Micro Balloons questions.

[HotRodaSaurus]

I have seen these mentioned in building topics as some kind of filler but dont know anything about them.

So a few answers to some questions please.

What are 'micro balloons' I have a bottle, they just look like powder.

How are they used as a filler and what is the advantage over other fillers.

Do you use them on resin or styrene parts.

Anything else I should know?

Thanks in anticipation, John.

[Ace-Garageguy]

Microballoons are very small empty spheres. They're hollow and VERY light, and they tend to float around if disturbed, like during mixing. DO NOT INHALE THEM. USE A GOOD DUST MASK, AT LEAST. A RESPIRATOR IS BETTER.

They're used as a LIGHTWEIGHT inert thickener for various resins (and CAA) rather than the much heavier and more common talc-based materials in products like Bondo. They come in reddish-brown (phenolic) and white (glass).

Mixed with epoxy, micro makes a very easy to sand, light and almost zero-shrink filler that adheres VERY well to styrene, resin, fiberglass, etc.

I use the stuff extensively on real aircraft, and a fair bit on models when I have a need for a high-build product with exceptional adhesion.

The white filled ares on these two models required something special, and epoxy-micro was the best choice.

I use West-System epoxy as the base for my micro filler. It takes 12 hours to cure-to-sand, but it performs better than Bondo (it's stronger, adheres MUCH better, and will hold edges that would flake and chip using Bondo or similar products).

On the custom Challenger wagon, immediately above, I needed something that would allow me to scribe these parallel lines in the roof, very close together. Bondo won't do it...epoxy / micro will.

For the Challenger One model at the top, I needed a filler that would NOT shrink over time, because of the faux brushed-metal finish.

Edited June 3, 2015 by Ace-Garageguy

[Longbox55]

Just to add to what Ace posted, they are also used in resin casting to make light weight castings and/or to reduce the amount of resin required for a given volume casting. Especially useful if one needs to make buoyant castings.

Edited June 3, 2015 by Longbox55

[Mike Kucaba]

Been using them for years now mixed with 30minute epoxy. Great filler to add to the arsenal of fillers.

[Art Anderson]

Micro Balloons and 30 minute epoxy can also be used to make hollow body shells as well! An old friend of mine from up in NW Indiana used to make incredible 1/25 scale race car body shells this way! He'd simply carve out the basic shape (slightly undersized) in blue insulation styrofoam, mix the micro balloons with 5 minute epoxy to make a fairly stiff paste, spread that over the styrofoam.

Several layers, or applications later, once the epoxy was hardened, he'd simply use files and sandpaper to carve those body shells to the desired shape, and once satisfied, he'd use his Dremel to open up such as the grille (or air intake) opening, and the cockpit area.

To truly hollow out the body shell, he'd go outside, and pour some acetone into say,the cockpit opening, and within seconds, pour the liquified styrofoam out through the air intake in the nose! After this, Bob would cut the body shell apart along where it's panel seams would be, clean up the inside surfaces, then do any smoothing out that still remained with spot & glaze putty.

He was so practiced at this technique, he was making model race car body shells with a material thickness of no more than .030", which resulted in some really cool model car bodies. I've tried that a few times years ago, in my Indy/USAC race car modeling period--it does work, and work very well.

Art

[HotRodaSaurus]

Thanks for these answers.

So would micro balloons be the best way to re-pop parts if the shrinkage is lest than plain old fibre glass resins or fillers?

In the past I had a model motorcycle with plastic wheels, an Airfix Honda 450 to be exact. The tyres only had one side of each tyre so I made silicone moulds the used ressin to cast these tyre halves. I did not build immediately and when I did attempt assembly the cast items had shrunk by about 0.5mm on diameter

I plan on re-popping a Cadillac hood from a Franklin Mint 1959 for my flat top project as the Revell Monogram hood does not look right and the AMT Ecto, the fluting is too deep.(Though I have not seen any topics reviewing this part).

Cheers all, John.

[Ace-Garageguy]

Thanks for these answers.

