The first few windows we resealed were the ones we removed to rebuild the rear walls. This is where we made our mistakes and figured out what works. Our two most important lessons learned was to use extra butyl take on the sides with an aluminum sided trailer to fill all the gaps and to give the butyl tape time to squeeze out before trimming. If you seal over the butyl tape too soon it will bulge the caulk out.
Check out our video to see how we reseal our RV windows (I must say I look unusually handsome)
https://youtu.be/belS_95xLcAWe also have additional details on our blog:
http://www.rvcircus.com/reseal-rv-windows-right-way/1-To get started, remove the window trim from the inside of the RV (itโs a good idea to support the window from the outside when doing this).
2-After the window is free youโll need to cut any caulk and pry the window out from outside.
3-Once the window is out of the hole youโll need to spend some time cleaning off all the old sealant. Make sure the surfaces are clean where the window seals against the trailer and be sure to remove all traces of silicone if it was used in the past.
4-Now that the window is clean apply the butyl tape all the way around the window frame. I add an extra layer of butyl on the sides where the aluminum siding is uneven.
5-Now that the butyl tape has been applied you can reinstall the window. Again, support the window from the outside so you donโt push it out when installing the window trim. When tightening the screws on the window trim tighten a little at a time and rotate around the window to pull it in evenly.
6-What I look for is that the butyl tape squeezes out and fills all the gaps around the window. I give it a day or 2 for the rubber to stop squeezing out around the windows before trimming it. I then apply a RV specific sealant to the edges to seal it nicely.
