i glued my first panels together tonight and have one question for you guys. i feel like i had to add alot of cabosil to get it to a mustard thickness....... is that the  case or is something wrong?

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RE: cab-o-sil

Yes, you need to add a lot to the epoxy to get a glue-like consistency. C-sil is mostly air. To get the same consistency as compared to wood flour you're looking at maybe five times the volume of additive.

RE: cab-o-sil


It takes an astonishing amount of the Cab-O-Sil to get to even a slurry/paste/mustard thickness.  I think the mix is more than 1 to 1 by volume, depending on how densely the Cab-O-Sil was packed (which is why we can't prescribe quanitities exactly).

By the way, some of you may have noticed that we're switching over from Cab-O-Sil (which is generic silica powder) to Cel-O-Fill, which is cellulose-based, like very fine wood flour.  It's a little easier to mix and completely benign to have floating around in a small shop.  Silica or Cel-O-Fill are for clamped, wood-to-wood joints where maximum shear strength is desired.  Wood flour is for making thick putty to fill gaps and create fillets.

(It's always "mustard" consistency in CLC manuals even though the stuff looks like mayonnaise.  I cannot stand mayonnaise, however, so it'll always be "mustard."  French's Yellow.)

More on goo.

RE: cab-o-sil

Thanks for your resposes, it seemed like a silly question but just wanted to be sure. Thanks again!

RE: cab-o-sil

While the shear strength of wood flour glue might not be the best around, it's plenty good enough. It's stronger than the outer ply of even BS 1088 okoume so the wood will fail before the joint. I did some experiments a few years back involving wood bought from CLC, epoxy/woodflour glue and a mallet and other tools and the wood always broke first.

CLC may want to reconsider including fillers other than woodflour to simplify inventories and kits. Builders may want to consider using only woodflour to simplify the mixing process, as well as sanding after the stuff's cured.



RE: cab-o-sil

 What color is this new "Cel-O-Fill" product? The woodflour fillets are much darker than the rest of the hull. I tried adding Cab-O-Sil to the wood flour but it doesn't effect the color of the fillets much. Would this new product more closely match the okoume color?


RE: cab-o-sil

Kevin, if you want lighter fillets, mix some bleached cooking flour in with your wood flour.  It's the same thing from a different source.  It will lighten the fillets up dramatically, as will using wood flour from a piece of maple, holly, hickory or other white wood.

RE: cab-o-sil

I'd also recommend adding a good helping of cab-o-sil (colloidal silica) to your fillet recipe and reduce the amount of wood flour (I use none)...I find the wood flour makes a lumpy, hard to spread mixture.  I use a main combination of West System colloidal silica, microfibres and just a touch of Microlite fairing filler (microballoons) to get the colour that I want so that it blends with the okoume.

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