So would micro balloons be the best way to re-pop parts if the shrinkage is lest than plain old fibre glass resins or fillers?

In the past I had a model motorcycle with plastic wheels, an Airfix Honda 450 to be exact. The tyres only had one side of each tyre so I made silicone moulds the used ressin to cast these tyre halves. I did not build immediately and when I did attempt assembly the cast items had shrunk by about 0.5mm on diameter

I plan on re-popping a Cadillac hood from a Franklin Mint 1959 for my flat top project as the Revell Monogram hood does not look right and the AMT Ecto, the fluting is too deep.(Though I have not seen any topics reviewing this part).

Cheers all, John.

OK, it's not the micro that limits the shrinkage. It's the epoxy.

Decent epoxy (not the useless...in my opinion...5 minute stuff) has far far less shrinkage than polyester (the usual 'fiberglass' resin that stinks to high heaven) or some urethanes.

If you use a decent quality casting resin...and mix it carefully and correctly... and you read and understand the product data before using it, you should be able to make all the parts you need with minimal shrinkage without going to all the trouble of using micro and epoxy. Guys have been doing it for many years.

Edited June 4, 2015 by Ace-Garageguy

[badcaditude]

I read articles about using Micro Balloons as a Filler. They NEVER said "How To". Most were Contest winners and such. I had to give this stuff a go. I (Foolishly) bought a Jar(?). There were no real instructions on it. Mixing a small quantity with water didn't help. I emailed the Magazine that Showcased said Models and asked how to use Micro Balloons. I should have known better. The only reply from said Magazine was; Micro Balloons are a filler for wood. It didn't matter how many articles in their Publication I referred to. There was nothing online and trying to reach the Manufacturer, lead to even more frustration.                                               

I still have the very same 10 Fl. Oz Jar I bought 10 + years ago and I never used it or tried to again. I keep it as a $4.99, reminder.

  I've been staying off this Site, because it's been ridiculous trying to sign in. It usually takes an hour or more. Today was the FIRST time it didn't.

 

"Never argue with an idiot. They will only bring you down to their level and beat you with experience". -George Carlin

[peteski]

I read articles about using Micro Balloons as a Filler. They NEVER said "How To". Most were Contest winners and such. I had to give this stuff a go. I (Foolishly) bought a Jar(?). There were no real instructions on it. Mixing a small quantity with water didn't help. I emailed the Magazine that Showcased said Models and asked how to use Micro Balloons. I should have known better. The only reply from said Magazine was; Micro Balloons are a filler for wood. It didn't matter how many articles in their Publication I referred to. There was nothing online and trying to reach the Manufacturer, lead to even more frustration.                                               

Mixing them with water? Why?  Did you look at this post earlier in this thread?  It sure shows "how to".

[Art Anderson]

I read articles about using Micro Balloons as a Filler. They NEVER said "How To". Most were Contest winners and such. I had to give this stuff a go. I (Foolishly) bought a Jar(?). There were no real instructions on it. Mixing a small quantity with water didn't help. I emailed the Magazine that Showcased said Models and asked how to use Micro Balloons. I should have known better. The only reply from said Magazine was; Micro Balloons are a filler for wood. It didn't matter how many articles in their Publication I referred to. There was nothing online and trying to reach the Manufacturer, lead to even more frustration.                                               

I still have the very same 10 Fl. Oz Jar I bought 10 + years ago and I never used it or tried to again. I keep it as a $4.99, reminder.

  I've been staying off this Site, because it's been ridiculous trying to sign in. It usually takes an hour or more. Today was the FIRST time it didn't.

 

"Never argue with an idiot. They will only bring you down to their level and beat you with experience". -George Carlin

Microballoons are NOT water-soluble whatsoever.  There are two types of them:   If they are "white", they are micro-sized GLASS balloons, if a yellowish color, the same thing but made from Phenolic resin.  They came into hobby use in the very late 1970's when R/C aircraft builders discovered their extremely light weight, and their ability to add bulk (and sandability) to common ordinary epoxy glue.

