# Are all pva's the same ?



## Streeter (15 Feb 2012)

My friend always insists on using evostik wood glue. I on the other hand tend to slum it with cheaper brands . I'm not aware of any adhesive failures to date. As evostik can cost up to 3 x the price of ,say, everbond or no-nonsense I do wonder if there is more to the differential than a pretty green container. So, is there actually any appreciable difference ?


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## Hudson Carpentry (15 Feb 2012)

Strength, different batch mix tolerance, open/drying times.


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## Streeter (15 Feb 2012)

I have no idea what batch mix tolerance is !
Drying time seems broadly similar to me , I don't think I've ever come across a glue that cures too quickly to clamp unless it's a roasting summer day so ,yes , that could be an issue. But I guess I'm really most interested in final strength. I can't find any test data on this .


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## Lowlife (15 Feb 2012)

PVAs can be very different, some of the cheaper brands in particular can dry to a rubbery consistency which is hard to sand, there's one that I used to use for modelmaking that sanded better than any other, I forget the name now but it's important on very soft woods that it's easy to sand. I can't say I've ever noticed any great difference in strength, but then I've never actually done any controlled tests on PVA as I have done with PUs for instance.


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## Hudson Carpentry (15 Feb 2012)

Streeter":331ax2w6 said:


> I have no idea what batch mix tolerance is !
> Drying time seems broadly similar to me , I don't think I've ever come across a glue that cures too quickly to clamp unless it's a roasting summer day so ,yes , that could be an issue. But I guess I'm really most interested in final strength. I can't find any test data on this .



When they mix the ingredients they will not be as strict with the mix ratio's.

How clear they dry is another.


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## Steve Maskery (15 Feb 2012)

My chemistry degree didn't cover PVAs, unfortunately, but I can say from personal experience that, no, they are not all the same. Definitely not.

My general reach-for PVA is Wudcare. It sets quite quickly; glue, clamp, make a cuppa and you are good to go on.

OTOH, for complex glue-ups I use one with a longer open time, like Everbuild or Evostick.

I've never had a PVA bond failure, but they certainly do not all behave in the same way.
S


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## woodbloke (16 Feb 2012)

Steve Maskery":2entsdov said:


> OTOH, for complex glue-ups I use one with a longer open time, like Everbuild or Evostick.
> 
> S



I used to use Titebond III, which is a great, if expensive glue. I now use the D4 Everbuild glue which is equally as good, but as I can buy it locally for less than a fiver (for a litre of glue) the TBIII isn't used any more - Rob


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## Dodge (16 Feb 2012)

I'm with woodbloke - I only use Titebond 1 or 11 which is actually an aliphatic resin glue and far superior to PVA.

One thing I do not like is PU glues that foam on curing as I have had experience of excess glue swelling in the back of a mortice hole during curing and when the sash cramp is removed the pressure is sufficient to actually push the tenon out again. :shock:


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## andersonec (16 Feb 2012)

D3 is the usual type sold by builders merchants and the sheds, D4 is an industrial type and used a lot by kitchen worktop manufacturers, personally I use Cascamite, shelf life is longer as it's a powder, only mix what you need, it can be used for exterior work and is stronger than the usual D3 PVA. 

Andy


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## Hudson Carpentry (16 Feb 2012)

I used to use EverStik's D4 glue (blue), it's a PVR not PVA and seems stronger to me but after using titebond I now only use TB1 and 3


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## yetloh (16 Feb 2012)

andersonec":2n42jvt4 said:


> personally I use Cascamite, shelf life is longer as it's a powder, only mix what you need, it can be used for exterior work and is stronger than the usual D3 PVA.
> 
> Andy




Me too. I particularly value the long open time, although I use Resinmite which is the same stuff but cheaper from AG Woodcare than Cascamit and is available in a 750g tub which I find the ideal size for me. 

Jim


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## Jimbob101 (16 Feb 2012)

Titebond glues are the only way to go. All of their glues are vastly superior to any PVA on the market and resist creep for laminated curved work. They are also wood coloured instead of opaque white and do not show up as much if you miss cleaning up a bit. You can also sand them as they are hard and not rubbery.


