Epoxy Recommendations

[Bustlebomb]

I've been reading and learning a bunch about epoxy. Seems like miracle stuff for some applications and I can't believe I've gone this long without using it.

I'm about to take the first steps and was looking for recommendations from those more experienced than I am (that means pretty much anyone at this point).

I've looked at West System, TotalBoat, US Composites, and System 3. All seem pretty similar. Does anyone have any experience or recommendations regarding these? Are there any others I should consider?

Thanks,

Matt

 

[psneeld]

Used US Composites to do my whole underwater with zero issues 10 years later, on my decks both main and flybridge with zero issues I 10 years, plus dozens of other projects.

Way less expensive than West (figure shipping though) and in my mind just as good....

Only small, projects with some of the others.

Love TotalBoat TotalFair for fairing.....

Old timers in the petroleum industry always said that only a few companies make epoxy, all the brand names just order what they want and relabel it.

 

[RT Firefly]

Greetings,
Mr. B. One of the potential problems with West System is a ketone blush layer which forms on the surface of cured epoxy. It must be removed for additional layers to bond properly. (at least this was the case some years ago-may have changed).


I have been quite happy with the results when using MAS epoxy and again, cheaper than West. https://masepoxies.com/product-category/marine-epoxy-system/


Edit: Bold should be corrected to AMINE BLUSH. Thanks Mr. s. Always getting those things mixed up...

 

[DNT99611]

Done a bit of glass work over the years. Up to and including building three boats from scratch. Picking an epoxy depends partly on what you are doing. I really like Systems Three and they have other products that go with it. I prefer the epoxies that are two to one over those that are 5-1. Just less chance to screw up the mix. I have not used US Composites so I can not commit on that epoxy.

 

[syjos]

I used WEST Epoxy for over 35 years for wood and FG build, repair, restoration. Great stuff.

Switched to System 3 Silvertip epoxy about 8 years ago.

I got tired of washing the amine blush off and sanding between coats with WEST

With S3 Silvertip, there is no blush to wash off and I can recoat within 72 hours without sanding.

I follow all the recommendations and technique outlined in the "Gougeon Brothers on Boat Construction" and S3s "Epoxy Book"

I still mix various fillers into the Silvertip epoxy for specific needs but rely mostly on S3 Gel Magic for adhesive and Quick Fair for putty. Both of these products are a time saver in time saved mixing and the quick cure time. The two products produce no sag, drip or runs.

I used S3 products in my recent projects:

https://www.trawlerforum.com/forums/s71/bluewater-40-pilothouse-roof-replacement-44834.html

https://www.trawlerforum.com/forums/s71/building-new-pilothouse-doors-bluewater-trawler-52621.html

 

[HTurner]

Greetings,
Mr. B. One of the potential problems with West System is a ketone blush layer which forms on the surface of cured epoxy. It must be removed for additional layers to bond properly. (at least this was the case some years ago-may have changed).


I have been quite happy with the results when using MAS epoxy and again, cheaper than West. https://masepoxies.com/product-category/marine-epoxy-system/


Edit: Bold should be corrected to AMINE BLUSH. Thanks Mr. s. Always getting those things mixed up...

Amine blush becomes a non issue if you use peel ply.


https://www.amazon.com/Infusion-Process-Bagging-Temperature-Resistant/dp/B081Z224BT

 

[RT Firefly]

Greetings,
Mr. HT. Thanks. Never head of that stuff. Amine blush also becomes a non issue of you use a product that doesn't "blush" in the first place. I'm not a chemist so I can't appreciate the added cost benefits of West, if any.

 

[Simi 60]

Amine blush becomes a non issue if you use peel ply.


https://www.amazon.com/Infusion-Process-Bagging-Temperature-Resistant/dp/B081Z224BT

Back in the day we used to use suit lining material
Much cheaper and then, easy to source.

I won't use it anymore, haven't for about 20 years
Wasted $$ imho , labour intensive to apply and remove and more rubbish to get rid of

Instead, as the epoxy firms up I pull a screed of runny bog across it
Easy to sand and if you are fairing anyway........

