Hi,

I know how to thicken CA but what is a good material to thicken 30 minute epoxy? Can backing soda be used as well.

Sorry for maybe a stupid question.

corn startch is one that i've heard

Use micro balloons, they come in two flavors, a brown colored one made of a plastic substance and a white one made of fiberglass. Both work well and much better than cornstartch etc. First mix the epoxy (use 30 minute or slower) well than add the microballoons mixing well as you add. You can add enough until the results is about like stiff peanut butter. This mix also sands quite well, not like pure epoxy. If you are making fillits, you can wet your finger with alcohol and smooth out the surface while it is still wet.

I have heard that fiberglass is good. In fact, it repairs boats hulls nicely too

Get some of the filler that West Marine sells. They have several types and it's way cheaper than the hobby shop stuff.

For thickening epoxy, many people have thier tricks.

From what I've tried, and read:

Micro ballons; as stated above, and very popular! Light weight / easy sanding.

Milled fiber: this is essencially shredded fiberglass; small strands. While it'll thicken the epoxy, it'll also add lotsa strength. You're introducing a 'random weave' of fibers. Not nesseccarily 'light', nor 'easy' to sand. Mostly used to 'beef up' structures. sanding not reccomended..

Balsa dust: Yeah, the stuff you get when building! save it, and add it to the mix. as good as 'micro ballons', cheaper, but not as light. sands OK, but does need a sanding.. (leaves a 'goose bump' surface)

Baby powder: Same as 'balsa dust, but a 'baby fresh scent' when sanding!

PB&J: Although sticky, does better at secureing bread to bread than balsa (or ply) to balsa (or ply)!!



There's soon going to be a time, when along with 'Milled Fiber' and 'Micro Ballons', we'll be able to purchace "Buckey Balls" and "Buckey strands"!!

The above answers are right, but, it really depends on what you are doing. If you want to use it as a filler, any of the methods will do. If you are using it where strength is a consideration, use fiberglass.

All the above methods are good if you are using the epoxy as a filler. If you simply want a pure epoxy that doesn't sag before setting up try the stuff from BVM.