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## Jake (16 Feb 2012)

Jimbob101":11b623fw said:


> All of their glues are vastly superior to any PVA on the market



The so-called aliphatic resin ones are a PVA - well, the actual glue bit in them is. The aliphatic resins are a modifier added to PVAs and other glues to increase the initial grabbiness - tackifiers - hence the gloopy texture. They do seem to add a lot of them, but the tackifiers do nothing to increase ultimate strength (in fact, all things being equal increased amounts tend to decrease it). What they do do is change the experience of using it in a way which is very cleverly calculated IMHO. 

Which is not to say they aren't good glues, but they are totally overhyped. 

I'd rather have a high quality euro-produced D4 cross-linking PVA at a un-hyped (but not bargain basement) price. I find the enhanced glorpiness of TB an irritant, given the increased difficulty of spreading it to the thinness which is actually required for a good bond.


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## woodbloke (16 Feb 2012)

andersonec":1gv33pl7 said:


> D3 is the usual type sold by builders merchants and the sheds, D4 is an industrial type and used a lot by kitchen worktop manufacturers, personally I use Cascamite, shelf life is longer as it's a powder, only mix what you need, it can be used for exterior work and is stronger than the usual D3 PVA.
> 
> Andy


Well...I do wonder about urea formaldehydes . 'Cascacmite' was the glue of choice when I started out years ago but I found even then that shelf life was limited...after a short while in the tin it became unusable as the powder never seemed to mix properly. Then there was the wastage if you mixed too much...a bit difficult to 'unmix' it and put it back in the tin. That said it's great for things like veneering and laminating, but the sheer 'user friendliness' of modern PVA's and their derivatives mean that for me at least, urea formaldehydes glues (and similar) are left on the back burner for every day usage in the 'shop. There's also the slightly worrying aspect that uf's go off glass hard, which makes them unsuitable where some flexiblility is needed, as in chair joints...one of the reasons why the late Alan Peters never used them, sticking to PVA's instead - Rob


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## Aled Dafis (16 Feb 2012)

I actually need some glue this week, so you guys reckon that D4 is superior to D3, and that the titebond stuff is overhyped. I tried TB3 and didn't get on with it as it was too runny, I found that it would drop beads of glue all over the bench/work/me...

Is D4 better for laminating also?

Cheers
Aled


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## Phil Pascoe (17 Feb 2012)

"Resin W" interior is good for glue chucks- you can wash off what's left easily. There are hardly any left now that aren't water resistant.
If open time is really critical, you can always damp the joint down first. 
Can anyone tell me why so many glues are supposed to be applied to one surface only? It doesn't seem to make much sense?


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## yetloh (17 Feb 2012)

woodbloke":1kza1b22 said:


> Well...I do wonder about urea formaldehydes . 'Cascacmite' was the glue of choice when I started out years ago but I found even then that shelf life was limited...after a short while in the tin it became unusable as the powder never seemed to mix properly. Then there was the wastage if you mixed too much...a bit difficult to 'unmix' it and put it back in the tin. That said it's great for things like veneering and laminating, but the sheer 'user friendliness' of modern PVA's and their derivatives mean that for me at least, urea formaldehydes glues (and similar) are left on the back burner for every day usage in the 'shop. There's also the slightly worrying aspect that uf's go off glass hard, which makes them unsuitable where some flexiblility is needed, as in chair joints...one of the reasons why the late Alan Peters never used them, sticking to PVA's instead - Rob



There is undoubtedly a lot of personal preference in glue choice, and rightly so because just about any quality glue that is suitable for furniture is more than strong enough. I have not found a problem with the shelf life of UF glues provided that some basic precautions are taken. The most important of these is to buy from a supplier who sells plenty of it so that you can be sure it hasn't been sitting on shelf for a couple of years. The second is to reseal the air tight plastic tub that it comes in these days as soon as you have decanted what you need. I also transfer it into a smaller tub when there is not much left in the original, to reduce the amount of moisture laden air above the powder, which probably helps.

Coming back to the comparative properties of UF v PVA I do think the much greater open time of UF is of great value. When people say that the open time of PVA is a non-issue i do wonder what sort of glue ups they are doing. Perhaps they use the glue up in stages approach but I think this is a poor second best compared with doing it in one hit. For me, the big advantage of this is that it eanbles the cumulative effects of minute squareness errors that can sometimes occur in a complex structure up to be counteracted by selective clamping without placing excessive strain on any particluar joint.

As for Titebond, I do use it for some things but I don't like it. Despite its gloopiness I find it still has a real tendency to slide around where UF gives useful tack. Where it does score is in speed of curing which makes it particularly useful for jigs and small items.

