Removing factory silicone sealant

[clotus]

Hey all!

Winnebago used NuFlex 311 Silicone sealant on all of the roofing joints and vents. The stuff seems to be holding up well on my 2017 Minnie Winnie. My gray tank roof vent just broke and has to be replaced. Of course this is near the skylight of my shower so the sealant for both are connected into one large layer of sealant.

I know the main negative of silicone is that once you use silicone, nothing will stick to it in the event you have a crack. While researching the vent cover I needed, I came across a few videos stating to not use Dicor on Winnebago's roofs because they use silicone and there will always be a very thin layer left on the roof causing the Dicor to not stick. The videos claim to only use NuFlex for this reason.

Question:

1) If the above was the case, wouldn't the NuFlex also not stick, because by nature, fresh silicone will not stick to cured silicon?

2)If that is true, I would have to ensure the roof was properly cleaned for either silicone or Dicor to stick, which means I could switch to Dicor without issue, right?

3) Will Mineral spirits followed up with alcohol along with vigorous rubbing clean all the residual silicone off the roof and allow new sealant to stick?

Thank you in advance for your thoughts and recommendations?

[jjrbus]

Agree with pauldub, I hate silicone. It must be mechanically removed with sandpaper or wire brush or it is still there.

[pauldub]

You need to use something abrasive to clean as much silicone off as possible and then flush it and do it again. It's pretty much impossible to completely remove the silicone contamination. I'm a silicone hater; however, the flowable silicone Winnie uses is very good stuff. When I replaced the skylight with a fantastic fan on my Winnie about a dozen years ago, I abrasively cleaned the roof surface and sealed the fan with the Winnie silicone.

[clotus]

Sounds like I can switch over to Dicor. Thanks for the replies, always nice to confirm what I was already thinking.

[bobndot]

On horizontal surfaces use Dicor self leveling.
On vertical surfaces , I switched from Proflex to 3m 4000 uv. It is very uv resistant and a lot easier to apply than the Proflex.
Both last and work well but you need to use ‘brite white’ in Proflex otherwise it will tend to yellow. The 3m goes on easier, it makes a nice even line when you use a wet finger to smooth it.

Apply a fine mist of denatured alcohol to the caulking bead using the spray bottle. The alcohol keeps the caulk from sticking. Use your index finger to smooth the bead of caulking with your finger before the alcohol evaporates

[fourthclassC]

My advice - remove silicone and residue as suggested. I use Proflex and Dicore interchangeably. Never heard of the one you referred to.

[pbitschura]

#2,3 are correct. Additionally, carburator cleaner followed by acetone work equally well. The key is still elbow grease and repeat process twice or even three times. Good luck.