Mix a sufficient amount of microballoons with epoxy (and with all due respect to Bill Engwer), 5-minute epoxy works quite well in this application) to a paste-like consistency, the resulting "putty" can be spread easily with any tool used as a spatula--used to do that very thing back years ago.  As I wrote above, it's also quite possible to lay up complete body shells with this material, mixed in epoxy as I mentioned, AND the added bulk of the microballoons to even the cheapest of 5-minute epoxy pretty much negates any shrinkage of that epoxy, at least when taken down to the sizes and scales that most modelers work in.

Art

[Dodge Driver]

Besides color, is there a reason to choose one micro type over the other?

[Ace-Garageguy]

Besides color, is there a reason to choose one micro type over the other?

Performance is very similar. I use the glass usually for plastic models when I have it in stock, simply because it's white and covers more readily with primer.

http://www.ez.org/canardpages/pages/chasingmars/Misc/Phenolic vs Glass K20 micro.pdf

[Ace-Garageguy]

Microballoons are NOT water-soluble whatsoever.  There are two types of them:   If they are "white", they are micro-sized GLASS balloons, if a yellowish color, the same thing but made from Phenolic resin.  They came into hobby use in the very late 1970's when R/C aircraft builders discovered their extremely light weight, and their ability to add bulk (and sandability) to common ordinary epoxy glue.

Mix a sufficient amount of microballoons with epoxy (and with all due respect to Bill Engwer), 5-minute epoxy works quite well in this application) to a paste-like consistency, the resulting "putty" can be spread easily with any tool used as a spatula--used to do that very thing back years ago.  As I wrote above, it's also quite possible to lay up complete body shells with this material, mixed in epoxy as I mentioned, AND the added bulk of the microballoons to even the cheapest of 5-minute epoxy pretty much negates any shrinkage of that epoxy, at least when taken down to the sizes and scales that most modelers work in.

Art

I agree with most everything Art has to say here...except...in my own experience, I've had adhesion issues with 5-minute I haven't had with the longer-cure stuff I generally use. What this has translated to for me has been a failure to featheredge as nicely, and an occasional tendency to pull up at the edge when subsequently hit with hot-solvent primers.

This would be in keeping with the general rule-of-thumb regarding epoxies...the longer they take to set and cure fully, the harder, tougher and more chemical resistant they are, and the better they adhere to a substrate.

PS. This is the phenolic product, reddish-brown. 

There is another lightweight inert filler / thickening agent you all may be interested in called "fumed silica". http://www.christinedemerchant.com/filler-silica.html

Edited March 7, 2017 by Ace-Garageguy

[badcaditude]

Thanks to A. Anderson, Ace-Garageguy, and modelcarmag.com for the help. I don't understand why no one from another Publication would answer my question. I gave up trying to use the Jar of Boom-Boom I have. It's another lesson learned the hard way. Thanks again.

Here's what I bought soooooo many years ago from a local Hobby Store; Northeast Hobby Products, Stock # NHP 201, 10 FL. OZ. Original White Micro-Fill, Ready to Use, Super light, Model Filler. This JUNK never did work. It didn't Stick to anything. Not even to Wood. 

 When I started building Model Cars, there was no Filler. I used Household Spackle. It came in a Box and I had to add water. It was a pain to get the mix right, but I figured it out. Then the Testors filler hit the Market. It worked alright. Next was Squadron Green Putty. It was better, but Green, It's Cure time was measured in days. That is, depending on how deep the the Damage was. If you didn't wait, it shrunk too much. I even tried the Automotive Red Body Filler Glazing Putty. It worked like the Squadron, and it Kept longer. The Squadron White is fine. It works like the Green. I was hopeful about the Micro-Fill, but after 11+ years of no REAL answers from anyone in the Hobby or the Company, I keep this useless Jar of hardened Garbage as a reminder. Don't Hold Your Breath When Asking For Help. No matter how well the product works on Plastic Models or how many other (So-Called Professionals in the Hobby) praise it. The ONLY answers I ever got were "This Product is for Wood ONLY". It didn't work on Wood either. It was like talking to my ex-wife.

