Polyurethane floor varnish VERSUS Epoxy

[lncc63]

Which is better for the top coat of a boat's bottom? Polyurethane (PU) I is more expensive so maybe it is better. I use PU on furniture. Used it on my router table which is now about 2 years old and I can still feel the varnish - pretty tough. I guess if it is used for floors, it must be tough.

[jem]

Which is better for the top coat of a boat's bottom? Polyurethane (PU) I is more expensive so maybe it is better. I use PU on furniture. Used it on my router table which is now about 2 years old and I can still feel the varnish - pretty tough. I guess if it is used for floors, it must be tough.

Polyurethane marine varnish is successfully used on many boats. I'm not exactly sure the formulation difference between standard polyurethane and marine polyurethane.

[Kayak Jack]

My thoughts are that probably the epoxy is considerably harder. Maybe I'm wrong?

If you are talking about the inside of the boat, varnish is OK. On the outside, below the water line, varnish is not necessary.

[banoe]

Finish the bottom with epoxy graphite combination the durability is incredable. Above the water line and inside a good quality exterior paint, marine paint, or marine urethane (House type ureathanes dont have enough UV protection to hold up in marine envroment.) You need to cover the epoxy with some kind of coating epoxy will not hold up to UV exposure. I know first hand my canoe I built two years ago needs to be sanded and recoated with epoxy because I didn't varnish after i built it.

[Oldsparkey]

Finish the bottom with epoxy graphite combination the durability is incredable.

When you get into a bunch of weeds you will think your boat has 4-wheel drive because they will not stick like they do to a standard glass hull, on blowdowns , stumps, logs and the rest ... you will slide over them and have very little damage (a lot less then the standard glass hull would have) to the bottom of your boat.

It is not an indestructible coating but it sure lets you have less destruction to the bottom of your boat then not having it there when you get into a tight situation.

Plus is is slicker then the normal glass bottom letting you use less effort to paddle..... This might be one reason the professional ,racing ,sailboats use it (less darg).

Chuck.

[lncc63]

Went by the local MC Home Depot here in the Philippines, to read the labels on the available PU. Unfortunately, none said they their's was UV resistant so I guess they were all for indoor use only. Will try others when I get the chance.

The epoxy manufacturer I'm using suggested I put a sacrificial clear coat of epoxy paint over the real paint. I'll have to recoat every few years but at least the color will not fade is what they said.

I think epoxy is harder since it is used for factory floors. On the other hand this may just be because epoxy is cheaper than PU.

I also read about graphite on forums - interesting. I started another topic for this.

[Oldsparkey]

This is just my thoughts and that with $. 50 cents might get you a 1/2 cup of coffee. Anyway here are ....... or should it be ....Is my thoughts ...... regardless............

Epoxy is a chemical mix of ingredients , when mixed correctly, is harder then any paint unless it is an epoxy paint.

Take a painted wall (when no one is looking) scratch it and the paint will flake off .......... Now try that with some epoxy on the same wall and what ever you are scratching with will be hard pressed to get or make anything more then a scratch on that surface.

Like I said ...Just my opion and that with $.50 cents will get you half of a cup of coffee ...... Warm and not hot like it should be.

Sunblock for your boat ....... Captaints Z spar varnish..(Contains Ultra Violet absorbers and filters).. Raka has it and that is what I use since I like to have the wood to be seen ... After all it is a wood boat.

Chuck

[lncc63]

Thanks Chuck. Like most people, I find it extremely strange that in a country with 7000 island there are only a few builders and we do not have many choices when it comes to materials.

You are right about epoxy being very hard. The epoxy guys told me a client of theirs once used a jack hammer on epoxy that had hardened on them. The epoxy "laughed" at the jack hammer. Epoxy is used here to repair cracks in structural concrete damaged by earthquakes, lest the jack hammer.

[Oldsparkey]

Down here in the land of Rednecks, confusion, hurricanes ... Then the rest of the time we are just having some fun on the water.

The ole boys with the Airboats have something called Steel Flex put on the bottom of there boats .... It is epoxy and you can guess what else but it is put on so it is a 1/4 inch thick.
This way they can take there Air Boats anywhere, water, sand, mud, fence posts. Logs, Jet Skies, cows, gators , hogs, bass boats and any thing else in there way or just over the hill (dry ground) and even down a paved road without any damage to the bottom of the boat.

Since we are not running a 0-540 air craft motor or a large block 8 V with all that weight and swinging a 72 inch prop but paddling a light weight boat the graphite (three light coats) does the same thing as far as protecting the bottom of our boat and since it is mixed in with epoxy ..... all the better.

I have to tell you an Air Boat is fun, especially with a 0-540 fuel injected air craft motor sitting on it ...( the motor on the boat was bigger, stronger and with more mussel then the air craft motor in our airplane) .

That was one of my patrol boats when I was with the Sheriffs Office ..... By the way it would go over 100 mph (Way over) without any problems and the hull was bullet proof , No really bullet proof...... It was a .......FIRE BREATHING BEAST........

Chuck.
Yep , they paid me to run it and when not on it then run around in the woods in a Jeep.