Is epoxy epoxy? Well known vs cheap brand epoxy.

[xellz]

Not only boat building materials are hard to find in Japan and really little choice, but they also cost a lot. For example 3 gal of System three SilverTip epoxy will cost about 550usd, there is much cheaper epoxy available of ebay or in Japan (but never heard of those company names). From what i could find, most problems come from not protecting ratios and instructions provided by manufacturer, i.e. better to avoid pump and read instructions. Since i want to paint over, how clear is epoxy is of no importance.

 

[PAR]

West System and System Three brand epoxies are the two most costly of the commonly available stuff. Japan has epoxy formulators in country and you can order epoxy online, usually at 1/2 to 1/3rd of the price of the big boys and yes it has the physical attributes of the major brands.

 

[gonzo]

Cheap epoxies usually have no technical support. That is worth a lot of money.

 

[upchurchmr]

20 years ago I built a kayak while in japan.
I ordered a kit, with epoxy, from the US.
Pygmy Kayaks. Pygmy Boats: Voted Best Wooden Kayak Kit http://www.pygmyboats.com/
The kit was the same price as in the US, don't remember the shipping.
You might be able to order just epoxy from them and see what the shipping would be.

 

[xellz]

Thanks for input, i thought about trying japanese epoxy on small project first before i go to larger boat. Difference between System Three and cheaper epoxy won't be that big on kayak, but on 30ft catamaran it's certainly noticeable.

 

[rwatson]

You might consider a mix. Brand name for exterior, no-brand for interior for example.

I did a strip plank canoe in West Systems. It has spent many years up side down, in direct sunlight. The seats, also done in epoxy/strip/plank at the same time look like new, while the inside of the hull has gone dark, and mostly opaque. The outside of the hull is painted a dark colour, which goes against a lot of advice to paint epoxied hulls a light color.

I guess the lesson is that even a brand name doesn't make epoxy anything but epoxy, and they all have their limitations.

 

[dinoa]

Checking out the data sheet for an epoxy helps.

 

[xellz]

After searching for a while i could not find dedicated marine/boat building epoxy local supplier, but something similar is available. Could find several examples of use, but no big projects, small boats or kayaks.
Some of properties for local epoxy (2 different epoxies, same price, same maker):
Viscosity when mixed: 580, 562

After curing:
Specific gravity: 1.14, 1.18
Compression yield strength N/mm2: 76.4, 78
Compressive modulus N/mm2: 2200, 2200
Bending strength N/mm2: 64.9, 69.3
Tensile strength N/mm2: 43.4, 50.8
Impact strength kJ/m2: 3.7, 3.9
Tensile Shear Bond Strength N/mm2: 20.4, 25.2

It's different from major companies in USA, but i'm not too sure how big is this difference. Since it was used successfully on kayaks i think i'll try it too. 2kg resin, 1kg hardener will cost me only 70usd.

 

[pauloman]

used to ship gallons of our Premium No Blush epoxy to a private boat builder in Japan. Thanks to new shipping regulations cannot ship outside the USA anymore.
check the msds or SDS sheets for chemicals used added to the epoxy

this link to compare different clear marine epoxies

www.epoxyproducts.com/mepoxies.html

paul oman
progressive epoxy polymers inc.

 

[pauloman]

don't put too much faith in the numbers. The formulators usually extrapulate them from the raw chemical suppliers numbers. Also, everything changes when you add fiberglass cloth into the mix (or fillers, etc.)
everyone will have similar numbers - it is sort of an apples to apples comparison. Look for % of nonyl phenol in the formulation. - Huge amounts not OK, lesser amounts are OK

paul oman

 

[fallguy]

Not only boat building materials are hard to find in Japan and really little choice, but they also cost a lot. For example 3 gal of System three SilverTip epoxy will cost about 550usd, there is much cheaper epoxy available of ebay or in Japan (but never heard of those company names). From what i could find, most problems come from not protecting ratios and instructions provided by manufacturer, i.e. better to avoid pump and read instructions. Since i want to paint over, how clear is epoxy is of no importance.

Make sure and get no blush epoxy. Anything else is a pita.

Another rookie error is viscosity. Compare to Silvertip.

Silvertip is my preferred epoxy. Surprised you can’t get it for 120 a gallon plus ship. Anything over a buck an ounce is too much. Send a message to rxcomposite and see if he has a recommendation.

 

[xellz]

used to ship gallons of our Premium No Blush epoxy to a private boat builder in Japan. Thanks to new shipping regulations cannot ship outside the USA anymore.
check the msds or SDS sheets for chemicals used added to the epoxy

this link to compare different clear marine epoxies

www.epoxyproducts.com/mepoxies.html

paul oman
progressive epoxy polymers inc.

What shipping regulations? I'm currently thinking on ordering all materials from boatbuilder central because i can't really get a decent source locally. Only marine plywood sold here is birch, which is quite a bit more heavy. But also thought that epoxy might be a problem and better to make sure i can import before ordering. They do have inexpensive marine epoxy and it was also used on Richard's own Skoota 28 and looks like there are no problems with it.

 

[fallguy]

I am a customer of bbc. I hold them in high regard. I would recommend using Silvertip for anything you intend to finish bright. It has better outgassing qualities than any epoxy I have ever used. The forum there is also helpful with nitty details.

 

[PAR]

The physical properties of SilverTip and Bateau's Marinepoxy are nearly identical, so buying SilverTip is just paying 2.5 as much for essentially the same thing. In fact, knowing where they're getting their raw stock, it's the same as most other formulators, so literally the same thing, except for minor additives in their hardeners.

Getting "blush free" formulations is just a marketing tool, really. Most home build shops, just don't have the environmental controls to take advantage of this, so if you're wise, you always assume a blush, even if a modest one (also bugs, dust, wood chips and other contaminates) and wash any cured surface, before applying another coating (of any type).

 

[pauloman]

Amine blush is caused by co2 in the moist air that forms a waxy film on the epoxy as it is curing. If the blushing happens to be bad it can mess up the adhesion of the next coat of epoxy , paint, etc. - (one more thing that can go wrong). So using a blush free epoxy is one less thing to worry about. - Why formulators even offer a blushing epoxy is beyond me.... (it is a bit cheaper of course) when a slight change in the formulation can 'save the day." Sort of like buying a car without seat belts or with seat belts....

paul
progressive epoxy polymers inc
epoxyproducts.com