Classic Winnebagos & Vintage RVs

Topic Boards => Coach => Topic started by: AOBrodie on July 11, 2021, 06:59 PM

Title: Factory exterior silicone caulking?
Post by: AOBrodie on July 11, 2021, 06:59 PM
I am getting ready to paint the exterior of my 72 Brave. It has a small bead of silicone caulking around every molding seam. The window frames, the aluminum extruded corner moldings, etc. I doubt this is factory, but thought I would ask. I'm going to have to remove/trim it so I can paint.
Title: Re: Factory exterior silicone caulking?
Post by: Oz on July 12, 2021, 12:24 AM
Yes, it's tedious, but necessary.  Otherwise, if you start to get leaks, you'll have to scrape the new paint off too.

And the calking along the body trim and beltline is extremely important or you'll get wood rot everywhere.   A major job to have to replace it all.  And you likely won't even know it until you're driving down the highway and a lower, front wheel well panel comes flying off.

Oh yeah, it's happened.
Title: Re: Factory exterior silicone caulking?
Post by: AOBrodie on July 12, 2021, 11:31 AM
So it is factory. And maybe previous owner redid at least parts of it? Thanks
Title: Re: Factory exterior silicone caulking?
Post by: Oz on July 12, 2021, 02:34 PM
Some looks like it could be old enough to be factory, but some doesn't. Like on the "nose" center stripm
Title: Re: Factory exterior silicone caulking?
Post by: TerryH on July 12, 2021, 04:24 PM
Silicone caulking on the exterior of an RV is a bane to ownership and usage. It is extremely difficult to remove completely. Other sealants will NOT adhere to it, including more silicone. In the photos you posted:
The first is silicone, deteriorating, poorly applied and incorrectly tooled.
The second is silicone, as above but worse.
The third is not silicone, somewhat better applied and tooled but showing evidence of adhesion failure. Cannot tell what it is but I would suspect it was not high quality and has likely hardened to the point it will not expand and contract as a correct, quality caulking will. Application was somewhat better than the two above. Tooling not.
The last appears to be similar caulking with no tooling. Due to the shadow on the right quality of application cannot be determined.
That you are painting your rig will greatly aid in the required removal of all existing caulking. Cutting away the old, sanding and thorough cleaning - including compressed air – will help.
I would recommend using a QUALITY polyurethane to recaulk.
Necessary steps are:
1. removal of existing.
2. thorough cleaning.
3. correct application of new using a good caulking gun (not the open orange big box store $1.49 special).
4. Tool, tool, tool.
If you skip or are lax in any of the above you are wasting your time and money.
An advantage of polyurethane is that it water cures, so using water when tooling will actually aid the cure. A second is that it will adhere to existing polyurethane with simple preparation.
If you wish any info on caulk application, tooling procedure and or suggested caulking brands post back.
Hope this helps.

Title: Re: Factory exterior silicone caulking?
Post by: AOBrodie on July 12, 2021, 06:57 PM
Thanks guys. Yes, Terry I'm interested in any tips
Title: Re: Factory exterior silicone caulking?
Post by: TerryH on July 12, 2021, 07:42 PM
Below are some older posts from here you may wish to read through first. The info in them won't necessarily strictly apply to your situation, but everything is adaptable. FYI, available through the 'search' box here.
https://www.classicwinnebagos.com/forum/index.php?topic=14410.msg88494#msg88494
https://www.classicwinnebagos.com/forum/index.php?topic=14301.msg87522#msg87522
The work you are undertaking - painting the outside with (good on you) proper preparation is a large job.
Anything I can offer I will, based on my experience only. There will, of course be those who disagree.
Should you not be confident in your caulking ability I may be able to offer a couple of suggestions to give you some practice. It is not rocket science, but it is a definite skill, particularly in an aesthetic situation.
Title: Re: Factory exterior silicone caulking?
Post by: Oz on July 13, 2021, 02:23 PM
Excellent responses, Terry!