Grinding sanding dust further to make wood flower?

[frosh]

I made a curry once that was very runny. My wife suggested that I add some fine corn flour. It worked a treat, and even tasted good. No science was needed for this solution.
Boatbuilding is a different kettle of fish. And the proper stuff is as cheap as chips; by the way does anyone enjoy chips with their fish?

[fiberglass jack]

only if you got some malt vinager, your right materals is cheap but some boat owners are cheaper really cheap

[Frosty]

Cheap or not so cheap, that is the question. I must be nice to be able to get iether. I think the emphasis is on the fact that it is possible to get away with a substitute and how good that substitute is. I for instance here on a small island west of Malaysia have a choice of 1 shop-- when they open!!, they have micro ballons (what ever they really are) and I think they were asking 26 dollars for a small bag about the size of a childs pillow or lap top.

So having ALL the time in the world I see nothing wrong with a bit of inginuitive thinking in the super market while the wife looks at hair dye.
Personally and I am by no means any kind of expert in this field but have had an unquestionable success with talc, It sands great!!

I cant get over this thing about absorbing moisture, if a material absorbs moisture in its container open or shut on the work bench,-- well ok but how can it asorb anything when it is totally emersed and surrounded by epoxy or resin? If its going absorb any thing then absorbing epoxy would be good no?
OR is it that talc will absob moisture to the point that it is unsuitable as a filler? in that case then we should say that talc has a short shelf life, but is in fact a good filler when fresh and dry??

Im fighting for Talc here simply because its all I can get( cheap) and its all I've been told I need ( localy) for my littel project' advise needed for foam job" Thread

[Joe6]

I've heard that talc works well, but I've never used it personally. But if it were all I could get, it's what I would use!

Joe

[gonzo]

Some materials, including fumed silica absorb water before being mixed. Containers must be kept well closed. Fumed silica, like lime has been fired in a kiln which takes all the water out; even the chemically bonded portion. It is always possible to lower quality and make something cheaper. However, if you use your own formula instead of what the resin manufacturer recomends, there is no warranty. That is, unless you provide one. Sanding dust is contaminated with all kinds of foreign materials. The worst is the surface wax. When resins cure, polyesters, vinylesters and epoxies, there is a layer of wax that migrates to the surface. That is why it needs to be sanded and dewaxed for proper adhesion of future laminates. You are adding all the wax residue to the mix with unknown results. In other words, you are incapable of providing any engineering calculations because the properties of the mix are unkown.

[SamSam]

I bought a big bag of Cabosil at a fiberglass supplies wholesaler a long time ago. The salesman said they sold a lot of it to McDonalds to put in their milkshakes to thicken them up. Maybe in an emergency, you can order a milk shake without the 'food' stuff. Sam
http://www.cabot-corp.com/cws/busine...1?OpenDocument

[ChrisF]

Well there you go. Obviously McDonalds could substitute and use flour in their food, but do they? No, they use the real thing, Cabosil, and if that isn't proof that it's better I don't know what is.

[Frosty]

What is Cabosil any way? It must be edable if Mc Donalds use it,-- well maybe not!!!!. If thats true then it must be cheaper . It seems like there is so much stuff to thicken stuff with.
After all said and done is it not just a method of increasing its viscosity for ease of handling for a particular application?

[frosh]

McDonalds, the most successful company in history, (slightly more successful than Coca Cola) uses Cabosil (thixotropic silica). They could be using the kids they employ for about $4 an hour to sand down chip board to create really cheap wood dust to thicken milk shakes, but they don't. This would save around $10,000,000 a year worldwide based on selling a billion milk shakes per annum, but they see it as false economy leading to a loss of market share.
Now I ask all you cheap skates, is your boat project more or less structurally sound than a McDonalds thick shake? And, would you like it to be?

[ChrisF]

Frosh, I understand it's actually a problem with the chip board supply that prevents McDonald's using it to thicken shakes. They're stretching the supply chain as it is, just to get enough to make burgers. Unfortunately the hole saw dust from the burger making process is too coarse for thickening shakes. Which brings us back to the original post, I guess.

[mobjack68]

Hey ernie, think thru your application, the harder the filler (lime, talc) the less flexible the fillet, matters not the cost. If you are using a material that leaves a less than desirable finish, cover the wet material with a strip of Saran Wrap, smooth it out w/ your finger wait for it to set, peel away the plastic, scuff sand and keep on keepin on. Test your plastic wrap for reactivity before covering a large area, stay away from waxed paper unless you specifically need the wax...
mobjack68

[Richard Hillsid]

I don’t feel up to typing right now but there is more to fillers than volume, you get elasticity, hardness, compression, sheer strength and numerous other qualities with them, microbaloons are ok in some application, but definitely not when looking for strength, wood dust, not in a production boat.

Here is a oldie system there are many other products on the market but most have used these at one time or another.




Filler Selection Guide
http://www.westsystem.com/webpages/p...ler_select.htm

-----------------------------------------------------
Adhesive Fillers vs. Fairing Fillers

http://www.westsystem.com/webpages/p...uide/index.htm

Fillers are used to thicken the basic resin/hardener mixture for specific applications. Each filler possesses a unique set of physical characteristics, but they can be generally categorized as either Adhesive (high-density) or Fairing (low-density).
Adhesive filler mixtures cure to a strong, hard-to-sand plastic useful in structural applications like bonding, filleting and hardware bonding.

Fairing filler mixtures cure to light, easily sandable material that is generally used for cosmetic or surface applications like shaping, filling or fairing.

ADHESIVE FILLERS

403 Microfibers
403 Microfibers, a fine fiber blend, is used as a thickening additive with resin/hardener to create a multi-purpose adhesive, especially for bonding wood. Epoxy thickened with microfibers has good gap-filling qualities while retaining excellent wetting/penetrating capability. Color: off-white.

404 High-Density Filler
404 High-Density filler is a thickening additive developed for maximum physical properties in hardware bonding where high-cyclic loads are anticipated. It can also be used for filleting and gap filling where maximum strength is necessary. Color: off-white.

405 Filleting Blend
This strong, wood-toned filler is good for use in glue joints and fillets on naturally finished wood. It mixes easily with epoxy and lets you create fillets that are smooth and require little sanding. Its color is a consistent brown, so 405 can be used to modify the shade of other WEST SYSTEM fillers.

406 Colloidal Silica
406 Colloidal Silica is a thickening additive used to control the viscosity of the epoxy and prevent epoxy runoff in vertical and overhead joints. 406 is a very strong filler that creates a smooth mixture, ideal for general bonding and filleting. It is also our most versatile filler. Often used in combination with other fillers, it can be used to improve the improve strength, abrasion resistance, and consistency of fairing compounds, resulting in a tougher, smoother surface. Color: off-white.

FAIRING FILLERS

407 Low-Density Filler
407 Low-Density filler is a blended microballoon-based filler used to make fairing putties that are easy to sand or carve. Reasonably strong on a strength-to-weight basis. Cures to a dark red/brown color.

410 MicrolightTM
410 MicrolightTM 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.

Filler Selection Guide
Filler Buying Guide

[chandler]

I save all the sandings from laminations, all the sandingings from fairing...get a pretty good combination of fine sawdust mixed with sanded epoxy powder.
Pretty much any composite construction is going to be coated with epoxy and glass so I think the water absortion thing is a mute point.
Just keep recycling your dust.