I used MAS for my boat
Had no problems with it at all.
I don’t recall spending that much for a gallon. Only $90/gallon for resin if you buy direct from MAS on their web site, although there will be shipping on top of that.
Anyway I think “we” like West Systems because they are established, and well known, being one of the first to offer their products at retail.
I’ve used them all
MAS, West, East, System 3, Raka. I’m currently sold on US Composites, less expensive than the others, but it WILL blush. Apply successive coats before cure or wait and wash off.
If I were building a bright finished stripper I would probably go back to Raka or MAS.
Blush is more prevalent in the
fast cure epoxies as far as I’ve found. Cleaning off the blush can be a pain and I always worry that I don’t get it all off. Since I use the fast cure for small areas cleaning it off isn’t a big deal but with a hull I’d suggest using an epoxy that doesn’t blush. The slow cure West systems doesn’t seem to blush too bad but it’s still not worth messing with. I’ve used Raka and liked it but I did find that it was difficult to saturate the fiber glass.
Epoxies
Hi Chip,
I’ve used both West Systems and MAS. West is a great epoxy with a lot of R&D behind it, but I still stick with MAS for several reasons. Here’s my comparison. Keep in mind I use the epoxy to build strippers, so an easy and complete wet-out is probably the highest priority.
West Systems has a honey color, kicks-off faster, gives off some really strong vapors, is more viscous, and you don’t have the option of mixing fast and slow hardeners.
MAS epoxy is almost colorless with the slow hardener, it gives you much more time to work before it kicks-off, it’s vapors are nowhere near as noxious as WS, is a lot less viscous, and you have the option of mixing the hardeners to adjust your cure time.
With WS, I ended up with very strong headaches even while wearing a good respirator. With MAS, I still wear a respirator as a precaution.
With WS I was always rushing to remove the excess epoxy before it kicked. With MAS, I have a lot more time. I live in Miami, FL and the temps. down here don’t help.
You don’t have to get new fillers/additives, the WS fillers will work perfectly with other resins. MAS Slow hardener is truely blush-free, and you can mix-in up to 30% Fast without blush. For cloth wet-out, it’s best to just use the Slow hardener.
Check out Defender.com, they have good prices on MAS.
Hope this helps,
Pedro Almeida
West’s superiority
West epoxy and other 5-1 and 6-1 ratio epoxies have a much higher water resistance. They were developed for the boating industry and meant to stand up to constant water immersion as on boats that are docked or moored. They are also superior under stress tests. Aircraft buildiers use 6-1 ratio epoxies and most industrial hi stress applications also use 5-1’s and higher.
2-1 epoxies will absorb water under scientific testing but no problem for people making light weight dry stored craft and perform fantastic for most normal use.
I use RAKA and was happy to find anything half the price of WEST. 2-1 is very convenient and they have an nice no-blush hardner. I do give WEST a lot of credit for starting the epoxy building revolution. Anyone remember ClarkCraft boats and epoxy? I think they were the first 2-1 home use stuff.
Amine must be washed off
The lore, at least, is that we need to wash off amine blush before we put any coating on top of it. Theoretically, the amine interferes with the overcoating’s ability to chemically bond to the surface.
So, anytime you are putting a coating over epoxy, and that includes a second layer of epoxy or whatever you are putting on top of the epoxy to prevent UV degradation, you need to wash down the existing layer of epoxy with soap and water. So, figure out all the recoatings you do, and add effort and time for washing and drying between layers, and that is how much extra effort the amine causes.
~~Chip
West Marine??
Next time you want West Systems in Annapolis go to the TruValue Hardware store at Hillsmere/Forest Drive. Getting epoxy at West Marine is crazy expensive. Don’t see how got $125/gal MAS resin at CLC, it’s $89/gal on the site, plus hardener it’s up around $165 for 1.5 gal mix.
The thing to remember comparing West 5:1 to MAS 2:1 is that you end up with less total mix per gal of resin with West.
Raka has worked fine for me at about 2/3 the cost of MAS/West at $98/ 1.5gal mix
MAS aroma
I wonder if they have cherry cough drop aromatics added to it. It doesn’t smell like any other epoxy out there. New Jersey is kind of the head quarters for artificial flavoring industry,maybe someone decided a fruity epoxy would sell?
Comparing Epoxies
Here is a link comparing a number of different popular epoxies under a variety of conditions.
http://oneoceankayaks.com/Epoxtest.htm
Thanks, Lee
Thanks for the tip on the Tru-Value. Who’d a thought?
Where do you get your Rakka?
I think I will carefully monitor my hardener/resin supply so they exhaust together, then switch to Rakka the next time I need epoxy.
I wonder if CLC web prices are up to date. I asked about the priciness and was told, it’s all based on oil and oil has gone up.
~~Chip
switching epoxies
Back to the original poster, pumps and fillers are not epoy specific so that should not make any difference in future decisions. If you have a bunch of left over hardener, I would stay with the same brand.
BTW, the epoxy odor “in the day” came largely from the highly volatile MEK (methyl ethyl ketone") that was used as hardener. You only used ounces of MEK to gallons of resin, which is s good thing cause that stuff was nasty.
recent Mas experience
A friend gave me about 2 ounces of Mas epoxy. I really spreads well. The little bit wat enough to put a fine coat all over the bottom of my stripper to hide the scratches.
I think the Mas is thinner than some varnishes I have used.
MEK is not a hardner for Epoxy
Chemically impossible ! It is a solvent from the same family as acetone.
MEK hardener
Correct. The actual hardenr is methyl ethyl ketone peroxide, but in the boatbuiding industry it was shortened to MEK.
OK
But as a paint technologist I know MEK as a solvent.
Pumps & Mix Ratios
The mix ratio, of resin and hardener, varies among epoxy systems. West is 5/1, I think MAS is 2/1, and I was looking at another brand that is 5/2. The West pumps provide the correct ratio with one pump from resin, and one pump from hardener.
As I am figuring this out, I see I could use the pumps for different ratios. Two pumps of hardner to one resin would give me the 5/2. Two resin and five hardner for the 2/1.
~~Chip
Blush free- Don’t believe everything
– Last Updated: Oct-19-07 10:23 PM EST –
they advertise. I've used both MAS and System 3's Silvertip resin's with slow hardener and have experienced small areas of blush with both. I've seen commentary on the Kayak Building Bulletin Board where others have made the same discovery.
There seems to be a correlation between temperature and high humidity which causes the blush to form in these "no blush" hardeners.
My SOP (standard operation procedure) now is to wash cured epoxy with water mixed with a little bit of ammonia, then lightly sand before applying more epoxy or varnishing. I do this even if the hardener is advertised as "no blush". Let the buyer beware!! : )
Tripp (two strippers complete and soon to begin on 2 1/2 more)
Pumps are not always reliable…
Air can get in and you won’t get a full pump and throw the ratios off a bit. Also one pump of each may give you more epoxy than you need and lead to waste or a really heavy boat.
Foolproof is keeping two separate measuring cups, measure resin and hardener separately then mix it in a third.