Micro baloons speeding up glue stting?

I've just used (tried to use) miro baloons in araldite and they made the glue set almost as I was mixing it!
Is this a normal reaction?
What epoxy is the favoured type?
Thanks.
Marty

I use Devcon 5 minute, get about 5 mins before it starts to gel about 3 when mixed with micro balloons, if you want to prolong the gel spread it out thinly on your mixing board, it's the exothermic reaction taking place.

http://en.wikipedia.org/wiki/Exothermic_reaction

So would I be better off using the standard "slow" epoxy?

In a nutshell yes, but is dependant on how much time you have to set the parts before the glue starts to gell. I only ever use 5 mins for gluing things together

I'm trying to stiffen up the cut aileron / wing edges on my Binary (as was sugested by Andy) The wings are grp with a foam core, I've run a hot iron down the edge to make the foam receed a little (also suggested by Andy) and now I just need a mix to stay workable long enough to fill the gap.
I think I'll pop out and get some ordinary epoxy and give that a go.

In that case I would use 1 hour, mixed with MB as you have done, I use West System 105 epoxt resin with 205 hardener, for filling 407 low density filler, for a more structural filler 403 microfibres, Colloidal Silica thixotropic paste 406. give a pot life of about 25mins

All available from

http://www.rutlands.co.uk/finishes-glues-&-materials/epoxy-resin-systems/epoxy-resin/WS101/mini-pack---300g

If you're after real strength then the slow 24 Hr Araldite is still the gear but if time/patience is an issue the the 5-10 minute stuff gets it done most times but Micro baloons will always shorten the curing time Some of the guys who play with big composite models tend to use the stuff like West Systems which comes in fairly large sizes and is mega expensive but I haven't strayed there yet. I like Gorilla glue a lot very good for gap filling and sticks like you know what to the blanket but does not look that nice on the eye

Rich wrote:In that case I would use 1 hour, mixed with MB as you have done, I use West System 105 epoxt resin with 205 hardener, for filling 407 low density filler, for a more structural filler 403 microfibres, Colloidal Silica thixotropic paste 406. give a pot life of about 25mins

All available from

http://www.rutlands.co.uk/finishes-glues-&-materials/epoxy-resin-systems/epoxy-resin/WS101/mini-pack---300g

as above, it's what we use in the Lifeboat repair world

Thanks for the input Chaps, I'm still grappling with the diversities of modern technology!

Generally, the slower the cure time for epoxy adhesives, the stiffer the cured adhesive is. They are usually stronger too.

For facing the ailerons, the main thing to have is a reasonable working time, but you want to use a thixotropic filler (so it doesn't "slump" or run out of the bit you are trying to fill). Using microballoons is good, using colloidal silica is even better (in terms of stiffness acheived). I used microballoons to minimise the weight gain, plus I didn't have any Colloidal silica at the time...

Cheers
Andy

Thanks Andy, as you've guessed by now I've acually started the binary! (at last lol)

well I really understood all that

johnoxleydean wrote:well I really understood all that

I'm NOT biting! lol

Look forward to seeing it completed by tomorrow then Marty .
I have all sorts of stuff here if you want to rummage through the boxes, pretty sure Ive got some colloidal silica "dust" as well as various epoxies - including devcon.

mmmm might not get it finished ....... in fact it's a dead cert it wont be coz we just opened a bottle so that as they say is that! ..... Happy days!
I've been dying to have a rumage through all your hidden goody boxes! lol

Andy Sayle wrote:
For facing the ailerons, the main thing to have is a reasonable working time,

Cheers
Andy

How would you know?

M

Because I did on on yours, to make sure it is as close to perfect as you can get. It should be ready just in time for the summer season too!

Andy