Find the appropriate curing method. The specific adhesive chemistry will determine the next tests.
Product and application
Select the system so that only relevant test steps appear. If no system is specified, the test will remain general.
01
What are you observing?
02
Identify the cause
03
For reference
All test steps in this guide can be used even without the guided process.
Terms briefly explained
Hand strength
The parts should be handled carefully. The connection is not yet fully load-bearing.
Complete curing
The curing conditions and times prescribed for the product were adhered to.
Adhesive gap
Distance between the two joining surfaces, not the length of the adhesive seam.
Pot life and nozzle life
Test the processability of a mixed quantity and the processability in the mixing nozzle separately.
Chemistry or product still unclear; 3 testing steps
Locate the product reference and technical data sheet. Only then change the temperature, activator, or mixing ratio.
1 · Storage
Has the material been stored within its shelf life and according to the data sheet?
Aging, humidity, separation of components or unsuitable temperatures can alter processing and hardening.
Record batch number, expiry date and inventory history.
Check for segregation, thickening, and contamination. Do not correct conspicuous material with unauthorized additives.
If the material quality is unclear, check a fresh, correctly stored batch for comparison.
2. Identify the product
Is the adhesive chemistry known from the label or data sheet?
The hardening process may require moisture, metal contact, mixing, heat, or UV light.
Read the product reference on the container and search for it in the finder.
Please refer to the relevant chemistry guide below for further verification.
3 · Order & Fixing
Is sufficient adhesive applied to the correct area and is the joint held still during the curing process?
Gaps in the order, incorrect contact points, and movements during curing can explain local failures.
Check the dosage and actual wetting of the contact surface.
Maintain fixation until the required strength is achieved; pay attention to air gaps and torn structures.
Document the error rate and distribution. Individual failures may indicate fluctuating process conditions.
2K system remains soft; 3 test steps
Check the mixture, temperature, and material condition.
1 · Mixture
Do the components, mixing ratio and mixing nozzle match the product data sheet?
Uneven application or unsuitable nozzles will leave unmixed areas. A general mixing ratio does not apply to all products.
Check the correct resin/hardener combination and prescribed ratio.
Check the cartridge piston, the discharge of both components, and the recommended mixing nozzle; pre-run the nozzle according to the manufacturer's instructions.
For dosing systems, check the actual quantities of both components. Document any streaks or unmixed areas.
2 · Temperature
Does the actual processing temperature correspond to the specifications for the product?
Cold temperatures slow down many curing reactions. A thin layer of adhesive may cure more slowly than a larger, mixed quantity.
Measure the temperature of the material, component, and workplace.
Adhere to the specified waiting and curing times. Use heat only within the product-specific curing plan.
Consider pot life and time in the mixing nozzle separately from the time until load-bearing capacity.
3 · Storage
Has the material been stored within its shelf life and according to the data sheet?
Aging, humidity, separation of components or unsuitable temperatures can alter processing and hardening.
Record batch number, expiry date and inventory history.
Check for segregation, thickening, and contamination. Do not correct conspicuous material with unauthorized additives.
If the material quality is unclear, check a fresh, correctly stored batch for comparison.
The reaction is only visible on the surface. 3 test steps.
MS polymers typically cure from the outside in. However, with UV products, a sticky excess can indicate exposure to oxygen.
1 · Differentiate chemistry
Was the hardening assessed inside the joint and not just on the excess material?
A skin or sticky surface alone is not reliable proof of complete curing.
Refer to the appropriate MS or UV guide for further testing.
Document joint thickness, moisture ingress and light path.
2 · Temperature
Does the actual processing temperature correspond to the specifications for the product?
Cold temperatures slow down many curing reactions. A thin layer of adhesive may cure more slowly than a larger, mixed quantity.
Measure the temperature of the material, component, and workplace.
Adhere to the specified waiting and curing times. Use heat only within the product-specific curing plan.
Consider pot life and time in the mixing nozzle separately from the time until load-bearing capacity.
3 · Storage
Has the material been stored within its shelf life and according to the data sheet?
Aging, humidity, separation of components or unsuitable temperatures can alter processing and hardening.
Record batch number, expiry date and inventory history.
Check for segregation, thickening, and contamination. Do not correct conspicuous material with unauthorized additives.
If the material quality is unclear, check a fresh, correctly stored batch for comparison.
Additional information from the source
Anaerobic products require suitable metal surfaces and a suitable enclosed gap.
Superglue requires a tightly sealed joint and reacts to moisture on the surfaces.
One-component epoxies require a specified temperature profile at the component. UV products require adequate light access and a suitable radiation source.
German version prepared according to the archived Permabond guideline adhesive-not-curing-all-chemistries.md. Always compare product-specific values and procedures with the corresponding technical data sheet.
