Rear Floor Replacement Question

[rburditt]

Hello, i have begun gutting my 1965 safari and have removed the rear most flooring that was rotten. luckily the steel in the rear part is in pretty good shape w/ mostly surface rust.

i am looking to get opinions/help on the replacement part. if i don't want to drop the banana wraps, what is the best way to fasten the channel around the perimeter of the airstream to the plywood? i feel comfortable using self tapping type screws to attach to the steel, not sure how to tackle the outside edges.

i saw a post somewhere (having trouble finding it again) where someone fastened a 4-6" strip under the channel with bolts and then screwed and glued the flooring to the splice strip (hope that makes sense). is that a good way to accomplish what i'm trying to do?

thanks so much for any help or info,
bob

[Tom Bray]

Your frame doesn't look all the much different from my 72 Safari.

I had to actually replace one of the cross members and reinforce the frame and another cross member.

After I got all that done, I painted all the exposed frame with POR-15. I bought the 6 little can package and that worked perfectly, I had 1 can left over at the end that wasn't opened. One can covered about as much as I could cover in one session so there wasn't a big problem sealing the can and then getting it open again.

There are a number of posts about putting the floor back in. Here are the steps we went through to put it back together.

I used marine grade plywood. It costs about the same as walnut veneer plywood, it is very expensive but I think it will ultimately be worth it (I have already flooded parts of it when the brand new water heater decided not to hold water). Up in Michigan, Menard's had the best price. Loews figured out finally that they could order it but the price was staggering. Home Depot didn't know what I was talking about.

I cut the 4X8 foot piece in half so I was dealing with two 4x4 pieces. I also made a template to cut the plywood out of some heavy rolled paper (I think it was the red stuff you use under laminate floors). From that template I made a 1/4 inch luan plywood template so I could make sure things still fit correctly - I ended up adjusting things slightly so it was worth it making the solid template. The new floor was an $80 piece of plywood that took 2 weeks to get so I didn't want to mess it up.

We used a couple of jacks and slowly separated the frame and the body by a generous 3/4", enough to slide the plywood pieces in. I was scared to death that I would buckle the shell so we took our time. Because the new floor was going in as two pieces I could get it around the jacks.

After the floor was in place (it took two of us in addition to the jacks), I lowered the shell back down on the frame. Then I used stainless steel carriage bolts to bolt the shell to floor (I will probably regret this if I ever have to replace the floor again). I also bent the bolts slightly after I got the nuts in place to lock everything in place. I also used a couple of grade 8 bolts, nuts, and washers to hold the frame, floor, and shell firmly together to avoid the dreaded "frame separation" problem.

Then I bolted the floor to the frame using more stainless steel carriage bolts. I didn't have elevator bolts that have been recommended by others. If you use the carriage bolts, make sure that they are counter sunk so that the floor remains flat. To make up for the lower strength of stainless steel over regular steel, I over sized all the hardware by one size - probably serious overkill.

For the floor seam I used a 1/2 inch thick plywood, 4" wide, running the length of the seam under the floor, centered 2" on either side of the seam. I used carpenter's glue (Liquid Nails variety) and then screwed the patch in place using counter sunk wood screws. I used two patches, one on each side of the center cross member, I didn't try and run it over the cross member. I ran about six 1 1/4" screws in from the bottom to hold things in place and then did the rest from the top using 1 1/2" screws. This approach did a pretty good job of leveling out the seam.

The old floor used a 1/2" piece of plywood to tie the two floor boards together which ran over a cross member. I ground off the old glue and removed the staples on the section that would accept the new floor, leaving the part under the existing floor untouched. When the floor went in, I used the carpenter's glue and screwed the parts together for good luck.

I was quite happy with the end result.

One last note. Make sure that before you bolt anything together, or if you do any welding that might shift things, have the bumper in place with all its bolts in place. The frame is very flexible when the floor is not holding it square and it might get ugly if it gets out of square.

Tom Bray

[rburditt]

Tom,
can you describe more about how you jacked up the body? Where did you put the jacks and how did it work? also, did you remove the banans skins? I'm guessing that when you slid in the new floor sections you did it from inside the safari, or did you slide them in from the outside?

thx,
bob

[Tom Bray]

I removed the banana wrap in the back. Be very careful with the curved parts, they could be difficult to replace (unless you know someone with an English Wheel who knows how to use it). The section directly behind the road side rear wheels tore while I was getting the water heater out which pretty much required replacing it. The other side wasn't much better and in the process of removing it I ended up having to replace it.

When I initially removed the floor I realized that the shell was sitting on the frame only on the outside edge and it started to deform. I put 3/4" thick boards between the frame and the shell so that it was supported properly. The boards were probably 6" long and 3" wide (any width over about 2" should work).

