Cascamite

[DIY Stew]

I intend using cascamite to stick some 9mm exterior grade ply together to give me 18mm thickness, is there a rule of thumb about how much cascamite to mix to cover a specific area ie approx 0.5litres will cover approx 1square metre.

TIA

Stew

 

[Louise-Paisley]

100 - 250g/square meter..

http://www.agwoodcare.co.uk/pdf/Resintite%20UF.doc

 

[Phil Pascoe]

Don't mix it too thick - you'll never squeeze it out.

 

[Steve Maskery]

And I recommend a small roller to apply it. You can get 4" ones from decorators' suppliers.
S

 

[yetloh]

Yes, not too stiff a mix, a nice even film that will need litle or no squeezing out which is easy to achieve with a cheap foam roller. No need to use a tray with the roller, just pour it on in a serpentine line over one board and use the roller to spread evenly.

Jim

 

[DIY Stew]

Thanks you guys feel a lot more confident now.

Louise the weights you have given are they just the weight of the powder or when mixed with water (sorry if I appear stupid but eh .......well I am)

Stew

 

[Steve Maskery]

Cascamite changes its consistency significantly with VERY small changes in amounts of water. A good tool to have is a small set of digital scales, because weighing out is more accurate than measuring out. A water bottle like we used in the chemistry labs at school is a good way of adding water, as a few drops can make all the difference.
If you mix it too thin it will have reduced strength and if you make it too thick it will be expensive.
It's a superb glue when you get it right.

 

[Louise-Paisley]

Thanks you guys feel a lot more confident now.

Louise the weights you have given are they just the weight of the powder or when mixed with water (sorry if I appear stupid but eh .......well I am)

Stew

It is not clear in the tech spec note I linked to, but I would suspect it is dry weight. There is a large range quoted so I think I would probably go middle of the range myself, especially as for your application you need it a bit thinner than normal and a nice thin coat.

This is the problem with Caskamite/ Resintite/ whatever else you wish to call it, you either waste some or you don't have enough. It does have a reasonable working time if its not too warm in the shop so if you need a bit more you can quickly mix up a bit extra if you have clean pots at the ready

 

[Louise-Paisley]

.
It's a superb glue when you get it right.

I was unconvinced until I got some and glued two bits of 18mm ply together edge to face to test it, it took a lot of effort to part them again!

The box I am making I am using a double rabbet joint but with hindsight that would not be at all necessary with Caskamite I doubt, stick like poo to a blanket

 

[adidat]

try for a runny honey appearance.

adidat

 

[RogerS]

..... A good tool to have is a small set of digital scales, because weighing out is more accurate than measuring out. ....

And go for jewellers scales as Cascamite is very very light.

 

[Louise-Paisley]

most digital kitchen scales these days are plenty accurate enough, mine go down to 1g which is as close as you will ever need I would think

 

[RogerS]

most digital kitchen scales these days are plenty accurate enough, mine go down to 1g which is as close as you will ever need I would think

Nowhere near low enough ...at least in the quantities I make. Also 1g is the lowest resolution and so any measurement is going to be +1 or -1 one gram. That's enough to mess up your mix.

 

[Lord Kitchener]

Try some PVA. Try sticking two offcuts together then try to separate them when the glue has dried. You might find you don't need Cascamite after all.

 

[JonnyD]

I would just buy a sheet of 18mm ply

Cheers

Jon

 

[Louise-Paisley]

most digital kitchen scales these days are plenty accurate enough, mine go down to 1g which is as close as you will ever need I would think

Nowhere near low enough ...at least in the quantities I make. Also 1g is the lowest resolution and so any measurement is going to be +1 or -1 one gram. That's enough to mess up your mix.

All I can assume is you are making matchstick models, the min quantity I have mixed so far was 10g and that was JUST enough for 4 smallish half lap joints! 1g in 10 is not going to make that much difference, most times I am mixing 40+g so 1 in 40 is even less. The OP was talking about gluing sheets of ply together which is likely 300g for a full sheet so now down to 0.33% error max with a 1g resolution.

 

[Mike.S]

I'm currently using Cascamite to glue 6mm MDF to MDF framework and find 175-200g dry Cascamite with 90-100g water (i.e. 50% of Cascamite weight) covers around 1sq metre. Scales I used are marked in 25g sections and not found a few grammes over/under to make any difference.

 

[RogerS]

most digital kitchen scales these days are plenty accurate enough, mine go down to 1g which is as close as you will ever need I would think

Nowhere near low enough ...at least in the quantities I make. Also 1g is the lowest resolution and so any measurement is going to be +1 or -1 one gram. That's enough to mess up your mix.

All I can assume is you are making matchstick models, the min quantity I have mixed so far was 10g and that was JUST enough for 4 smallish half lap joints! 1g in 10 is not going to make that much difference, most times I am mixing 40+g so 1 in 40 is even less. The OP was talking about gluing sheets of ply together which is likely 300g for a full sheet so now down to 0.33% error max with a 1g resolution.

Well, there you go then.

 

[Sgian Dubh]

The following mixing instructions are for urea formaldehyde adhesives that come as a white or brown powder that already contain both the resin and the hardener. Adding water to this powder activates the curing reaction. The glue must be mixed in non-metallic containers such as a plastic bucket or glass jar to avoid contamination and prevent adverse reactions in the glue, eg, failing to cure.

• * In separate measuring cups measure out by volume:
  * 3.5 parts glue powder.
  * 1 part cold water.
  
  * Put about half or three quarters of the water into a mixing pot.
  * Add all the glue powder.
  * Stir the powder into the water vigorously using a stick, eg, a piece of dowel. Remove the lumps to make a thick sticky paste.
  * Add some of the remaining water and keep stirring.
  * Continue adding small amounts of water and stirring until the glue reaches a single cream consistency.
  * It is now ready to use for regular joinery, eg, mortice and tenons, dovetails, panel glue-ups, etc. Apply the glue with a stiff brush.

Open time of the glue at room temperature is approximately 10 to 15 minutes, ie, you have 10 to 15 minutes from the moment you start applying the glue until the time you tighten up the last cramp to leave the glued up assembly to cure. Pot life may be up to an hour. This mix dries hard enough to remove cramps, etc in approximately four hours at normal room temperature, ie, about 21°C or roughly 70°F. Increasing the temperature speeds up the cure time, eg at about 95°F (35°C) it sets in about one hour. Full cure occurs over twenty four hours or more.

For laminate bending, veneering, etc the glue may need a little more water in order to make it easily brushable or rollable. Avoid making the glue too thin and runny because this weakens the bond, but it also extends the cure time which can be useful if your glue-up, assembly and cramp application is complex.

Clean up the mixing pots and glue application brush as soon as possible after a glue-up using hot water and dishwashing detergent or soap. Clean up is easy at this stage and takes just a few minutes. Slainte.

 

[Ian down london way]

I made my own ply once from veneer - rotating each by 60degrees. This was to make a blank for making some hand cut (well Hegner cut) clock cogs, where I needed the teeth to be strong in all directions. Anyway, using PVA glue, the resulting ply was incredibly rigid. Way more than commercial play. Mind you, it was also way more expensive.