MAS epoxy question

[canoebuilder7]

I'm building a strip canoe and will be using MAS low viscosity epoxy for the first time. I've built a few before but used WEST.
My question is what can I expect using the MAS as far as workability, curing time and so on. Any tips or tricks I will find helpful?
This will be for the inside and outside of the hull using 6 oz. cloth.

[Thorne]

Welcome to the Forum!

I suspect we'll need more info -=- as there are various kinds of MAS epoxies with (I think) various speeds of curing. Also what temp range is your shop?

What design of strip canoe, and what materials? There is a LOT of good experience here, so you've come to the right place.

[canoebuilder7]

Using MAS low viscosity epoxy with medium hardener.
Hull is mahogony. Accent strips, decks and sliding seat will be walnut. Gunwhales black ash. West 105 will be used for bonding, MAS for wetting out the glassed hull inside and out. Shop temp can be whatever I want it to be. I generally keep it about 65.
Solo canoe 15' long. No rocker in the stern, 1 1/2 inch rise in the bow starting 2' ahead of center. Building it for a friend as her birthday gift.

[Canoez]

With the ability to tailor resin/hardener combinations and the shop temperature, you should be able to make the MAS behave as you wish - just like the West System. Check the manufacturer's literature about cure times and temperatures and compare to what you were using from West System (Was it the 105/207 combo or something different?) This should give you an excellent base of comparison for the curing times. If you are working with a new system (new to you, that is..) I would experiment a bit first to see what works best. I find I like it a bit warmer than 65°F for working epoxy - 70°-75°F, but I use either the System 3 GP resin with Medium hardener and the West 105/207 combinations.

To avoid wasting material, have somebody available to help and mix what you need as you need. (Mix thoroughly!) So long as you're getting it spread on the boat after mixing, you shouldn't be worried about cutting your working time short.

Thorne, as usual, has hit it on the head - specifically what is your concern about workability? Wetting charactersitics, penetration, bubbling, etc?

[canoebuilder7]

Wetting charactersitics, penetration, bubbling, etc?


Yes, all of those.

[crazyriver23]

You will be pleased using Mas epoxies. I have used the fast, medium, and fast hardener with success on several projects . Great epoxy.

[Canoez]

Yes, all of those.

All are enhanced by using at a bit higher temperature, so a bit above 65° would be nice unless you need extra working time. The big bennies are that at a warmer temperature, the epoxy's viscosity is lower, so penetration is better and air retention is less. The downside of the lower viscosity is trying to apply to vertical surfaces and avoiding runs. Pay close attention for bubbles, runs and starved spots like usual and you should be just fine. Make sure that both the hull and the epoxy have come up to the desired temperature before you start work.

Oh, and BTW, a cabinet scraper is great to remove cured runs in epoxy, should you have any. DAMHIKT. :rolleyes:

[abe]

I have used MAS low viscosity resin and slow hardener at shop temps in the 80 degree F range. Would most likely use the medium hardener at a colder temp.

I have a video somewhere that would answer your questions Canoebuilder. Where are you located??

This is covered with two layers on outside and one inside using 6 oz glass as well:

http://cheerio.zenfolio.com/img/v3/p366720220-3.jpg

As Canoez suggested, have someone around to mix the next batch. You will not have the time to pay attention to both processes.

abe

[canoebuilder7]

Very nice boat Abe. I'm in Minnesota.
The gift recipient is going to mix epoxy while I apply it.
Thanks for the advice all.

[Chan]

I love Mas epoxy, unfortunately my local supplier, Hamilton Marine, stopped carrying it!
Smells better blushes less and sands more easily than west or system3.

[earling2]

I've used a lot of both WEST and MAS. I would use either. The pluses of the MAS, as I see it, is that it does saturate the glass a lot faster, which is great if you're doing really heavy layups (7, 8, 9 layers of 1708 or 1808 biaxial knitted reinforcements)--otherwise I can't say that getting WEST to soak into a layup has ever been a problem. I would say that either epoxy has a tendency to run and sag when applied like a coating. I did have a major problem with MAS that I NEVER EVER had with WEST, which is that it refused to allow gelcoat to cure days after a layup--meaning it was still "green" when I applied the gelcoat, which would not have happened with WEST during a similar cure time. So that's a slight glitch to be aware of if it applies. On the other hand, MAS is way easier to mix because of the ratios--with WEST you're pretty much limited to using the pumps, which is slow as hell if the temp. goes down below 60F or so--and the cheap ones break, get dirty, etc, constantly leak--and the good crank pumps costs hundreds of dollars. This is a pretty big concern, I'd say. But does depend on the quantities being mixed. Relatively speaking, WEST is a pain to mix in larger quantities, and a lot fussier about the ratio of harder to resin.
Also, MAS doesn't blush--another nice thing.
So, in short--MAS penetrates faster, doesn't blush, but on the other hand, doesn't set up with quite the authority that WEST does (at least in my experience), and a full, definitive cure is important if you intend to do any sanding, or finish painting/gelcoating, or if the part for any reason needs to be able to resist deflection. I did a 47 foot yacht's keel repair, used about 200 gallons of vacuum bagged WEST and used WEST for that reason--did not want any ambiguity whatsoever as to the state of cure.
Also--MAS, if laid up in a pile of cloth, remains somewhat liable to "cold flow"--ie, the panel of hardened resin/cloth will actually bend a bit, like super stiff taffy, for some time after supposedly curing. WEST will only do this when literally "green," which is a pretty short window (and can be seen because it's... surprise ... greenish in color)
They both can use the same fillers and etc.
Both have slow and fast hardeners, though I think possibly the WEST hardener is a bit more toxic (?)
So--both great products, somewhat different qualities.
MAS has some cool stuff, too--like their 2 minute epoxy--great for small repairs but when they say 2 minutes, that's what they mean. And not a second longer.

