Does Polyester bond to Vinylester in a layup?

[Midday Gun]

Quick question, can't find a definitive answer.

I know some boats have the first layer of the hull skin as vinyl ester & the rest as polyester.

Does this mean that Polyester resin will form a primary bond with a vinyl ester layup as long as its within the window? Or is this essentially just a secondary bond?

 

[fallguy]

Other contributors with experience can offer more.

I was only a googler for you because I am curious.

WHICH RESIN TO USE?? EPOXY vs. POLYESTER vs. VINYLESTER – LBI Fiberglass Products https://www.lbifiberglass.com/which-resin-to-use-epoxy-vs-polyester-vs-vinylester/

 

[Midday Gun]

Thanks, I read that one. Was just wondering if there was any trick to it.
Does it have to be laid wet on wet etc.

 

[fallguy]

Well, contributor @ondarvr is one of a few with expertise in this area.

I will make some assumptions that bonding to fully cured esters requires mechanical key as much as anything.

Some chemicals can be reactivated with thinners, but this is probably heresy here.

see if ondarvr offers any wisdom

in general, I would not feel good about following ve with pe, but I believe it is following peanut butter n jelly rule (I am just biased, pay no attention to me)

 

[ondarvr]

You can switch back and forth between the two as if they are the same product, they're 100% compatible. And you can blend the two together and use it that way too.

All the normal rules apply for laminating over an existing layup. Still tacky, go right over it....fully cured, sand the surface.

 

[rxcomposite]

know some boats have the first layer of the hull skin as vinyl ester & the rest as polyester.

We were doing that during the mid 90's and never had any problem. Since ours is a continous process, the Polycoat is laid to tacky dry VE.

With good ISO resin these days, I think it is an overkill.

 

[Midday Gun]

Great, thanks for the quick responses.

The reason for asking (other than curiosity) is that I've had to replace some floors & replace rotten core around the keel area of my boat, the original moulded in liner had some splitting & cracks + was debonding in areas.
I've pretty much finished repairing all the structural areas using vinylester resin.

There are some areas where I removed the liner in way of the under settee lockers to gain access to the outboard ends of the floors, I need to build some thickness back into these areas, I was thinking I could use a layer of matt with vinylester for the superior secondary bonding & then build up the thickness in a cheaper ISO poly resin.

 

[trekker]

You can switch back and forth between the two as if they are the same product, they're 100% compatible. And you can blend the two together and use it that way too.

All the normal rules apply for laminating over an existing layup. Still tacky, go right over it....fully cured, sand the surface.

Good stuff as always, Sir.

 

[fpjeepy05]

You can switch back and forth between the two as if they are the same product, they're 100% compatible. And you can blend the two together and use it that way too.

All the normal rules apply for laminating over an existing layup. Still tacky, go right over it....fully cured, sand the surface.

In agreement.

One addition, still tacky will be a primary bond, and sanded will be a secondary bond.