Hi all,


Since this is my second kit (G/P Extra 300s .40) being built I ran into a part where it is telling me to use Microballoons.

Ok Where can I purchase these micro's? and can I make them with something instead of buying them? If I can make them can you tell me how.

This is a new one on me.

Thanks in advance,

You can get them at most hobby shops. There are two types, one is fiberglass, the other a form of plastic or phenolic material. These are just hollow balls and used as fillers to mix with your epoxy. They make the mix sand a little easier, weigh a little less than pure epoxy but are not as strong as pure epoxy. Use as little epoxy as possible with the mix to keep weight down. A stiffer mix does tend to stay in place better (doesn't run or drip). You can use balsa dust or saw dust instead but that doesn't mix as easily or as well.

I have tried taking sawdust (file down a balsa sheet) and mix with C/A or epoxy. It seems to work for me.

I AM NOT A BUILDER!
I just make changes!

You can get a small container of them from hobby suppliers for an outrageous price, or you can mail order a 1 gallon sized package of them from Wicks Aircraft Supply, or Aircraft Spruce. It will cost about $6.00 for a 1 gallon bag, vs about $6.00 for an 8oz bottle from the likes of Tower.

They are very small spheres of phenolic glass. I am not familiar with how they are made, but I doubt many of us have the equipment it takes.

Safety caution: use a dust mask when handling and sanding this stuff.

Vince

Microballoons are tiny hollow glass spheres that look like confectioners sugar. So you won't be making them (G). They are used as a filler to lighten epoxy to make fillets. I have an old bottle from K and B Mfg. but I don't know if it is still available. There have been warnings not to ingest this stuff as it is as bad as fiberglass if it gets into your body.

Dave Segal

Thanks for your replies. Now I did read that I can substitute Talcum Powder for Microballoons. Has anyone tried this? And how much talcum powder should I use?


Thanks again for your replies.

Geistware: I've tried using sawdust and CA and found it really nasty to sand- it's like rock. Maybe this method would be used for gaps on internal joints? Not that I'm a pro or anything, but I've really screwed a fuse I'm fixing using that method. What application do you use it for?

But I've never used Micoballoons....being so new at this.

DS: as I'm mentioning in this post, sawdust and ca gets really hard. I know that epoxy gets hard like that too. Does Microballoons make the epoxy easier to sand to shape?

Yes the micro ballons make the epoxy easier to sand.
If you use talc make sure it's the industrial kind not the perfumned kind. You can get it at Home Depot some times. The talc and epoxy will be heavier.

Good to know.

Mixing talc with epoxy will not give you the same results. The microballoons mixture will be much lighter and easier to sand.

Vince

As I understand it the red microballoons are phenolic and are easier to sand. I used them years ago on full size sailplane repairs and sanding was easy. Of course I mixed them with some softer material than epoxy. I have since used the "white" microballoons on model floats, since it was all I could get, and found them not the easiest to sand. Probably easier than epoxy alone and certainly lighter.

RSprinkel, What are you using it for? Might be easier to to tell you what to use for a particular purpose.

On my Extra 300S 40 it is telling me to use this microballoon to glue the pushrod tubes to slots at the end of the fuse.

Sorry maybe I should have said that in the beginning. Is there anything else I can do besides using the micro's?

Thanks again for all your replies.

I would forget that stuff and just use epoxy.

I would just use Goop, won't go anywhere. Have you used it before?

Goop, never used it nor have I heard of it. Can you give me alittle more info on it please.

Thanks

I t's a type of hard rubber glue that you can glue just about anything to anything with. Formers in fibreglass etc. Won't let go. you can buy it in Automotive,Hardware Home Depot, places like that. Once you have it you'll find many uses for it.

Gentlemen Microballoons, at least the red ones will show thru the covering if you use light colored covering. I use spackling compound[found at wally world or hardware stores] Get the one the is lite in the box so it will not add more weight.Sands good and is lite colored and does not show thru. When I say lite in the box I mean when you pick up a can of it it will feel lite compared with some others.Bob

I know it gets hard but I use it for strength and filler. Never thought about using it for the purpose of bondo.

Hmmmm options options options.


Thanks for all your replies. All have been very helpful and will keep all this in mind. Maybe get this thing done tonight.

Again Thank You all.