 

[Lepke]

I've used 100s of gallons of West Systems. Built several boats and repaired many. Never had an issue, no blisters, delamination, etc.

But any major epoxy should work fine. And any epoxy is better than the best polyester resin.

 

[Frosty]

I've used 100s of gallons of West Systems. Built several boats and repaired many. Never had an issue, no blisters, delamination, etc.

But any major epoxy should work fine. And any epoxy is better than the best polyester resin.

Agree with this. I've used WEST, System Three, Raka, and a couple of other lesser known ones.

I ended up settling on WEST because of their technical support people, who are fantastic ("met" them when I had a problem with another brand and their own tech people were not that helpful and I called WEST who still helped me out). It's also easier to find locally if I run out in a pinch; but they are all good.

I never found blush to be a big deal (3M scrubbie and water), but then too, I try to hit the chemical bond window vs. letting it cure. Also to be fair I'm now in a warm/dry area and blush is more often a thing in cooler/damper areas (you can feel it, it's waxy feeling although it's not wax).

Reason I started out with System Three is that it was a mix ratio I could easily do just with cups, whereas WEST, at 5:1 made that tricky. I've since found that a cheap, easy to find scale makes that a non-issue and I can now make any size batch easily and don't need specific cups (great use for all those blister packs I used to have to throw away).

There are also now some other products that can be handy depending on what you are doing (WEST 610, Gflex, Gflex thickened, and 5-minute; and System Three Quckfair are all products I use often and keep on hand in addition to the good old plain epoxy and separate fillers of colloidal silica, and WEST high strength).

In summary, I'd say all marine quality epoxies are good. Concentrate on proper prep and technique (rounded corners when fiberglassing, chemical bond "green stage" window if going for that, precise mixing, etc.)

Edited to add: And high quality personal protection for eyes, skin, and lungs.

 

[sailormike]

I have used a lot of west-system epoxy with great results I especially like the pre-thickened self mixing caulk tube gflex stuff works awesome on small quick jobs and for filling spots

Agree with this. I've used WEST, System Three, Raka, and a couple of other lesser known ones.

I ended up settling on WEST because of their technical support people, who are fantastic ("met" them when I had a problem with another brand and their own tech people were not that helpful and I called WEST who still helped me out). It's also easier to find locally if I run out in a pinch; but they are all good.

I never found blush to be a big deal (3M scrubbie and water), but then too, I try to hit the chemical bond window vs. letting it cure. Also to be fair I'm now in a warm/dry area and blush is more often a thing in cooler/damper areas (you can feel it, it's waxy feeling although it's not wax).

Reason I started out with System Three is that it was a mix ratio I could easily do just with cups, whereas WEST, at 5:1 made that tricky. I've since found that a cheap, easy to find scale makes that a non-issue and I can now make any size batch easily and don't need specific cups (great use for all those blister packs I used to have to throw away).

There are also now some other products that can be handy depending on what you are doing (WEST 610, Gflex, Gflex thickened, and 5-minute; and System Three Quckfair are all products I use often and keep on hand in addition to the good old plain epoxy and separate fillers of colloidal silica, and WEST high strength).

In summary, I'd say all marine quality epoxies are good. Concentrate on proper prep and technique (rounded corners when fiberglassing, chemical bond "green stage" window if going for that, precise mixing, etc.)

Edited to add: And high quality personal protection for eyes, skin, and lungs.

 

[Lou_tribal]

I have yet to find any major difference between epoxy brand except price and marketing.
I am using exp system epoxy and very happy about it. A bit cheaper than other brands like west or east system. What I like the most is the various hardeners, slow, medium, fast, and uv resistant. This is something I would look for whatever the brand is, very convenient when you need to adapt to naturally variable temperature outside and usage.

L

 

[Moonfish]

Another happy MAS Epoxy user. Very low harmful VOCs, too.

 

[RedRascal]

I used U.S. Composite epoxy the make my stitch and glue 14' buzz around boat over 7 years ago. Once in awhile the boat will bash through some chop or a wake that will jar it and flex the gunwales. So far no issues with the epoxy letting go anywhere. At the time U.S. Composites seemed like a good value. The boat is my avatar.

