Strength differences between aquadheres

[Arron]

Hi Folks,
It seems Selleys now has 3 versions of Aquadhere PVA.

1. Interior.
2. Quickset, The quick dry formulation
3. Exterior, The crosslinked stuff

I was wondering if anyone has any information on the differences in bond strength.

I'm assuming:
1. timber to timber bond, both in good condition.
2. NOT end grain gluing.
3. Interior use, not exposed to moisture.
4. Allowing overnight to set, to eliminate differences in setting time.

I know I could ring Selleys Technical and ask, but I havent found that really useful in the past.

cheers
Arron

[crowie]

G'Day Arron,
Sorry but I can't help with a correct answer,
but I'm interested in what the "panel of experts" comes up with.
Thank you in advance for the knowledge of others.
Cheers, Crowie

[bsrlee]

I bought a bottle of the 'Interior' - it should have been marked 'Inferior' - the glue was so thin that most of it ran off when I tilted the board :o

The 'Exterior' grade seems to be close to the old regular Aquadhere, but I don't think it is water resistant like Titebond 2 is supposed to be.

There is also a 'Polyurethane' glue, but it has no expiry date on the bottle, so I have my doubts about it - it probably just has poly resin as an inactive filler, not as the active glue like Gorilla Grip or the other Polyurethane glues which have a 12 month self life - I've found the Australian Syntec Polyurethane glue to be much superior to Gorilla Grip.

[Arron]

I bought a bottle of the 'Interior' - it should have been marked 'Inferior' - the glue was so thin that most of it ran off when I tilted the board :o


true its thin. That doesnt seem to affect its holding properties though. I think its a good thing if you need to spread it over large areas quickly.



There is also a 'Polyurethane' glue, but it has no expiry date on the bottle, so I have my doubts about it - it probably just has poly resin as an inactive filler, not as the active glue like Gorilla Grip or the other Polyurethane glues which have a 12 month self life
I've had a couple of bottles of that stuff. Once you open it, its shelf life is measured in weeks. I end up throwing most of the bottle out.

cheers
Arron

[Bushmiller]

I know I could ring Selleys Technical and ask, but I havent found that really useful in the past.



Arron

I wouldn't be overly hard on Selleys. When we built our house I was attempting to build a spiral staircase using laminated ironbark and box. I had bought Selleys' formaldahyde glue.

It literally fell apart the day after gluing. I contacted Selleys technical dept, who asked me to send samples of the timbers and the glue I was using.

They shortly contacted me to say they had had the same trouble. However about two weeks later I heard from them again. They had been successful with their rescorcinal glue. They asked me how much of the original glue I had bought and sent me the equivalent amount for free.

That was about twenty years ago. I suppose the same bloke may no longer be there:rolleyes:.

Regards
Paul

[Arron]

OK, so I rang Selley's today. The technical guy claims the bond strength is the same between Interior and Quick set. I would have preferred to see some test results, but I guess I'm satisfied with that.

cheers
Arron

[Zed]

from what I know the Aquadhere range of cross linke PVA's are similar to the titebond range of cross linked PVA's. interior grade is like titebond 1 and the exterior is like titebond 2 or 3.

you'll find that the titebond 3 (and or Aquadhere exterior) set "Harder" (I assume this means the cells bond in the polymer structure more rigidly and thus repel water better.) because they are harder they resist springback more and are thus more useful for bent form laminations.

I find that buying Aquadhere from blunderings 250ml at a time the most expensive option. obviously the more you buy the cheaper it is. I actually bought a 4 litre bottle of titebond 3 for a series of bent forms for this reason from Carburetor-tech for $90. works out the same price or thereabouts. this is the best option IMHO if you can use 4ltr before it goes off.

AWR did a test on all the cross linked pva's in an old issue and the summary was even the cheap shyte is good enough for most applications. they are all stronger in bond strength than the wood itself (when tested to 1) destruction and 2) water logged ) and very little difference between them.

some woods repel better and need to be scraped fresh before glue up. and some timbers again are better with a polyurethane foamy glue. eg tassie BW.

so in summary buy fresh glue use it fast and keep your surfaces clean.

[Zed]

just thought I'd show you the cabinet. its bent form in bluegum, tassie oak skin and carcase is iron bark. all titebond 3.

[soundman]

There are three commonly used families of PVA glue.

Modified PVA...the normal white glues..there is a bit of fiddling with the chemistry but mostly it comes down to % solids...the more solids the stronger the glue and the thicker it will appear.

PVA alaphalactic resin glues.... the yellow glues ( mostly yellow) they are significantly stronger, go off faster, more resistant to moisture and the cured glue is much crisper, it creeps less and sands better.

Crosslinked PVA glues.....often yellow but ya cant count on the colour.... they cure significantly stronger, and are pretty near to waterproof.

anybody claiming that a equal quality white glue is as strong as a yellow glue is having a lend.

Go onto the AV syntec site and look thru their selection of glues.... that will give you a real good idea of the PVA range and properties.

I have not baught a sellys retail package of anything for a very long time....they are retail packers these days and very little more.

As for the watteryness of the current domestic adquahere.....well.....it comes down to solids......and solds cost money.

cheers