Vinyl Ester Resins
 

Here's an open question:

Byron used to use polyester resins for a ton of molding and the planes still seem to finish and fly well enough, but it's out of vogue and really is smelly-epoxy's stronger etc...

What about Vinyl Ester resins? Has anyone had any experience with molding up fuselages/parts with it? From a brush-over review of the qualities, it seems to have better properties than poly, but less strength than epoxy.

Can it be used successfully (easily) for composite laminates where carbon fiber is used?

Pot life, thin film and working time?

Biggest deal for me-cure time to pull from the mold?

RE: Vinyl Ester Resins
 

Thats what I use building full scale and I find it much better in ever way. I have had great success molding parts with it.

RE: Vinyl Ester Resins
 

I used it once but the one I used had a lot of health issues related
to using it. I'll stick to epoxy as there are a lot of alternatives offered
for what I do and also the model stuff without to much worry.

Only my opinion
Chuck

RE: Vinyl Ester Resins
 

expresspilot-

Where were you using it in full-scale application? I'm really interested in working and cure time. Also, I'd like to know if there's as much of an issue with shrinking as there is with polyester.

I'm molding as well and my plane's got a ton of parts. Vacuum bagging one at a time is kind of out of the question (it'd take a year to make one plane), so I'm either going to have to build a manifold vacuum bag system or switch to a quicker setting resin. Cost also helps-a bunch.

Toxicity's not an issue for me-I've got the selection personal protective equipment, ventilation etc.

RE: Vinyl Ester Resins
 

Chuck,

I have 6 ports going out of my 3/4hp pump and it works fine. As for the vinyl ester resin, the viscosity is lower than PER but almost everything else is the same. It's more tempermental when it comes to temp/humidity and it takes a little bit longer to B-stage. It's very ideal for vacuum bagging as well as vac infusion.

RE: Vinyl Ester Resins
 

Thanks-I know I could and probably will, make a manifold system-I also need to make a resevoir and install my vacuum switch/regulator. The thinner viscosity is what I want-I also like the idea of doing vacuum infusion molding and will probably give it a go this summer after I pull my first plane parts from epoxy (Proset).

It sounds like I need to try the vinyl ester out. Still haven't heard any real cons on it.

When you say "tempermental on temp. and humidity" - I live at 95% and 95 degrees on the Texas Gulf coast, so I got both. I'm guessing you mean it'll kick faster at higher temps and humidity. Much different than epoxy?

Again, thanks for the reply.

RE: Vinyl Ester Resins
 

Recommended humidity range is around 70%, similar to PER and Epoxy. Once in a while I do get parts that b-stage, but it'll never fully cure even if I introduce heat. With VER, you can use as little as .5% of MEKP if the weather is too warm. If working time is important and the weather is too hot, or cold, I just skip the the MEKP and switch to a UV cure chemical. That gives me as much working time as I need and the part will cure in 3-5 minutes as soon as I turn on the UV lamp or put it out in the sun light. I'm slowly converting all my work to closed molding as well to comply with MACT '04.

Evan

RE: Vinyl Ester Resins
 

What's a good source for UV cure resins? That seems like the ticket for me since some of my molding needs quite a long open time and 3-5 minute cure time upon exposure seems like a dream. When you say 3-5 minutes, how much longer to full strength? Lot of exotherming with the UV cure?

RE: Vinyl Ester Resins
 

That's it.. full cure in about 10 mins. You can only do about 3/16 thick of a laminate at a time however. Anything thicker and the UV might not reach the mold side of the laminate. Exotherm is about the same. I can't think of the name right now so I'll send that to you as soon as I find it.