Poly vs Vinyl?

[jim lee]

I've read that "VE is not as easy to work with as poly." Or at least things along those lines. My question is; Why do people say that? I know I'm pretty new at all this, but.. I haven't seen any difference between working with poly vs vinyl ester resins.

What makes one harder to work with than the other?

-jim lee

[Herman]

Personally I do not see a problem in it either. I use and sell both.

I guess it has to do with the more complicated mixing and the use of other curing agents that might be involved, depending on which type of vinylester you use, and whether it is pre-accelerated.

I can imagine that people that use polyester like "bucket of polyester, spoonfull curing agent, 3 rounds with roller for mixing, use it" might feel it is scary to do the pre-acceleration themselves, and use different curing agent than "product X".
Most of the polyester industry is pretty conservative.

Also most vinylesters do get better after a postcure. The same is true for polyester, but in a lesser extent.

Above is a view from the polyester side of things.

From the epoxy side of things, there is less of a problem, as these people are used to mix and measure, work with different curing agents, etc. Their major concern is the smell. (and I cannot blame them)

[gonzo]

You can't tell the difference. They wet the same cloth or mat at the same speed. Vynilester is more stinky.

[War Whoop]

The VE is better to use as it can be tuned to the temperatures and time frame with the accelerator and promoter and there are a number of inhibitors that will allow a lot of room in the time frame for bagging operations.

[ondarvr]

Depending on the exact VE, it may not wet out the glass as well and they tend to be stickier, which makes them feel thicker and sometimes a little tougher to roll the air out of. When sprayed they typically don't have as good of a pattern, this isn't a big problem with resin, but can be with VE gel coats, the poor spray pattern and a tendency to trap air means you need to be more careful in applying them.

Even though they feel thicker and a bit sticky, they still tend to sag and/or drain out more than polyester resin, so it can take some extra work for a good result.

Over the years they've become more user friendly and the types used in the marine industry can be much easier to use than products for the corrosion market (chemical tanks and such). So much of reputation for them being more difficult to use dates back to the marine industry first using the corrosion type formulas from many years ago.

[Herman]

About adjusting times on vinylester: Everything I do on vinylesters, I can do on polyesters as well. I probably need different ratios and different promotors, but it is not something that makes a big difference.

[ondarvr]

The main reason for VE's needing to have the promoters added by the person using them is because they tend to be less stabile than polyesters.

[tunnels]

Have used both and there very little difference Ve is just a better grade of resin than poly . If i was building a boat for myself id use VE anytime !! depends on the price mind you !.
Have used both through a saturater gun and theres virtually no difference !Sprays the same , rolls out the same ,goes off and gels the same!!

[jim lee]

Thanks ondarvr, that answered my question.

-jim lee

[War Whoop]

Originally Posted by Herman

About adjusting times on vinylester: Everything I do on vinylesters, I can do on polyesters as well. I probably need different ratios and different promotors, but it is not something that makes a big difference.

Well each to his own I have got 5 Hours out of a polyester before they were having a problem with pulling rings marking the surface, and in testing 19 hours out of my Vinlyester.