Epoxy Glue With Filler: Buoyancy Characteristics

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Hello,

Are there any low density fillers that when mixed with epoxy glue or similar would produce a floating matrix when set? I only require to fair a shape and structural strength is not important.

Thanks,

BlowingOldBoots
 
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Most epoxy resins, as you're probably aware, are denser than water (but slightly less dense than polyester). I imagine that some fillers (such as microballoons) would lighten that slightly, but perhaps not as much as you'd need for your mysterious application. On the other hand surfboards float pretty well, but that's due to a lightweight core. Would that be a practical solution?
 
It's just to repair a dan buoy and fashion a shape that would sit better in my holder.
 
I always remember a demonstration from Adam Hart-Davies, where he build a structure out of jelly, and it was hopeless and kept flopping over and couldn't hold it's own weight. Then he did the same thing but mixed pasta in with the jelly, as an aggregate. Straight away, the jelly had structure and could hold its form...

Does that apply in this case? surely you just need to mix some sort of lighter than water substance into the epoxy that won't dissolve, and you'll have something strong and floaty... Maybe even balsa wood shavings or chunks?
 
The filler that I have found most easy to sand after curing is the brown type (sorry for ambiguity). Microballoons are white, so its not that. There is another white filler that is even harder / denser. It is not the wood fibre type filler either (more yellow than brown and it certainly is not the small tub of graphite - very difficult to sand afterwards.

It has the consistency of talcum powder, is a light to middle, brown colour and really is much easier to sand than all the other fillers _ very easy to sand in fact_ (and I've tried most of them. If the tub at the chandlers has a staple through the lid so you can't see the filler, ask them to open it.
Maybe the West site if there is one has a picture?


BlowingOldBoots said:
Hello,

Are there any low density fillers that when mixed with epoxy glue or similar would produce a floating matrix when set? I only require to fair a shape and structural strength is not important.

Thanks,

BlowingOldBoots
Click to expand...
 
Microballoons are meant for this, so must be the thing. I'm pretty confident I've created mixes that would float when set. The resulting material is not very strong and not very abrasion resistant. I can imagine it going a bit horrid with abrasion if rattling around in a metal holder.
 
gadget user said:
The filler that I have found most easy to sand after curing is the brown type (sorry for ambiguity). Microballoons are white, so its not that. There is another white filler that is even harder / denser. It is not the wood fibre type filler either (more yellow than brown and it certainly is not the small tub of graphite - very difficult to sand afterwards.
Click to expand...
The brown microballoons are phenolic resin spheres... http://www.mbfg.co.uk/epoxy-resins/microballoons-filler.html
The white ones are glass micro spheres.
 
Yes the foam floats do tend to fall apart even if only used for drills and the odd demonstration.

The use of epoxy may not not be the best solution as it's effected by UV light if left exposed. Coating it can be a problem as it needs priming as well.

You could use standard resins if you first coated the foam with an epoxy the used standard resins with filler to get the shape then finish with light rovings to provide a hard surface.

Good luck and fair winds. :0
 
Been out in the cold to look at the tube.

I thought it said 401, but the West site says:

410 microlight fairing filler

http://www.westsystem.com/ss/410-microlight/

http://www.westsystem.com/ss/filler-selection-guide/

One big tube has lasted me years and it is so easy to work with.

From the site:
410 Microlight™ is the ideal low-density filler for creating a light, easily-worked fairing compound especially suited for fairing large areas. Microlight mixes with greater ease than 407 Low-Density filler or microballoons and is approximately 30% easier to sand. It feathers to a fine edge and is also more economical for large fairing jobs. Not recommended under dark paint or other surfaces subject to high temperatures. Cures to a tan color.

Guess SP have a different product because the 410 has been left in the cardboard tube and never been affected by moisture (sp product says to keep it dry)

Approx £10
http://marinestore.co.uk/Merchant2/merchant.mvc?Screen=PROD&Product_Code=MD430118
 
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Syntactic foam

In essence what you are talking about is Syntactic foam, this is used extensively in the offshore oil industry, were a resin is mixed with some form of light weight gas filled spheres.

http://en.wikipedia.org/wiki/Syntactic_foam

If you Google Syntactic foam or syntactic buoyancy you'll find a whole heap of references and suppliers, it's often cast into complex shapes and is available in sheet form, with different depth ratings.

It's quite possible to make your own by mixing micro-spheres with epoxy or polyester resin, generally the more spheres you can mix in the lighter the finished materiel will be. It also helps if the sphere are largest which is compatible with the application, shape, mechanical strength and depth rating.

I hope this helps.
 
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