessons, don’t clean tail lights with denatured alcohol
Learned a very expensive lesson this morning. Used some denatured alcohol to clean some condensation spots in one of my tail lights. After I placed about a half ounce or so in the light, swished it around for about 20 seconds, tilted the light so all the alcohol drained out then followed up by placing a shop towel in the lens to absorb any residue fluid. Reinstalled the taillight and grabbed a bite of breakfast. About 15 later I was leaving for work and the lens had a crack from top to bottom. Dang it. What a rotten way to start my day. Sunset Porsche can you hold.
Last edited by Kuhl997.2!; 12-30-2021 at 07:37 PM.
12-30-2021, 07:59 PM
#2
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I would have assume the crack was caused by induced stresses in the aged plastic during the physical removal/cleaning/install steps, not the usage of cleaning alcohol per say.
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fuzebox (12-30-2021)
12-30-2021, 08:14 PM
#3
Rennlist Member
Really a bitter lesson to learn.
Good that you conveyed what happened here so that others can learn / benefit from the experience.
Good that you conveyed what happened here so that others can learn / benefit from the experience.
12-31-2021, 09:05 AM
#4
RL Community Team
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I was told regular rubbing alcohol would do this, but that denatured alcohol was safe.
12-31-2021, 11:35 AM
#6
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Snakebit (12-31-2021)
12-31-2021, 05:29 PM
#7
Thanks for at least sharing so that others can learn from the experience.
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myw (03-15-2022)
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12-31-2021, 05:32 PM
#8
Rennlist Member
Sorry for your experience, as it is so discouraging and certainly makes a sour note for the day-and the day after. Not forgetting how bad a day the lights went through!
Applause is warranted for your telling the world of your mishap to serve as a Public Service Announcement.
It is a dangerous world out there with chemistry and chemical products, especially organic materials. All plastics will be attacked by some chemical and the time of contact and the temperature will have a major affect. This is why it is dangerous to make general statements about "compatibility". We all know that some plastics will be attacked readily by many solvents, such as acrylics ("plexiglass") wiped with acetone will be an immediate disaster. However there are more situations where the chemical is not an actual solvent (meaning disolving) but still chemically incompatible. This is where the sinister chemical works slowly and quietly and without fanfare but still destroys the plastic part. This is what happened to your lights. The injection molding process which is under 20,000 psi when molded still has a high stress that resides in the part when cooled and removed from the tool. A high stress still remains in the part. A chemical that is incompatible comes in contact with the part and the attack results in reliving the built in stress which results in cracking ,crazing , micro fissures , etc.
All alcohols are bad for use around most plastics. As far as the acrylic taillights, there is really no solvent that is safe. A quick wipe with a diluted isopropyl cloth and a quick rinse may be O K but nothing more. Denatured alcohol is by far the worst and should be only used for making shellac or if you really know what you are doing as it will appear to work great today and next month you will find that the part is cracked. If you are hell bent on using alcohol for something then use the bathroom rubbing (isopropyl) and quicky follow up with good ole soap and water.
Be safe out there !
Applause is warranted for your telling the world of your mishap to serve as a Public Service Announcement.
It is a dangerous world out there with chemistry and chemical products, especially organic materials. All plastics will be attacked by some chemical and the time of contact and the temperature will have a major affect. This is why it is dangerous to make general statements about "compatibility". We all know that some plastics will be attacked readily by many solvents, such as acrylics ("plexiglass") wiped with acetone will be an immediate disaster. However there are more situations where the chemical is not an actual solvent (meaning disolving) but still chemically incompatible. This is where the sinister chemical works slowly and quietly and without fanfare but still destroys the plastic part. This is what happened to your lights. The injection molding process which is under 20,000 psi when molded still has a high stress that resides in the part when cooled and removed from the tool. A high stress still remains in the part. A chemical that is incompatible comes in contact with the part and the attack results in reliving the built in stress which results in cracking ,crazing , micro fissures , etc.
All alcohols are bad for use around most plastics. As far as the acrylic taillights, there is really no solvent that is safe. A quick wipe with a diluted isopropyl cloth and a quick rinse may be O K but nothing more. Denatured alcohol is by far the worst and should be only used for making shellac or if you really know what you are doing as it will appear to work great today and next month you will find that the part is cracked. If you are hell bent on using alcohol for something then use the bathroom rubbing (isopropyl) and quicky follow up with good ole soap and water.
