Vinyl Ester Resin Question . . .

[tpenfield]

This may be a question for @ondarvr and perhaps a few others.

I have been using vinyl ester resin on my current project (extension bracket for outboard conversion).

The resin I was getting is 'Fiberlay Orca 555 Vinyl Ester' . . . originally I was getting the resin from a website 'fiberglassandresin.com' but it looks like it was merged/bought-out by Fiberglass Warehouse.

I found a supplier locally for my materials and their vinyl ester resin is 'Advanced Coatings 13886 MVP Vinyl Ester'.

Both products seem like they would be reasonable choices for my purpose.

I've used a few gallons of the 13886 and am finding it slightly different to work with. The 13886 seems a bit thicker and in one instance has cured in an unusual way (see picture).

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It looks like individual fibers have dried out (resin depletion?), where as the entire piece was thoroughly wet-out and had excess resin standing on top before curing. This piece is laminated to Coosa BW26. My technique has been to apply about a 1/16" layer of resin to the Coosa using a rib roller to spread it evenly and then apply the biaxial cloth so the resin soaks up into the cloth. Then apply more resin on the cloth as needed and work it with the resin roller until the cloth is completely transparent.

In other instances the curing of the 13886 has been fine.

I'm not good with chemistry stuff . . . more of a physics guy, so just wondering about the difference in the 2 brands of resin and if there are special considerations in using the 13886 resin going forward?

T.I.A. for any insight on the resin differences and guidance on their use.

 

[ondarvr]

Fiberlay buys it from somplace else and puts their own code on it. And historically they won't tell you what brand it actually is.

The difference in viscosity is why you experience the dry spots, it's soaking in at a different rate, and lower viscosity resins tend to wet out the fibers better.

The physical properties are fine with both, the physical properties of the Advanced Coatings resin may be slightly better though. When a VE resin is formulated for best properties it tends to be a little more difficult to use. Plus overall styrene content could be different (I didn't look at the sds for either one), higher styrene content makes it easier to use. At one time Fiberlay didn't list the properties of the resin in detail, for viscosity it said "varies", same for gel time.

There may be another option from them for VE, so ask.

 

[tpenfield]

OK, thanks for the explanation. I was thinking the Advanced coatings might be better. I bought two 5 gallon pails of it, and may need a third

Perhaps it was a bit dry on my laminate and maybe the Coosa continued to absorb the resin as it cured. It's funny that the resin pulled away from the top strands in a few places, making that sporadic cross-hatch pattern. I had not seen anything like that before . . .

I did a second piece afterwards and it looks fine.

 

[rxcomposite]

The resin you are using is too thin. It drains before it can kick off. Technicians will usually bump it off by adding MEKP so that it sets before it can run. When laminating vertical surfaces, thickener is added to the resin to prevent run off. Cab-o-Sil or microbaloons will work.

 

[ondarvr]

Micro balloons do not prevent draining or sagging, that's what silica does. Micro balloons will make the resin rather opaque though, so seeing what you are doing becomes difficult. Plus it will make it more difficult to wet out the fabric.

Depending on the exact fabric and substrate you can get different failure modes that can lead you in the wrong direction.

And VE doesn't respond as well to fumed silica as polyester does, so sagging may be more of a problem, adding more silica to an already thick VE just makes it more difficult to work with. The exact VE formula comes into play too, that's why I said VE formulated for better performance may be more difficult to work with. If you formulate a VE for ease of use as the primary goal, you may not get the same level of performance. For general laminating this isn't as important, but most VEs are formulated for certain/different types of applications, so ease of use isn't at the top of the list of requirements.

 

[rxcomposite]

Micro balloons do not prevent draining or sagging, that's what silica does. Micro balloons will make the resin rather opaque though, so seeing what you are doing becomes difficult. Plus it will make it more difficult to wet out the fabric.

Depending on the exact fabric and substrate you can get different failure modes that can lead you in the wrong direction.

And VE doesn't respond as well to fumed silica as polyester does, so sagging may be more of a problem, adding more silica to an already thick VE just makes it more difficult to work with. The exact VE formula comes into play too, that's why I said VE formulated for better performance may be more difficult to work with. If you formulate a VE for ease of use as the primary goal, you may not get the same level of performance. For general laminating this isn't as important, but most VEs are formulated for certain/different types of applications, so ease of use isn't at the top of the list of requirements.

Strange you say. This is not what we practice.

 

[ondarvr]

What part?

Micro balloons increase viscosity, but they don't stop sagging, if you think they do you don't understand the subject that well.

 

[rxcomposite]

You are preaching like it is a religion. I am the light and all others be damned. You make composite materials sound like it is a complicated text and only you can decipher the text and interpret. I can call our technician and answer any of your question.

This a forum where intellectuals share thoughts, ideas, and experience. Not a venue for you to inflate your ego.

Goodbye Guru.

 

[ondarvr]

Not trying to inflated my ego, my goal is to try to make sure people get accurate information.

When someone starts down the wrong path, or tries to dispense inaccurate information, I'll attempt to explain things so those involved in using the products get the best results.

Frequently people get offended by being supplied accurate information that goes against their unfounded beliefs.

I don't get into the engineering of laminate schedules because that's not where I make my living. But I can get into the details of what fabrics, resins, barrier coats, and gel coats to use to achieve the desired properties or finishes for a specific product or project in different types of processes. And this includes building tooling.