Cascamite / Extramite / Polymite

[Me!]

After looking through some old posts on the forum, it seems that people think Cascamite is a very good glue for external joinery. So, I decided to buy some to try it for myself. I have found various places that claim to sell Cascamite, but then find it is actually Extramite, or Polymite. Does anybody know please if these three are all the same, or do I need to get the correct one?
Thank you.

 

[biffvernon]

They are all the same - some of the packs actually have two of the labels on them!

White powder. I find some of the instructions a bit odd so ignore them. I put a spoonful of powder into a pot and add drips of water stirring vigorously until a liquid thin enough to paint on to the wood but not so thin that it runs off. I paint both surface (sometimes the instructions say coat just one surface). Clamp the joint an leave overnight. A few hours in warm weather, longer in winter.

 

[Flyfisher]

Yes, same stuff but the name has changed over the years because of company/marketing changes.

I've still got a leftover tin of cascamite (and branded as such) from the time I built a wooden canoe in the mid-80s. The canoe is still going strong, I'm not so sure about the shelf-life of the tin.

 

[Me!]

Well, it seems to be back to being called Cascamite again!
I've just bought a new plastic tub of the stuff in a local shop in Bury St Edmunds today. Hopefully I'll get to try it out this weekend.

 

[88v8]

It has absolutely no gap-filling qualities, so your joints need to be accurate.
They also make a two-pack adhesive called Cascophen which is better. You're most likely to find it at a chandlers.
Some time ago I spoke to a techie at Humbrol who described Cascamite as 'water resistant' and Cascophen as 'totally waterproof'. It is also good for 'difficult' woods such as teak.
The downside of Cascophen is that it has a shelf life, whereas Cascamite will last for ever in the tin if kept dry.

Ivor

 

[biffvernon]

It has absolutely no gap-filling qualities, so your joints need to be accurate.

Really? I thought it filled gaps pretty well. (Not that I've ever made a joint that isn't perfectly accurate and tight :wink: )

Try mixing some sawdust into the mixed up cascamite for extra gap-filling volume.

 

[88v8]

It has absolutely no gap-filling qualities, so your joints need to be accurate.

Really? I thought it filled gaps pretty well. (Not that I've ever made a joint that isn't perfectly accurate and tight :wink: )

Try mixing some sawdust into the mixed up cascamite for extra gap-filling volume.

PVA glues fill gaps OK, but Cascamite makes a thin almost liquid glue - soup vs porridge.

Ivor

 

[biffvernon]

Ah, you've been following the instructions on the pack! Don't do that. Put a spoonful of powder in a yoghurt pot or suchlike, add water drip by drip stirring vigorously with your applicating brush until you get a thick, sticky, gloopy liquid that only just drips off your brush. Thicker than PVA. It will fill any sized gap but may be less brittle and fills an even bigger gap if sawdust is added.