Are more expensive epoxies better?

[StoneCrab]

I'd like to hear from others about their experiences with different brands of epoxy. It seems that West Systems is the default for marine builds and repairs. It is expensive, but is it worth it?

There are many companies out there that just repackage epoxy from the big three. So who has the best epoxy at the lowest price?

Have you ever bought an off brand and wish you hadn't?

[Chotu]

No. Most epoxy is equivalent for most projects. There are some special features (no blush, low viscosity for infusion, fast/slow, hand lamination formula), but basic epoxy is basic epoxy for most every use.

Any reasonable brand name for mission critical stuff, any brand at all for not so critical.

For instance, building my boat I used:

Mas Infusion Epoxy
System Three Silvertip Hand Laminating Epoxy
System Three General Purpose Epoxy
Raka Epoxy


I used the right one for the right job. Silvertip is formulated for lamination. So that’s what it was used for. General Purpose is a little more bendy/soft so it was used where that’s an advantage. Fairing was a lot of epoxy with no structural use at all so I gave Raka a try for that. Mas has a damn good infusion epoxy. It worked flawlessly.

I’d stay away from West for big projects. Not financially worthwhile.

If you’re looking for cheap, general purpose, it’s hard to beat Raka.

[Lepke]

I only use West Systems because of experiences with the cheap stuff. I use to buy in 55 gallon drums so I used a lot and built whole hulls with it. Oldest ones are still going strong with no blisters, delamination, and other FG hull problems like you get with the cheaper epoxies and polyester resin.

[slug]

Originally Posted by Chotu

No. Most epoxy is equivalent for most projects. There are some special features (no blush, low viscosity for infusion, fast/slow, hand lamination formula), but basic epoxy is basic epoxy for most every use.

Any reasonable brand name for mission critical stuff, any brand at all for not so critical.

For instance, building my boat I used:

Mas Infusion Epoxy
System Three Silvertip Hand Laminating Epoxy
System Three General Purpose Epoxy
Raka Epoxy


I used the right one for the right job. Silvertip is formulated for lamination. So that’s what it was used for. General Purpose is a little more bendy/soft so it was used where that’s an advantage. Fairing was a lot of epoxy with no structural use at all so I gave Raka a try for that. Mas has a damn good infusion epoxy. It worked flawlessly.

I’d stay away from West for big projects. Not financially worthwhile.

If you’re looking for cheap, general purpose, it’s hard to beat Raka.

I agree

You only need expensive , specialist resins for technical work

For general work go cheap

Viscosity is an issue ... check you chosen resin viscosity

Thin viscosity resins run out of heavy fabrics and are best for light weight fabrics and finish work

[Chotu]

Originally Posted by Lepke

I only use West Systems because of experiences with the cheap stuff. I use to buy in 55 gallon drums so I used a lot and built whole hulls with it. Oldest ones are still going strong with no blisters, delamination, and other FG hull problems like you get with the cheaper epoxies and polyester resin.

I’m sorry, but it’s nearly all the same stuff. It’s just BPA (the resin) and an aliphatic amine hardener. Only the tiniest of tweaks are made.

All the brands (except Raka) I listed are used in the absolute top of the line racing boats with carbon and pushed to the edge of their physical properties routinely. Especially Mas who has seen a lot of their product go into making carbon masts and 200’ tall wind turbine blades.

These products are all independently tested in labs for physical properties. These properties are on the spec sheets. Elongation, etc... They meet or exceed these properties.

There are no epoxy failures except user error.

[Allied39]

I have been using system three for 20 years now, have literally used hundreds of gallons. Regular epoxy, silver tip and clear coat as well.
Early on I had a crazy mechanical engineer friend who had issues with west (Crazing in a barrier coat application) and he went deep into the research and found the elongational failure of west to be low. He put me onto system three and his word was good enough for me.
20 years and hundreds of gallons later and I believe it was good advice.
Merton's supply up in MA has been my supplier all these years and he is great.

I do not care to argue with trolls or those that do not agree, I simply do not care, just answering the OP.

[Boatguy30]

I find all the resin it self to be basically the same. I have used very resin with many different companies hardener and it all works together. To me the hardener seems to be the main difference between companies.

Not sure I've every seen a hull built with "cheap epoxy" that had blistered. Does the previous poster have any pictures of that and records of the "cheap epoxy" used?

