Plastic Tank Problem Info: The fix is in. See last post.

[ducatiz]

Update: 4/14/2013

I've had a tank that I coated with Caswell's original coating (not the red type) since about November 2010.

That was the first tank I coated.  It was basically new, had only one tank of gas that I rode home with and immediately drained.

That bike has had about 6000 miles on it, and has sat stored with a full tank of gas ever since being coated.

I drained the tank and removed the fuel assembly and used a fibre optic to examine the coating inside.  I am looking for delamination of the coating, or any other oddness.

After looking for nearly two hours, I can't find anything that looks out of place.  The coating was prepared according to Caswell's instructions, excluding the screws.  I used a wire brush to "scuff" the interior.

I have since modified the coating method, by using a rinse of xylene and then reducing the mixed coating with xylene to make it easier to apply.

This seems to result in a FAR smoother application and it's much quicker, you just have to turn the tank more since the reduced mix is far more liquid.  I would still do it in two coats, so use half of the mix and let it get tacky, then pour in the second half.

Xylene is 100% compatible with PA6 nylon and after rinsing with solvent (water based) to remove gasoline residue, letting it dry completely (and shrink) I rinse with a very small amount of xylene.

Also, when you rinse the tank, you'll see "pimples" inside.  These are artifacts of the roto-moulding process.  Air bubbles trapped in the surface.  I used an Xacto knife and very carefully "lanced" these so that the coating would go inside and not sit on top of the thin surface of the bubble.  You have to make sure to remove enough of the bubble so the coating enters the bubble's "void".  Rinse with the xylene AFTER doing this.  This also gives the coating additional physical structure to adhere to and it fortifies the tank a bit as the airspace is filled with coating.

My tank that I coated in 2010 has no measurable expansion.  No issues.

Note: I have nothing to do with Caswell's except as a customer. I've corresponded with Lance Caswell to get information about the product, but nothing more.  

If you have any questions about this, feel free to email me.