John Hilley
Well-known member
A Google search shows lots of self leveling silicone caulks
cleaning old sealant between fiberglass roof skin and awning rail
- Thread starter gbdave
- Start date
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Gary RV_Wizard
Site Team
I saw that too. I wonder if the "silicone-based" caulks are as hard to remove as 100% silicone? I often see caulks that are latex + silicone or "siliconized latex", e.g. for kitchen and bath applications.
This caulk guide/comparison on the Lowes website is helpful in contrasting silicon with latex caulks but doesn't address urethane or butyl at all.
http://www.lowes.com/cd_Caulk+Buying+Guide_779276357_
This caulk guide/comparison on the Lowes website is helpful in contrasting silicon with latex caulks but doesn't address urethane or butyl at all.
http://www.lowes.com/cd_Caulk+Buying+Guide_779276357_
Clay L
Well-known member
This is a cross section of the roof edge that may be of interest. It shows the sealant and drain holes.
Xsection
Customer service told me they use a thin flexible blade to remove the sealant. I asked if a utility knife (the kind with replaceable blades) with the blade extended would work and he said it would.
Xsection
Customer service told me they use a thin flexible blade to remove the sealant. I asked if a utility knife (the kind with replaceable blades) with the blade extended would work and he said it would.
John Canfield
Site Team
Well, shazam - that's a new one on meJohn Hilley said:
. I always learn something around here.Clay - thanks for the cross-section pix of the sidewall extrusion. Winnie had a model of of that in the visitor's center a few years back and probably other dealers for a show/tell.
Well I received the caulk's I ordered from Lichtsinn today and sure enough the stuff on the roof is self leveling silicone - NuFlex 311.
The roof sidewall joint part number sealant is Stone Mason gutter and siding sealant in clear.
The dealer installed a fantastic fan in an area that had a vent so they had to put an all new vent in and It looks like they used Dicor on that...so I need to keep all these things straight - 3 sealant on one roof.
The roof sidewall joint part number sealant is Stone Mason gutter and siding sealant in clear.
The dealer installed a fantastic fan in an area that had a vent so they had to put an all new vent in and It looks like they used Dicor on that...so I need to keep all these things straight - 3 sealant on one roof.
John Canfield
Site Team
Great tip David! We happen to be in a city with a Harbor Freight (always a must visit for me) so I'll look for one of those.
WILDEBILL308
Well-known member
Depending on your skill and ability. We used a weir or stiff nylon tube or bottle brush about a 3/8 or 1/2 diameter cut off and chucked in a high speed drill motor but not a Dotco. this will clean the sealing off quickly. You have to know what you are doing so you don't get into the fiberglass. I have also used the same brush with steel bristles but you have to be careful or you could go through the fiberglass.
Bill
Bill
navy flier
Well-known member
- Joined
- Aug 8, 2009
- Posts
- 66
Having done this job twice in my estimation there is no "easy" way. You just have to plan on spending the time and energy to do it correctly. The major problem with virtually every tool I have tried is getting something long enough to get to the problem and still have enough stiffness to do the job. The major problem is the curvature of the roof. If you use something like a cordless drill you have to use a long shaft to get the drill above the roof curve. Personally, I would not use a wire brush tip because of the possibility of damaging the fiberglass. I don't even remember what I used but having done it twice I do not want to have to do it again. I do know that when I was done there were a great many of my small tools around the job site.
I have no clue as to what the original sealant is but I get my replacement sealant (NuFlex 331 for exterior siding and trim) from my RV repair shop and they get it by the case directly from Winnebago. In large letters on the side of the tube is the word SILICONE. The original sealant had areas that had cracked down the middle and those are the areas that I cleaned and resealed. After a year the reseal looks much better than the original. The first time I tried this I used Stone Mason Gutter & Siding sealant. That also cracked and is why I had to do the job a second time.
The NuFlex 311 sealant gbdave mentioned that he received is a self leveling joint sealant that is silicone and has a large label stating that fact. My RV shop also gets that in case lots from Winnebago and only uses it on the roof for sealing vents, etc.
I have no clue as to what the original sealant is but I get my replacement sealant (NuFlex 331 for exterior siding and trim) from my RV repair shop and they get it by the case directly from Winnebago. In large letters on the side of the tube is the word SILICONE. The original sealant had areas that had cracked down the middle and those are the areas that I cleaned and resealed. After a year the reseal looks much better than the original. The first time I tried this I used Stone Mason Gutter & Siding sealant. That also cracked and is why I had to do the job a second time.
The NuFlex 311 sealant gbdave mentioned that he received is a self leveling joint sealant that is silicone and has a large label stating that fact. My RV shop also gets that in case lots from Winnebago and only uses it on the roof for sealing vents, etc.
The products Lichstinn sent me with the Winnie parts #'s on them were NuFlex 311 self leveling silicone for the roof and Stone Masons clear for the roof rail raingutter seal and all sidewall applications. The Stone Masons is a urethane if I am not mistaken. It is interesting to learn about these differences and especially how silicone is universally viewed as not a good thing, yet Winnebago uses a fair amount of it. The self leveling NuFlex on the roof is a little disappointing to me as you cannot repair a cracked area without completely removing the old sealant, unlike Dicor which is what I am used to and made inspecting and repairs a very painless process. Essentially the entire run of NuFlex must be removed whenever a repair is made in order to ensure a proper seal according to the fellow I spoke with at Lichstinn.