[snort]

Raka was cheaper and worked just as well, so I've kept buying it.

[a64pilot]

I think a lot of it has to do with the experience of the user. It’s sort of like Sailrite, a professional knows exactly what they need and don’t and can pick what they want in an old used way less expensive machine, but those of us who know next to nothing really benefit from Sailrites videos and customer support etc. it doesn’t make us a pro of course but can reduce a lot of the rework and disappointments.

Like those mixing pumps for instance

[Jammer]

I have used WEST and Total Boat (house brand at Jamestown Distributors). They are both good.


I can get WEST resin and hardener anywhere and it will always perform predictably.


For a $2500 boat project of which $500 is epoxy I am unwilling to experiment to save $100 or $200. I do a major project every couple of years and don't work with enough volume for it to be worth keeping up with vendors and products that come and go or that are cheap for a while and then get priced up. Total Boat is now very close to WEST in price, so why bother.

[geoleo]

Originally Posted by StoneCrab

I'd like to hear from others about their experiences with different brands of epoxy. It seems that West Systems is the default for marine builds and repairs. It is expensive, but is it worth it?

There are many companies out there that just repackage epoxy from the big three. So who has the best epoxy at the lowest price?

Have you ever bought an off brand and wish you hadn't?

CLEAR FG Coatings is just as good as WEST and has more varied selections. That Smith stuff is a regret. System 3 stuff varies in quality from can to can.

[mlydon]

I’ve stuck with system 3 silver tip, as it doesn’t blush (never has on me, anyway)

Last year I bought some cheap stuff from us composites - long cure, for a club boat-building project. The stuff practically NEVER set - took weeks.

Matt

[Chotu]

Originally Posted by mlydon

I’ve stuck with system 3 silver tip, as it doesn’t blush (never has on me, anyway)

Last year I bought some cheap stuff from us composites - long cure, for a club boat-building project. The stuff practically NEVER set - took weeks.

Matt

This is probably the most significant difference in epoxies used for hand lamination. Getting a non blushing formulation is key.

I have so much experience in this area, buying resin by the 55 gallon drum, that I can no longer go near epoxy as I’ve developed a severe allergy to it. Lol

[Spot]

Here is what I have used:
-AdTech Probuild Marine (1 quart, gateway drug from polyester to epoxy)
-Resin Research Kwik Kick (3 gallons)
-Greenroom Old Number 7 (3 gallons)
-Custom Polymer Designs (same company as MAS) (1 gallon)

The last 3 are considered 'surfboard' epoxies, clearer formulations with some UV resistance and the Resin Research and Greenroom have optical brighteners so the leftovers in the cup end up looking light blue or green. I have been happy with all of them and try to follow the basic safety things as far as avoiding skin contact: gloves, not sanding until cured, and not using acetone for cleanup.

If I had to choose a lifetime supply of one at this moment I would pick Greenroom as it seems to be the most forgiving especially for clear top coats as used on surfboards. I like the CDP too, made locally, but I am not going through it enough to justify the minimum order of 7.5 gallons for a custom formulation.

The Greenroom was used on my dinghy that sits upside down outside. The epoxy did fine for 3 years in the sun provided there was cloth as part of the mix. Places where I had used the epoxy as 'paint' over bare wood gradually failed over the course of those three years, which has been attributed to lack of skin thickness (thanks to the member of CF that offered this theory) and the movement of the underlying wood causing the epoxy film to crack and allowing the wood to see moisture. I have seen this failure mode on other wood pieces with epoxy only too. Painting that boat should be on my list...

I have yet to try West, Raka, and System3.

I have thought about doing sample boards of each of the 3 I have left and leaving them outside for a year but I have not done that yet either.

[chris95040]

Why is West is considered a premium epoxy?

I end up using it a lot because local hardware stores have it, but when I have projects planned I order "Basic No Blush" from Progressive Epoxy Polymers.

West System blushes - you need to wash before sanding to get rid of it so that your subsequent bond doesn't fail, and this washing step can be a pretty serious burden in certain tasks. I've had bonds fail when i skipped this step - i thought i'd get away with fairing some dips without washing first. The repairs, west on west, plopped right out.

I feel like I must be misunderstanding something significant because I can't imagine why we choose to live with blush when non-blushing epoxies with similar strength are readily available.