Does this still look good to use? It is milky in color and the rim is a bit crusty.

Looks like my jar and I would use it. If you don't like the results, you can always lightly sand it off.

Looks good to me.

 

In my experience,... You will know when it has gotten old and thickened because it won't apply the same.

👍

3 hours ago, FrnkNsteen said:

Looks good to me.

 

In my experience,... You will know when it has gotten old and thickened because it won't apply the same.

That one looks fine to me....mine actually dried out, but I just put a bit of water into it, stirred it with my powered-paint stirrer...applied it to a rod and it worked just fine. So even dried out doesn't mean it's 'dead'.

It's good.

This stuff lasts forever. The apocalypse will come and a thousand years later, you can just add some water to the jar and it'd still be good.

Lasts forever.... got it. I am always one to play devil's advocate, and I am always one to be suspicious of chemicals and how they relate to my overall health- which matters to me.

 

So I thought I would take a look under the hood of U-40 and see what shakes out. Here is a link to the safety data sheet:

 

https://www.bestmaterials.com/PDF_Files/U-seal-MSDS.pdf?srsltid=AfmBOopc_MrtepM1ivBPQ3TxaLT1Ncz72shZ0-wzvT-0MHBTXGGKuAs0

 

Next, I asked google search "is u-40 cork sealer hazardous to health?"

 

Response:

 

Yes, U-40 Cork Seal is hazardous and can cause harm if inhaled, ingested, or has prolonged skin contact, so it should be used with caution. It is important to ensure the area is well-ventilated, wear protective gear, and keep the product away from children, pets, and food. 

Health hazards

Inhalation: High concentrations of fumes can irritate the respiratory system and cause central nervous system effects like headaches, dizziness, and nausea.

Ingestion: Ingestion can cause nausea, vomiting, and diarrhea, and may lead to permanent damage.

Skin contact: Prolonged or repeated contact can cause mild irritation. 

Safety precautions

Ventilation: Always use the product in a well-ventilated area to avoid inhaling fumes.

Protective gear: Wear a face mask when applying the product, as advised for chemically similar products.

Storage: Store the product safely, keeping it away from food, drinks, and animal feed.

Supervision: Keep the product out of reach of children and pets, or use it only under proper supervision.

Hygiene: Wash your hands after use."

--------------------------------------------

 

So the primary chemical contained within U-40 that causes harm to human health is called bitumen:

 

"Bitumen (according to SAX’s) : moderately toxic in case of skin contact – low toxicity from swallowing – if heated to decomposition, emits acrid fumes and irritating vapours. -Acute toxicity : LD/50 (oral/rat) > 5000 mg/kg LD/50 (skin, adult rabbit) > 2000 mg/kg Anomalous exposure to product vapours heated to high temperatures can cause irritation of mucous and airways."

 

So my next obvious logical question to google search is "can "bitumen" be absorbed through the skin?"

 

Google response:

 

"

Yes, components from bitumen, such as polycyclic aromatic hydrocarbons (PAHs), can be absorbed through the skin, and prolonged or repeated contact can lead to irritation and dryness. This dermal absorption is a significant route of exposure that can contribute to the total internal dose of harmful chemicals, according to research. 

How skin absorption happens

Direct contact: Contact with neat bitumen, cutback bitumen, or fumes from heated bitumen can lead to skin absorption.

Contaminated surfaces: Workers can be exposed through contact with contaminated tools, clothes, and other surfaces.

Fumes: Aerosols and vapors from hot bitumen can deposit on skin and be absorbed. 

Health effects

Local irritation: Repeated or prolonged contact can remove natural fats from the skin, leading to dryness, cracking, and irritation.

Systemic effects: Dermal absorption contributes to the overall internal dose of chemicals like PAHs, which may have long-term health effects.

Molecular damage: Studies have shown that dermal exposure to bitumen can cause molecular reactions in the skin, such as irritation and changes in cell behavior. 

Protection and first aid

Personal protective equipment (PPE): Wear appropriate gloves and protective clothing to minimize skin contact."

 

And my next obvious logical question for google search: "can "bitumen" cause cancer?"

 

Google response:

 

"Yes, occupational exposure to bitumen and its fumes can cause cancer, particularly lung cancer and tumors in the upper aerodigestive tract, according to organizations like the International Agency for Research on Cancer (IARC) and the US National Institute for Occupational Safety and Health (NIOSH). Bitumen fumes contain polycyclic aromatic hydrocarbons (PAHs), some of which are known carcinogens. The risk depends on the type of bitumen and the specific work being performed, with oxidized bitumens used in roofing classified as "probably carcinogenic to humans" and hard bitumens used in paving classified as "possibly carcinogenic to humans"

 

And that folks is all I need to know. Chemicals = bad for my health. And this "lasts forever" chemical that I put on a fishing rod to protect the cork is not in my health's best interest.

 

Why would I stand there thinking I am doing a great thing in protecting my cork while poisoning myself in the process as bitumen leeches from the U-40 and is absorbed through my skin with each prolonged contact?

 

I have to ask myself what is more important? Keeping cork looking new or living longer as a healthy human?

 

I think I like plain old cork now even more! I appreciate threads like this to help inform me so thanks for the inspiration to check out U-40. I learned something today so thanks BassResource!

 

Honestly 

The same things can be said about almost all chemicals that we all have in our homes. 
 

MSDS are for informational purposes that are for the eye of the beholders to accept and if people want to live thier lives around every printed word and  every precaution listed its their choice.  

All products should be used in the manner recommended by the manufacturer. 
As long as I don’t inhale, touch, smell or taste it, I’m good 
 

I use the stuff before any rod gets rigged regardless of cost. 
 

 

 

 

 

 

Mike

Oh, Good Grief....

 

So don't huff it, spray it all over yourself, burn it or eat it?? Got it! No problem!

 

I choose to just have some common sense and not overthink every little thing!

 

If I ran from every product that had warnings on their MSDS, I wouldn't touch much of anything!

I guess I am doomed 🙂

On 12/2/2025 at 8:49 AM, ike8120 said:

I guess I am doomed 🙂

 

Me too.

Last time I applied U-40, I spilled it. I have a hole in my garage floor through which I can see a street in downtown Hong Kong.

 

Seriously though, EVERYTHING it seems like is known to the state of California to cause cancer. Car wreck? It’s known to the state of California to cause cancer. Eviction? It’s know to the state of California to cause cancer. 
 

Im not trying to “downplay” anything, but as stated above, if I looked at every MSDS sheet for everything I have come into contact with in the last 50 yrs, I would be horrified. And, if I asked WebMD why I broke my toe, it would be “cancer”.

 

All of that said, I haven’t used U-40. What I do use is tru oil from Birchwood Casey. It’s available locally at Cabela’s and is cheaper than U-40. 

I keep saying that eventually they'll declare Distilled Water as hazardous.

Recant studies indicate that saliva causes stomach cancer, but only when ingested in small doses over a long period of time.