Jump to content

Recommended Posts

I just recently purchased my 86' Nissan Sunrader 18' and had a little surprise when I started digging around.



The floor feels solid and all appliances worked so I didn't really think to check when I got it, but after opening up the seats in back, noticed that there is a patch of wood around the water heater that has started to decay. A lot of the plumbing has been redone, so I'd imagine there was a problem that was fixed, but maybe to late.



First, I am going to remove the water heater because I have plans of installing a tankless and so I can access the whole area. Then I am going to use a wood rot repair epoxy called PC Rot Terminator. It is supposed to be a structural wood repair curing harder than wood.



Then I am going to lay new plywood down over that area, and over the main floor.



A couple of questions for people who have laid down play wood to stiffen up the floor of a Sunrader:



Did you screw it down or glue it down or both?


Did you us any floor dampener like the foam under hardwood floors?


Did you do it all in one piece?



I see being able to easily do it in three pieces and only having to take off a couple cabinet doors.



Thanks



I'll include pictures of the rot and fix later.

Link to comment
Share on other sites

I put down plywood over my very soft Sunrader floor. Use 1/2 inch. I didn't and I have to redo it. Don't use thicker than that. Too heavy and Sunrader floors need to have a tiny bit of flex. PC rot is crap. I ended up using regular resin and hardener. Plywood screwed down but I do think glue and screws would have worked better. Construction grade , not quick dry.

Linda S

Link to comment
Share on other sites

Hi Linda,

Thanks for the reply. I had read good reviews about PC. But you never know. What type of resin? Fiberglass epoxy? Should I layer in souls glass strips?

Link to comment
Share on other sites

Also. The floor is surprisingly sturdy. Same with the upper bunk and I'm 185lb.

It was probably sitting on an angle and all the water ended up in the back corner.

Looks original. TheC side fiberglass comes down and over the top layer a few inches.

I'm feeling pretty silly for not checking this out first. I love a good project and I'm going to end up rebuilding the rear dinette floor up. I could have done that with any old junker though. Hopefully the truck engine and chassis are as good as advertised.

Here is a picture of the yucky rotted floor. Down to the foam board. :(

And another good picture of my finished Fantastic Fan. This thing sure pushes some air. Wiring was easy. Simply figured out which 110v wire it was, and switched the hot over to a 12v.

post-7981-0-52470900-1412468455_thumb.jp

Link to comment
Share on other sites

I have a 1980 Nissan 18' Sunrader. I had a foot and a half square patch of rot similar to that in my Sunrader floor in the cargo compartment area. Missed seeing it when I purchased as it was under a piece of vinyl someone had put in the compartment. Looks like it was from a plumbing leak as it was directly under a T-junction. But it could also have been from water leaking in around the fitting for the city water hookup as that hose ran right down to the T providing a highway for external water to travel on. Plus my cargo door gasket was leaking as were the tail lights. It rotted in a low spot caused by the carriage bolt that holds the floor down to the framing. Photo of my rot area as seen by looking in through the cargo door.

post-6369-0-53144100-1412476792_thumb.jp

I cut out the bad area and replaced it with Okume marine plywood topped with fiberglass cloth and epoxy resin. Did the whole of the cargo area with the cloth and resin since it is an area where there are a lot of thru holes in the walls. Outdoor cords plus hoses and such get stored in that area so I wanted a waterproof floor that could be mopped out.

Because I had the typical saggy bouncy floor issue I also used a half inch overlay of plywood. We coated both sides of the plywood with fiberglass cloth and resin before it was installed. To install I pre-drilled screw clearance holes and countersinks in that half inch sheet so that the screws would be free to pull up against the original floor. To prep the original floor I washed it, let dry. Then sanded it and brushed on a layer of epoxy resin. To install I worked with a friend and using slow set epoxy that we thickened with a mix of wood flour and also reinforcing fibers. I used a notched trowel to spread my custom mastic mix. Then we dropped the new layer in place and screwed them together. Photo below is of when we were laying out the screw holes to pre-drill and countersink them in the previously fiberglass coated 1/2" plywood for installation. You can just barely see the red chalk lines for the hole layout. My cabinets have been removed so this plywood piece will extend under the new cabinets. It helps to work with a friend as resin can kick off faster than one person working alone can mange. The larger diameter holes in the plywood sheet are to clear the carriage bolts that hold the coach to the frame of the truck. I put removable filler plugs in those large holes so if I ever wanted to transplant the coach to a new truck it would not be impossible to remove those bolts. The piece is cut from a 4x8 sheet of plywood, at the edges in the rear cargo area small sheets of plywood complete the overlay job. At the sides where the wheel well comes down you will need to belt sand the backside of the plywood thinner as the fiberglass from the wheel well is raised up above the floor level at the transition area. I did leave a small gap between the plywood and the wheel well for easier installation. Afterwards I thickened epoxy with wood flour and filled and leveled that gap. The thick epoxy also filled in over the slightly recessed screws that hold the floor down to make those holes waterproof and flush to the surface.

