New Winnebagos, roof edge questions/observations

Who ever it was that said its not a big deal, we'll send them the bills for the repair.

Tomcat F15
"walk in the other persons shoes before you make a judgement based on your feelings.

[Stan Birch]

I'm somewhat surprised that no one on this forum is using polyurethane sealant for their Winnie lap-joint!

The primary problem with the stuff Winnie uses, is that it has absolutely zero elastomeric properties. And with the significantly expansion co-efficients between fiberglass -vs- the aluminum drip rail, it doesn't take all that long for the stuff Winnie uses, for the seam-caulking to be compromised. The whole effort demonstrates a significant engineering deficit on Winnie's part, in that particular area. :-(

My initial attempts to keep abreast of caulking-failure were so ineffectively addressed with Dicor Lap Sealant 501; that I suspect that is what Winnie is using. While it might work for rubber membrane roofs, it's not all that great for a fibreglass-to-aluminum interface.

Dunno anything about Eternabond, other than that it is ULTRA-EXPENSIVE! Not something that might attract my attention, when the whole matter can be effectively addressed for a mere five bucks!

After continuous failures offered by the status quo, we eventually clued into an effort long-ago adopted by the marine industry. Polyurethane sealants tend to offer the best long-term solution to Winnie's short-term kludge. :-(

Within the permanent-solution scenario, marine focused products like 3M 5200, 3M 4200 or Sikaflex 221/229 merit primary consideration.

[ISLAPP]

Stan,
Don't know if the stuff you are talking about would work or not. But my thought is that you would have to remove all the old caulking before applying that stuff. Then you still need to monitor over the years.
Eternalbond cost about $45.00 for a 4"wide by 50' long roll. You only need to use 2" wide strips on the sides so there is more than enough to do both sides and probably the front or end cap. I would rather pay the 45.00 and apply that than to mess around cleaning out all that old caulking.
JMHO
Mike

What I don't understand is why you need to use 2' of eternabond in a 1/4" gap? The polyurethane sealeant will do this application just fine, and it will adhere very well with great elastometric qualities. As Stan said and as I'm quite aware, it's used extensively in the Marine Industry. If that sealant can hold to that environment, it certainly will hold up in this application. I've used it and it works just fine. Just don't buy the cheapest polyurehtane you can find, for this application only the best will do. And if you need to remove it, it can be done without damaging the items it's sealing, and no special tools.

I keep a tube of clear and bright white in my supply box at all times.

Tomcat F15
Scouts Moto--"BE PREPARED"

[dirko]

Hi Ho: The sealant specified by WI is actually bright white polyurethane. This does seem to work ok, but is apparently not permanent. Eternabond is touted as a permanent fix. Since we have had a number of people who have lost their roofs in a wind I don't think this is merely an academic subject. However, lots of things on a motorhome require periodic maintenance so this can be looked at as just one of those things. Could one split the 4-inch wide eternabond tape in three and apply just 1 1/3 inches of eternabond? Probably, but it would require more care in making sure it is bonded and wouldn't really save anything in the long run. At least that's my current take on things.

[Stan Birch]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by ISLAPP:
Don't know if the stuff you are talking about would work or not. But my thought is that you would have to remove all the old caulking before applying that stuff. <HR></BLOCKQUOTE>
Absolutely! The old caulking *must* be removed to provide a clean surface for the polyurethane to adhere to. By far, the most common cause of sealant/paint failure, is inadequate surface prep.

The entire procedure isn't nearly as challenging as you might imagine though. The old Winnie stuff is readibly soluable in paint thinner, and cleans off easily. For getting into the lap-joint itself, I used a solvent soaked cloth, wrapped around a paint stir-stick.

In applying the polyurethane, I first taped off the area appropriately with masking tape; applied the polyurethane with abandon; and then finished off the area by swiping it with one of those rubber-tipped caulking squeegies that leaves a perfect 1/4 round finish. After ripping off the masking tape, and residual material is easily removed with paint thinner, leaving a professional looking seal, even for the most inept.

The great thing about marine grade polyurethane sealants, is that they combine the the two essential characteristics essential for an effective long-term solution:

1. They possess tremendous adhesive characteristics on an adequately prepared surface;

2. Their elastomeric characteristics exceed that of any other sealant.

I agree that modest differences in cost is hardly an issue, if you are using something that ensures and easy permanent fix. It only took a a half cartridge of polyurethane to do the entire perimeter of our 32" roof; which translates to less than $5.00. Since polyurethane cleans up so readily with paint thinner, prior to curing; I find it very easy to work with.

[Stan Birch]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Dirk Ostermiller:
Hi Ho: The sealant specified by WI is actually bright white polyurethane. This does seem to work ok, but is apparently not permanent. <HR></BLOCKQUOTE>
This specification is certainly not something contained in the servicing literature accompanying my '99 rig; not am I aware that Winnie has changed from their Dicor 501-type sealant in any of their more recent rigs.

If you are talking about a phone call to Winnie, then you might expect to receive a plethora of different answers.

Merely specifying "polyurethane" is a rather vague and misleading answer. Polyurethane characteristics vary significantly from one to another. You might reasonably anticipate that normal household polyurethane caulking available at Home Depot, is substantially inferior to high end marine grade stuff like 3M 5200/4200 or Sikaflex 221/229. Their is a world of difference between the two.

[dirko]

Hi Ho: I totally agree with you, Stan. It took me a little over a tube of polyurethane (probably because I'm a little messy and ended up with some on a paper towel). However, I had to do almost the entire seal on a 35U and was able to get much more in the crack than WI did. I prefer acetone as a solvent (instead of paint thinner) because it doesn't leave an oily residue.

