TESTIMONIAL

May 1,2004

Dear Mr. Murtha:

I have tested the Presets that you sent me and find that they are as good as you claimed they would be. I could detect no observable tearing of the face paper on the sheetrock which, combined with the backing paper provides most of the strength of the sheetrock. The tearing which occasionally occurs when using screws is in my opinion, one of the major causes of failure. Another factor to consider is the increased shear area that derives from the diameter of the Preset being larger than the diameter of the screw alone. Consider a ceiling application: The Drywall panel is supported by the holding capacity of the screws, which is limited by the shear strength of the sheetrock. The area in shear at each screw is the surface area of a cylinder that would be extruded by whichever holding device is selected(screw, nail, etc.). That area is described by the formula A= Dt where t represents the thickness of the panel and D is the diameter of the extruded cylinder. From this you can see that a device with a larger diameter provides a larger area to resist shearing forces. Based upon the sizes of the Presets and screws that you sent me, the 0.336" diameter Preset would result in a shear area that is almost 7% larger than that which the 0.3215" diameter screw head would provide. I think that your idea to modify a pneumatic nailer to utilize the Presets also merits serious consideration. I examined one model of such a tool, and believe it could be easily adapted. If so, installation of sheetrock using pneumatic nailers could become the industry standard once the cost vs. benefit is realized. The time to install a panel of Wallboard could be reduced by a factor of about four by my estimate.

I wish you luck with your endeavor.

Cordially,

Richard C. Macy

PHONE:

1.917.578.1555

email:jmurtha@pre-set.com