Roof Radius Caulking Cracks

[creativepart]

Originally Posted by Farco

Do not use the Manus bond. Manus chalks up and breaks down fast. Winnebago stopped using it.

I had a gap in a front corner radius where the front cap meets the body side and used Manus Bond on it 3+ years ago. There has been zero chalking and it’s holding up very well.

We don’t know why Winnebago stopped using it. It could be a cost or manufacturing issue not related to performance. We just don’t know.

I hated working with it. It’s very messy and difficult to clean up. But the results have been great, so right now it’s at the top of my list.

[tim myers]

Has anyone else used the Windex method of smoothing out the silicone caulk? I think this is what AZ Expert does

[Farco]

Yes
It’s the spray foaming glass cleaner you use.
Worked for me.
This job is messy but if you take your time it’s not AS messy.

[BobC]

Manus Bond has never been a problem for me here in the Sacramento area, plus my MH is stored outside all year. I wonder if humidity or other conditions when it is applied could be a factor. I've always done it when it's dry and warm.

Make sure you check the expiration date on any sealant before buying or using it.

If you have a MH on which Eternabond wouldn't be too distracting like mine, you can add a strip of it for added protection. That way the sealant is protected from the sun and elements. However it's a pain to remove.

[wyocamper]

Originally Posted by BobC

If you have a MH on which Eternabond wouldn't be too distracting like mine, you can add a strip of it for added protection. That way the sealant is protected from the sun and elements. However it's a pain to remove.

On mine there was no more than 1/8-3/16 gap between the filon and channel on one side, and less than that on the other. It would have been a mess to try and force caulk into a non-existent gap, so I decided to just go with the Eternabond the entire length, 2" Tan color. It doesn't blend in perfectly but well enough for me. I rolled it out with a 1.5" nylon roller wheel as I went. The occasional bubble or crease smoothed out after a few days of sunshine, and the bits of stray adhesive cleaned up easily with some rubbing alcohol.

[BobC]

I purchased 4" wide Eternabond and split it to 2" using a razor knife and straight edge. It was an easy process since the sticky side is protected by a peel off layer. It only takes a few minutes to split enough for your roof, leaving you some leftover 4" tape for other projects.

A 50' roll of 4" tape is $59.49 on Amazon vs $39.95 for a 50' roll of 2" tape which isn't enough for both sides for most MHs.

[cruizerEd]

Originally Posted by bigb

Anyone considered 3M 5200?

5200 is pretty thin. I'd be concerned it would run down in to the gutter and prevent water from draining. Maybe if you do it in cold weather that might work.

5200 is basically permanent. I don't know why that would be a problem but if later you discover there is some reason to pull it out maybe even replacing the roof you would be looking at a really big job getting it out.

5200 is flexible but maybe not flexible but a bead that long may not flex enough to keep from distorting the roof.

[Park Super]

Here is an update from Winnebago. As far as I can tell Winnebago has never used Manus Bond. They used a product made in Canada designed for roof gutters, Stone Mason Gutter and Siding sealant. This product seems not to be available in the US.

Litchsinn RV is maybe the best source for Winnebago parts. I e-mailed them and this is what they wrote to me concerning the joint adhesive.

"If it is the white sealant that is 0702889-10-000 @ 11.855/caulking tube
If it is the clear that was 094401-04-000 but is now part number 351157-01-000 @ 43.15/caulking tube.
Give me a call if you would like to place an order.
Have a great day!"


A search for Part number 0702889-10-000 returns Manus Bond.
A search for Part number 094401-04-000 returns Stone Mason Gutter and Siding sealant.
A search for part number 351157-01-000 returns nothing that I could find.

[Park Super]

https://www.youtube.com/watch?v=BJz7doxPQXg

[BobC]

Originally Posted by cruizerEd

5200 is pretty thin. I'd be concerned it would run down in to the gutter and prevent water from draining. Maybe if you do it in cold weather that might work.

5200 is basically permanent. I don't know why that would be a problem but if later you discover there is some reason to pull it out maybe even replacing the roof you would be looking at a really big job getting it out.

5200 is flexible but maybe not flexible but a bead that long may not flex enough to keep from distorting the roof.

As a former sailboater, I agree with cruizerEd. I'm not sure if anything on an RV is a candidate for 5200.

[bigb]

Originally Posted by BobC

I'm not sure if anything on an RV is a candidate for 5200.

I can attest that it works great for attaching metal brackets to fiberglass body parts, slightly more flexible than the factory epoxy and once dry, permanent. I used it to re-attach the brackets on my front clip after the factory epoxy failed.

[BobC]

Originally Posted by bigb

I can attest that it works great for attaching metal brackets to fiberglass body parts, slightly more flexible than the factory epoxy and once dry, permanent. I used it to re-attach the brackets on my front clip after the factory epoxy failed.