 

[mike66]

https://epoxyproducts.com/
Crazy website, great products. No blush.

 

[Bkay]

On my last boat (wood/epoxy construction), the builder favored West for any structural work. He said he had confidence in their QC and you don't want an epoxy failure in structure.

For wetting out fiberglass or dynell coverings, he favored System 3. He said it was thinner and wet out materials better.

I did a barrier coat with Fiberglass Coatings, Inc epoxy and felt it was too think when mixed and was more sensitive to mixture ratios than I would like. I'm a fan of the metered pumps - I expect any epoxy to work within the range of accuracy of those pumps. However, even though I didn't like working with it, the barrier coat worked for the rest of the time I owned that boat. So it performed as expected.

I have personally used TotalBoat and West for a number of projects and they are close enough for me as an armature to not have a major preference. I will go with TotalBoat due to price most of the time. But if I were doing something critical, I'd stick with West.

I think for the most part, the differences are very minor between the major brands.

 

[FF]

"I think for the most part, the differences are very minor between the major brands"

One big difference is how flexible the glued up part needs to be..

A small boat mast will need to be less stiff , so use the proper hardener.

 

[Simi 60]

"I think for the most part, the differences are very minor between the major brands"

One big difference is how flexible the glued up part needs to be..

A small boat mast will need to be less stiff , so use the proper hardener.

The highlighted bit is where its at imho

As mentioned further up thread there are very few resin manufacturers out there.

The supplier I use in Australia and have done for 30 years make their own and, on occassion have modified hardner's for me for particular projects.

 

[Frosty]

One big difference is how flexible the glued up part needs to be..

A small boat mast will need to be less stiff , so use the proper hardener.

If this pertains to epoxy, I don't understand it.

I have worked with epoxy quite a bit, but of course there is always more to learn. But the way I have used the hardener is strictly by ambient temperature. For example, if I'm using WEST, and it's hot out, I'm using "Slow" hardener. If it's cold where I'm working, I use "Fast" hardener. It's also permissible to mix them for a medium.

For choosing a hardener with the basic (105) "standard" type epoxy, here is another. It's based on temperature (note that physical properties of cured resin do vary slightly, but unless you can control the temperature where you are working, you kind of have to go with the one that suits the temp):

https://www.westsystem.com/hardener-selection-guide/

***************

If I want something with slightly different physical properties, then I'd use a different type of resin to begin with (vs. varying the hardener). Say, G-flex if I wanted it slightly more flexible. Or etc.

Here is one of the references I use. This is for WEST, but as mentioned above, most marine epoxy brands have equivalents.

This is to compare physical properties of the various different types of epoxies they have:

https://www.westsystem.com/products/compare-epoxy-physical-properties/

 

[Circumnavigator]

I see several posters above who have chosen their epoxy based on the mix ration -- 2:1 is easier than 5:1. I've used West system for almost fifty years and have always used their pumps in various sizes, so the mix ratio is not an issue -- you just put in the same number of strokes of each of the two pumps -- the resin pump pumps more per stroke than the hardener pump. No muss no fuss.



I use fast hardener in all but the very hottest weather. 404 High Density Filler for strength and 407 Microballoons when I need to sand it.


Jim

 

[Bustlebomb]

Thanks all for the information! You've provided really helpful input and I appreciate it.

Also, (something new to me) I was not aware there were UV-resistant hardeners.

 

[psneeld]

I see several posters above who have chosen their epoxy based on the mix ration -- 2:1 is easier than 5:1. I've used West system for almost fifty years and have always used their pumps in various sizes, so the mix ratio is not an issue -- you just put in the same number of strokes of each of the two pumps -- the resin pump pumps more per stroke than the hardener pump. No muss no fuss.



I use fast hardener in all but the very hottest weather. 404 High Density Filler for strength and 407 Microballoons when I need to sand it.


Jim

I used West System at work because it was easier for the boss to buy and stock it for fleet repairs. It may have been easier for the beginners with the pumps. Experts often just weigh as the most accurate mixing ratio.

