There are 2 brands that do work well.
The one I use is the Dicor non leveling caulk. It comes in a few colors, since the campers I work on are white, I use that. Pick your color accordingly.
This post can help the learning curve on how to apply it. It is not the only way, but it is a repeatable way and others can learn it. It does work well.
I have found RV Upgrades to have it at lower cost then many. They will charge freight if your order is less then $100, but it still may be cheaper than other places. I'm not affiliated with them in any way, just passing the tip along. https://www.rvupgradestore.com/searc...ag+lap+sealant
The other brand is made by Geocel. RV Proflex This kind. https://www.geocelusa.com/product/pr...xible-sealant/
The Proflex is different then the Dicor. Fiberglass sided campers use it a lot as it does come in clear. Then color is not an issue as campers do come in a lot of colors. I have also seen it on aluminum sided campers. It is very different to work with then the Dicor. Each has it's own characteristics.
If your camper has a rubber roof, you can use the Dicor, even the non leveling on the rubber roof. You cannot use the Proflex on a rubber roof. Not a show stopper, just mentioning it.
A few tips, your old putty tape is most likely black from dirt and mold. Clean it very well before caulking. You do not want to trap the mold under the caulk and the dirt does not allow a good bond. If you use soap or detergents to clean the putty tape and scrub, this can be more forgiving to be dry. If you use a petroleum based cleaner, like mineral spirits or alcohol etc. you should wait 2 or 3 days after the cleaning to let it 100% evaporate off. Mineral spirits will clean well but it must be followed by a high flash cleaner to get the oily residue off of it. If you do not let it evaporate off, you will trap the cleaner residue under the Dicor and it will melt the putty tape and Dicor and then go to goo on you.
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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