Sarnafil Repairs??

Sometimes repairs on old Sarnafil PVC membranes are routine, but other times they seem nearly impossible to weld.

Most of the time I have good results cleaning with acetone or weathered membrane cleaner (formulated for TPO and EPDM.)

Years ago one of the guys also used MEK first, then acetone to activate the old surface.

Last night I just had bad luck getting new detail flashing to weld to ten year old roof. Welding at a drain sump, of course, with a wet surface...

What has worked dependably for y'all? Thanks!

I feel your pain. Just another reason I much prefer Fibertite, which we've welded at 30 years without much effort, a swipe or two with acetone and it's good to go. But when one must, aged membrane cleaner seems to work as well or better than anything. Whenever it's possible, we weld to the underside of old Sarna.