I never found it better or easier than almost every other major marine epoxy brand and never used West on any of my personal boat in 40 years.

Its a personal choice but there is really no evidence one epoxy is better than another. I hated the pumps so 2:1 mix was almost always easier to eyeball with a bit of care.

 

[FlyWright]

22 posts later and no one asked what his epoxy project is?

Isn't anyone else curious? ...or did I miss it?

 

[Frosty]

I see several posters above who have chosen their epoxy based on the mix ration -- 2:1 is easier than 5:1. I've used West system for almost fifty years and have always used their pumps in various sizes, so the mix ratio is not an issue

I was one of those people. Used System 3 simply because I could easily mark cups and mix "by eye" very accurately.

For my particular situation the WEST pumps didn't work very well. But that's because I was often transporting the epoxy, so then do I move it with the pumps attached (not sealed)? Or do I remove the epoxy coated pumps and put the caps on, then carry the pumps in a baggie. Neither appealed. I would also occasionally get a burst of air when pumping (now what is the ratio?).

That said, I know many many people who use the pumps successfully and love them. With a dedicated epoxy cart, why not?

Or at work I used to have access to one of the WEST gear pumps. Oh my, like butter! Ungodly expensive for the hobbyist though.

Anyway, I have no idea why I did not do this sooner, but I bought a relatively inexpensive digital scale and calibration weight, and now I can mix any size batch of WEST all day long with great accuracy. The epoxy lives in the cans with the stock lids on so can't spill when I take stuff with me places. And I can mix in any shape container (as can you with the pumps). My only regret is it took me so long to start doing it this way

Another idea I have seen people use (but have not tried myself) is they pull epoxy and hardener each into their own syringe, then push out whatever exact amount they need (obviously this is limited to relatively small batches).

One of the things I really enjoy about working with epoxy/fiberglass is that there is always a new tip to learn from someone else (or to discover while working). Makes it more enjoyable (kind of like boating in that way).

 

[jgwinks]

I've been using US Composites for several years now and like it. Works as well as WEST and is quite a bit cheaper even with the shipping. 3:1 mix but their pumps are the same size so you have to count the strokes, 3 resin to 1 hardener. Crazy thing is they sell different pump sets for their different ratio epoxies even though the pumps don't regulate the ratio. Uncured it seems to be more water soluble than WEST, much easier to wash off with soap and water. I worked in a wood boat building shop for a while that used System Three, also good stuff. WEST kind of invented boat building with epoxy and I think we're still paying for that R&D if you buy their products, and of course that R&D still applies no matter whose product you're using. The only real advantage I see to WEST now is if I run out of whatever I'm using I can go to most any boat store and get some now. Shipping takes about a week from US Composites. I've also used TotalBoat and it seems identical to WEST, I wonder if it's actually contact manufactured by them.

 

[Rufus]

M.A.S.for me. No issues or special procedures for dealing with (non-existent) amine blush, and extremely low VOC. My spouse and I were working inside a heated boat storage building where the management was very restrictive regarding VOC as it impacts other owners working inside the building. Users who like West System probably haven't tried M.A.S.

 

[Fish53]

Did my entire deck and wash rails with Hawk two years ago and no problems at all plus cheaper than most.

 

[sean9c]

Ya, that's not really a thing.

"I think for the most part, the differences are very minor between the major brands"

One big difference is how flexible the glued up part needs to be..

A small boat mast will need to be less stiff , so use the proper hardener.

 

[FlyWright]

Ya, that's not really a thing.

In your opinion?? Do you have facts to back up your assertion?

 

[Frosty]

In your opinion?? Do you have facts to back up your assertion?

I was confused by that post too and responded in post #19. Don't know if I was backing up anything; but I had never heard of varying the stiffness of epoxy by changing the hardener so I asked in case I could learn something. I also posted links to the information that I have gone by when working with epoxy (i.e. hardener is about ambient temps while doing your work and some different epoxy types have different properties of tensile strengh, flex, etc. - but not due to adjusting the hardener as you use it.