When it came time to jack up the rear, I placed another board under the ones between shell and the frame and centered the jacks so that they were under both the shell edge and the wood. I think I put the jacks between the two frame sections and they were propped up off the floor using a bunch of 2x12 boards.

The first floor section went in from the inside. That was the piece on the road side of the AS. Once it was in place I moved one of the jacks under it, pretty much centered between the 2 frame sections, but still had the extra wood on it to spread out the load and had it underneath both the wood and the edge of the shell. I then removed the second jack.

I think I tried to put the second piece in from inside and there was some problem so I ended up angling it in from underneath. I don't remember exactly what the problem was and it would be worth it to try again from the inside.

After I got the both floor sections in place I removed the jack. That was when I put the bumper back on and it didn't fit (the holes didn't line up). In the process of moving the frame around, I also figured out that the shell and the frame were slightly offset from each other (not by much but enough so that the frame to shell bolts didn't line up). After I got everything square, the bumper, frame and shell all lined up with the respective holes.

The real point is to make sure everything lines up before putting in any bolts. Also be patient and don't rush. Also try not to do anything that you can't form a plan to put it back the way it was.

I hope this helps. As you can tell, I muddled through it. When I got tired I forced myself to quit so I didn't make a huge mistake.

Tom Bray

[malconium]

Bob,

You may have been looking at a post that I made a long while back regarding adding the strip of material around the edge. I think that would work just fine but did not actually do it myself. I have another suggestion for your consideration though that I think would work fine.

Are you familiar with the type of nut that can be attaced to a piece of wood on one side and then have the bolt attach from the other side? The name I am familiar with is t-nut. The following website was at the top of the list for a search for the key word "t-nut". The photo shows what I was thinking about.

Tee Nuts | Fastener SuperStore

My guess is that there are other types available too. This type should be readily available at the big box stores or most any hardware store.

OK - so here is the idea. You need to be able to drill the holes in the edge of your plywood in the locations that you want the bolts to be placed. Once you do that you can attach the t-nuts to the bottom side of the wood, slide the plywood into place and add your bolts from the top. You could either insert the floor plywood, mark the holes and take the plywood back out to add the t-nuts or you could make a paper template or thin plywood one on which you mark the holes.

I think that I would use some glue of some sort to attach the t-nuts so that they won't fall off the bottom before I could get the bolts in place.

Also something else to consider is that this approach will only work if there is no metal under the floor plywood that also needs to have the bolt through it. Generally if there is then you can use self drilling screws from above.

As an alternative I think that you could use wood screws from above into the wood. Just use more of them than you would bolts and you should be fine. Decking screws would be good for this except that they are usually flat heat. You can get washers though that will fit the screw side of the flat head. Otherwise I suggest pan head screws.

I hope this helps...

Malcolm

[Tom Bray]

I am not sure I would trust the T-Nuts. These really aren't all that strong and are usually made out of stamped material (i.e. cheap steel).

Wood screws will also be mainly steel and most don't have much of a coating on them. If they get the least bit wet they are going to rust and loose their holding capacity. Plus they only grip a small section of the wood, which is plywood. I think I would prefer using compression to hold things together.

The original bolts and nuts were steel and many were pretty much gone when I started removing them. That is why I used the stainless steel ... the only problem with them is that removing them will probably require a grinder.

I was pretty happy with the carriage bolts. You drill the holes, stick them up from the bottom and give them a good whack with a hammer and they embed themselves into the wood ... they should stay there long enough to get a nut on them. It is easier to have two people though.

That is my thought process at least. Others are entitled to theirs also.

Tom Bray

[malconium]

Tom,

I certainly agree that bolts are a good solution. I was simply trying to propose some alternatives that would allow putting things back together entirely from the top without having to remove the belly pan or bannana wrap.

If I were to use screws I would consider using treated decking screws or maybe even stainless steel ones. I suppose that there might be some types of toggle bolts or expansion bolts that could be used from above too. Maybe there are other varieties of t-nuts that would be stronger. I guess one fundamental question too is just how strong is strong enough?

Malcolm

[rburditt]

first of all, thx to everyone for all of the insightful replies. i haven't had time to research the t-nuts fully and wanted to before i replied. i have a few thoughts on all of this. first off, i am really trying to avoid removing the banana wraps if possible which means i wont have access to the bottom side of the plywood to use bolts (unless i use something like t-bolts). maybe i'm being a bit paranoid, but i feel like the less i take apart, the better off i am and the less likely i am to screw something up. also, regarding the rusted bolts, etc...i'm wondering if this is from age or water leaks or what. after all, my trailer is 43 yrs old and if i can prevent leaks as i rebuild, how many years can i expect my screws to last? i would think that if i rebuild properly and inspect for leaks occasionally that deterioration of the screws will not happen in the timeframe that i own it, if not MUCH longer. is this a crazy assumption?