Hi Brad,

I've never used Bristol Finish but I have friends who swear by it for their sailboat. It's definitely an isocyante-based urethane.

I'm with Bill on this one. I looked up the application sheet and the MSDS as well. Directly from Section VIII Protection Information:

"Where overspray is present, a positive air supplied respirator (TC19C NIOSH/MSHA) is recommended. If unavailable, wear a vapor /
particulate respirator which respirator manufacturer recommends as effective for isocyanate vapor or mist. NO PERSONS SHOULD BE ALLOWED IN THE AREA UNLESS
EQUIPPED WITH THE SAME RESPIRATORY PROTECTION."

The 3M 6001 filter you named is not recommended for isocyantes. Bristol Finish WILL release isocyantes into the air when sprayed. When brushed they stay bound in solution.

What's curious is the application sheet only references brushing and rolling. Spraying is no where to be found...

I personally will not spray any isocyante-based urethane myself. I'll let the pros do it. They have the training and the equipment to do it safely. I'll stick to rolling and tipping it...

/ Dan