Avaiojet

Every bit of glass work I've done has been with polyester laminating resin, reduced with acatone. I do microballoons the same way.

I think the stuff is great. I've made cowlings and other items, This same resin can be used as glue.

Epoxy glass? What is that stuff?

I see cowlings made of it, "white?" and it doesn't seem as flexible? A bit Brittle?

Resin isn't a good glue for it?

With this said, what are "our" glass vendors using? Or selling us?

What Vendor uses what material?

How can you tell if it's poly or epoxy.

Which is of the better quality and why?

Thanks

CK

Mike Emilio

Sounds like you've only worked on smaller items Charlie.

- Epoxy glass is simply using epoxy with the fiberglass, instead of polyester or vinylester resins.

- How can you tell the difference?
Epoxy is a bit harder than polyester.
Also, even after a week, with polyester you can still detect the styrene smell.

- The white stuff is usually gelcoat, but can also be an epoxy or polyester pigment.

If the white is on the inside of the part, it's most likely a secondary spray coat with something like Endura, or some other urethane.
Other than those primary methods, the white might be generated by trying to thicken the epoxy or polyester with something like microballoons, cabosil, fumed silica, and others.

I have epoxy pigments of various colous, it's way more expensive than the polyester counterpart.

- A fiberglass vendor will sell you anything you want to buy. I find that most vendors have never really used anything they sell, so in alot of ways, you take a chance when they recommend something for you to buy. Many sales people only know what some other customer might have said to them.

- Which is better???
Geez, , , that's a loaded question, with a million preferences.
This is difficult to say. It depends alot on what your working on. Size, vrs time, vrs chemical characteristics, etc, etc.
Another biggie, is that epoxy is way more expensive than polyester.

I find both about equally the same to work with on small stuff. I do however preferr polyester mainly because I use an industrial Binks spray system.
However, if you want to make your own preshaped G10, then there's a variety of epoxies available with different charateristics, like heat and flame resistance etc.
Also, if your making a larger part, then polyester has severe limitations. You might not be able to work quick enough with it before it starts to gel. The working time is even more critical if your going to vacuum bag anything.

Mike Emilio

("Which is better" continued)

As I mentioned above, if you do big stuff, polyester may have limitations with the working time.

There's many methods for application: like a simple hand lay-up, or vacuum bagging, or even infusion for the seriously big stuff.

Most small parts would be a hand lay-up or vacuum bagged either epoxy or polyester.
But were time is critical, then epoxy gives the extended working time necessary for large bagging.

For infusion, then a slow cure epoxy is about the only way to go. Believe me on this one, it might save you alot of grief if you ever do it. For some scenarios, there's some specially made vinylesters designed for infusion.

These pictures are of a fuselage that's 11 feet long x 14" wide.

The part was vacuum bagged using polyester that was sprayed in.

The working time for something this big is about border line using polyester. A hand lay-up would have been much less stressfull.
Something this size would be better in epoxy, either bagged or infusion. But then the costs go up big time for the epoxy.

Spraying polyester increases your working time because you can get a big part done quicker, and that's good.
Drawback is that the equipment is rather expensive.

To infuse a part this size would take about twice as much epoxy than merely vacuum bagging it.
There's alot of wasted epoxy with infusion set-ups.
And then the preparation cost are a slight bit different then simple bagging.

Hope my ramblings might have been of some use to you.

You can get an idea that determining "which is better" has so many variables, and mostly driven by the type of job.

Mike Emilio

Charlie, , ,

Are you looking at making fiberglass parts for the Bamboo Bomber??

Your an experienced builder, some of these questions are seriously rather basic.

Care to say what the interest is??

Avaiojet

Mike,

The questions may seem basic, but as I said, I only have experience with polyester resins.

The Epoxy stuff I've purchased appears to be lacking in quality.

In a round about way, I was really asking, "Which Vendors makes junk and who doesn't?"

We know the quality from all glass vendors isn't the same.

Most likely I'll make my own cowlings and other parts from polyester resin. Which I believe is a far better product than the Epoxy's?

You have enough glass experience to write a book or offer DVD. So,am I correct?

Yes, I'm thinking the BB.

Thanks Mike,

Charles

I

Mike Emilio

Not sure what your referring to here.
- The raw materials like outlets that basically sell cloth, resin, and such, , ,or
- Finished product, as in a fuselage kit?

There's only so many manufacturers of chemical resins or cloth. You'll probably find that most, if not all sales outlets in a given area, probably all carry the exact same stuff from the same manufacturing source. It's quite common for a supplier to buy in 45 gallon barrels, and break it down into smaller single cans, , , then put their own name on it. But it's all basically from the same manufacturer.

If your referring to finished parts, then yes, I would most definetly agree there could be major differences between parts manufacturers.
As usually with such a topic on an open forum, one can expect hundreds of opinions towards the exact same kit being good or bad.

