MAS Epoxy

[goatherder]

I've read on this forum about the different types of epoxies people are using. MGS seems to be a favorite. West System does not. Actually I've used West System and can attest to the exotherm and blush problems. There's another Epoxy out there called MAS, and they sell a low-viscosity resin made specifically for fiberglass layups. They claim no blush, no VOC's and have three different hardeners which are blendable. Here's the link:

 

http://www.masepoxies.com/public/index.cfm?fuseaction=prodbrws.publicdetail&productid=69471

 

Now, I realize that this product was designed for boats. Boats are designed to take alot more of a pounding than a plane. So if a resin is strong enough for a boat...shouldn't it be strong enough for a plane?

 

How can I determine the suitability of this product? Is there a test?

 

The reason I'm asking is that West Marine sells this stuff, and I have a wholesale account with them. I can probably get it for about half the cost of MGS from Wicks.

 

I know, I'm a cheap bastard. I want to build a plane...but I got kids to feed too.

[Big Steve]

Since our little airplanes have no support from the designers there will probably not be anymore appoved epoxies so unless you want to really be an exsperimentor you build with the approved epoxies. I bet any good epoxy system would do the job but remeber who's life you are testing it on. STeve build on

[rickh]

I've read on this forum about the different types of epoxies people are using. MGS seems to be a favorite. West System does not. Actually I've used West System and can attest to the exotherm and blush problems. There's another Epoxy out there called MAS, and they sell a low-viscosity resin made specifically for fiberglass layups. They claim no blush, no VOC's and have three different hardeners which are blendable.

 

Now, I realize that this product was designed for boats.

West, System-3, Pro-Set, and MAS are all used in boats

How can I determine the suitability of this product? Is there a test?

Test the archives. All recommend West, Pro-Set, MGS, AeroPoxy, ...

I know, I'm a cheap bastard.

I think we all are, that's why we're building our own go-fast planes. Price a Lancair recently?

 

Though I suspect any epoxy, that meets strength properties, would work for a pure layup, there's a bunch more involved. Like peel strength of a secondary bond, and there are lots of them. TG is also important, don't want the wings sagging if parked on the ramp over night in Fairbanks on June 21.

 

Know what you mean though ($$), but at 17,500 MSL with my family/friends in back, I'm a bit leery of experimenting with the glue that holds everything together. Eat some beans and rice once a week (it's not that bad). 14 gallon$ of glue isn't that much in the big picture.

 

Rick

[steve]

i used mas on mine. i call and had a long talk with the desiner engineer and he would heat up the spar in a box or tent. it is very close to what is aproved

and better than the west slow.

[brainfart]

> How can I determine the suitability of this product? Is there a test?

 

In some countries epoxy manufacturers can submit their products to the local FAA equivalent and have them approved. That's how the MGS resins got their "suitable for gliders and powered aircraft" rating and good reputation. The requirements for the German rating are mentioned in some MGS datasheets (MGS used to be a German business, and several other European countries have adopted the German standards).

Similar testing of resins is done by other organisations for other purposes, e.g. for boat building, wind turbine blade manufacture, railroad use etc. While most resin systems easily fulfill the boatbuilding test requirements, only very few get approved for aircraft use.

I seem to remember one of the critical tests involved simulating the bending of a part made with that resin some 2*10^6 times, that's where many resins with otherwise great mechanical properties fail. Other requirements involve the usual mechanical properties at different temperatures, Tg requirements and also some dynamic testing.

[goatherder]

Thanks for the info guys.

 

Steve - I would like to come and take a look at your project if possible. It might be a while though...as I write this I am in the middle of the Gulf of Alaska, steaming toward Dutch Harbor. I'll be fishing for a month or two.

 

I'd like to take a look at both yours and Mfreyer's projects when I return.

 

I'm leaning toward the MAS epoxy as well. I'll get the MGS spec sheet and them call MAS (as you did) myself for comparison.

 

I wanna build cheep...but not if it means using anything substandard.

[steve]

Thanks for the info guys.

 

Steve - I would like to come and take a look at your project if possible. It might be a while though...as I write this I am in the middle of the Gulf of Alaska, steaming toward Dutch Harbor. I'll be fishing for a month or two.

 

I'd like to take a look at both yours and Mfreyer's projects when I return.

 

I'm leaning toward the MAS epoxy as well. I'll get the MGS spec sheet and them call MAS (as you did) myself for comparison.

 

I wanna build cheep...but not if it means using anything substandard.

a guy from Boeing stopped by and gave me a tip for epoxy and it comes from california and its 1/2 the price of mas (locally the boat shop stopped having my slow on the shelf..i fired them)

[goatherder]

Yeah, I can't imagine Boeing is paying $100/gal for the resin they use. What brand did he say it was?

[Marc Zeitlin]

... So if a resin is strong enough for a boat...shouldn't it be strong enough for a plane?

If strength was the only characteristic of an epoxy that mattered, then yeah.

 

How can I determine the suitability of this product? Is there a test?

There are lots of tests that usually include making up test coupons and pulling them on an tensile test machine. You test for tensile strength, bending strength, shear strength, peel strength, etc., and all the associated moduli. You test for creep, Tg, exotherm, post-cure temperatures, hot-wet knockdowns, cold-dry knockdowns, etc., etc.