post-6369-0-37053600-1412476675_thumb.jp

Everything is snug and dry now. Just need to put in some type of waterproof, impact resistant,cargo liner on the walls back in the lower compartments as the lower area of the plywood wall panels got dry rot in them. I used PVC lumber for the new blocking behind the walls down at the floor level. The original particle board blocking was of course ruined from the water. I intentionally left the patched area in the floor a bit low as a bit of a resavior and put in a small drain tube in the middle on the theory that eventually leaks will happen again in that area and I won't always see them right away. I also put a couple of small drain tubes in my entry door well as it too can accumulate water.

You can get aluminum tubing in the hobby section of the hardware store. After you drill the holes in the coach coat the inside of the hole with epoxy before pushing the tube in. Be sure you run a pipe cleaner through the inside of the tube to remove any epoxy that might have entered into it. You can flair the end of the tube that is on the inside and use a countersink to set it flush to the floor. You don't need a large diameter hole as these types of leaks are not high volume ones.

I put in two more small drain holes in the overcab area at the low area at the transition where the overcab bed floor board stops and the nose of the shell wraps back under. Once again a notorious area for accumulating water if the windows or clearance lights leak or if there is an issue with the screws on the body join trim band breaking through the fiberglass. I decided to give water an emergency exit ;)

Link to comment
Share on other sites

Okay. End of the day. Pretty good start.
Next get the appliances out and get the floor cleaned and prepped for resin

I'll probably use some fiberglass fabric in some especially compromised areas.

I'm going to hit as much of the floor as I can get at.

Then I'll do the whole back in one piece of 1/2" marine plywood.

What do you all think about doing some kind of insulated vapor barrier?

Also, the storage box on the drivers side sits below the floor making the need for a cut out. What do you all think about getting a different box that would just sit on the solid new floor instead of making a cutout in the new floor.

This also gives me the opportunity to make a wrap around dinette if I'd like.

Who here has the wrap around and do you like it? I noticed the 18'er back widow comes up at an angle making that back seat on the wrap around not all that comfortable. Opinions??

post-7981-0-34132200-1412477433_thumb.jp

Link to comment
Share on other sites

One more thing. I tried and tried to get the propane connection off the water heater but couldn't

Any tips? I'm about to cut it. I figure it's easy to fix with new fittings.

Link to comment
Share on other sites

Thanks for all the info Corbin.

I think my floor is definitely at the point where cutting out the bad piece is a probability.

I'm worried about fitting in and securing the new piece structurally.

Did you just fiberglass over the top of the new piece?

Link to comment
Share on other sites

Okay. End of the day. Pretty good start.

Next get the appliances out and get the floor cleaned and prepped for resin

I'll probably use some fiberglass fabric in some especially compromised areas.

I'm going to hit as much of the floor as I can get at.

Then I'll do the whole back in one piece of 1/2" marine plywood.

What do you all think about doing some kind of insulated vapor barrier?

Also, the storage box on the drivers side sits below the floor making the need for a cut out. What do you all think about getting a different box that would just sit on the solid new floor instead of making a cutout in the new floor.

This also gives me the opportunity to make a wrap around dinette if I'd like.

Who here has the wrap around and do you like it? I noticed the 18'er back widow comes up at an angle making that back seat on the wrap around not all that comfortable. Opinions??

Use some pillows behind you to take care of the comfort issue in the rear dinette. They can be attached with velcro so they don't slide around. As to a wrap around dinette, its too tight of a space for it to be of any practical use as far as seating goes.

