cleaning old sealant between fiberglass roof skin and awning rail

Hi, we have a new to us 2011 Itasca Cambria that has the original silicone cracking and separating between the roof skin and awning rail. I found an old thread on here where folks are talking about this issue, but cannot locate it now. Following is the link to the service bulletin on Winnies web site.

http://www.winnebagoind.com/resources/service/pdfs/2010-10%20Roof%20to%20Sidewall%20Joint%20Sealing.pdf.

I cannot figure out what I am supposed to use to clean the silicone out properly from both a tool and cleaner standpoint.

I have ordered the correct sealant from Lichstinn  and will get after it in the next few days. Where does water go that gets in here? I see no evidence of water in the coach, and there is a few feet where the original sealant is very cracked and degraded.

Thanks all,
Dave

Hi Dave, welcome!

Enter caulk in the search box at the far upper right of this page and have fun reading!  Removing old sealant is a challenge - you need to preserve the color coat (assuming you have full body paint) while just peeling the old sealant off.  I forgot what I used when I was removing old sealant but a dull wood chisel or piece of hardwood with a sharp edge would work.

My general purpose solvent of choice is now MEK unless you are in California where they have banned every useful solvent  :.

John, on the same subject.  My 2002 Horizon 36LD doesn't have any sealant between the roof edge and the gutter at the top of the wall.  What's up with that? I live in Louisiana where we can use any chemical (and we usually manufacture it too) known to man to clean the surfaces.  Is MEK a brand?  Beau

Why do you think it is silicone? I don't think Winnebago used silicone at the factory and probably nobody else added any yet. Other common seam caulks, e.g.urethane and butyl, can usually be removed with mineral spirits and cleaned up after with alcohol just to be sure.

MEK is a high potency solvent type (not a brand) that can soften paint and even plastics. It's in the same family with acetone and lacquer thinner, so I would not use it unless nothing else worked. If you do use it, wear gloves and wipe the surface with a rag dampened with the MEK, so that you don't slop too much around.

gbdave said:

Hi, we have a new to us 2011 Itasca Cambria that has the original silicone cracking and separating between the roof skin and awning rail. I found an old thread on here where folks are talking about this issue, but cannot locate it now. Following is the link to the service bulletin on Winnies web site.

http://www.winnebagoind.com/resources/service/pdfs/2010-10%20Roof%20to%20Sidewall%20Joint%20Sealing.pdf.

I cannot figure out what I am supposed to use to clean the silicone out properly from both a tool and cleaner standpoint.

I have ordered the correct sealant from Lichstinn  and will get after it in the next few days. Where does water go that gets in here? I see no evidence of water in the coach, and there is a few feet where the original sealant is very cracked and degraded.

Thanks all,
Dave

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That caulk is butyl based not silicone. Be careful not to use silicone where it isn't specified. It makes it real hard to caulk with anything else in the future, including silicone.

This is all very confusing 

The rep at Lichtsinn stated the sealant used on the roof is self leveling silicone. And NOT to use something like self leveling Dicor lap sealant as it wouldn't adhere to the silicone used. He stated the silicone if needing repair should be removed completely and re-doing it, vs cleaning and adding Dicor  if you find cracked sealant in the Dicor the way I am used to.

He also said ti use "acrisol" spray from an automotive store to remove silicone.

I am not sure what the sealant is between the roof skin and awning rails, but that is what is cracked and needs removal and resealing. The prior owner obviously neglected that job. Thankfully the coach was under a cover in the desert so it should not have been to exposed it the three years it's been around.

Every time I hear more I feel more confused.

I was hoping to use Dicor self leveling lap on the roof and Geocel to caulk the vertical surfaces. I think I will call Winnebago to hopefully get some clarification. I am hoping that being on top of things now will be early enough. The coach when picked up last week from the dealer was supposed to be sealed, cleaned etc. It wasn't until getting it home and going through it carefully that I am realizing that the delivery repair promises were mainly hot air....