Be safe out there !
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12-31-2021, 05:35 PM
#9
Rennlist Member
12-31-2021, 10:49 PM
#11
Three Wheelin'
Sorry for your experience, as it is so discouraging and certainly makes a sour note for the day-and the day after. Not forgetting how bad a day the lights went through!
Applause is warranted for your telling the world of your mishap to serve as a Public Service Announcement.
It is a dangerous world out there with chemistry and chemical products, especially organic materials. All plastics will be attacked by some chemical and the time of contact and the temperature will have a major affect. This is why it is dangerous to make general statements about "compatibility". We all know that some plastics will be attacked readily by many solvents, such as acrylics ("plexiglass") wiped with acetone will be an immediate disaster. However there are more situations where the chemical is not an actual solvent (meaning disolving) but still chemically incompatible. This is where the sinister chemical works slowly and quietly and without fanfare but still destroys the plastic part. This is what happened to your lights. The injection molding process which is under 20,000 psi when molded still has a high stress that resides in the part when cooled and removed from the tool. A high stress still remains in the part. A chemical that is incompatible comes in contact with the part and the attack results in reliving the built in stress which results in cracking ,crazing , micro fissures , etc.
All alcohols are bad for use around most plastics. As far as the acrylic taillights, there is really no solvent that is safe. A quick wipe with a diluted isopropyl cloth and a quick rinse may be O K but nothing more. Denatured alcohol is by far the worst and should be only used for making shellac or if you really know what you are doing as it will appear to work great today and next month you will find that the part is cracked. If you are hell bent on using alcohol for something then use the bathroom rubbing (isopropyl) and quicky follow up with good ole soap and water.
Be safe out there !
Applause is warranted for your telling the world of your mishap to serve as a Public Service Announcement.
It is a dangerous world out there with chemistry and chemical products, especially organic materials. All plastics will be attacked by some chemical and the time of contact and the temperature will have a major affect. This is why it is dangerous to make general statements about "compatibility". We all know that some plastics will be attacked readily by many solvents, such as acrylics ("plexiglass") wiped with acetone will be an immediate disaster. However there are more situations where the chemical is not an actual solvent (meaning disolving) but still chemically incompatible. This is where the sinister chemical works slowly and quietly and without fanfare but still destroys the plastic part. This is what happened to your lights. The injection molding process which is under 20,000 psi when molded still has a high stress that resides in the part when cooled and removed from the tool. A high stress still remains in the part. A chemical that is incompatible comes in contact with the part and the attack results in reliving the built in stress which results in cracking ,crazing , micro fissures , etc.
All alcohols are bad for use around most plastics. As far as the acrylic taillights, there is really no solvent that is safe. A quick wipe with a diluted isopropyl cloth and a quick rinse may be O K but nothing more. Denatured alcohol is by far the worst and should be only used for making shellac or if you really know what you are doing as it will appear to work great today and next month you will find that the part is cracked. If you are hell bent on using alcohol for something then use the bathroom rubbing (isopropyl) and quicky follow up with good ole soap and water.
Be safe out there !
12-31-2021, 10:55 PM
#12
Three Wheelin'
12-31-2021, 11:03 PM
#13
Three Wheelin'
Yeah, you know, there may be a lot of truth her if you think about it. The application of isopropyl will, generally result in heat being released, so the tail light surface will have a lower temp than ambient. Obviously, this can result in a crack due to differential heating. So, if you are really worried about isopropyl cracking plastic, apply it in a cold environment where the temperature differential is minimized.
12-31-2021, 11:49 PM
#14
Burning Brakes
Yes, apparently IPA doesn't bode well with many plastics, even though it seems like its a nice cleaner initially.
Here's a video I found with a quick YouTube search that shows a crack being formed in a hair trimmer part.
Of course, our P-car lights might be from a different plastic material, but this is a cautionary tale on using concentrated IPA as a cleaner.
Here's a video I found with a quick YouTube search that shows a crack being formed in a hair trimmer part.
Of course, our P-car lights might be from a different plastic material, but this is a cautionary tale on using concentrated IPA as a cleaner.
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Wayne Smith (01-01-2022)
