How we research
Every technical claim on this site is tied to a source and graded. Where the evidence is thin, we say so rather than rounding it up to certainty.
Where the information comes from
We work down a fixed hierarchy of sources, and what a source is allowed to support depends on where it sits in it.
| Tier | Source | What it can support |
|---|---|---|
| 1 | Manufacturer technical datasheet, product datasheet, application guide | Substrates, cure times, strength, temperature limits, restrictions |
| 1 | Safety data sheet | Hazards, handling and storage. Never proof that something bonds |
| 2 | Material manufacturers, engineering bodies, universities, published standards | Material properties and independent verification |
| 3 | Specialist adhesive suppliers and professional technical retailers | Practical application guidance |
| 4 | Forums, reviews, community experience | Discovery only. Never enough on its own for a technical claim |
| 5 | Amazon and other shop listings | Whether you can buy it in the UK. Nothing else |
How we grade confidence
- A, manufacturer verified. The manufacturer's own technical documentation says it.
- B, strong evidence. Independent technical sources support it, or several credible sources agree.
- C, inferred. Reasonable from the chemistry, but not verified for this exact claim.
- D, unverified. Not enough support. We do not publish these as recommendations.
The rule we care most about
We never turn an inference into a manufacturer claim. If a datasheet says a product bonds “metal and most plastics”, that is exactly what we record. We do not quietly translate it into “approved for polypropylene”, because the manufacturer never said that and polypropylene is precisely the plastic that phrase usually excludes.
Where we have made a judgement of our own, the page says so and grades it lower.
Why some pages say we do not know
A page only goes live once the pair has a recommended chemistry, preparation guidance for both surfaces, enough sources behind it, and a verified product you can actually buy. Until then it stays unpublished. A bond that fails costs you the repair and sometimes the item, so an honest gap is worth more than a confident guess.
Keeping it current
Datasheets get revised and products get withdrawn. Every source has a review date, and a scheduled check flags documents that have changed or disappeared. When the evidence behind a live page drops below the standard, the page comes down until it is fixed.
Products and money
We recommend a chemistry before we recommend a product, and product order is set by how well something suits the job. Commission never changes the order. See the affiliate disclosure for the details.