1998 Winnebago Minnie 32WM Restoration

[BarryLS]

This thread is dedicated to my Minnie's restoration. Purchased on the last day of January 2022 with known water damage and still leaking, I intend to repair and restore "Gertrude" to her former glory, at least mechanically and interior wise. I may or may not decide to make Gertrude pretty on the outside. We shall see.

Gertrude has the Ford Super Duty chassis which is the name given to the E-450 in 1998. She has the V-10 engine which is something I wanted in a gas MH.

Gertrude has 58K miles presently and runs very nicely. Engine and transmission seem to be in excellent condition. Front brakes are shot and I will replace the rotors and calipers before putting her on the road. Rear rotors look pretty good.

She has new rubber. Went from the bank one mile to the tire place where I had already arranged for six new tires. What was on there were dangerous.

I started the process of the restoration today (technically yesterday as it is now 12:03 am here in North Carolina), tearing out some of the previous repair attempt in the cab over area. That is the worst of the water damage, and the shower and skylight above being next. It will be a complete rebuild of the cab over and will probably redesign what Winnebago did. That design is not a great effort IMO.

I started an album with some pictures:
https://www.winnieowners.com/forums/...albums440.html

My original first thread in the introductory section:
https://www.winnieowners.com/forums/...wm-363298.html

And a Picture of Gertrude a couple hours after purchase with her new rubber:
https://www.winnieowners.com/forums/...cture2670.html

[BobC]

Good start. In the future, although it's more work, you should think about posting your photos in the thread once they're in your album. It's a lot more reader friendly to not have to shift back and forth to your album.

[BarryLS]

Agreed Bob, I tried to post that picture with no success, so finally settled for the link until I figure it out...



Edit:
And it still doesn't work. I'm using the image button and the address shows up in the edit mode

[BarryLS]

OK, search is your friend and I found it.

As she sits just after the new tires were put on.

[DGRBRUV]

Thanks Bob, good to see your new thread and photos. Your RV looks like a nice project to take on. Cheers

[BobC]

Originally Posted by BarryLS

OK, search is your friend and I found it.

As she sits just after the new tires were put on.

Great.

I've also found that it's quicker, especially with multiple photos, if you open Winnieowners in two tabs, one with your post open and a second with your album open. That way, you can go to the album tab, copy the image's "BB Code" and paste it to the open post in the post tab. There's no need to click on the image icon.

[BarryLS]

Thanks Ian and Bob.

I found another way to post the photo that doesn't require using the gallery or an http address. I can place picture directly from my computer which is always the best way. As long as the forum is there the pictures will be there.

Here is the thread describing the procedure:
https://www.winnieowners.com/forums/...st-355670.html

[BarryLS]

Late this afternoon I started tearing into the area of the roof that is problematic, just above the entry door on the passenger side and above the slider on the driver side. The center area is reasonably good. The damage is about 2 foot or so back from what I would call the beginning of the cabover section. The cabover bottom or "sleeper board" rot was caused by a failure of the bottom trim caulking which then catches water and wicks into the whole bottom area. So, rot form the bottom up. On the passenger side it seems apparent the awning pulls on the sidewall and once there is a loss of the caulking seal, water enters and rot begins. I could see the sun through the seam once I pulled some of the inner laminated plywood away. This construction is a lot thinner than I expected. The foam looks to be an inch or less thick with the typical 1/8 luan on each side. I'm not sure what the failure is on the other side, but it doesn't really matter as it will all have to be ripped off and replaced.

I was mostly interested in how the roof transitions into the cabover roof in order to design my replacement. The walls below the roof have some delamination but not as bad as I would expect. I think I can just repair those pretty easily.

For the moment I plan to remake the cabover as a single plywood/fiberglass/epoxy structure that will have no seams and no trim to caulk and fail. I have to determine just how the transition to the roof is made, but I'm thinking a complete roof is eventually what I will end up with. I *think* I can start the roof replacement from the front and work my way back rather than all at once. I should even be able to tie the new roof to the old temporarily so that we can use the motor home.

The exterior height of the 31WM is listed as 10 ft 10 inches with AC. My plan at the moment would increase this height by 1.5 inches or so as I would go to a 2 inch thick foam and 5mm or 1/4 ply laminated on each side, plus the fiberglass covering on both sides. The roof would then get epoxied and glassed to the sidewall, so no seams, no caulk, and no trim to leak. I just have to consider the weight and determine if that is a problem. If so I may drop down on the ply and use the 1/8th originally supplied by Winnebago. With the glass properly laid up and the additional separation between the top and bottom from the thicker foam, it will still be much stronger than the original.

Might not be so clear what I have in mind But if you understand it and have comments to make please do so. I'm open to suggestion

[BobC]

These videos may be of some help and there may be more on AZ Expert's Youtube channel:

https://www.youtube.com/watch?v=7l0JMVbBetA&t=295s

Note that the description mentions that he was already doing a roof repair but I can't find the video if there is one. Pretty much all Winnebago fiberglass roofs have the same construction and AZ Expert has plenty of videos of replacing them.

