On May 8, 2010, I posted about my Smooth Prime disaster. Since then I found that heat will soften Smooth Prime and then it can be brushed off with two or three swipes from a wire brush. I used a propane torch applied for a half second, then brush while it's still hot. I suppose a heat gun might work also. I read the directions label on the can. It said to use PolyFiber 310 Prep to clean the fiber glass. The description of 310 Prep in the Aircraft Spruce catalog is basically the same as the Metal Prep #79. These are both alkaline detergents that will clean off oil and wax. The detergent holds the wax in solution until it can be rinsed off. This action is unlike acetone, MEK and other solvents that will let some of the wax re-deposit. I had some Metal Prep #79 on hand, so I used that. The cowl and forward deck were still a little damp when I put a coat of Smooth Prime on the now bare clean fiber glass. Adhesion was excellent. Now I can get on with the painting.
Sid Wood Tri-gear KR-2 N6242 Mechanicsville, MD, USA smw...@md.metrocast.net ----------------------------------------------- Finishing a RR factory made cowl after making some mods and bumps and fitting to the firewall, I sanded off the glaze on the outside gel-coat, wiped all surfaces, inside and outside,with acetone and applied Smooth Prime. The Smooth Prime adhered to the gel-coat and the new fiberglass as advertised. The inside rough fiberglass, 23 years old, had the Smooth Prime shrinking, cracking and flaking off in small and large pieces. Some areas adhered quite well; others could be plucked off; others fell off. What's going on? Any suggestions for Smooth Prime remover? MEK, acetone, alcohol, water, paint thinner, and paint stripper have no effect on cured Smooth Prime. Sid Wood