But I do like having the long bench bench to stretch out on and I have put a removable, adjustable backrest into my redesign of that area so I can use it as a recliner. I now only have the back bench and not the side benches but the supports for side benches are built in should I want to reverse things. Not likely as I needed desk/workbench space for my daily use. I still have a pull out eating surface plus the desktop surface too so I won't miss those too hard to get into dinette sections with center table. The top of the desk is 6' long and 2' deep. It holds self inflating pads for sleeping if needed. My back couch is also 2' deep and can be used for sleeping. I sleep in the overcab.

post-6369-0-45944600-1412483793_thumb.jp

Link to comment
Share on other sites

Got the water heater out thanks to Corbin. Thank you for the suggestion.

And the floor is looking pretty bad. It's all soft down to the under sheet. Is it metal? Maybe aluminum?

I'm not sure how this section is structurally supported.

Corbin - did you take yours to the bottom replacing foam board as well?

Thinking of building up marine plywood fiberglassed and stacked to fill the gap in between the propane bracket and the floor. That would make me feel better.

Well. Here it is. Hopefully I can make it as good or better than is was.

post-7981-0-83896200-1412530808_thumb.jp

Link to comment
Share on other sites

Got the water heater out thanks to Corbin. Thank you for the suggestion.

And the floor is looking pretty bad. It's all soft down to the under sheet. Is it metal? Maybe aluminum?

I'm not sure how this section is structurally supported.

Corbin - did you take yours to the bottom replacing foam board as well?

Thinking of building up marine plywood fiberglassed and stacked to fill the gap in between the propane bracket and the floor. That would make me feel better.

Well. Here it is. Hopefully I can make it as good or better than is was.

The floor in a Sunrader is a laminated sandwich, aluminum facing the ground, foam bonded to it, plywood bonded to the foam. At the joint line between plywood sheets there is a wood strip the same thickness of the foam. The plywood sheets are stapled to that wood strip along the join line.

I did not need to replace the foam on my fix as it was not in an area where there was traffic so it had not compressed and was not damaged. But having worked in industry for many years I know a fair amount about bonding different kinds of materials together. So I can offer a little advice on that to help you.

The metal on the underside according to the Sunrader brochures is aluminum. My inspection of that surface verified that it is indeed aluminum. I did not do anything to the metal as it was in good shape. I did have to replace part of the wood strip at the join line between plywood sheets as it was under the rot area and it too had rotted. You can put in solid wood strips along the edges of your patch to give those edges a good solid support. Solid wood blocking can also be put in the area where your propane bracket is. White Oak is a good choice for you wood strips as is IPE (Iroko) as those woods are rot resistant but hard enough for good screw holding strength. Sometimes lumber yards have IPE cutoff scraps as it is now a popular choice for high end exterior deck projects.

You can replace the foam if you feel it is warranted due to being overly compressed. Just measure it and replace with the same thickness. The blue Dow board foam is the most dense of the insulation foam boards so that will give you the best strength from a readily available foam product. Pink Dow board is slightly less dense but will also work. The white, softer beaded insulating foam boards found at Lowes and Home Depot are not as rigid so will not be as good for support. Tip: Easy way to cut foam board is to score it with a utility knife about 1/4" or so deep and then snap along the score line. Avoids that foam dust clinging to everything situation.

The appropriate adhesive to bond polystyrene foam boards to the aluminum does not leave you with a lot of choices. Water based adhesives won't work as you don't have a porous surface to help the water evaporate. Many of the non water based contact cements won't work as the chemicals in them melt foam. There are some foam safe construction adhesives but since there is no way for the VOC content in a widespread area to evaporate it does not cure quickly or evenly between the foam and metal. Only very slow setting epoxy can safely be used with foam as the exothermic heat reaction will melt foam. 3M 78 spray adhesive is made for bonding polystyrene foam board to metal or wood. Not going to be easy to find but perhaps a local insulation company may have it on hand.

http://www.amazon.com/3M-78-Polystyrene-Insulation-Translucent/dp/B001EUOAGK

Another adhesive choice that will be easier to find is to use a polyurethane foam adhesive as in the Gorilla Glue type. You will need to very lightly dampen the surfaces as it is a moisture cured glue and then work quickly on assembly. Have some weights next to the work area to use for clamping as that glue is an expanding one so you want enough pressure on it to keep it flat. You don't want to put screw holes in the aluminum layer so just weigh the pieces down and give the glue time to cure. A couple of days of cure time should be enough before you remove the weights.

However since you are creating sandwich of materials that won't be moving around if you have fiberglass over the plywood the adhesive used to bond the layers is not as critical in such as small area as it would be if the area of the floor was much larger. Obviously it helps but the fiberglass cloth with resin will be doing much more of the structural work in the repaired area than will be gained by adhering the foam in place. So don't stress out about that part of the job.

