Weatherproof PVA Evo stik glue what are the differences

[Woody Alan]

Hi

Has anyone noticed any differences between weatherproof PVA evostik and internal only evostik. For example grab time, full cure time, glue line colour, creep factor (no not that sort of creep) I have bought a gallon because I have some floor to lay, but I will have some over and I don't want any issues when using it for making furniture.

Cheers Alan

 

[Steve Maskery]

Alan
Exterior is resistant to water. It won't survive being submerged continuously, but it will survive the occasional shower. Internal won't.

I don't know of other differences, but that doesn't mean there aren't any!
Cheers
Steve

 

[frugal]

The Woodworker did a review of about a dozen or so different glues including Evostick and waterproof Evostik. In their tests they did not look for water proofing ability but just in joint strength. The upshot seems to be that for hardwoods the waterproof evostik gives a stronger joint and for softwoods the non waterproof evostik give better strength joints.

As to their other properties I belive they are pretty much the same.

I have bought some waterproof just because a lot of the joints I am currently doing are in hardwood.

 

[newt]

The waterproof version seems to have a longer open time.

 

[Woody Alan]

Thanks guys no major problems then? If the only "issue" is longer open time, then for me that is a bonus. I don't like panic glue up's, I want something that's a little more relaxing.

Alan

 

[scrimper]

for softwoods the non waterproof evostik give better strength joints.

I have found this too, I glue up lots of softwood panels from 1 1/4" to 2" strips and find the interior PVA much better, FWIW I don't buy Evostick brand I buy the 5ltr Bondloc tub from Toolstation for £8.42. I have even used the cheap PVA builders Bonder without any problems.

FWIW a far as I am concerned apart from the fact that one is waterproof I don't see that brand makes a lot of difference, PVA is PVA and I can't see how apart from setting times and cost one PVA can be better than another

I do wonder how they make the water resistant one different though; it looks the same and smells the same, I wonder what is added to make it water resistant?

 

[Jake]

I don't see that brand makes a lot of difference, PVA is PVA and I can't see how apart from setting times and cost one PVA can be better than another

That's often said, but I think it is a bit like saying that alcohol is alcohol so all alcoholic drinks are the same.

Try here for some hint at the complexities of the chemistry and the variables in play (over and above simple solids content):

http://www.chemquest.com/store/polyviny ... sives.html

I do wonder how they make the water resistant one different though; it looks the same and smells the same, I wonder what is added to make it water resistant?

The PVA is modified so that the molecules cross-link as the glues set. There's a simple example here: http://www.sci-experiments.com/slime/slime.html

 

[scrimper]

I don't see that brand makes a lot of difference, PVA is PVA and I can't see how apart from setting times and cost one PVA can be better than another

That's often said, but I think it is a bit like saying that alcohol is alcohol so all alcoholic drinks are the same.

No disrespect but I don't think that is a very good analogy, Alcoholic drinks are not all made from the same thing, wine is made from grapes and beer from hops while cider is apples, yet AFAIAA Pva uses the same ingredients.

My own experience is that apart from the difference between interior and exterior PVA I have had the same results no matter what brand of PVA I used, I used to use top branded PVA but I found no difference to results when I used the economy brands it was just a lot easier on my pocket!

 

[Jake]

No disrespect but I don't think that is a very good analogy, Alcoholic drinks are not all made from the same thing, wine is made from grapes and beer from hops while cider is apples, yet AFAIAA Pva uses the same ingredients.

I did say 'a bit like'. I'll settle for "all alcoholic drinks made from grapes are the same" if it improves the analogy for you. The real point is as per the link - PVA itself varies (molecular weight), and there are a whole bunch of modifiers and additives which alter the characteristics of the glue.

My own experience is that apart from the difference between interior and exterior PVA I have had the same results no matter what brand of PVA I used, I used to use top branded PVA but I found no difference to results when I used the economy brands it was just a lot easier on my pocket!

That may well be right. I'm not saying that cheap is necessarily bad, or that expensive is necessarily better. No doubt there is a lot of 'brand-value' in the price of the big names, and a smaller name can produce just as good formulations as a bigger name, and sell them at a lower price. I also suspect that very few items are stressed enough to test any half-decent formulation to the point where you would notice even a major difference if there was one.

"(Some) cheap ones are as good/good enough" is a different argument from "they are all the same thing", is my (only) point.

 

[scrimper]

From the tone of your reply it's seems that I have offended you, in which case I am sorry, as a 'newbie' here I tried not to be too confrontational but I guess I have failed! :shock:

 

[Jake]

You haven't offended me at all!