I'll stick with the White Squadron Putty, Dupli-Color Primers and Paint. I'll still use automotivetouchup.com for projects that need a Factory Color. My Conspiracy Theory Chevy Caprice, the pain in the ascot PIRANHA Super Spy Car, 1966 Chevy C-10 my Pop's used for TV Repair, and too many others to list.  

[Ace-Garageguy]

24 minutes ago, badcaditude said:

Thanks to A. Anderson, Ace-Garageguy, and modelcarmag.com for the help. I don't understand why no one from another Publication would answer my question...

Most likely 'cause there's nobody over there who knows. Microballoon is used frequently in flying RC model planes, but not much in other hobby models.

My extensive experience with the stuff comes from real aircraft applications, and years of experimenting on static models.

[SfanGoch]

I've mixed the phenolic microballoons with Magic-Sculpt two part epoxy to reshape body contours. The combination is thinner than applying only the Magic-Sculpt and, once hardened, It's easier to sand/file into shape and can be polished to a glass-smooth finish. 

[badcaditude]

Thank for your help.

For some years, "Their" people knew and couldn't stop talking about Micro Balloons when one of their Contributors built a Model using it as a BETTER Filler. But when asked, I'd get the "Party Line". (It's for Wood) Makes one wonder WHY. I thought being a Member/Subscriber, "They" would share information. People share Ideas, Tips, and Products openly to them, but it takes a Decade for "Them" to share. A couple of months ago, "They" FINALLY announced, They Will Be Doing a "HOW TO" on Micro Balloons. Personally, I'm Insulted. Quite frankly, they can write a book on it. I'll never buy a Tube, Jar or, Box of it. I think it's far too late.

I've done some experimenting with Softening Polystyrene and using it to fill Pinholes in Models. The AMT 1964 Mercury Marauder's Right Front Fender was my Test Mule. As it turns out,  it was fine for the deepest part, but Squadron Putty and Dupli-Color was needed to finished the rest. What a pain it was to soften it with Testors Liquid Cement.

Here's one for everyone to try. Polystyrene Rod (about) 1/16". I used it as a Welding Rod by putting a short piece in my Variable Speed Drermel, finding the (Closest to) right speed, and Welding two pieces at 90 Degrees together. It's fun to watch pretty strong too. Give it a go. If my Dremel spun more slowly, it might've looked better. I thought about using a Pedal or a Dimmer Switch to slow it down, but having been electrocuted once, I just don't like messing around with Electricity.

Edited January 2, 2018 by badcaditude

[SfanGoch]

Nothing worse than a clique of insiders who guard their methods as if they discovered how to make gold from seawater. If you don't use the right "high sign" or whisper the correct password, we ain't lettin' youse into the mystical inner circle, see? In other words, chase yourself, dead game sport. 

 

[Art Anderson]

19 hours ago, badcaditude said:

Thank for your help.

For some years, "Their" people knew and couldn't stop talking about Micro Balloons when one of their Contributors built a Model using it as a BETTER Filler. But when asked, I'd get the "Party Line". (It's for Wood) Makes one wonder WHY. I thought being a Member/Subscriber, "They" would share information. People share Ideas, Tips, and Products openly to them, but it takes a Decade for "Them" to share. A couple of months ago, "They" FINALLY announced, They Will Be Doing a "HOW TO" on Micro Balloons. Personally, I'm Insulted. Quite frankly, they can write a book on it. I'll never buy a Tube, Jar or, Box of it. I think it's far too late.

I've done some experimenting with Softening Polystyrene and using it to fill Pinholes in Models. The AMT 1964 Mercury Marauder's Right Front Fender was my Test Mule. As it turns out,  it was fine for the deepest part, but Squadron Putty and Dupli-Color was needed to finished the rest. What a pain it was to soften it with Testors Liquid Cement.