Dave
Dave
Ernie n Tara
Well-known member
FYI Silicone is about the slickest stuff known to man. Back in my rubber molding days, we produced parts molded from both urethane (may be the stickiest stuff known to man) and conventional polymers. The mold releases that work best for some urethanes are usually silicone based.
One of the first things I was told when I started designing conventional rubber parts was that we did not allow silicone based mold releases in the plant. In fact, it was an automatic termination if you hrought some into the plant.
Allegedly, someone had actually used some in one of our plants (before my time) and they had to close the plant because of the contamination causing debond problems. I take that with a grain of salt, but silicone is really slick stuff.
Ernie
One of the first things I was told when I started designing conventional rubber parts was that we did not allow silicone based mold releases in the plant. In fact, it was an automatic termination if you hrought some into the plant.
Allegedly, someone had actually used some in one of our plants (before my time) and they had to close the plant because of the contamination causing debond problems. I take that with a grain of salt, but silicone is really slick stuff.
Ernie
Clay L
Well-known member
When I had the factory repair my roof to side wall joint they only replaced the bad sections plus a foot of so on each end of the failed parts.
Clay L said:
Clay, that is acceptable in that joint. That is where they are spec'ing the Stone Masons and I did exactly as you describe. The self leveling stuff on the actual flat portion of the roof is what I am referring to in regards to having to remove it all. For example, on my rear cap and roof seam there is a small 2-3" crack in the sealant that according to Lichtsinn will require removing all the sealant and starting anew. I figured I could make a nice cut clean the area well and patch it, but was told that it wouldn't adhere to itself on the edges and I would create two cuts now instead of one crack. If you go right over the old stuff apparently it will just come off...Would love to remove and then replace with a Dicor or like self leveling sealant if I am going through that much work. Anyone ever do this?
John Canfield
Site Team
I was on my roof yesterday and noticed where the rear cap meets the sidewall-roof radius, the sealant has pulled off yet again :. I've sealed this at least three times and Winnebago has sealed it two or three times, sealant isn't working well here probably due to stresses. I think I'll use some fiberglass cloth and WEST epoxy on it for a permanent repair.
. I've sealed this at least three times and Winnebago has sealed it two or three times, sealant isn't working well here probably due to stresses. I think I'll use some fiberglass cloth and WEST epoxy on it for a permanent repair.
Gary RV_Wizard
Site Team
I would be leery of that approach, John. If the rear cap moves enough to pull the sealant loose, it's probably going to break the fiberglass cloth bond too. Or stress crack the cap itself if the bond is stronger than the cap material. The cap is moving in relation to the roof, with all the strength/stress of a 32,000 lb+ motorhome hurtling down the road at 60 mph. You probably aren't going to stop it with a mere patch across the top edge. At least not for long.
Unless Winnie can improve the cap mounts so it doesn't flex as much, what you really need is a sealer that is more flexible and can withstand the constant "working" of the seam. Eternabond tape might do it, but there are probably caulks that are softer and stretchier that would work too. Maybe caulk + Eternabond. Butyl caulk might work - I think it has better stretch & expansion characteristics than most types. 3M makes a class of automotive caulks called "body seam seal" that are designed for this sort of thing, but they come in several varieties and I'm not sure which might be best for this. Here's one of them:
http://3mcollision.com/3m-flexiclear-body-seam-sealer-08405.html
And some more: http://3mcollision.com/catalogsearch/result/?q=body+seam+seal
http://www.autozone.com/autozone/accessories/3M-12-oz-grey-Dynatron-auto-seam-sealer-caulk/_/N-25na?itemIdentifier=167027_0_0_
Unless Winnie can improve the cap mounts so it doesn't flex as much, what you really need is a sealer that is more flexible and can withstand the constant "working" of the seam. Eternabond tape might do it, but there are probably caulks that are softer and stretchier that would work too. Maybe caulk + Eternabond. Butyl caulk might work - I think it has better stretch & expansion characteristics than most types. 3M makes a class of automotive caulks called "body seam seal" that are designed for this sort of thing, but they come in several varieties and I'm not sure which might be best for this. Here's one of them:
http://3mcollision.com/3m-flexiclear-body-seam-sealer-08405.html
And some more: http://3mcollision.com/catalogsearch/result/?q=body+seam+seal
http://www.autozone.com/autozone/accessories/3M-12-oz-grey-Dynatron-auto-seam-sealer-caulk/_/N-25na?itemIdentifier=167027_0_0_
John Canfield
Site Team
Thanks for the head's up Gary. That thought had crossed my mind but the entire area involved is only six or eight inches long. I'll think about this for a couple of months before I make a move.Gary RV Roamer said:
Gary RV_Wizard
Site Team
John...I edited to add some products to my suggestion above. Take another look.
John Canfield
Site Team
Good, there's a couple of products that might work depending on how large of a bead they are designed for - thanks Gary.