 

Or you can just believe the manufacturer, which is not something you should do when their product is not normally used for airplanes. Especially when they don't supply 1/2 of the information that you'd like to know.

 

The reason I'm asking is that West Marine sells this stuff, and I have a wholesale account with them. I can probably get it for about half the cost of MGS from Wicks.

There are places to scrimp on costs - maybe no leather seats - maybe no full stack in the IP. A major structural component that even at full cost will be about 5% of the cost of the airplane ($3K / $60K) is not it.

 

I know, I'm a cheap bastard. I want to build a plane...but I got kids to feed too.

You're talking about $1500 max. for the thing that holds the plane together. IMO, anyone that uses a non-approved epoxy such as MAS is an idiot.

 

MAYBE it's fine - but do you (or anyone else advocating using it) have the resources to determine that? Should you take the MFG's word?

[goatherder]

You're talking about $1500 max. for the thing that holds the plane together. IMO, anyone that uses a non-approved epoxy such as MAS is an idiot.

Yep, you're right. As usual. What are you...some kinda rocket scientist?

 

No MAS for me.

[Marc Zeitlin]

Yep, you're right. As usual.

Can you point that out to my wife, please?

 

And remember, that $1500 will be spread out over 3 - 10 years - drink a little less beer and you've got the money :-).

 

What are you...some kinda rocket scientist?

Well, rocket engineer, or rocket engineering manager, anyway. Going on 7 months now running the Rocket Motor program at Scaled.

[TMann]

No MAS for me.

No mas!

Everyone seems to be quoting Roberto Duran these days.

[goatherder]

Ok Mr. Rocket Man...what kind of glue are you guys smearing on that fancy plastic spaceship?

 

Is it a proprietary product or something that's commercially available?

 

It still just amazes me that something made of plastic can be made to withstand the forces and heat of space flight and re-entry. From an engineer's perspective I'm sure it all makes sense...but for most of us oxen it seems alot like PFM.

[steve]

 

You're talking about $1500 max. for the thing that holds the plane together. IMO, anyone that uses a non-approved epoxy such as MAS is an idiot.

 

MAYBE it's fine - but do you (or anyone else advocating using it) have the resources to determine that? Should you take the MFG's word?

are you going to listen to some one that used bondo on his wing ??

i think Marc is a fool (smart ill-bet) but a fool nun the less.

build with mas and you get 118% big deal, mgs 120% ,west 95%,

polymers have been out for 20 years now and according to ding done here.. they all are getting worse not better...! IMO

[Marc Zeitlin]

Ok Mr. Rocket Man...what kind of glue are you guys smearing on that fancy plastic spaceship?

Scaled uses a variety of different epoxies based on the particular need. Many pre-pregs, as well as a few room temperature cure wet layup epoxies that require very high post-cure temperatures for full strength and properties. On rare occasions, wet-non bagged layups with low temp. cure and post-cure.

 

And as one of my co-workers likes to continually remind me, as a noun, it's not "glue", it's "adhesive", and as a verb, it's not "glue", it's "bond" :-).

 

Is it a proprietary product or something that's commercially available?

Almost always commercially available stuff.

 

It still just amazes me that something made of plastic can be made to withstand the forces and heat of space flight and re-entry. From an engineer's perspective I'm sure it all makes sense...but for most of us oxen it seems alot like PFM.

You need to remember that SS1 and SS2 are never going more than about 3,000 mph on the suborbital flights. The heat generation is extremely small in relation to the orbital re-entry of something like the Space Shuttle, which is going 17,000 mph on re-entry - around 6 times as fast. The heat generation is related to the velocity squared, so the SS has to withstand around 35-40 times as much heat per unit area as SS1/SS2. You could never use this type of construction technology on orbital spacecraft - the only reason it works is that we're only in space for about 4 minutes, going about straight up and straight down.

 

Back to the question at hand: Listen - there are lots of folks that have use non-approved epoxies, non-approved foams, and non-approved <whatever> in their aircraft, and it's rare that something like that will cause a problem (but you do read about it on occasion, and wonder what kind of a fool would substitute materials without knowing whether it was appropriate). Like I said, it's very probable that any decent epoxy would work fine - it's the fibers that take the loads in most cases. And it's probable that foams of equivalent densities would work fine as substitutes as well, and have, in many instances. But there are over 2500 instances of aircraft built with the APPROVED materials, and NONE have ever had a structural failure due to material choices. To me, the statistical evidence is clear, when the cost of adhering to the recommended materials is a small part of the overall cost.

 

Is it possible that MAS (or many other epoxies, or foams, or whatever) would be approved if Burt or Nat were in the business of doing so at this point? Sure - pretty likely - it was late in the game when MGS was approved, but it was a well known, approved glider epoxy, used extensively in Europe, so the approval was simple. But neither Burt nor Nat (nor anyone else with the wherewithal) is currently in that business. I suppose that if Gary Hunter told me that MAS was a reasonable substitute, I'd believe him, because he's an epoxy expert that has been dealing with these materials for many years. But there are no epoxy experts on this forum - I certainly don't consider myself one.