structural wood adhesive
powdered resin wood glue
Specifically formulated for exterior joinery exposed to weather. This adhesive produces a bond stronger than the timber itself. The powder system gives extremely good gap filling properties, ensuring rain does not enter the joint. Use externally where a high bond strength/gap filling is required.
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at a glance product info
application and advice
Use 2 parts of Cascamite powder to 1 part of cold water.
NOTE: Mixing by weight is recommended for accurate and consistent glue mixes.
Add Cascamite powder to water, stirring rapidly until the powder dissolves.
Any small lumps will quickly dissolve.
Up to 20% extra water can be added to improve flow.
It is advisable to allow the mixture to stand after mixing to allow entrapped air to escape, bubbles or foam in a glue line can cause a weak bond. Cascamite is now ready for use. The mixture will remain usable for approx. 3 hours at 15°c
At higher temperatures the usable life is reduced and in hot weather it is advisable to mix only sufficient glue for immediate use (standing the mixing vessel in cold water will help prevent shortening of the usable life).
tack time: 3 hours at 10°c, 45 minutes at 20°c, 20 mins at 30°c cure time: Keep and check remainder of mixed glue, cured when hard
Joints should be smooth and well fitted. Apply the glue using a stiff brush to one surface only.
Assemble and clamp (pin or screw) the joint whilst glue is wet.
Keep the joint under pressure until set (approx. 6 hours at 15°c)
A damp cloth can be used to remove excess wet adhesive.
NOTE: - At temperatures below 10°c (5O°f), a period of up to 2 or 3 days may be required before the glue sets. During cold weather, it is therefore essential that joints under pressure be kept in a warm place.
Gel Time Guide:
20°c - 1-2 Hr
30°c - 30 Min
70°c - 1.5 Min
100°c - 33 Sec
Coverage should be 100 to 250 grams/sq. metre
NOTE: - If bonded wood is to be turned on a lathe it is recommend that the bonded wood is seasoned for a minimum of one week before turning.
USE OF PRESS ON ADHESIVE
The press pressure influences penetration of adhesives because it is the driving force for hydrodynamic flow. The pressure applied on the adhesive will force it to spread and penetrate into porous, fibrous material and into the roughness of the surfaces. The bond quality is affected by the amount of adhesive penetration into wood substrate during manufacture. An optimum adhesive penetration is needed to provide a reliable glue line thickness (GLT).
The press pressure is one of the main factors to control the GLT in addition to adherent, adhesive, machining, and adhesive spreading. GLT should be controlled because it directly affects the strength of bonding. One of the most important reasons for the occurrence of a thick glue line is insufficient pressure in the gluing process. Generally, thick glue lines lack strength. Pressure must be applied uniformly and adequately because synthetic resin based structural wood adhesives are not able to form strong bonds in thick and variable thickness glue lines.
The GLT ’s for wood joints are generally between 0.127 and 0.178mm. Optimum press pressures should be determined in relation to GLT. In low-density woods, high pressure forces the adhesive so deeply into the wood that there is insufficient adhesive to fill the bond-line, and it may cause over-penetration and inferior bond strength. On the other hand, low pressure causes a decrease in shear strength, does not provide close contact between the surfaces, and glue line remains partly poor.
The optimum press pressure was found to be 12.5kg cm . It may be risky to use pressure higher than 12.5kg cm or lower than 7.5kg cm at this level of spreading rate and heat with the UF adhesive because of possible
bonding and joint starvation problems, respectively.
The press pressure may depend on wood species, the moisture content of wood, adhesive properties, other press parameters, factory conditions, and strength requirements.
We recommend tests be conducted to establish the customers optimum press pressures.
1 Ideally the moisture content of the substrates should be 9% ± 2% with no more than 3% difference between the two surfaces to be bonded, otherwise stresses are built into the joint, which may result in wood or joint fracture. If the wood is too damp, the dilution effect will weaken the adhesive performance.
2. Although the workshop conditions may be above 10C, wood brought in from unheated storage conditions may well be below this temperature and should be allowed to warm to above 10C before attempting to bond it.
3. Some species of oak can be particularly dense resulting in difficulties in the adhesive penetrating the surface. In such instances, the surface should be removed by sanding to open the pores of the timber and double spreading may prove necessary to ensure both surfaces have sufficiently "wetted" out.
4. Some timbers, and particularly maple can be over prepared by planeing the timber; this leaves a “ glassy" surface, which is detrimental to the bonding process.
5. Oily timbers, such as teak, present problems with the "oils" inhibiting a satisfactory bond.
Degreasing is normally required; this can be achieved by wiping the surface with methylated spirit
Sanding can also remove surface grease, but if the adhesive is not applied shortly afterwards there are likely to be problems of case hardening where the oils have surfaced again.
Timber bought as kiln dried and stored under cover will present no problem.
Perhaps as important as the glue is the preparation the joining surfaces, especially for Oak and oily timbers, Teak, Iroko etc.
Timber direct from machining has a slightly glazed surface and the surface fibres are compressed by rollers etc, far from ideal and it is essential that the surfaces to be joined should be ridded of this unwanted smoothness.
Use a scouring plane (blade with fine points), hacksaw blade, or very coarse sandpaper. Plywood must be, treated in the same manner. Dust with a bristle brush, oily timbers should be degreased
with methylated spirit. The faying area should be abraded as close to bonding as practically possible.
As important as preparation, is working in the correct temperature and that means, within reason, as warm as possible, 20C is ideal. At higher temperatures the glue becomes much less viscous, easier
to apply and penetrates the timber instead of laying on the surface, a better glue line results.
For the best results both surfaces of the joint should be glued. Use good quality brushes. Surfaces once glued should not be exposed to the air for any length of time. Do not over cramp; it’s possible to starve a joint this way.
A minimum of twenty minutes closed assembly time should be allowed before the application of pressure.
Just bring the surfaces firmly into contact. This will enable the glue to penetrate the surface fibres of the timber and avoid excessive squeeze out.
Synthetic glues may cause dermatitis in some people. As a precaution, any glue spilt on the hands should be removed immediately with soap and water before it sets.
Avoid the formation or spread of dust in the air. Wear suitable protective clothing, gloves and eye/face protection.
Store in a cool, dry place with the lid tightly closed.
health, safety and the environment
Ensure good ventilation. Keep out of reach of children. Contact with eyes - wash immediately with warm water. Remove excess from tools and mixing vessels before washing in warm soapy water.
Do not empty into drains or watercourses.