Co-incidentally, isn't it simply amazing how four big names in model kit sales, all of a sudden seem to be comming out with an F-14 kit, all about the same time???

Mike Emilio

What kind of epoxy did you buy?

There's basically only 2 types and maybe 3 classes.
Mixes can be 1:1, or 4:1, or 5:1, and a bunch others.
Some depend on heat curing, while others are happy at room temperature.

- Blushing epoxy (precipitated salts of amine carbonate)
- Non-blushing epoxy

- Regular viscosity
- Laminating viscosity
- Super thin watery viscosity

Lower budget resins like West etc are quit common, mostly because it's cheaper, and the stores can sell much faster.
Non-blushing varieties are about twice the price.

Ed Smith

Have you ever got that wrong!

I was not going to chip in here as Mike was giving you all of the information you needed. Your above statement prompted me. Epoxy is superior to polyester in every respect. To start with with, the catalyst for polyester is a very, very dangerous material. The slightest hint of that stuff in the eye and the sight in that eye WILL be lost over time. IT CANNOT BE WASHED OUT! There are all sorts of poor quality polyesters around. Hardware Stores, Automotive Stores and in some cases even Walmart. If you buy from these places there is no consistancy let alone anybody with any application knowledge. For general purpose use, the two best brands are West Systems and MGS epoxy resin. Both have their own characteristics. Both are top quality. I use one MGS epoxy resin for all of my resin needs. Making molds, Making parts, Making Carbon props, Gluing on wing skins, mixing with microballoons and as a finishing resin. Try all of that with one type of polyester. That is if your eyesight is still good.

Ed S

Avaiojet

What Vendor makes the green, or the blue, or the white cowlings and wheel pants I see.

I have some of all of that.

There was a time whem Epoxy was brittle.

Charles

Deadstik

My Feedback: (8)

Charles,

The Green Glass was done by Zigsaw and some of the Southern Aircrafters kits (Atlanta and Bootlegger) These were Polyester and honestly had more pinholes per cubic inch that any layup method I've seen. The white fuselages that I do are white due to being painted in the mold with PPG primer. The main reason I do this is because it gives my customers an almost ready to paint fuselage with zero pinholes plus when a mold is pre painted there is even less opportunity for a part to permanently stick to the mold. I manufacture vintage pattern kits and some of my molds are over 30 years old. I take great care to polish, polish and repolish prior to using mold release. I do NOT use PVA. I find that the aerospace epoxy that I use has better temperature tolerant charactoristics than polyester and, as Ed said, is MUCH safer to work with. The strength you can build in by using only S grade fiberglass and epoxy is a matter of choice. You always get what you pay for and my customers prefer to pay a bit more and get a much better quality product. I've attached a couple of pictures to show you a T2A MK II fuselage that was painted in the mold and then the fuselage and tuned pipe tunnel after they have been pulled. It takes a learning curve to get it right, but once learned, it is certainly epoxy is the best way to make quality parts.

Dan
Carolina Custom Aircraft
[email protected]

Mike Emilio

I'm loosing ya Charlie, , ,

- In case of polyesters, it could be a white, black, or grey gelcoat.
- In case of epoxy, it could still be a white or black tooling epoxy
- There are also neutral gelcoats, specifically intended for pigmenting to any color.

Remember, any clear polyester or resin can allways be tinted to just about any color at all.
Or alternately, simply painted in the mould.

What vendor, , , , , , just about any kit manufacturer in the world can do that!
Or home shop around the corner from you.

Tinting epoxy is no big deal. This 4 oz jar is about $25.00, but will tint a heck of alot of resin.

I'll use the low budget resins like West, for basic laminating etc. But if there's anything else to be glued inside, then the final inside coat would be a non-blush, non-amine, variety.

Avaiojet

Can somebody give me a "list" of the "favorite" Vendors that make glass parts? No kit manufacturers please, just those Vendors that make glass parts.

Like cowlings and wheel pants. You know, the guys that do OEM.

I'll start it off:

Stan's Fiber Tech
T & D Fiberglass Specialties,


Anyone know any others?

Charles

Mike Emilio

What ya got in mind now Charlie?

Seems your going in another direction from your original post.

Any of those guys aren't about to tell you their trade secrets.

Avaiojet

I've been on track.

Just add to the list?

Charles

Mike Emilio

Your questions started either so very basic, or otherwise totally opinionated to a thousand interpretations.

I can't see what direction your going in, if nothing more than making posts, or now simple google searches you can easilly do.

It all seems quite meaningless now.

Sorry, , , You've lost me on this thread Charlie.

Avaiojet

Mike,

Just because there's "Google" doesn't mean every Vendor will come up.

I'm sure even glass guys, like you know, one or more Vendor's. Haven't we all made a purchase here and there? I know I have. I was glad to stop making wheel pants out of wood.

Thing is, I know the chemicals have changed, and for the better, my interest is the Vendor using the best materials. I still think polyester laminating resins have an edge over epoxy resins.