Most dealers can't hear you after they get you to sine the paperwork.
For your information MEK = Methyl Ethyl Ketone a very strong solvent. I like Acetone for cleaning and surface prep. You can use a plastic scraper made out of Polycarbonate to clean the old sealant. I would think you wouldn't have to get all the sealant out of the joint just make it flush so you can run a Fillet seal over the old. I would use some blue masking tape to make it a neat job.
Bill

Here is the Winnebago Sealant Callout Sheet for the 2011 Cambria
http://www.winnebagoind.com/diagram/2011/174775a4.pdf

It uses Winnebago Part #072889-10-000

Here is the roof to sidewall caulking Service Tip
http://winnebagoind.com/resources/service/pdfs/2010-10%20Roof%20to%20Sidewall%20Joint%20Sealing.pdf

According to the Service Tip, silicone has been used and must be thoroughly removed. The recommended caulk is actually a urethane caulk. It is Manus 75AM

This Service tip gives additional caulking information
http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CCAQFjAA&url=http%3A%2F%2Fwww.winnebagoind.com%2Fresources%2Fservice%2Fpdfs%2F2000-04%2520Exterior%2520Sealants.pdf&ei=34kjVOTAM8jjsASxwYKoDw&usg=AFQjCNGSKv-4GKNjtpomij333H-u4TRytQ&sig2=KLRwk3ViWEv42zRQpRyrmQ

Plastic razor blades work great to help remove old sealant.  Once you get the old sealant loosened up it's fairly easy to use a pair of needle nosed pliers to grip and pull fairly long lengths of the old sealant out.  I found lacquer thinner good for cleaning the area once the bulk of the old is removed.  Just be careful not to drizzle lacquer thinner or any cleaner down the side.

beau2x said:

John, on the same subject.  My 2002 Horizon 36LD doesn't have any sealant between the roof edge and the gutter at the top of the wall. ..

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Push on the roof edge where it enters the aluminum extrusion - if you can push the roof skin away from the extrusion, then you need to add sealant.

The rep at Lichtsinn stated the sealant used on the roof is self leveling silicone.

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The guys at Lichtsinn are usually pretty good, but I've never heard of a "self-leveling silicone" or its use on RVs.  There probably is such a thing, but I would double check that advice with Winnie Customer Service.

The Winnie sealant callout chart shows sealant "C" [#072889-10-000] for the roof seam and "C" is listed as a urethane, not silicone. See the last URL that John Hilley cited to relate Winnie part numbers to sealant product names & types.

The tip on the roof re-seal says that IF silicone has been applied, it must first be removed. Not clear whether that silicone may have been factory-applied, or they were just covering the possibility that an owner may have already used some silicone on that seam as a repair. It is a fact that nothing sticks to silicone, which is why it has very limited use in RV construction.

Gary RV Roamer said:

The guys at Lichtsinn are usually pretty good, but I've never heard of a "self-leveling silicone" or its use on RVs.  ..

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Nor I, but I think some people use silicon as a general term for any kind of caulk or sealant.  In any case, you do not use a self-leveling sealant on the roof-sidewall joint.

Not to hijack the thread, but a question and something I have noticed over the last 15 plus years of servicing the roof to side wall joint.  Why is it when I do the press on the fiberglass roof edge to test the joint opening, it's nearly 100% of the time that the sealant has lost it's bond on the aluminum gutter and not the fiberglass??  Has anyone else took note of this?  Over the years I have tried some of the better commercial metal roof adhesive type that come in a tube and still it lets loose at the aluminum.  I have found the urethane caulk to be the longest lasting, yet at times have seen it fail in as little as 6 months.  I'm a big fan of lapping the joint with Eternabond, especially now that they offer 4 colors to choose from.  Anyway you go the better the prep job you do before applying sealant or Eternabond the longer it will last.  Please move if you feel it hijacks the thread.

howdymi said:

..  Please move if you feel it hijacks the thread.

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No, you're good right here - close enough  .

I've had the same experience with having to redo certain areas of the roof-sidewall joint and almost every time it's near the cap.  I suspect there is enough flex to where the bond breaks after a certain amount of stress and age of the sealant.  Options are to Etrnabond the joint (LK23 did his) or use 3M 5200 in the joint.  5200 is the most tenacious sealant I have ever encountered.

