Are all pva's the same ?

[CHJ]

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.

 

[Jake]

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.

 

[jimi43]

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.

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

 

[woodbloke]

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

 

[Phil Pascoe]

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).

 

[yetloh]

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

 

[yetloh]

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

 

[woodbloke]

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

 

[yetloh]

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

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

Jim

 

[Jake]

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.

 

[JonnyD]

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

 

[Tusses]

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

 

[Tomyjoiner]

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!