On the other hand, I think you're going to write the book on this one.

[BarryLS]

Thanks for the link, Bob. I've run across that fellow in my searching and he clearly has experience and understanding on his side. One thing I notice is my roof and sidewall seems different from the later Winnebago's. That junction of the roof and sidewall is substantially different from what I see so far and what the parts manual indicates.

In that particular video - I have a problem in that area on the driver side. The filon is gone, probably blew off, and in its place is a fiberglass mat material. It also appears they may have used polyester resin rather than epoxy. I'll repair that at some point by pulling off the mat, adding the proper luan backing and putting on a new piece of filon.

The AZ expert pretty much follows the original plan as best I can tell. That is probably the most cost effective way to repair a roof or the cab over. I'm adding up the materials for the cab over and a new roof, doing it my way, and the material cost will probably be close to $2K. I'd hate to pay the labor bill to go with a reconstruction of this type.

OTOH, once I get it stripped back further I may see the beauty of the original method and just try to fix it. OTOH 2, AZ Expert in one of his video's about roofs pretty much just shakes his head when mentioning needing repair all the way to the inside. I tend to think a complete panel replacement may be easier in that case. I may find out different as I get further into it.

I have some experience with composite construction and I understand the engineering, so I may be better equipped than the average to contemplate a redesign. I just have to be careful as I know how big projects tend to not get completed...

[BarryLS]

One thing I need to find out is more about the material filon. So far I know it is some sort of glass reinforced plastic material. My planning may change if I discover I cannot get epoxy to stick to it properly as I would plan to tab the roof over onto to the filon on the sidewall.

Tomorrow or this weekend I'll need to make some leveling blocks. I measured my level this afternoon and she leans about 2d in the front and 3 in the rear. With the track width and a little geometry I should know the shim height I need under the tires. For example, with a 2 degree out of level and track width of 76 inches in the front, the shim height is 2.65 inches, so a piece of 2x6 and 5/4 x 6 should give me 2.5 inches and be close enough.

[BarryLS]

As I noted in another thread, I have the slideout working:

https://www.winnieowners.com/forums/...ml#post3913369

It really does make a big difference in the room in the living area.

Today I finally got the oil and filter changed. I had trouble getting underneath. Normally with my vehicles I have a ramp setup I drive up to gain working clearance, but I'm pretty sure it's not rated for the weight of the MH. I took the aluminium running boards off, they need some refurbishing anyway, and that gained me the few inches I needed. I changed the air filter but I forgot about the fuel filter, so I need to get one and replace it.

I'm still studying the cab over and roof for restoration. I think I'll try to do the cab over and about 4 feet back on the roof with my "new and improved design" and tie that in to the old roof and do the back part later. It's the front that is really bad. Now if I could just settle on the new and improved design. I don't want to tear anymore out until I've decided what and how, and have the time to do it. I suspect that's a month or more away. I have a beach house that needs some work before mid may when summer rentals begin and that will take precedence, along with my working life. When I settle on a design I'll post up the drawings for comment and critique / suggestions.

[BarryLS]

I learned a bit more today...

I took some more of the roof out from the inside to further my study of what was originally there. The Winnebago roof sandwich consists of a 3/4 thick slab of foam (4x8 I believe) with 1/8th luan plywood glued to each side. The inside is covered with something quite thin that has no structural quality, perhaps it's just paint. On the topside is the filon covering, glued to the luan plywood. At each side, where the roof meets the vertical sides, there is a 3/4 by 3.5 inch board that continues the foam sandwich panel. Since the Minnie is 99.9 inches wide and typical foam and plywood is 96, some method has to be used to stretch this dimension. Without measuring it, it appears they shortened the foam panel length to fit the width - the two 3.5 inch boards on each side. There is also a tubular metal member that appears to be 3/4 by 2 spanning the roof as a part of this sandwich. Didn't check it, it might be aluminum or steel. I don't know how many or how often these are spaced in the roof as I only see the one, right at the roof to cabover roof junction.

It is a much thinner structure than I had imagined, really just an inch thick. It does the job though, right up until it gets wet.

I'm guessing that a four foot wide section of this weighs about 40 pounds. Adding up the components of my proposed 2.25 inch thick structure comes out to about 60 pounds. That would end up adding 125 pounds or so to the roof, a figure I'm comfortable with.

My cad PC is dead at the moment so I only have some hand drawings so far, but I am looking at 2 inch thick, 4x8 sheets of EPS foam (building foam) that will get slightly redimensioned to fit my wood parts. 1/8th ply epoxied to both sides, then a layer of glass and epoxy on the top and two layers on the bottom (tension strength), a 2 inch x 3/4 stringer on each side that will connect to the end pieces that fit atop the vertical side panels. Those end pieces will have a routed curve to allow fiberglass to make the curve from the top to the side, tabbing the structure to the sides, no seam. Inside I will create a filet at the junction and tab that in as well. Basic stuff that boat builders do all the time as well as others. I can do this one panel at time if I wish, but I'll probably do one with the cab over rebuild, and then do the rest at the same time when I have an extra week. I can build the panels and set them aside until I'm ready.

