"Thimble" attachment?

Finally got it done with toggle-bolts. Found stainless steel bolts that fit the toggles then a dab of silicone seal and tighten `er down.

The rivnuts didn't get a good purchase on the thin 'plastic' material so I went to the toggles.

Thanks again for all the suggestions!

Padlin wrote:
I used nutserts, also called rivet nuts by other manufacturers Rivet Nut Set. Much like a rivet but you're setting a nut into a bigger hole, crimp it in place, then use a stainless steel button head screw to attach the cup washer to the trailer. I think I used #10's. You need to be careful as the sidewalls are pretty darn thin and the Filon is fairly fragile, take your time drilling and tighten the screws by hand. I had to drill out the washers for the bigger screw, maybe you can get away with a #8. I've done roughly 8 or them over the years.

I like the rivnut solution as I have used them for bodywork fasteners on the race bikes. Don't know WHY I didn't think of them.

Thanks all for the suggestions!

I used nutserts, also called rivet nuts by other manufacturers Rivet Nut Set. Much like a rivet but you're setting a nut into a bigger hole, crimp it in place, then use a stainless steel button head screw to attach the cup washer to the trailer. I think I used #10's. You need to be careful as the sidewalls are pretty darn thin and the Filon is fairly fragile, take your time drilling and tighten the screws by hand. I had to drill out the washers for the bigger screw, maybe you can get away with a #8. I've done roughly 8 or them over the years.

I used a 1" hole saw and went through the bed from the back side to replace a few cup washers.I replaced the insulation and covered the holes with plastic plugs from Lowes.

rivet washers might help or...

The cup washers (that's what the 'thimbles' are called, so I found out) on the sides of my Starcraft were held in place with stainless pan head screws. The washers along the top are riveted and as soon as I get time to drill them out I plan on replacing with screws for them as well.

The screws seem to hold very well and like you I put caulking in the hole before tightening so that it would seal around the cup washer.

Jon

Get washers made for rivets.

If you can get to them from the inside try using washers This will increase the 'grip' area. Large diameter with the hole just big enough to accept the rivet before you expand it....Lowes Home Depot.