I'll have more information about that by the end of the day. I have a personal resource I'll bother today.

Thanks for your help and interest.

Charles

MTK

Nice work Ed.

One other resin I have found excellent besides the two you mentioned is Pro Bond. It's another Gougeon Bros product as West Systems is. Pro Bond 125resin with 229 hardener is unsurpassed for consistency over time in terms of workability, pot life, curing character and its strength isn't shabby either. Viscosity is very low, about as low as it gets. I use it for practically everything that requires epoxy

Polyester resins are more brittle, weaker materials and shrink more than epoxies. One more thing...the epoxies mentioned are not the garden variety you will find at your local HS. Generally you would have to mail away for these unless you happen to have a well stocked Marine Shop around your home.

One 'advantage" Polyester resins may have over epoxies is that one does not need a curing agent necessarily like the organic peroxide they generally include in the packages. This stuff is indeed dangerous if not used correctly. One can fairly easily cure polyester by exposure to UV light (which can also be dangerous if not used correctly). I've used the sun for curing PE resin with excellent results

MattK

Avaiojet

All this information has been helpful and appreciated, thank you guys, however, here's my original questions again, some of which have not been answered.

[quote]With this said, what are "our" glass vendors using? Or selling us?

What Vendor uses what material?

How can you tell if it's poly or epoxy.

Which is of the better quality and why?

Thanks

CK [/quote/

Mike Emilio

All your questons have more-or-less all been answered.
Many in post #2.

Your now just repeating them Charlie.

TFF

I think it comes down to the parts being made. For wheel pants and cowlings, it really does not matter; everyone wants to have the latest and greatest but with those just have to hold shape and hold paint. A fully composite airframe has totally different needs as you know. When real aerospace epoxy became available at reasonable prices years ago, people did not like it because it did not react the same as the polyester stuff. Epoxies seem tougher and not as brittle but flexed, but when the layout and orientation was changed to suet it made a better part overall. If the venders are not buying from Aircraft Spruce they at least used their catalog to figure out what they want to use. Except for the few who are in high end aerospace jobs the Aircraft Spruce catalog is the bible.

TeamSeacats

I have experience using both and can tell you unequivocally that from a performance/material standpoint epoxy is a superior product in nearly every way than polyester. The only advantage that polyester has is that it is easier to mix and less sensitive to improper mix ratios. Vinylester resins are very similar to polyester resins but approach the mechanical properties of expoy - but they have a short shelf live. Everything you need to know can be found here:

http://www.c-cyachts.com/images/comp...oxy_v_Poly.pdf

Avaiojet

Jake,

With all due respect, what does a "marine" study have to do with "aeronautics?" These are model airplanes.

In the Marine industry, weight is needed for ballast, so the materials can be heavy.

Airplanes, where weight is a factor, always have light, but strong, substructures and are covered with various materials. Certainly these materials have become more chemically complicated and are now a necessary asset to add strength to the substructure.

Real aircraft included.

Charles

Scorpion Racing

I think the point Jake is making is that the marine industry is where polyester resins are primarly used, so the studies are more related to that field. The study is aimed tward showing the guys that build (boats or anything else for that matter) with polyester resins, that an epoxy offers increased performance. If all you are using a poly part for is a cowl or wheel pant, it won't matter what you use. If it is a structural piece (fuselage, wing, etc.) you need to decide what is more important to you. A light, strong structure, or a cheaper more brittle polyester part.

Avaiojet

Scott,

I keep hearing "cheaper more brittle." That's what I disagree with. There was a time when the Epoxy products were absolute junk, and I can prove it.

Wanna buy some of this junk? Because I still have a bunch of it. I think, the popular use, has much to do with the ease of purchasing Epoxy products?

Thing is, it took years for Epoxy to be improved. And as I mentioned, one supplier actually advertised, "New Flexible Epoxy." I don't make this stuff up. So what does that tell you. Tells me Epoxy was once inferior and brittle.

Polyester resins will stick very well as a secondary adhesive. Not so true with Epoxy.

My main reason for this Post, which has gone every way, sideways and loose, was to find out which suppliers are using Epoxy and which ones are using Polyester.

No one has answered that? Don't want to mention supplier's names probably?

Doesn't matter, because I have the information I need to accomplish what I have to do.

Thanks for the reply and interest.

Charles

Mike Emilio

Also, the boating industry pretty much came out with vacuum infusion techniques.

Charles, , , you wrote, , ,
This has been answered so many times, in so many ways, , , but your not seeing it.
It all depends on your job. Big, small, money to spend, equipment you use, job complexity.
I can easilly see a company that might use both!

What your insisting on is beyond being reasonable.
There's a thousand manufacturers, your not going to see any of them give out their trade secrets, and you'll just get the standard ho-hum replies like, I think this?, or I think that?, or maybe it's?, or it might be?

Care to post your findings , , , say, , , maybe only what 5 of the top companies are using?