I am sure you will have good luck. The one issue I ran into is that modern metric plywoods are not an exact thickness for the original plywood in the Sunrader. You can fair in along the edges for a gradual transition by using micro balloon filler in epoxy resin. Be sure to sand it within a day or two at most or it will be hard work leveling it once it cures to full strength hardness. In the areas such as under a water heater or in other utility areas you don't see the floor level on a daily basis anyway so it is not so critical to have the floor surface perfectly level. It is one of those locations where functional is good enough versus visual perfection.

Link to comment
Share on other sites

Awesome! Thanks for another great post Corbin.

My mistake. Thank you jdfrost64! That pointer got me starting this morning.

I have the area all cleaned up in a rectangular shape around the zone best I could to the edges, but there is rot to and under the edge.

So Im thinking scrape under the lip of fiberglass on the edge best I can and then epoxy inject fill that space. The other option is getting a piece of plywood to actually slide under that lip.

BUT...I keep on toying with the idea to just seal all of the foam board with epoxy, along with under the lip, then crisscross fiberglass fabric until the void is filled. Like a lasagna :)

What do you think of that.?

First I need to get a support under it and level it out because I noticed along the very rear of coach metal floor support, the foam is slightly dropping and is cracking along it.

Any suggestions on attaching blocks to the rear support propane support bracket to reinforce underneath? I can make the block, but cant figure out how to attach it to the two bolts without going through the floor.

Thanks again everyone for reading and post your knowledge.

The soon to be,

Snowrader

Link to comment
Share on other sites

I can't make any suggestions about the propane area as my 18' Sunrader is not configured exactly the same as far as locations of the propane and other compartments in the rear in relationship to the beams.

You can read up on how to lay in and repair fiberglass in boats before you start and that education will give you more in depth details about how to approach this. This is very much like replacing a section of decking in a fiberglass boat. Here is a tip you will want to know for checking if wood is rotted: A flat bladed screw driver will press very easily into rotted wood. If there is appropriate resistance it is likely the wood is not rotted. Test on a piece of good wood to get a concept of how much resistance there is in good wood when you press a flat blade screw driver into it. A number one flat blade is fine for this task, the size that fits a #4 screw versus a thicker flat blade used on a #10 screw.

First thing in making a plan for a repair is you have to know what you have going on in there. To keep you on track and to have a visual guide to help your thinking you need to make a map of the floor pan. Start by making some dimensioned sketches and filling in the information you do know. Width and length of the floor. Where the structural beams under the body are located in relation to the rear and side walls. Where the visible damage is. Add to the map any joins in the plywood floor sections. Where the propane tank is located.

Before you start working on the floor I suggest you search the forum on how to stabilize the motorhome from the ground so it does not shift as you are working. Then you will want to support plywood plates against the bottom side of the aluminum in the areas where you will be taking out the plywood and foam and replacing it.

Next since the damage goes under the fiberglass that was added to tie the inside of the pre-fabricated shell to the flooring panel you will need to explore under that area to see what kind of structure is at the outside edge of the flooring sandwich panel. I suspect there might be a strip of solid wood out at the perimeter of that panel. If that is the case it is quite possible it too has rot in it. If so then you need to find out exactly how far of a distance that piece is rotted as that piece should be removed and replaced with a new piece of rot resistant hardwood. You will remove the white foam and dig out the bad wood. Then you will cut a new piece of replacement wood and slide it into place under there. Epoxy is perfect for securing it, no mechanical fasteners such as screws or nails are needed. Cutting back the fiberglass that is over the existing floor is OK just don't cut into the outside shell. You can leave that pre-existing fiberglass cloth a couple of inches wide at the wall if you want to. It should then be easy enough to dig out damaged wood and slide in a new piece if needed. You can put new fiberglass cloth in to tie the shell and the floor back together. You will start the cloth about 4 to 5 inches up the wall and then drape it down and around onto the floor about the same distance over the plywood as it was originally done. But at the edge of the original fiberglass take a grinding wheel or a coarse sander and bevel upper surface at the edge to a thinner section before you lay in the new cloth. Fiberglass cloth does not do well 90 degree abrupt angles, it likes to be laid in over a smooth transition of surfaces. Fillet with resin thickened with wood floor or other suitable filler into any 90 degree corners before you install new cloth.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...