Microballoons always a red/brown color?

 Hey all......  Just got some microballoons from a marine vendor. "Marpro" brand. They are a red/brown color. I need to make some putty for a board repair and wanted the lightest weight and easiest to sand; strength not really important. But I would like the putty to be white! Are "microballoons " always this red/brown color?

 I do have some cab-o-sil I could use, but was under the impression that microballoons would make the lightest weight putty?

 Thanks.......    Brian.

The red balloons are stronge phenolic resin, the white ones are light but weak and brittle, normally for fairing only…

oops, double.

I don’t know about the red stuff - not the “microballons” I’m familiar with.  The classic white stuff is a mineral expanded under heat and it puffs up into little hollow spheres.  Makes great putty - light, easy to sand - if you mix it up thick enough. The cab-o-sil makes for a stronger filler which is hard to sand.

 

	<h2>TAP Cab-O-Sil • Makes Non-Sag Gel</h2>

	
			
	Makes resin thixotropic, without increasing viscosity. 

Controls sag and allows work on overhead surfaces. Can create non-sag
putty. Increases the hardness of resin.

INSTRUCTIONS: Mix Resin and Hardener thoroughly. Gradually stir in Cabosil to desired thickness. Curing process begins when Hardener is added, watch working-time. Creamy Texture: 3 oz Cabosil per gallon of Resin-Hardener mix. Paste Texture: 3 oz Cabosil per quart of Resin-Hardener mix. Combine Cabosil with milled fibers for a non-sagging structural adhesive or with microballons to impart easier sanding.

 

	<h2>TAP Microspheres • Glass Spheres</h2>

	
			
	A light weight, white filler of hollow glass spheres 

that add particles of air to solid materials. Use with polyester or
epoxy resins. It can displace 4 to 6 times the weight of resin. Improves
fabrication and sanding characteristics of resin.

INSTRUCTIONS: Light weight, white filler adds “particles of air” to solid materials. Use with polyester or epoxy resins. Can displace 4 to 6 times the weight of resin. Improves fabrication, sanding, and
handling characteristics of resin. Reduces shrinkage. Experiment with ratio of filler to resin to find formula best suited for  application. Cure time can be affected by use of fillers.

i’ve gotten both…

best to pick some up that you can actually see or call someone and ask them before shipping.

Foamez

Fiberglasssupply

Tap plastics

You probably have phenolic microbaloons. You want “hollow glass microspheres.” 3M product.