I stand corrected. I'll amend my comment to not being appropriate for anything on an RV roof. Maybe the ladder?

[tim myers]

I really liked the Lichtsinn video, lots of good information there even if they were a little vague on sealant types. Basically they refer to non full body paint and full body paint. My Journey is in between non and full. The base material of the walls is white, they masked off areas of the walls and painted the rest of the coach with auto type paint, including the radius roof edge. Then they applied additional vinyl graphics to the walls. So I do not have FBP. but since my radius is painted would need the clear silicone.

[Don G]

Please correct me if I am wrong, but the function of the caulk on our Roof Radius Caulk is mechanical and not for water proofing. The caulk keeps the radius tucked inside the extrusion which also acts like a gutter to run away any moisture. As long as it is keeping the roofs edge from coming out of the extrusion you are ok?

Thats what I thought when I was on my roof and washing out the gutter with my hose. It was a week after that when I noticed the wall in my bathroom was bubbling. I popped a bubble and there was water inside. I could not find any other source for the leak and did nothing with the gutter until the end of the summer with no further leaks.

[Free Ranger]

I'm in the same situation as most of you on this but cannot find either a local or a reputable online source for Manus Bond 75 AM Clear. Do any of you have a good online source?

For those of you who have successfully used it on the roof radius line, do you have to remove all of the OEM caulking/sealant first? My factory caulking (Navion 24V) is still in relatively good shape but it is starting to dry out a bit and I'd like to stay ahead of any problems before the summer.

Thanks!

[Americanrascal]

I've always purchased the Manus Bond 75 AM clear on Amazon. But I notice they don't list it at this time and it does seem to be either in limited or no availability status at this time. I wonder if its a seasonal production thing???

Hoping it comes back on line soon as I need to get some for some work on the rig. May have to revert to Proflex otherwise (yuck- that would be a bummer)

[cruizerEd]

Originally Posted by Don G

I popped a bubble and there was water inside. I could not find any other source for the leak and did nothing with the gutter until the end of the summer with no further leaks.

I'd look at your sky light or vent seal or anything in the area. This thread references a video that demonstrated that the radius caulk is not a seal. In fact there is accommodation for water to get through the calk and be drained away.

It is important to not block the gutter below the roof radius and defeat the design by letting the caulk go below the edge of the radius. This is why I would hesitate to use any think like 5200 that can drip into the channel and block it.

My skylight came from the factory with a built in leak. There we gaps around the corners of the skylight that I figured were not an issue since it came that way. It wasn't until I pulled to covers off of the screws holding the skylight liner up that I saw they were rusty. Three full days of work later the rot was dug out, new wood was epoxied in and the sky light was properly sealed.

[cruizerEd]

I used about 100 short lengths of heavy guage copper wires inserted vertically to create a space between the roof fiberglass and the rail. I caulked between the wires and then waited a week or more for the heavy bead of caulk to become stiff enough. Then I pulled the wires and caulked the remaining spaces although this was probably not necessary.

The caulk is about 1/8 thick from top to bottom so I believe it will hold much longer than if you let most of it be squashed out and have only a small triangle of caulk left over.

If I have to do it again I'm going to look for some sort of backing material that will be stiff enough to create a gap and absolutely keep the caulk from getting into the gutter. The wire was a PITA to deal with but it worked.

[BobC]

1. I see a lot of links for Manus Bond 75 AM clear on Google. Here's the first one that popped up, just below manus.net, the manufacturer and Amazon (out of stock). They appear to be a legitimate industrial supply company. It's not like you're risking $$$. I don't think it's a product that someone is likely to be scamming. You could contact Manus and ask them for a supplier. I've ordered supplies and parts from many online suppliers over the years, including eBay, and have never been scammed.

https://www.sunshinesupply.com/mn75a...&custcol3=5786

2. Alternative to copper wires (cruiserEd) - I don't know why they stopped but, on my 2002 Suncruiser, Winnebago used round screen spline in the bottom of the extrusion. It helps hold everything in place while applying the sealant. It comes in different sizes so you'll have to do some estimating. I don't remember what I used. If you buy it from a screen door company or someplace else that sells it in bulk, they'd probably give you some samples. I've seen older drawings of the roof edge construction that shows it in place but didn't see any after a quick search.

https://www.homedepot.com/b/Doors-Wi...-5yc1vZ1z18iav

[bigb]

I was going to fix that small spot today but now thinking maybe I don't need to open a whole fresh tube for that little separation, let me explain: The separation is on the fiberglass side, about 6". It is still adhered to the aluminum channel. My reasoning is that the Proflex is not there to seal anything, it is just there to keep the filon from coming un-tucked and since it is adhered well to the aluminum it will still do it's job, and I don't see it going anywhere. It's stored indoors and will never, ever see freezing temps. Thoughts?