In previous posts I have not been too happy with some of the System Three specialty products like GelMagic and EZ-Fillet.  I still say they do not live up to some of the marketing hype, but once you get to know them they do have some good points.

The standard way to make fillet paste is to mix regular epoxy using a pump and then add one or more fillers to it as thickeners.  A number of squirts from the resin pump followed by the same number of squirts from the calibrated hardner pump, mix for a minute, add some wood flour and maybe some microfibers or cabosil and you're ready to go.  You can control the consistancy of the paste to what ever is needed.  Also, the type of hardner gives more or less working time.

EZ-Fillet comes in two buckets that are too thick to pump.  You have to scoop out a thick goo and mix in another container.  Because it starts out thick the mixing can be more difficult and they even recommend mixing and then pouring into another container and mixing some more.  But be careful -- too much mixing and the "crystals" will break down.  When the goo is a uniform dark brown (instead of red with green streaks) it is ready.  I found this mixing to be the worst part of this system.  But after doing a few batches I got used to it and it wasn't too bad.  I just stopped cleaning the measuring devices between multiple batches and only cleaned them after the whole job was done.

Once the EZ-Fillet is mixed it has a pot life of 20 minutes.  When it starts to kick you can feel the heat suddenly build and you better be done because that's it.  Fortunately, once it is mixed it has just the right consistancy to pour into a caulking tube and start immediately to apply a nice bead for the fillet.  I was able to lay down a 20 foot fillet in just a few minutes leaving plenty of time to smooth it out and cleanup excess.  This part of it was much better than the standard method and resulted in some nice, clean fillets.  On balance I can recommend the EZ-Fillet product if you can accept the dark brown color.  They might have some pigments available to lighten the color, but I didn't worry about that because all the fillets are getting covered with black carbon fabric anyway.

GelMagic, in standard bottles, is even a bit harder to use.  First, the pot life is cut in half.  You have 10 minutes at best so you better be quick.  Again the heat comes on fast and once that happens anything left in the cup gets too hard to use.  It is also hard to get the blue resin out of the bottle.  It does not really pour.  You have to hold the bottle upside down and squeeze really hard to push a thick tube of resin out into some measuring device.  The hardner is a bit easier to pour.  Again, mix in one container, pour into another container, mix some more until the colors all blend to a whitish glue looking color (don't mix too much).  Then apply and clamp quickly -- remember only 10 minutes.

Since my first purchase of GelMagic I found that System Three offers GelMagic in the u-TAH Cartridge (TM) which is used from a caulking gun and is automatically mixed by some special, throw away mixing tips.  I would never by GelMagic in a bottle again.  I will only buy GelMagic in the u-TAH Cartridge.  However, even with the u-TAH system, you have to finish within 10 minutes so this product cannot be used on some bonding projects that take more time to position properly.  For example, fitting the shear clamp to the side panels cannot be done (at least by me) within 10 miunutes.  I did use GelMagic to glue in the stem and transom.

The bottom line is that EZ-Fillet and GelMagic (u-TAH Cartridge) are good products for the intended applications.  EZ-Fillet seems a better way, on balance, than the old style way.