In 1994 Glas-Weld made a quality test from England (BS AU 251:1994). 
We can sum up the test results by saying that Glas-Weld was approved on all the testing points and received green light to repair freely, without restrictions, even in zone A.
Certain damages however, largely enough for risking optical disturbances, should not be repaired.
GlasWeld does always repair with care and quality to guarantee the satisfaction of our customers.
All GlasWeld technicians are trained to do an ocular inspection of the damage, and then they decide, in consultation with the customer, whether the damage should be repaired or not.
If the customer is not satisfied or the repairation is not approved by the official authority, the repair costs will be returned.
Guidelines for glass repairs from the Swedish Glass-authority GBF.
The Swedish Glass-authority GBF has elaborated instructions on how reparations should be executed. These are however only guidelines, but it’s recommended to follow them to the utmost possible extent.
- In Zone A it’s allowed to make reparations which have a diameter of up to 1 cm.
- In Zone B it’s allowed to make reparations which have a diameter of up to 1,5 cm.
- In Zone C it’s allowed to make reparations which have a diameter of up to 2,5 cm.
- In Zone D it’s allowed to make reparations which have a diameter of up to 4 cm.
Zone B, C and D shouldn’t be repaired when two damages lie closer to eachother than 10 cm.
Below are some test results:
1: UV-radiation: All sorts of stone damage glue does become discoloured after being exposed by ultraviolet radiation for a long time. The test was made during a long period of UV-exposure, and the discoloration was permitted to come up to a maximum of 25%. The discoloration from Glas-Weld ran up to only 0,8%.
2: Mechanical strength: You bend an undamaged laminated glass until it breaches and can thus judge where the maximum strain is. A stone damage in the middle of a laminated glass was being repaired. Then it was possible to find out how much the repaired glass could be bent before it cracked. The lowest value a reparation needed to approve was 30%. The reparations of GlasWeld showed a durability of 98,3%. That is three times better than the minimum demand.
3: Light distortions: The purpose is to limit light refractions (distortions) in the reparation. First directly after the reparation, then after a period of accelerating aging. The maximum value for reparations before aging isn’t allowed to exceed 4%. We measured 0,68%. The maximum value after aging isn’t allowed to go beyond 8%. Glas-Weld measured 1,58%.
What Glas-Weld has known for a long time is that the reparations that we make are very qualitative, something that was proved by this comprehensive quality test.