The seams of each panel will get covered with additional glass to tie them together and waterproof the structure. Once it's all up, the glass will need to be painted to protect it from UV, and that will need to be maintained.

The panel cost will be around $175 each, depending on the final design. I'll need 6 or 7 of those.

That should create a super strong roof without seams to fail or keep caulked. And since all the wood will be coated with epoxy, even if it gets wet it will never touch the wood itself, assuming I use the standard procedure of coating the inside of any holes with epoxy.

I'm now thinking about openings for vents, AC, etc. Rather than a plain hole cut in the panel, I could create a fiberglass flange that is above the opening so that no screws or bolts would penetrate the roof. I have to think further on that, as well as plan for things like solar panel mounting and dish mounting.

Wiring will get routed the same as I think it is now, channels in the foam.

This might be hard to imagine without a drawing. Not sure I'm describing it that well. If your imagination is good please make any comments or suggestions as you see fit. My skin is thick

[BarryLS]

Some pics of the roof area...

The first is a foam piece that came right out after I peeled back some of the delaminated plywood. It went from one side to the other, part of the roof core. Th foam is only 3/4 inch thick.

The 2nd is the "hole" that piece came from. What you see on the top is the luan plywood that was on top of the foam, the filon covering is on the other side of that.

The 3rd shows two items of interest. The wood piece that is on the end of the foam, a 1x4, actual size 3/4 x 3&1/2. This is the edging of the foam. Also you can see the metal strut or joist that spans across. On the end is welded a flat piece that rests on the wall. It is bent in this picture, probably from stepping in this area while on the roof.

The 4th pic is just that piece of 1x4 removed for clarity.

I am not sure how many of the metal struts there are or the distance between them. I assume they are there for additional strength as this is a rather thin roof structure IMO. Pretty low R value as well, probably less than 5.

At the moment my plan calls for 2" foam with an R value of 10. And gobs more strength from the composite sandwich.

[BobC]

Yuck!

If I understand your plan, you'll be building what amounts to a foam cored, fiberglass boat deck for a roof. Good plan and it will be much stronger than Winnebago's. My 2002 Itasca Suncruiser's roof appears to have 2" - 3" of foam in its sandwich. It's in fairly good shape but there are some areas of the roof where the Filon isn't fully adhered.

As a former sailboater, I can appreciate how strong your roof will be.

[BarryLS]

That is a good description. If it were a boat I would use plywood rather than foam, or I would be using the high priced foam materials available for building strong lightweight decks. In this case I'm staying reasonably economical by using EPS foam sheets like you get at Lowes/HD for building.

I'm still fine tuning this sandwich but I have a design that will work. I think

Looks like the cost of each 4 foot wide panel will be just under $200 and I need 6-7 of them, depending on how I construct the cabover area. I'm trying to find a more economical way, but I doubt I'm going to find anything significant. The panels will be epoxied to the walls, and the glass over from the roof onto the wall. There will be no seams to leak or caulk.

My question now is why wasn't it constructed this way from the beginning. I may be missing something. Perhaps the shifting and twisting of the structure makes this way problematic. OTOH I think it makes for a more rigid structure less prone to the tweaks. The roof will attach on the inside as well. Something to consider anyway.

[BarryLS]

One question that comes to mind is planning for new items and future items, things that mount to the roof on the outside, on the inside or come through. I can see new LED flush lights for the interior. Only the wires are an issue as the light can be placed anytime. Then there are the vents, I'm thinking of adding new ones with fans. There are three now, one powered in the bathroom. There is the AC unit on the roof and a TV antenna, plus the vent for the refrigerator. I'm thinking I'll have the mounts ready for a satellite dish and for solar cells.

Anything else I should plan for?

[BobC]

I think you've covered things but you might want to plan on installing plastic conduit for your wires so you can add wires in the future with maybe a unobtrusive access point or two. You should then be able to pull new wires as necessary, at least to the nearest access point or existing fixture. Just make the conduit as big as you can so pulling new wires isn't too difficult.

Now that I think of it, an even better alternative would be a two wire chases with removable covers (could look like crown molding) along the edges where the two sidewalls meet the ceiling, with conduit to the fixtures imbedded in the foam. That way your actual pulls for new fixtures would be relatively short. For short runs from the chase to new fixtures you could simply poke a metal fish tape through the foam from the new fixture to the wire chase.

Your A/C's 120V AC wiring would need to be kept separate from your 12V wiring. It's unlikely that you'd add any more 120V fixtures to the ceiling, so access shouldn't be a problem.

[tderonne]

A sneak peek at your roof structure.

[BobC]

This is a repair on a 2014 Minnie Winnie. It looks like they're using 1/4" plywood for the decking.

https://www.youtube.com/watch?v=Qp3brTV8OtA&t=987s

And another video from the same channel about a 2007 overcab repair:

https://www.youtube.com/watch?v=8SdXUiPsryg