[neilm]

I noticed there is a MAS resin and a MAS Flag resign. Is it best to use both, one as adhesive and the Flag for glass work?

Neil

[Captain Blight]

One thing about the pumps: they are standard foodservice pumps, as far as I can see. They look the same, weigh about the same when I heft them in my hand, they are all relatively the same thing doing the same sort of thing. So if you need a cheap source of epoxy pumps, look no further than your local restaurant-supply store. They will have what you need at a really good price.

As far as I can tell, in this day and age, a cap is a cap is a cap. These pumps should fit on just about any normal, appropriately sized container.

I may be wrong but I really don't think so. I'll see if I can scare up an old WEST pump and do some comparing.

[MiddleAgesMan]

Use the MAS Resin for sealing and glass, FLAG for laminating and fillets. You could use Resin everywhere but it would require more filler to acheive the same consistency as FLAG. IIRC FLAG is an acronym for filleting, laminating and glueing.

[James McMullen]

MAS is too sensitive to cold and wet temperatures for us to use around here in our minimally heated shop. System3 has been better behaved for us in situations where we can't get the temperatures up to 70 degrees--in other words anytime between September and July.

[Chan]

The beauty of MAS is you don't need pumps, just measure it 2 to 1.
I've used west and their pumps and the biggest draw back is if you don't use it everyday you have to prime the pumps and pump out a bit of air with the resin and hardener, especially the hardener, which is wasted as you have no way to measure the air and the epoxy so it's wasted.

[LeeG]

It works great. IIRC Medium will blush. If you're working at 70degrees I wouldn't mix up more than 8oz or let it sit in the pot for more than 5min.

Regarding pumps I stopped using them and used mixing cups and syringes as the case may be.

[George Roberts]

I believe that the MAS fast hardeners may blush. But I could be wrong.

[JimConlin]

I love Mas epoxy, unfortunately my local supplier, Hamilton Marine, stopped carrying it!...

It is being distributed through Port Supply, the wholesale side of West Marine.

[MiddleAgesMan]

MAS slow and medium hardeners are said to be blush free. But I recently saw some blush-free Fast hardener either in a store or in an ad.

I never tried their Fast but I can vouch for the Slow and Medium--never a sign of blush.

[ccx2]

I have used MAS low viscosity resin and slow hardener at shop temps in the 80 degree F range. Would most likely use the medium hardener at a colder temp.

I have a video somewhere that would answer your questions Canoebuilder. Where are you located??

This is covered with two layers on outside and one inside using 6 oz glass as well:

http://cheerio.zenfolio.com/img/v3/p366720220-3.jpg

As Canoez suggested, have someone around to mix the next batch. You will not have the time to pay attention to both processes.

abe
Thats a PRETTY boat. I would maybe like to build one like that next winter[building a Garvey this winter], can you tell me more about it? Please pm me so as not to highjack this tread.

[MiddleAgesMan]

The MAS pumps worked fine for me but I was never sure the restricted hardener pump was providing exactly half the amount of the resin pump. Whatever inaccuracy there was did not matter, though. The stuff cured just fine.

As for air in the pump affecting accuracy, there's an easy solution. If it's been a while since you used the pumps just push slow and easy at first. You might get air at the beginning but as you ease it down you will feel resistance from the liquid once it is reached. You might get a tiny extra squirt as you clear the last of the air but the 2 to 1 ratio MAS has engineered into their products gives you fairly wide latitude and an extra drop or two of either ingredient isn't going to hurt. It's really very forgiving.

[JimConlin]

'Burping' the pumps is a good precaution. The need to do it is a function of the viscosity of the material. If it's warm, it's no problem.

It's a good idea to clean your pumps every now and then. Use acetone or lacquer thinner for the resin pump and hot soapy water for the hardener pump.

[paladin]

For all glue work I prefer the System Three T-88 product, mixed 2:1 or 1:1 depending on the resin. It's the right consistency to stay in the joints and grooves and the overflow is easily scraped away. When it comes to putting fabrics on the inside or outside of a craft then M.A.S. and something other than fiberglas needs to be the winner.
I need to spend more time drawing on my proposed new boat......