Both glues seem to be 2-part epoxy, but is one much better than the
other? I know JB Weld contains metal dust, but does that really add
much to the strength - I suppose it's a bit like the gravel in
concrete...?
It really comes down to purpose. I love JB weld for making/repairing
parts, and it's ability to handle high temps. However, I wouldn't use
JB weld to glue wood, or wet out fibre glass. Araldite (slow) is more
fluid and soaks into wood better, each has it's own character, as do all
adhesives.
Joules
It's a bit more complex than that - just as, say, Copydex has less
holding power than superglue, so different epoxy resins will have
different strengths and weaknesses.
Indeed - the Araldite you can buy over the counter represents just a
fraction of the entire range...most of which is only available in
commercial sized packs.
JB-Weld sets harder, and has enhanced tenacity ( i.e. it sticks better
). However, you can get superior capillary action from Araldite if you
gently heat it, which makes it better at getting into small cracks.
I don't know whether the particles in JB-Weld make any difference to
its strength - I suspect it's more about making the final product
roughly match its surroundings.
Regards,
The Araldite you get in shops in two small tubes or a double syringe is
simply crap compared to any fresh "proper" epoxy - West, NHP, Fibretech,
Aeropoxy, SP or the like, take your pick - whether for glueing or
laminating.
I have written this before, but if you have only used Araldite, and then get
a fresh supply of a good epoxy - you will simply not believe they are the
same stuff.
I haven't used JBWeld, so I can't comment.
I mostly use NHP for glueing and West for laminating, and I use quite a lot
of epoxy - there are some better ones, but those are good value and work
extremely well.
No comparison to Araldite, it isn't even in the competition, never mind the
same league.
Stephen Howard writes ..............
It certainly makes it harder and more 'machine-able', and gives the
ability to apply it more thickly without it flowing away.
Mike
Also, Araldite can be given much greater strength by not just warming it,
but by really heating it. The old data sheets used to quote increases gained
at various times at various elevated temperatutes. The only determining
factor is the progressive darkening with higher temperatures, upto the point
at which it starts to char.
I imagine that that is how Ciba were able to demonstrate a 15 ton Ciba
tanker, suspended from a 1" square lap joint in a 1" steel strap hung from a
crane.
Also, there were many industrial liquid Araldites, not available on the
public market, due to the danger of allergic skin reaction . A friend used
some from work to repair a Hoover floor polisher, and also to laminate -
with paper and wire - a firewall for the Microplas car body he was fitting
to a Buckler space-frame chassis. This was over 50 years ago.......
Dave.
I can't agree!
I don't know about the current supplier/maker of domestic Araldite, but the
original - made by Aero Research Ltd., and bought by CIBA was a good high
strength wood and metal glue, developed from their wartime research into
high strength wood glues - e.g. Redux (Resorcinol/formaldehyde) that were
used to build the Mosquito twin engined bombers
I used to rebuild laminated wooden squash racquets - Dunlop Maxply ones,
that had been smashed and dumped in the bin at the club I used to play at. I
used two-pack CIBA Araldite, and layers of 1millimetre hardwood 3-ply (birch
or ash?) - the stuff used in model aero making, a lovely material. The
damaged plies in the racquet were removed, and new ones of the 3-ply tongued
in, liberally coated with Araldite, and all bound up tightly with copper
wire before being baked at a moderate heat. When cool and hard, the wires
were stripped off, the glue and wood trued up for shape, the stringing holes
reformed, varnished and the finished job taken to the Harris's Sports Shop
branch at the club. There the manager would lean the frame against the shop
wall, and press on it with all his weight! If it passed this test, he would
have it restrung. I still have a couple that I kept, but many were rebuilt
for their owners, after they discovered the saving!
Dave.
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