I called Winnebago this am and the rep I spoke to said whatever the call sheet was specifying was what to use, and that it would be the same as what was originally put on...and that the two (new and old) are compatible and can be used together.

The bulletin that says to remove silicone is vague at best, since it doesn't state if Winnie used silicone or not. I asked about Proflex Geocel and two of the techs looked it up and said no.

After going over the rails more closely today it appears that only a foot or so has degraded. The sealant is dry looking but when I push on the rest the skin moves inward but stays stuck to the sealant. I was surpirsed by how the roof skin is seemingly only held in place with the j-rail. I can now see why this is critical to keep that seal holding...it really does hold the roof down!

Proflex RV is a tripolymer and Winnie calls for urethane. Probably work fine anyway, but might as well use what the factory specs. Geocel makes a urethane called PUR 50, but you can probably find some other brand in an RV store, or even Lowes or Depot. Urethane caulks shouldn't be hard to find.

GE's GE29000 Infinity sealer is a urethane and many hardware stores carry GE sealers. DAP makes one too, called a urethane construction sealant. Also Loctite.

You might contact the manufacturer of whatever sealant you decide to use and ask if they have or recommend an adhesion promoter/primer. My background is in aerospace but many Mil Spec products are sold under different names. Many sealants to get the best performance on aluminum require an adhesion promoter/primer
Bill

Regarding the self-leveling silicone:
My 2004 Winnie has factory installed self-leveling silicone around all the vents, antennas, shower sky light and everything that is relatively flat on the fiberglass roof.  They also used it around the original satellite dish base which I just removed last month.  It's definitely silicone and it levels out to about 1/4 inch thick.  After 10 yrs it was still very much adhered to the fiberglass and alum base.  My new HD sat dish is sealed with NuFlex 311 Self-Leveling Silicone from Camping World and when cured looks just like a factory install.

Regarding the roof-to-sidewall seal:
Having 15 yrs of experience with 2 Winnebago's,  what I've noticed about the roof to sidewall joint, is that there is quite a bit of lateral movement/stress that breaks open what seems to be a good seal.  Once I decided to put on a rather thin fillet of urethane, thinking it would be a lot easier to remove and reseal in the future.  But what I found was front to back stretching of the sealant.  it was gripping well and has quite a bit of elasticity, but after time it was letting go in spots.  So then I realized you need sealant down in the groove to provide a good mechanical seal. 

When my coach was brand new, there was a crack in the radius of the roof.  The dealer repaired & repainted the fiberglass and resealed about 2 feet of the seal with regular silicone ...BIG Mistake!!!  It took many, many attempts to reseal that area with the proper sealant.  NOTHING will adhere to cured silicone and it is VERY hard to get the surface totally clean of silicone.  By the time you find something that will remove silicone, you're removing paint and fiberglass resin too.  Now almost 11 yrs later, that is the first spot where the seal breaks open.  I can't imagine the headaches  where somebody used silicone the full length on both sides.

Happy trails,
Bill

I have built 3 boats. I agree with John, 3M 5200 IS the best thing to use. As far as Uv deterioration of 5200, I have some on my roof vent now for 7 years, can't even pull it off. If you can get it just under the lip of the fiberglass in the rail Uv can't get to it anyway as it will be under the roof fiberglass. I have never found anything that sticks to aluminium better. My tug boat has it all around the outside helm & now 12 years latter it is still great & that boat sits in the water in my backyard slip with the Alabama sun beating down on it. If you want good adhesion & don't want to keep redoing it you can't beat 3m 5200. Art

Duner said:

Regarding the self-leveling silicone:
My 2004 Winnie has factory installed self-leveling silicone around all the vents, antennas, shower sky light and everything that is relatively flat on the fiberglass roof. ..

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Bill - maybe a terminology thing?  Dicor is self-leveling sealant but after looking at their specs, it doesn't mention what it is based on, silicon or otherwise. 

Art In Mobile said:

..If you want good adhesion & don't want to keep redoing it you can't beat 3m 5200. Art

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5200 is amazingly tenacious.