If its hard to remove leave it in place and seal over it.
How to remove old sealant from rv roof.
On the other hand a caked and hard to remove old sealant means that you can just leave it be.
Cleaning the old sealant first is essential.
Working on an aluminium roof of my old lazy daze mh i found that the roof sealant was easy to cut away by using a harbor freight multi purpose tool that had a chisel shaped blade.
One such brand is epdm roof cleaner.
The roof and sealant are clean.
Then you should be able to seal right over the old one without any problem.
This cleaner even if left to dry.
If however the old sealant has become brittle and is flaking or peeling off then it will be necessary to remove all of it and start over.
In those instances i would also remove the roof vent itself and put fresh butyl tape under the flange and re secure it to the roof.
Clean the area with an rv roof cleaner and follow up with a good rinse with a wet sponge then once dry clean the area with a rag soaked with denatured alcohol.
If the sealant and the roof are clean you should be able to apply a new one easily.
One of the things about removing old sealant is the type of sealant cleaner you use.
Clean the old sealant if need be.
Remove old sealant from rv roof.
Not all new dicor lap sealant products work with every roof cleaner or sealant removal.
In this video we begin tackling the monumental project of resealing the exterior of the rv.
The same process should be repeated for all components secured to the roof.