Is this plan a sound rear end floor rot patch?

[Tony S]

Hi folks,

I am trying to avoid taking down the bathroom dividing wall.

Can a person get away with patching the rear plywood floor rot up to the first cross member only?

This cross member is a full depth one with no 5/8” plywood scap on top like Airstream has when they came to the 4-foot joint with their plywood.

If possible my plan is to go from in the c channel to the first cross member and ½ lap the two pieces, the existing still solid plywood and the new replacement plywood, Then epoxy glue the ½ lap and elevator bolt and screw through them both.

I figure it is real strong but don’t want to go wrong.

Do I have to bite the bullet and tear out the wall and go back to the 4’ cross member?

What do you think. Please any advice.

Thanks in advance

Tony Scolaro
Rogue River

[RichardT]

Sounds like a great plan to me.

[TG Twinkie]

I agree. Good plan.

[Tony S]

Cool

I will post pics as I proceed.

The plan is to cut with Skil saw, finish up with Multi tool to wall, about a quarter inch on x member. Set up a straight edge and use a straight bit in a router to cut away half of plywood thickness leaving a quarter inch full material of original plywood on x member . So I will have about an inch of material 1/2 lapped in middle. I will epoxy and elevator bolt it together and down. Along with the screws I got from VTS.

I will splice it the same way over the longitudinal frame member so install will be in 2, if not 3 pieces.

I will put epoxy on the edges ahead of time.

I did buy Marine Plywood for the job. It is expensive but probably the best and it is the only one I found that was a full 3/4" (instead of 23/32nd) and matches up with original

Thanks

Tony

[eljay]

I'm subscribing to your thread to check out the photos and progress. Good luck.

[aquinob]

Thats what I'm doing, dont see any problem with it. Do post some pix along the way.

[Splitrock]

[Tony S]

Thanks for the Posts

The Floor Splice Instructions take the magic or mystery out of it. I would suggest using Titebond Three instead of an Elmers. Titebond Three was not around back then. Water proof.

I will post pictures as I go along. I need to get the Univolt out of the way.

Question Now that I have all the elevator bolts and screw out, and just took out the 2, 3/8 hold down bolts the bumper is moving independent of the body
like it has Rear end separation or something.

I take this is normal due to the lack of the floor being attached and rotted plywood busted away??

Could someone ease my mind.

Tony

[barts]

There is (often) a bent piece of steel that slips under the ply but on top of the frame; this is riveted at the C channel to the skin. Once the plywood is rotten, the skin can move relative to the frame - which is what you're seeing. You need to make sure that metal is sound. I replaced ours as it was completely rusted out with a stainless one I made, and riveted it about 3" up from the C channel as well for extra strength.

While you have the bathroom out, that's the time to really make this (misdesigned) joint strong.

DO remove the steel plate that the rear storage cover hinges on; this is a conduit for water right under the plywood - rot city.

- Bart

[Tony S]

Hi Bart

I read that in one of your previous posts in the past. I don't have the rear storage there being a Land Yacht. I will check it out in the morning. I don't think mine is rotted out but I did see something which may cause me to have to change it out. There seemed to be some decay from dissimilar metals.

I will use stainless as you suggest if I have to.

The thing is the movement wasn't there until I removed the bolts after making a cut across the first x member in from the back.

I will see and post pics

By way I have always enjoyed your post and blog.

Thanks

Tony

[Tony S]

Well today I cut the some plywood floor out of the bathroom and got a good look at things.

I was pleased the frame wasn’t all rotted out. Quite good. So now all the highest likelihood of rotted frame has been explored . Out riggers look good too, Again that is the good part of paying the price I did for a trailer that was used throught out its life and not left in a field.

Bart, however, knew what he was talking about. The bent steel angle plate is pretty badly corroded. It is there but it is corroded. Also the aluminum that slides in the same area with the hinge on it for the bumper compartment door is showing the results of contact between dissimilar metals.

You can see in the pics I only cut a 6” section out that will be replaced with 10” aluminum flashing and will not show when bathroom is put back together.

I also ended up lightly jacking up the frame in back, mostly stabilizing the trailer as I walk about it.

Anyway the pictures should tell most of the story. Besides that bent piece of steel that slips under the plywood but on top of the frame being bad, I can't complain.

Bart, do you have pictures of the repair you did and any showing the new additional row of rivets?


I have to ask again it is normal in its current state of deconstruction to have movement between the frame and the body?

Tony

[Protohyp]

Yes it is normal...unless you have your stabilizers down the connection of that angle and the shell bolted to the frame keep it as one unit with the shell supporting the frame so without any of those the cantilever behind the axles will be unsupported so the flame will flex. Personally I think if you have that much out why not replace the whole 4' section? I know it might be tedious work but keeping that whole rear section as solid as possible is your best bet at not having to do it over again and it might be arguable that only a 2' section might solve it but you might be able to slip the 4. plywood under the closet walls or whatever walls you have back there.

[Tony S]

Thanks for the confirmation of that. Taking it back to 4 feet makes sense I know. I have a strong system with the 1/2 lap epoxy and screws/elevator bolts but I am going to pause and think it through. It seems, quite normal I suspect, I spend many more hours looking for answers and try not to commit any sins.

Tony

[barts]

You really don't want that hinge support under the plywood - work out something better. I'm afraid I repaired the rear end separation largely w/o pictures in a frantic blur of effort while webspinner was in England w/ the good camera.

Here's a cross section of what I did....

I ended up running some heavy aluminum I had between the frame rails to support the storage compartment cover hinge which has worked out fine.

- Bart

[Tony S]

Bart thanks for taking the time to draw it out. Yes I can see all that.

So I guess what I do is drill out the rivets along the belt deal ( don't know what to call it) around to about the lights or so and slip the old steal out. That will be easier than putting in the replacement. I will round up some stainless steel and someone with a break or do a home effort between some 2x 4s or something.

Now I am debating going back to another x member. I feel the 1/2 lap and epoxy will make it stronger than the wood itself but I think epoxy is a brittle bond without much flex. So like everything I research and ponder at least 3 x the work I get in doing a thing. It would be longer without you alls help.

Thanks

Tony

[barts]

I used gorilla glue when I did mine; titebond III would work really well. Construction adhesive works too. I fastened the floor patches together with laminating screws, which look like really heavy duty wallboard screws. They're there just to hold things together while the glue dries.

With the rear floor gone, you can slip the metal up and in from the inside w/ only a few rivets out.

- Bart

[Bunkroom]

Epoxy will work but is a pain to work with. Construction adhesive is easy to use supplied in tubes, it's inexpensive, has long open time, and is very strong and somewhat flexible when cured. It is probably more like the glue in your plywood than epoxy is.

If your marine plywood has any kind of coating on the exterior, glues may not bond as well as they do to wood. Your lap detail eliminates that problem.