1998 Winnebago Minnie 32WM Restoration

[BarryLS]

Tim, thanks for that. Where is that from? It doesn't appear to be quite the same as what I see. Those struts for example, they look like flat plates similar to what is in one of the video's Bob posted. I have a tubular strut at the junction of the cab over, but nothing I can see that looks quite like the flat piece. Thanks for the view though.

Bob, thanks for the links. One of those I had found earlier, and I agree it appears they are using 1/4 ply for the replacement.

All of these that I see always seem to have around 2 inch thick foam in the roof. Mine is confirmed to be 3/4 inch, quite a difference. Separation distance of the panels adds a tremendous amount of strength.

[BobC]

The two links were from this Youtube channel:

https://www.youtube.com/channel/UCPb...Qukf6uk8waWcoA

The first one was linked in the comments to this video by AZ Expert:

https://www.youtube.com/watch?v=EewwqoINDn4&t=79s

Clearly Winnebago determined that 3/4" wasn't thick enough over the years. I think one of the biggest cause of failure, regardless of thickness, is failure of the adhesive due to water incursion, age or other factors. When new, the 3/4" panels were probably pretty strong.

[BarryLS]

Bob, I agree, the 3/4 panels were adequate as designed. I can walk on them and they seem fine until I get up to the front where the worst water damage is located. From what I see, the luan ply is what comes apart the worst. The 3 plys separate and get wavy. Water is the enemy and the plywood is not an exterior rated plywood. Marine ply would be nice but expensive. The alternative is to make sure every piece of wood is encapsulated in epoxy. That's my plan along with eliminating seams that have to be caulked.

I'm out of epoxy and went to get some at the local boat store today. No dice, lot's of hardener but no resin. I just wanted to do some tests. Anyway, I bought some West systems repair kits, resin and hardener in packets ready to be mixed. A bit expensive but I don't want to wait until I can get an order here. I'll make up a sample composite panel to see how I like it

[BarryLS]

Watching that last video is painful. Clearly the top and bottom sheets of ply did not adhere to the foam for whatever reason. The strength of a composite like this is in the lamination. It's just like an I beam, where the plywood "skin"is the same as the horizontal steel of the I beam. bending puts the top and bottom of the I beam into tension and compression, the vertical part of the I beam has little to do with the strength other than providing the separation between the top and the bottom.

I have no clue what they did to solve this one, but bonding the top and bottom sheets are required to develop the strength.

[BobC]

AZ Expert has a ton of videos on Winnebago roof replacements. He applies new Luan with a spray contact adhesive and follows with Filon, with another type of spray contact adhesive. The Filon is one full length sheet. Here's a link to a multi-part series. He names the adhesives, starting in Part 2 for the Luan to foam adhesive.

https://www.youtube.com/c/AZExpert/s...uery=winnebago

[tderonne]

Originally Posted by BarryLS

Tim, thanks for that. Where is that from? It doesn't appear to be quite the same as what I see. Those struts for example, they look like flat plates similar to what is in one of the video's Bob posted. I have a tubular strut at the junction of the cab over, but nothing I can see that looks quite like the flat piece. Thanks for the view though.

I just googled "Winnebago Superstructure" and clicked on images.

Looks like maybe the frontmost beam/strut/joist isn't flat like the others in the image I grabbed?

But I also don't know what year that image represents. Winnebago has tweaked things over the years. Winnebago will send you pdf drawings of your motorhome model. I have the pdfs of my walls and roof for example. Tells me exactly what I have.

[BarryLS]

Bob, yes, I've been going through them. They are quite good at what they do. I'm going a slightly different way, but that is probably due to the reality that they have paying customers that expect a reasonable price for a functional roof repair. Since the material cost is low compared to the labor costs I'm probably going to just replace the entire roof, inside and out. That's actually easier to me, at least for the worst part up front. There simply isn't a way to salvage any of it. I may decide to repair the back part, at least for the time being. It's OK on the inside except above the shower. Lots to learn and I appreciate the links to people that are experts.

Tim, yes, the front one looks like a tube. Its just further forward than the one I have. I suspect that may be a later model with the thicker roof.

"Winnebago will send you pdf drawings of your motorhome model."
That's a revelation. I'll have to contact them and see if I can get them for mine. Appreciate the tip!

