Hi Guys,

There's plenty of info online about coating and laminating resins, but I still can't figure out the difference.
I'm sure 5 minutes with the correct person would answer all my questions, but I haven't been able to find that person in my area!

I did use the search to find similar topics before posting, but couldn't find my answer (apologies if this exists on the forum elsewhere).


To a layman (that's me!), laminating and coating seem like synonyms, what is their specific conotation in the world of composites and resins?
What is the difference between EL2 Epoxy Laminating resin, Epoxy Coating resin and Epoxy Gelcoat ? (the ones on easycomposites sales page for example)


Finally, I have a carbon-kevlar canoe polo boat that has been badly UV damaged, and the resin has flaked off.
Recoating this, what should I be using? Laminating resin? Coating resin? or Gelcoat? Maybe even just regular repair resin would work?



Thanks very much for any help, hopefully I can pass any knowledge forward in the future (kayaking is getting more popular around here!)

The differences are in viscosity, mechanical properties when cured, UV resistance and maybe some additives.
Laminating resins have to wet out fabrics fast, so they usually are on the runnier side. Coating resins are applied on the surface, so they should self-level, build up some thickness and ideally they are a bit more UV resistant, although all epoxy resins will eventually be attacked by UV and will turn yellow regardless of what some manufacturers claim. Some resins more than others, that often has something to do with the hardeners employed.
Epoxy gelcoats are usually thixotropic, they are kind of liquid when stirred but will turn semi-solid when left alone, kind of like ketchup, so they can be applied to molds and stick to vertical surfaces. This is usually done by incorporating fumed silica into the resin. Ideally they should be the most resistant to UV.

Thanks for the reply brain, much appreciated!


I've only ever used a regular repair resin on my kayaks, but even then painting onto the sides has been "drippy" at times. So a laminating resin is out of the picture.


It sounds like for re-doing the top layer of a composite kayak you'd want to be using a coating resin? (Better for UV and self-levels)
I had thought that gelcoats more suited to moulding than painting but again, I don't know much about it!
Is painting with a gelcoat a poor idea?

The technical difference between "laminating" & "coating" is still eluding me
To me laminating is layering some solid material (plastic) over another, while coating would be more to do with liquids and painting.

Obviously a laminating resin is a liquid, so I'm not sure the distinction in this case.

So am I right in thinking that in composites, a laminating resin is applied first, to bond the materials into the specific shape etc. and a coating resin is used on top of that as a finish?
(It seems like in every other field 'laminating' would describe the process of applying the finishing/outer layer )

Then a gelcoat and a coating resin have similar applications, but a gelcoat would be injection moulded and the resin painted?

Yes and no. Depends on the application, the process used etc. Gelcoats are generally sprayed or brushed on, and largely perform the same function as paint. Generally you would apply a gelcoat to the surface of a mould, or in the case of tooling gelcoat, to the surface of a plug. They are thixotropic (not the same as thick, a substance can be thick without being thixotropic) and don't need to self level, because they take on the surface of the mould or plug. Coatings on the other hand are generally applied to an already completed laminate. To reduce the amount of finishing work, they need to have good self-leveling properties. Often the function of gelcoats vs coatings cross over, and which one you use is dependant on the application and the process you are using.