This is what I used to repair tears in the Darco membrane
Flexmend Belly Tape | Mobile Home Repair
This page shows me using it. Scroll way down to the bottom.
You may be able to find Flex Mend in other outlets then the one I posted. If you have a near by mobile home supply/repair place they also may carry it as they use similar if not the same underbelly material.
The FlexMend is a permanent patch. The surface needs to be clean before putting it on and then rub well. A little hair dryer heat helps too. Just do not add too much heat as it will melt.
For a quick temporary repair I have used Gorilla tape but it does not hold well long term. Over time the edges come up.
Hope this helps
Current Sunlines: 2004 T310SR, 2004 T1950, 2004 T2475, 2007 T2499, 2004 T317SR
Prior Sunlines: 2004 T2499 - Fern Blue
2005 Ford F350 Lariat, 6.8L V10 W/ 4.10 rear axle, CC, Short Bed, SRW. Reese HP trunnion bar hitch W/ HP DC
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