epoxy

[gert]

Are there "LEEDS" aka "eco freindly" epoxies?

[Thorne]

????

Oxymoron

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I don't know what a "Leeds" is and can't find it on the web, and not sure how a relatively permanent and somewhat allergenic glue/material can be eco friendly -- we may need to define terms here...

;0- )

Are you referring to manufacturing policies, disposal sites, or ? Many of the non-epoxy subsitutes or traditional boatbuilding materials (lead putty, pine tar, etc) are often regarded as less eco-friendly, so in comparison it may still be a 'greener' option.

[JC 72]

At least cured epoxy is fairly inert, as long as you don't burn it. Ahh, but there is nothing quite like the smell of pine tar in the morning.www.tarsmell.com John

[katiedobe]

LEEDS is a construction trades designation for the levels of constructing a building (house or commercial) in an environmentally friendly way. Currently there are levels of awards given, (gold, platinum etc) that show how much you love the environment. Things like using a "living roof" or collecting the rainwater to flush the toilets with. Also a lot of improtance is put upon healthy air for the people in the building, ie: using non Petroleum based floor glues or non-offgassing glues in the plywood sheathing and subflooring. Also using sustainable resources or renewable resources, like wheat board, bamboo ply etc.

I cannot think of any epoxy that is leeds certified.

[bainbridgeisland]

(Warning, the following information has been gleaned from a carrier working with epoxy system, I am not a health care professional or a Chemist)

I recommend you look into polyamide based epoxy systems. The lowest toxicity industrial hardener I know of is polyamide based. It is actually an epoxy resin itself but has been used to cure epoxies for at least 40-years that I know of. My recollection is that it is made from rendered animal fat. The hardener is available without solvents usually called 100% epoxy. Toxicity of polyamide resin (hardener) without dilution by solvents is considered very low.

One well-known product line that uses this hardener is 'Versamid' by Henkel Corporation. I have recommended Versamid 140 for years as a low toxicity hardener for epoxy resin. Viscosity is too high for fiber glassing (except by experts) but it is a good all around adhesive. Other Versamid resins such as Versamid 100 or Versamid 115 are lower viscosity. Viscosity is lower because the molecules are smaller. This affects the cured product. For example smaller molecules create a cured product that absorbs more water. However, this does not mean that the finished products made from the smaller molecules are not water resistant.

Almost all industrial epoxy resins used for boat building (not hardeners) are from one family, commonly called DGEBA (Diglycidyl ether of bisphenol A). Toxicity is generally low but varies slightly with refinement of impurities left from the manufacturing process. Resin is available without solvents, usually called 100% epoxy.

Using these products (without solvents) together produces an adhesive that does not off-gas during cure (at least not significantly). So you have a combination of a very low toxicity product and a low toxicity product that do not off-gas. When cured this epoxy compound is approved for food service and even oxygen systems.

[Thorne]

Seems like you might a slight 'conflict on interest' as far as green ratings go -- after all the most eco-friendly wooden boat would be a mound of decomposing wood...

Depending on how you look at logging, using epoxies and other unfriendly materials to preserve a wood boat may be the most eco-friendly solution over time -- say 60 years? Otherwise you'd end up logging wood for the same boat several times over, plus all the transport, milling, and processing environmental costs.

And if the more eco-friendly epoxies have less water-resistance, you might end up being a little too organic yourself...

;0 )

[WX]

Botecoat is pretty good, there is also a range of paint calle Aquacoat, it's a 2 part epoxy that can be thinned with water and clean is with water. It not meant for areas that are permanently immersed though.

[bainbridgeisland]

...And if the more eco-friendly epoxies have less water-resistance, you might end up being a little too organic yourself...

Boat building epoxies are really good in water. However, all epoxies are affected by water, some more than others. The polyamide family is in the average range (maybe above average) of water resistance when considering epoxies used for boat building.

Much more water resistance is available from epoxy compounds than boatbuilding epoxies provide. However, handling, cost and toxicity make them impractical and the additional performance is not needed.

[katiedobe]

That is one of the issues that people in the sustainable movement look at. How many times does a building need to be built. How long of an impact does our actions have on the earth. The leeds people are not "crazies" who want to stop progress. They are intelligent people who want to help ensure that the earth and it's resources are here for many future generations. They advocate for sustainabl harvesting of lumber from both the rainforest and the NW forests. They realize that jobs are essential to the people who live in and near the rainforest. They just want to make sure that there are jobs for the grandchildren and great grandchildren of the people working the rainforest now.

[Thorne]

I suspect that only some elements of a wooden boat can be considered on the 'eco-friendly' perspective.

Some elements like glues and fasteners will either be un-rated (like epoxies apparently) or chosen for non-biodegradability like silicon bronze fasteners over SS or mild steel.

But this is where the traditional boatbuilding recommendation to use local woods and minimal modern glues certainly comes into play...

;0 )

[Brian Palmer]

You can always request a material safety data sheet (MSDS) for the materials that you are considering and compare the solids content and volatile ingredients, along with the permissable exposure levels and other hazard information. Higher solids means less evaporates into the air. That would be the most objective source of information.

-- Brian