[CaptBill]

I have posted this many times over the last 2 years, but here goes again: Winnebago's specified sealant for this roof to wall joint is a Manis-Bond bright white urethane (HV), part number 072889-10-000 and is 7.40/tube. I would imaging that other elastomeric adhesives will work equally well. You should never use silicone or other regular household calk, as they are not a very good adhesive.

I have sent the Winnebago document specifying the sealant number, along with a drawing of the roof/sidewall joint, and their procedure for replacing it, to quite a few people here on this forum: Link
I would have posted it here again, but unfortunately, I have changed computers, and no longer have that e-mail-attached document.

Maybe one of the recipients might still have it, and could post it if anyone was interested.

[EZ]

I agree with Stan and Dirk about the marine caulk. I did the 3M 5200 quick cure and it has held up exceptionally well.

My procedure differs a little from Stan's. I use a popcicle stick tapered on the end down to a 1/16th inch edge. Slipped it into the caulk and it took about 10 minutes to remove one side of my 30B. Most of that time was spent repositioning the ladder. I prefer acetone as a cleaner because it leaves no residue.The popcicle stick is soft so that it does not mar or scratch the fiberglass. Also, if you press the popcicle stick in the channel and slide it along ahead of your caulk gun you are assured of having sufficient depth of caulk in the seam.
Once the stick is moved ahead the seam will close and any excess is removed as Stan indicated leaving a nice professional look.

[RKL2]

Stan...will the Marine 5200/4200 caulk accept paint?....My coach was customed painted and the pint scheme rolls over the roof....The company that painted it does exclusively custom coach paint work and used a clear silicone applied per Winnebago instructions. Also will paint thinner or acetone remove the applied paint..
My seams are bonded when pressed at this time....Thanks....RKL

[Fred B.]

Betcha a doorknob to a doughnut I can apply eternabond quicker than you can apply the poly stuff.
I talked to a Winnie rep at the cleveland rv bust er show & he told me the roof was changed in 2000 & had a gasket in it. I guess they let anybody work these shows. It sure would be nice if they had someone who knew what he was talking about.
In the meantime I won't let Winnie sell me full body paint & have to put eternabond on it. wouldn't that be a mess.

[N8XV]

Just a couple simple questions about the Winnie roof discussion. It's looks like the best two sealants are Polyurethane and Eternabond. In cases where both have been properly applied how many have seen Polyurethane fail and be replaced??? How many have seen Eternabond fail and be replaced??

[Stan Birch]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by RKL:
Stan...will the Marine 5200/4200 caulk accept paint?....My coach was customed painted and the paint scheme rolls over the roof....The company that painted it does exclusively custom coach paint work and used a clear silicone applied per Winnebago instructions. <HR></BLOCKQUOTE>
Dunno if 3M polyurethane sealants will accept paint. Nothing on the 5200 cartridge indicating that it is paintable.

Even if it is paintable, it's the kind of temptation I would be inclined to avoid. The propensity for most types of caulking to fail in the roof/sidewall lap joint, suggests that the joint is subject to a substantial amount of movement and flexing. If that's the case, then any paint applied to the caulking is going to randomly flake off; which might end up looking worse than using no paint at all! At best, there are additives that can be added to quality automotive paints to provide them with a *bit* more flexibility, to address issues related to flexible automotive components such as "rubber" bumpers, et al.

While still enjoying at least one of the few meager benefits emanating from abstract poverty,; i.e. with a mere default white fiberglass roof and white drip rail, none of this has ever been an issue. :-) On my rig, even the most badly munged caulking job doesn't look all that bad! :-)

But hey! Even if we were fortunate enough to have a full-paint rig (just kidding), I think I'd tend to direct my focus in the direction of doing a *really* neat job of caulking. With the use of masking tape and an appropriate rubber squeegee, the whole effort isn't really all that challenging! Try to think of the endeavour as mere "pinstriping!" Regardless of your ultimate intentions, it won't in any way look conspicuously out of place.

[lizbroughton]

Have used Eternabond. Very difficult to work with. You can only peal off about 1/4" backing at a time. Used GE sealant. Now MH is in the shop getting the roof done. Thanks for all your info.

2001 Chalet (Winnie)

[doc]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>You can only peal off about 1/4" backing at a time. <HR></BLOCKQUOTE>

Sometimes it is a bit difficult to start the backing peel off, but if you can only get a quarter of an inch at a time, then you gotta be doing something wrong.

[RonP]

Interesting that this topic came back up today as I have just applied Eternabond to my MH roof this weekend. I did the passenger side yesterday afternoon-temp in the 60's. Tape was somewhat hard to handle as it sticks to anything it touches,but no problem getting the backing off-took about 1 1/2 hour. I did the driver side this morning with temp in low 50's. That made all the difference-I was able to lay the full length into the gutter and then went back and pressed the rest on to the seam and roof. It only took about 1/2 hour to finish. Guess everything has a learning curve-kind of like when I put the tow plate on my Tracker last weekend-but that is for another topic.

[Dick N.]

Question for RonR. When you put it in the gutter the full length did you take off the back or just enough to put in the gutter before finishing. Also, did you use the full width of the tape. Some are cutting into smaller width. Are you satified how it looks? I just checked mine and it feel andlooks ok so maybe I'll do mine before problems start up.

[RonP]

Dick N,I took the backing completely off of the 2in wide x 37' length as I pushed it into the gutter. The tape curled away from the roof until I went back to press it over the seam on to the curved roof section. The results look good and not that noticable unless you were looking for it. All of the roof seams were still good based on my push test-you can't tell just by looking-and this was done as a preventive measure. Hope this helps.

[ottersea]

Question! If polyurathane is a good sealant and eternabond is a good tape, would using both be overkill or a good plan. First sealing it with the poly and then taping over that?