Is "marine epoxy" any different than regular epoxy?

[SKMT]

Is there anything special about "marine epoxy". I'm not talking about epoxy for water tanks or to cure underwater. Just an epoxy for gluing/sealing stuff on a boat -- is there any reason to pay for "marine"?

[belizesailor]

No, be automatically suspicious of anthing with the word "marine" in it...its usually just an excuse to charge several times more (marine plywood exluded) for the same stuff.

That said, there are varying qualities of expoxy resin.

[more]

Originally Posted by SKMT

Is there anything special about "marine epoxy". I'm not talking about epoxy for water tanks or to cure underwater. Just an epoxy for gluing/sealing stuff on a boat -- is there any reason to pay for "marine"?

read here
https://resin-expert.com/en/guide/ma...ne_Epoxy_Resin

[tkeithlu]

Nice summary, more, and thanks for posting it. Curiously, it calls itself a summary of marine resins, but doesn't make a separation between a "marine" resin and non-marine. It seems to be a matter of quality if the distinction exists at all.

[Chotu]

Originally Posted by SKMT

Is there anything special about "marine epoxy". I'm not talking about epoxy for water tanks or to cure underwater. Just an epoxy for gluing/sealing stuff on a boat -- is there any reason to pay for "marine"?

There is definitely no difference at all. Don’t even think twice about that.

There is hardly a difference between top dollar epoxy and the lowest price when you can find either.

[s/v Jedi]

I have never seen a “marine epoxy”? Or is this the small blister packaged diy stuff?

[Locquatious]

Having worked for years, formulating epoxy based products for the 3D printing industry, I can attest that different epoxies and different epoxy mixtures will have different properties. I have not formulated for marine applications, but have developed formulations having superior moisture and water resistance, superior UV resistance, greater strength, or flexibility, or heat tolerance, etc.

It is very likely that some companies have formulated their products for the marine environment and brand their products for "marine use" for that reason.

[arcticmonkey]

there are excellent epoxies out there... application determines choice
most epoxies I have used (like cold cure in BC) can be researched then chosen for its properties you are looking for

[P3sailor]

Yes, there is a difference...in price! Epoxy's may vary in quality and what they can be used on or with but I don't believe it would make much of a difference whether for marine use or otherwise. Just like I don't believe there's a specific marine grade fiberglass and resin. It's all about marketing. I could be wrong, just sayin'.

[Bill Seal]

What about this that I found on the all-knowing internet?

What kind of resin do you use for fiberglass mat?
Mat has a light binder that holds it together. During lay-up, it requires styrene to break down that binder and allow for complete resin saturation. Epoxy does not contain styrene and therefore cannot be effectively used with the mat. Use polyester or vinyl ester resin with these applications.

[BAD ORCA]

Originally Posted by Bill Seal

What about this that I found on the all-knowing internet?

This is true or was true. I worked extensively with resins and epoxy was not used with fiberglass matt ever. Newer matt like the bi-axial stuff may be an exception. I have moved on to other stuff and am out of the loop on newer products so i cant say if this is still true, but i would be careful and do a fair amount of research using it even witht the biaxial/matt laminate.

epoxies are generally the same base ingredients but are formulated for the end user to have different characteristics depending on their purposed use. They can vary greatly in ability to withstand different stresses, heat, mass, UV, adhesion etc...

No one knows exactly how they been changed except the chemist and the intended supplier/ distributor, but my suspicions are that most marine epoxies have been formulated mainly to be thinner, so they may wet out cloth better, have controlled/timed hardeners and UV additives while still having good adhesion properties with some flexibility.

So yes they can be different but it depends on your end use. There are lots of equal or superior epoxies that are cheaper that can do the same thing West Systems can do at half the price, but you should research this a little if its critical application.

I would be the most careful about UV/exterior applications. You absolutely do not want an epoxy exposed on the exterior unless its formulated to withstand UV. Most epoxies in my experience have no ability to withstand UV and will break down rapidly once the process starts. Also adhesion while remaining slightly flexibly are probably very relevant. You wouldn't want to get a filled potting or tooling epoxy for filling in flexible seams for example and certainly not for laminating, and you certainly wouldn't want a laminating epoxy for filled structural applications.

So i guess to answer your question, yes there are differences but i agree marine epoxies are way overpriced.

[s/v Jedi]

Originally Posted by Bill Seal

What about this that I found on the all-knowing internet?

In the US you need to use stitched matt (never seen it) with epoxy. In Europe they have matt with a binder that is compatible with epoxy.

Now the good news: in the US you can get products like 1708 which is matt stitched to a biaxial fiberglass and apply both in one go. Very popular and works great. It’s available in several weights but 1708 is the most popular one.

[goboatingnow]

Originally Posted by s/v Jedi

In the US you need to use stitched matt (never seen it) with epoxy. In Europe they have matt with a binder that is compatible with epoxy.



Now the good news: in the US you can get products like 1708 which is matt stitched to a biaxial fiberglass and apply both in one go. Very popular and works great. It’s available in several weights but 1708 is the most popular one.

1708 is a designation for a product in Europe called “ combination mat “. Available widely for both polyester and export resins.

[chasfgr]

Apart from the exorbitant premium you pay for marine epoxy, it should cure at lower temperatures and under water, than the standard.

[belizesailor]

Originally Posted by tkeithlu

Nice summary, more, and thanks for posting it. Curiously, it calls itself a summary of marine resins, but doesn't make a separation between a "marine" resin and non-marine. It seems to be a matter of quality if the distinction exists at all.

Thats because chemically there is no difference. Its all about quality.