Now, if someone can come up with a glue with the open time and tack of UF plus the cure time and flexibility of glue bond of PVA, then that would be a winner.

Jim


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## woodbloke (17 Feb 2012)

I think I was probably buying the uf stuff in large tins and not using it quickly enough, or not decanting it into smaller pots when the big tin started to get say a third, or half-way down.
Interesting and valid point about complex glue-ups Jim, which are a bit of a 'mare at the best of times. My solution of late has been to always try and break a complicated gluing situation into a series of much smaller ones. Even so, the rate that PVA's and similar glues go off and grab :evil: in the hot weather mean that I've got to be really organised and get the cramps on within 10 mins, after that it's a bit of a no-hoper. I may well give uf's another shot later on - Rob


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## jimi43 (17 Feb 2012)

I'm 100% with Dodge....Titebond I for non-waterproof needs is the one I use simply because it has never failed me...even on guitar neck breaks which has to be one of the ultimate tests of strength. It resists drag with superior tack and as mentioned above is aliphatic resin...pva with modifiers which are important.

I think the hype is due respect for something that works better than most, a respect from me from experience...which means I choose it and pay more.

For waterproof PVA type uses I use the waterproof Evostick in the blue tub.

I absolutely cannot get on with UF glues at all. I have tried all suggestions from those who love it and it is still not working for me...but I like the colour of the tub from Titebond....lovely purple colour... :mrgreen: 

Cascamite (and variants) can go off quite easily and then it is useless but for clean new wood with a fresh batch works well...particularly on butt joints

One tip I got from a model maker for rapid hard fixes and repairs is mixing PVA with CA glue...a good quality one. It works!

Jim


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## Sgian Dubh (17 Feb 2012)

woodbloke":1uycs1oy said:


> My solution of late has been to always try and break a complicated gluing situation into a series of much smaller ones. Even so, the rate that PVA's and similar glues go off and grab ... in the hot weather mean that I've got to be really organised and get the cramps on within 10 mins, after that it's a bit of a no-hoper. I may well give uf's another shot later on - Rob



Rob, liquid hide glue has a useful extended open time of about twenty minutes, and that might be an alternative to UF adhesives. When I lived and worked in Texas-- brutally hot and humid mostly, at one point I just about gave up entirely on PVA and aliphatic adhesive formulations and switched over to liquid hide glue for most standard assembly jobs: even in Texas in July or August I got about 15 minutes to do a glue up with this stuff. As is the case with all adhesives liquid hide glue has its plus and minus points that I'll not elaborate on here. On a side note, you can extend the open time of PVA or aliphatic resins with up to ~5% additional water mixed in, which is sometimes useful. Slainte.


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## CHJ (17 Feb 2012)

I tried several brands of PVA but the creep of even the supposedly low creep PVA's was enough to spoil the joint interface on coplanar surfaces after a while, presumably because it allowed the woods to move independently.
I use Cascamite these days for all turnings that require a glue up that are bigger than a dab of CA will fix.
I reduced the waste of Cascamite in storage after the first loss by decanting it into 4 smaller screw topped jars with a good seal as soon as the tub was first opened.


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## Jake (17 Feb 2012)

jimi43":x5430zru said:


> as mentioned above is aliphatic resin...pva with modifiers which are important



All decent manufacturers will use various modifiers, including aliphatic resin tackifiers. Only some of them (usually American) add yellow dye and pretend that it is a totally different glue from PVA because those modifier resins have been added. I know it's good glue (my subjective dislike of its excessive glorp aside) but that sort of marketing bull-solidwasteproduct really puts me off.


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## jimi43 (17 Feb 2012)

Jake":100b0cao said:


> jimi43":100b0cao said:
> 
> 
> > as mentioned above is aliphatic resin...pva with modifiers which are important
> ...



I ignore the BS entirely Jake and go by my experience. That is my value of the product which I won't be moving from unless I find another better. I do try others just in case and so far...no candidates have surfaced. TB2 and TB3 I am not so keen on.

