Silicon is fine, I have been using it for glazing work for 40 years including in vehicles. It is a good sealant and you can see when it needs replacing with good maintenance. Polyurethane is used more for adhesive, so right to stick windows in with. But if just sealing around, silicon is better.
Well can't argue with that! Because you have used it for years successfully.
I will agree to disagree. Silicone will not make it on the exterior of the rv.. The seals have previously been done in a polyutherane one and to do any repairs won't work as the silicon doesn't adhere. I did try.
I know they used polyutherane as the rv come with a sealant call out sheet and the forums in America all say not to use silicon but due to shipping chemical restrictions I couldn't get it shipped.
I have then researched and used a sealant who's name escapes me I will check tommorow to great effect to reapply over the factory caulking along the slide trims and it adhered great and looks as good after a year and hasn't picked up the dirt.
I guess there's more than 1 way to do a job and it's probly best to stick to the original method to ensure good adherence.
Do you know there's a lot of leaky baths out there where the silicon has lost adhesion a people don't notice.
Water kills rvs so a flexible polyeutherane adhesive sealant would be my choice.
I will update tommorow with what I used and leave it to the op to make his mind