[BarryLS]

I should probably mention that I've not been surprised by any of this. I knew there was substantial roof issues. With the reasonable mileage (58K) and the fact that it seems to run quite well with a good transmission, I felt it was perfect for me. I didn't want to spend a lot preferring to put in some sweat equity as needed. Plus, had I spent more I'd still be looking at making changes to it.

I'm happy at this point. Work ahead, but nothing all that difficult really. I'm going to enjoy turning this into a nice home on wheels

[tderonne]

Originally Posted by BarryLS

"Winnebago will send you pdf drawings of your motorhome model."
That's a revelation. I'll have to contact them and see if I can get them for mine. Appreciate the tip!

In the past I contacted owner relations via email at [email protected]

I don't see that email listed at the website anymore. May still work. May need to contact them via other methods shown at the "contact us" page.

[BarryLS]

Originally Posted by tderonne

In the past I contacted owner relations via email at [email protected]

I don't see that email listed at the website anymore. May still work. May need to contact them via other methods shown at the "contact us" page.

Thanks Tim!

[BarryLS]

This afternoon I started on the cabover tear down. I got the front part including the window all torn out. Sawzall is your friend here since I was not trying to save anything.

First things I noticed were the rusted screws under the trim. Any leak and the end begins since the screws that hold it all together are just mild steel screws and will rust. Add to that the fact that Winnebago builders missed putting in any screws in the curved portion of the trim even though Winnebago engineers placed holes for the screws in the trim...

Anyway, a few pictures. The window lying flat on the inside, some of the general destruction, the cardboard that I used to make a template of the lower curved portion, and some calculation notes done quickly to confirm my plan for the reconstruction.

The radius of the curved portion is 6 inches. In a circle that would have a circumference of 37.7 inches. A 2 inch thick structure would then have a circumference of 50.26 inches. With a bit of math we can determine the slices of material required to fit this curve. Selecting a standard 1.5 inch think board, for example, that would be ripped to 2" thickness for the curve, ends up with a 1.142 inch width at inside. That requires ripping the board at an angle to yield the 1.142 value. Geometry gives us the blade angle required.

I will probably use 1 inch thick material rather that 1.5. I might use all wood. I can get some nice 5/4 pine that is 10 foot long to get the near 100 inch span I need. It is an actual thickness of 1 inch. I inch thick gets closer to perfection in laying the parts in the circle. I may use the foam board and rip the pieces from foam and glue those up, with wood pieces on the end. It all gets covered in fiberglass and epoxy.

I don't think I'm going to put the window back in.

The flat sleeper bottom has to be 1 inch thick to match the original, fixed by the sides location to the Ford cab top. I plan to make the flat above the curve 2.25 inches thick matching the rest of the new roof. The original is 1 inch. The 2.25 includes a 2 inch foam slab plus 2 sheets of 5mm plywood and the fiberglass epoxy.

Questions or suggestions are appreciated...

[BarryLS]

Some more pictures:
The template of the lower curve and some quick notes of the making parts to fit.

[BarryLS]

No rain in the forecast so she is open for tonight. I'll finish tearing out the remainder tomorrow and then cover it all up.

My wife has renamed Gertrude to the Birdhouse. She says birds will be nesting in there shortly

[BobC]

You're making great progress and I like your engineering approach. Good idea on not putting the window back in, one less thing to worry about. I suspect they're only used by kids hanging out in the bunk. In any case, the newer Minnie Winnies don't have them.

[BarryLS]

Thanks Bob.

I also noticed newer models leave the window out. I'm still debating that but I know leaving it out makes the structure stronger and eliminates a potential leak.

I thought I included a closeup of the side wall, I've added it here. It shows the aluminium tube that everything fastens too and the skins over the foam wall structure. The outer skin has delamination but it will be repairable. The inner skin has less delamination but has rot of the plywood along the bottom. You can see where I cut some of that out exposing the aluminium tubing.

The new parts will get screwed to the aluminum with a layer of thickened epoxy that will actually hold it all together nicely.

The other side is not pictured but will require more work as the Filon tore loose on that side and the owner repaired it with what appears to be fiberglass mat. I'll get it cleaned up and splice a new piece of the filon there to make it look smooth.