Jim


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## woodbloke (17 Feb 2012)

jimi43":ldu0p58y said:


> I ignore the BS entirely Jake and go by my experience. That is my value of the product which I won't be moving from unless I find another better. I do try others just in case and so far...no candidates have surfaced. TB2 and TB3 I am not so keen on.
> 
> Jim



...as long as you don't use TBI for veneering and then try and wash off the tape with a nylon scourer and hot water  as I did once.
Just once :wink: - Rob


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## Phil Pascoe (18 Feb 2012)

Personally, I wouldn't water the p.v.a., I would wet the joint -it stops the moisture being drawn from glue too quickly, but the glue itself stays thicker and less likely to squeeze out.
I used cascamite for about 20yrs before I before I went to a ships chandlers one day and saw a bottle of rapid hardener for it---------hell! the stuff goes off like lightening. Aerolite is a very good glue that sets only with a hardener- it was developed in ww2 to glue mosquitos together-I don't know if it's still made. The two hardeners are dilute formic acid and dilute phosphoric acid, but I can't remember which way around they went. I switched them around, and I seem to remember that it made little difference, so maybe it's just that it's acid (it was 30yrs ago).


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## yetloh (18 Feb 2012)

phil.p":lgp09soj said:


> Personally, I wouldn't water the p.v.a., I would wet the joint -it stops the moisture being drawn from glue too quickly, but the glue itself stays thicker and less likely to squeeze out.
> I used cascamite for about 20yrs before I before I went to a ships chandlers one day and saw a bottle of rapid hardener for it---------hell! the stuff goes off like lightening. Aerolite is a very good glue that sets only with a hardener- it was developed in ww2 to glue mosquitos together-I don't know if it's still made. The two hardeners are dilute formic acid and dilute phosphoric acid, but I can't remember which way around they went. I switched them around, and I seem to remember that it made little difference, so maybe it's just that it's acid (it was 30yrs ago).



Don't know about Aerolite, but one way to speed up curing with Cascamite is to add heat, when it can be very fast I believe . Never tried it myself - a bit tricky to arrange on a big glue up.

Jim


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## yetloh (18 Feb 2012)

Just Googled Aerolite and see that it is available from Axminster. They quote setting time as 25 minutes to 3 hours depending on temp. but nothing about open time.

Jim


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## woodbloke (18 Feb 2012)

yetloh":23i57okv said:


> Just Googled Aerolite and see that it is available from Axminster. They quote setting time as 25 minutes to 3 hours depending on temp. but nothing about open time.
> 
> Jim


...and have you seen the price Jim? :shock: - Rob


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## yetloh (18 Feb 2012)

woodbloke":yv9dm1du said:


> yetloh":yv9dm1du said:
> 
> 
> > Just Googled Aerolite and see that it is available from Axminster. They quote setting time as 25 minutes to 3 hours depending on temp. but nothing about open time.
> ...



Yes, I did. I think I'll stick  to normal UF.

Jim


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## Jake (18 Feb 2012)

I haven't used Aerolite, but my late father did a few times. One advantage in terms of open time is that the application is catalyst to one face of the joint, and the UF mix to the other face. So the open time is very variable, depending on when you introduce the two. I mostly recall it stinking badly, which I assume was the Formic acid catalyst. He also used to use Cascophen now and then, the RF version, again a two-parter. I find it difficult to see the advantage of either over epoxies these days, pick the slow hardener and the fact it is pre-mix becomes fairly irrelevant unless it is hot summer. Cascamite is at least a good deal cheaper than epoxy.


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## JonnyD (18 Feb 2012)

Ive gone back to using U F resins for veneering and laminating. The Borden UL39 resin mixed with the UH21 hardener gives excellent results and cures fast in around an hour in summer and probably 2 hours in winter depending upon temperature. If youve got a heated press it can be seconds. http://www.adkwik.co.uk/index.php?dispa ... t_id=29861

cheers

Jon


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## Tusses (18 Feb 2012)

after using screwfix cheapy PVA that I bought in bulk many years ago, I was very happy with it.

It ran out, and no longer available, so I tried many other cheap brands.

I ended up with TB ... in gallon (us) jugs, it's as cheap as any other 'decent' glue. and I've never had any problems with it


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## Tomyjoiner (18 Feb 2012)

Hi streeter, before i used to make my own windows an doors i used a mate
Who had his own workshop an. He made me a box sash which i had to go 
Back to as all the joints opened up, on talking to my mate he told me he
Had ran out of cascamite so he used some pva when i asked him was it at
Least d4 he said he didnt know he bought a batch off a website all
He remembered was it was less than half price. Now i make my own things an
Only use cascamite or pu for outside work. My moral is the old phrase
YOU GET WHAT YOU PAY FOR!


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