Here's one for everyone to try. Polystyrene Rod (about) 1/16". I used it as a Welding Rod by putting a short piece in my Variable Speed Drermel, finding the (Closest to) right speed, and Welding two pieces at 90 Degrees together. It's fun to watch pretty strong too. Give it a go. If my Dremel spun more slowly, it might've looked better. I thought about using a Pedal or a Dimmer Switch to slow it down, but having been electrocuted once, I just don't like messing around with Electricity.

I was using K&B Microballoons back in the late 70's for laying up 1/25 scale Indy Car bodywork.  Used the stuff over that then-new blue insulation styrofoam,  sealed with 5-min epoxy.  Once I got the shape down, and reinforced the cockpit sides with 1/2 ounce fiberglass cloth, I simply layered the mix on, until I got a thickness and the basic shapes.  Once that was done, I opened up the radiator air intake, any openings for axles/suspension, the belly pan engine vent and the cockpit--simply took the body outdoors, and poured acetone into the cockpit, kept doing that, until all the melted styrofoam was gone (only a little bit of cleanup to get any the stray epoxy off the insides of the body.  Next, I finalized the bodywork by cutting the various panels apart as needed.  Did several of them back in the day.

Art

[Ace-Garageguy]

20 hours ago, badcaditude said:

Thank for your help.

For some years, "Their" people knew and couldn't stop talking about Micro Balloons when one of their Contributors built a Model using it as a BETTER Filler. But when asked, I'd get the "Party Line". (It's for Wood) Makes one wonder WHY. I thought being a Member/Subscriber, "They" would share information. People share Ideas, Tips, and Products openly to them, but it takes a Decade for "Them" to share. A couple of months ago, "They" FINALLY announced, They Will Be Doing a "HOW TO" on Micro Balloons. Personally, I'm Insulted. Quite frankly, they can write a book on it. I'll never buy a Tube, Jar or, Box of it. I think it's far too late...

Frankly, I'm kinda the magic microballoon go-to guy, and I showed most of my processes (that I developed, including specific product numbers, mix ratios, etc.) freely years ago, on multiple forums. To date, I've still never seen anyone do things with the stuff like I do, but there's never any shortage of "experts" willing to take the credit for something they lifted somewhere else.

And saying "it's for wood" sounds suspiciously like a misunderstood reference to the fact that I said in one of my long, involved build threads, that after MUCH experimentation, I'd settled on the West System epoxy (which was indeed developed initially for wood) as the optimum binder for the microballoons, being the best compromise between good adhesion, featherability, and ease of handling generally.

Not to worry. Unless "they" pretty much copy everything I've ever written on the subject verbatim, it will all be wrong information anyway.

Edited January 3, 2018 by Ace-Garageguy

[Miatatom]

OK everyone, now that you've convinced me to try this stuff, where can you get it? I can just see me walking into Lowes and asking where they keep the micro balloons.

[Ace-Garageguy]

3 minutes ago, Miatatom said:

OK everyone, now that you've convinced me to try this stuff, where can you get it? I can just see me walking into Lowes and asking where they keep the micro balloons.

http://aircraftproducts.wicksaircraft.com/item/aircraft-fillers/micro-balloons/b23-500--g?

http://www.aircraftspruce.com/catalog/cmpages/bubbles.php

[Miatatom]

Thanks, Bill!

[Miatatom]

Just ordered a pound. Any suggestions on handling this stuff? I can use my spray booth for handling and working with it. How do you store it? Looks like it will come in a plastic bag. I'd think something more substantial would be a good idea. Does it pick up a static charge?

[Art Anderson]

4 minutes ago, Miatatom said:

Just ordered a pound. Any suggestions on handling this stuff? I can use my spray booth for handling and working with it. How do you store it? Looks like it will come in a plastic bag. I'd think something more substantial would be a good idea. Does it pick up a static charge?

Tom, back in the day, the first microballoons were phenolic resin, but microscopic glass "bubbles" pretty much became the norm by the mid-80's.  Those aren't prone to static electric at all, in my experience, they have just enough weight that they don't even blow around much.

Art