I need to thicken some epoxy this evening, and I don't have access to microballoons at the moment. Can anyone suggest an alternative that won't weaken the epoxy? Thank you!

Anything that you add to epoxy will weaken its' strength as an adhesive. However if you want an alternative to micro baloons try talc powder or baking powder.

Cheers,

Colin

Balsa dust as well, works, easy sanding.

I mananged to 'score' a bag of 'milled fiber' in one kit. used most of it, but still have some left. It's basically glass fibers, but really small. So, you get soem added strength, and a thick epoxy mix.

Use longer cure time epoxy when thickenign it.

Thanks, guys. I'll try your suggestions.

In the future, try getting a bag of cotton "flox"- milled cotton fibres used just like micro., only waaay less expensive. Available from aircraftspruce.com, or Wicks aircraft supply.

Thanks, Jetts. I may try that.

just make sure you get it exactly where you want it and smooth. Flox makes it very hard, and it won't sand! Micros makes it weaker, but it sands. Also look at cabosil. Don't use micro where you need more strength. Use flox there.

The real advantage to microballoons is that they are lighter than most (all?) other fillers. At a ratio of 4:1 or 5:1 balloons to epoxy it makes a foam like material that is easily cut and sanded. If weight is not a concern use something cheaper.

I second the balsa dust. I have a bag attached to the discharge shroud of my disc sander, always keep a jar full of the dust. It's cheap and easy to sand.

BO