Hi everybody, I'm trying to stick glass to metal (specially Aluminium) with glue Loxeal UV 30-24, and I also use UV lamp (Osram e27/es 300W), but I have some problem with that. sometimes they stick very hard at first but will seperate in somedays easily. Do anyone know about that? How should I do? How should I clean the glass? or something like that to stick them better.... Best Regards Ati
Glass and metals have different expantion ratios. Have you taken this into account? Often you have a sheet of rubber in the middle of the join.
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What are you trying to glue together, i.e is it heat related item? Araldite is a good bonding material for glass to ally. Wipe/clean the glass with methylated spirits and a bit of fine wire wool on the ally to give it a key grip, dont gouge the ally.
-- Sir Benjamin Middlethwaite
If it gets hot, use high temperature silicone.
Epoxy should work OK if you degrease both thoroughly
What loads are present on the bond line?
Aluminium will rapidly form an oxide film that will always make bonding difficult, the glass would probably also benefit from an etched surface either chemically or mechanically.
One method that does work (used in some composite structures)
Use Scotchbrite to clean the aluminium, degrease in isopropyl alcohol, remove and dry, then submerge the aluminium completely in epoxy resin and abrade the bonding face with a clean swab of Scotchbrite (while keeping the aluminium completely submerged) Remove from the resin keeping a continuous film of resin over the bonding face and then immediately bring the bonding faces together, clamp and leave to cure.
Another alternative that might work better with less preparation would be a polyurethane adhesive such as Sikaflex or Betaseal (as used for bonding car windscreens)
thanks for your reply... with which material should I degrease them? I also need to know the time of UV that glow to the glue to stick and the require tempreture.
For this strategy, total immersion is not necessary. Excluding the oxygen from the metal surface is the name of the game. It is worth experimenting with simply using scotchbrite or wire wool with a bit of the UV cure adhesive on the metal , applying a bead of adhesive and curing. From the original post I gather that the adhesion to glass is good. Have you tried making a glass to glass testpiece to check that your batch of adhesive is good? Finally what sort of environment will the bond be in? In the aerospace industries a number of catastrophic failures occurred in bonded aluminium members like mainspars. While the stress was far better distributed than riveted members, creeping corrosion undermined the bond. I believe a technology to remedy this has been developed.
John Schmitt
What is wround with the oxide layer anyway?
Its tougher than the aluminium by and large.
Ther is no need to remove anything more than loose corrosion and geraese. The epoxy - especially if warned a little - will bond beautifully to the microporous oxide layer.
It's a bastard for adsorption. All sorts of stuff which can compromise a bond like to adsorb onto it.
It doesn't like chlorides either. Think fingerprints, the chlorides were implicated in those airframe problems. Come to think of it, chlorides were a big problem for welding titanium on the A12. They are a nearly universal corrodant for metals.
John Schmitt
Indeed, so clean it first, then thin the epoxy and let that adsorb in...;-)
Its possible to use isopropyl alcohol to thin epoxy to get it 'runy' - the alcohl evpas and the epoxy then sets...
Oh, no argument about road salt and alloy wheels.
It appears that you do not know the difference between adsorption and absorption. Methyl violet adsorbs onto glass out of alcoholic solution. You can then wash the glassware until you are blue in the face and it will still desorb in an appropriate solvent, giving a purple solution as evidence.
John Schmitt
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