[BarryLS]

Day 2 of the cabover teardown is complete

Finished the driver side then proceeded to remove the top roof of the cab over. The Birdhouse now sits with the cabover tarped up. I will need to restore both sides before starting on the enclosure. The enclosure will get made in 5 pieces:
1) The bottom or sleeperboard as it is called
2) The curved portion that makes the transition from the flat bottom to the slope up
3) The slope up that had the window
4) The curved piece to transition from the slope to the upper roof
5) The upper roof which is at a slight angle and meets the flat roof at the cabover junction

I'll make the two curved parts first as getting exact measurements for the other parts is difficult. Once they are made I can put them in place temporarily and make the measurements needed, or just install them and then add the other parts.

The flat roof behind the cabover will get replace at least 4 feet back. 4 feet because that is the width of the panels I have designed for 4 foot wide foam and plywood. That may be all I do for now, or I might just work my way back with a complete re-roof. I'm inclined to do it all now as some of my ideas depend on a complete new roof.

One thing I am considering is mounting a pair of round rails along the perimeter of the roof. A very long roof rack if you will. I can incorporate those into the design of the new panels quite easily and mount them later if I wish. It would be 1.5 inch round CM tubing running the length a few inches above the surface. Feet would bolt to studs incorporated into the wood on each panel end and there would be a cross brace at each end and in the middle. I can then add cross pieces that are adjustable as desired. I'm thinking that I can then mount to this structure solar panels, satellite dish, TV antenna, etc without having to penetrate the roof itself. It could even carry something light like wooden kayaks. Just a thought.

A question - How much use does anyone make of the roof vents? Since I see the number one use of the Birdhouse as being summertime with AC on and plugged in or operating on the generator, I'm not seeing a great need for vents other than the bathroom. Windows should be enough on nice days I would think. But I have zero experience so please let me know what you think.

So, pictures in this one:

1) driver side top you can see the painted on material used to seal everything up. Looks like it was pretty good stuff, just a few years too late

2) driver side bottom as the trim comes off. You can see the previous repair with glass mat. That will need to be reworked and a new piece of filon added or glass cloth with fairing filler.

3) A picture up top showing the 1x4 that is on each side of the normal roof panels with foam between.

4) A wooden cross piece, 1x2 that joins each side together. I'm not sure what the joinery was but that was still intact.

More in the next comment...

[BarryLS]

More pictures:

1) Just before the upper roof comes off

2) The upper roof detached on one side

3) The upper roof now gone

4) Close up showing the regular flat roof with the tubular metal strut in place. That will get replace going back 4 feet by a new panel.

[BarryLS]

A couple more:

1) The debris field, and this is after I cleaned up a bit
2) Buttoned up with tarp for protection until the next work day


It will be a week or so before I get a chance to work more on this area. Meanwhile I will get materials ordered and start setting up to fabricate the parts I need to make.

Mechanically I need to investigate the leveling jack system. According to the previous owner one of them was not working. It's probably a solenoid but I need to figure out how it works and then test it. Since the slide is working I know the hydraulic pump works.

I will have to come up with something to jack the front up and get the tires off the ground a couple inches so that I can safely replace the front brake system. I have my faithful 3 ton Walker jack, now half a century of service I need to check if 6000 pounds is enough, but I think it is for the front. I'll just need a pair of heavy duty jackstands in that case.

[creativepart]

Have you considered ending the roof at the cab? Do you need a “cab over?” Kind of like a box truck? Maybe with a angled wind brake?

[BarryLS]

Originally Posted by creativepart

Have you considered ending the roof at the cab? Do you need a “cab over?” Kind of like a box truck? Maybe with a angled wind brake?

I did consider that for a moment. It's a good suggestion.

I rejected it for several reasons. Properly enclosing the top of the cab is probably as much work as fixing the cab over area. You would definitely need an aerodynamic aide which would be suspiciously similar to the current cab over. That could be tied into the cab to solve two problems at once, but then the current design gives me that.
Plus, while I don't really need the area for sleeping, it's a good spot for a larger TV. Last, if I ever sell, the cab over is probably a good feature for younger family's.

Thanks for the thought.