Good source of Polymite (Extramite/Cascamite)?

[woden]

Given that Polymite (formerly known as Cascamite, then Extramite) has a short shelf life I'm concerned about buying any from my local hardware store as the pots have been sitting on the shelves for months. Indeed, they seem to date from sometime before the change from Humbrol's ownership: the Extramite labels are visible beneath the Polymite ones. That or the labelling of Extramite pots was running way ahead of glue production at the factory!

Eitherway, the stuff has been there for ages in the local stores. So is there anyone in mail order that has a good enough turnover of Polymite to ensure you're not getting glue that's already months old by the time it arrives? I know Axminster supply it but do they sell much, I wonder? The glue probably isn't as popular as it once was.

 

[woodbloke]

The glue probably isn't as popular as it once was.

I think you probably have it there. I haven't used the stuff for years, but at one time it was the only glue I did use. There's such a decent variety of good PVA type adhesives available now that it's little wonder that it's not used much...that's my feeling anyway.
The only thing that it's really good for is laminating as the glue sets glass hard and of course it's quite water resistant as well, but then so is D4 PVA. I use a D3 PVA at the moment which is pretty waterproof (not for continuous immersion) and I find it ideal for general 'shop use and veneering - Rob

 

[woden]

Where does Titebond III rank on the PVA scale - if it even is a PVA? The thing that has always attracted me to Casca/Extra/Polymite is that when you mix it correctly it has a nice thick consistency; the result of proper mixing means that it doesn't run easily and has good gap filling properties when it comes to rough joinery.

However, it's said Titebond III is like this: thick, doesn't run easily and can fill gaps - I wonder how it compares to Polymite? Apparently, TIII is also completely waterproof (does that include premanent immersion in sea water? Hmm) so that's one area where it has a diffinate edge over Polymite.

 

[ivan]

Try toolstation.com, their "cascamite" is called Resintite. As a screwfix lookalike they should have a good turnover and they seem to drop minority interest items quite quickly, and they have always stocked this one. (mine has always been OK)

 

[woodbloke]

The thing that has always attracted me to Casca/Extra/Polymite is that when you mix it correctly it has a nice thick consistency; the result of proper mixing means that it doesn't run easily and has good gap filling properties when it comes to rough joinery.

When Cascamite (or whatever) is mixed correctly (at least how I was shown how to do it) it should drip quite freely off the end of the mixing stick as it has a thinner constituency than you first imagine. If it's thick and gloopy then the ratio of powder to water is wrong - Rob

 

[newt]

Titebond 3 is very runny more than any other PVA I suspect, it is very good when sliding tight joints together. Cascamite is as Rob says rock hard when cured and I think its main advantage over PVA is, it is totally water proof and there is no creep. Titebond 3 leaves a dark line.

 

[woden]

Newt, Cascamite (there have been so many needless name changes I don't think anyone will ever call it anything else!) isn't completely waterproof.

It was very popular back in the 70s/80s and before with dinghy builders; another good urea-formaldehyde used in this field was Aerolite. My uncle and dad built a GP14 dinghy in the late 70s using Cascamite; building yachts out of the stuff would be another matter - you'd be asking for trouble if it was holding stuff together below the water line as they're permanently immersed during the season. Dinghys are only in the water when in use: they're hauled out afterwards and have time to dry.

However, despite appearing somewhat knowledgable from the above I only discovered this after a major blunder. Dad had to make up a replacement rudder for his wooden yacht as its previous one had fallen off on the mooring. I urged him to use Cascamite as it's cheaper than epoxy and anyway this boat is only a stopgap until the new one he's building is finished. Aargh, didn't I discover a few weeks later that the stuff isn't suited to permanent immersion; Humbrol, the proprietors at the time did a phenol based adhesive - now Polyproof - that is designed for yacht building. Mind, Polyproof works out as being even more expensive than epoxy!

Interestingly, the rudder has held up - though, it's only into its second year. There's a chance that it might survive as the season isn't that long - May to September - and it's a fresh water lake; it could be a good test of Cascamite when immersed for lengthy periods - albeit a 'kids, don't try this at home' one as you could end up ship-wrecked if it all goes pear shaped! :shock:

 

[newt]

Woden your probably right, I used Aerolite when I built my dingy, however cascamite is advertised as waterproof, but I suspect as you do that total immersion my not work. It is I believe creep proof.