Water damaged cargo pass through doors

[dkperez]

I don't know who or what "DH" is. The only "multitool" I know of, or could find online, is a little thing with a bunch of small blades in the handles of a pair of pliers...


I was thinking I may try cutting through the styrofoam and separating the thing into 2 halves, then scrape the styrofoam off the back of the outside coating. If I can co that, things should be reasonably straightforward from there.


As for elongating the holes - I kept thinking there was some magic tool that did it, but I've got a Roto-Zip, I've got Dremel tools, I have a several routers. so, if it really is a "drill a round hole then brute force make it oval, its not hard, just boring and prone to me doing something dumb.

[dkperez]

Progress and new challenges...





I separated the front of the panel and the back. The back is a total loss. Whatever the covering that was on there, it was attached to the plywood, which as it collapsed and splintered and all that tore the covering - it LOOKS to me like the vinyl wallpaper I've seen. But, I'm not overly concerned about the back - it's inside.


I scraped all the styrofoam junk off the back of the front cover. It LOOKS like fiberglass but I don't see the random fiberglass strands in it or matting. It mostly looks like the liquid stuff you roll the glass strands into when you're making fiberglass parts.


In any case, a little 120 grit in a random orbit sander and it's smooth and ready to be attached to whatever goes behind it.............


Which is the NEXT question. I checked the frame/channel this panel goes into. It's exactly 3/4 inch wide. The OLD panel was just the tiniest bit less then 3/4 thick, so it fit easily in the frame/channel. But, this means I CAN'T use something that's 3/4 thick because with the fiberglass front panel on the front of it, it'll be too wide to go in the channel.


I'd like something readily available, sturdy, light, waterproof and easy to work with (cutting, drilling, so on). Given the problems with plywood, I don't see using that again. Pressure treated would be usable but it's HEAVY and rough. It looks like Home Depot has it in 1/2".


Another option is the white PVC panels Menard's has - smooth on one side and textured on the other. It's the same stuff I built the generator box from, and it's not real heavy, it's definitely waterproof and it's easy to work with. It is supposed to be available locally, and comes in 1/2 inch thick, 4 x 8 panels, so I can get both doors out of 1 panel.


EITHER of these will be 1/2 inch, so I'd have to shim the back side, which is no big deal. The PVC is about 20% LIGHTER than the 1/2 inch plywood, so the panel would weigh about 15 pounds instead of 19 for the plywood.


And finally - gluing the front piece on - Can I use contact adhesive? I HATE contact adhesive and it hates me! Can I use construction adhesive? What would work well for gluing a fiberglass piece onto PVC?


OR, do I NOT glue the front piece onto the substrate? Just put the pieces together with the knobs and lock and put the thing in the frame.



Thoughts on best choice for this situation?

[HiWay-OurWay]

From the Permabond site:

What is the best adhesive to bond fiberglass?

Several types of adhesives bond well. Understanding the desired cure process as well as what the bond will need to endure will help us choose the best adhesive for each carbon fiber application.

Cyanoacrylate – also known as instant adhesives, super glue, crazy glue, ca glue, etc. For bonding carbon fiber reinforced polymer consider a black, toughened grade such as 735 low viscosity or 737 medium viscosity. For clear bonds consider Permabond 731.

Two component epoxies – Permabond two part epoxies cure at room temperature and provide strong bonds to fiberglass.

Structural acrylics – MMA grades such as TA4246 are very strong carbon fiber bonders.

Polyurethane adhesives – All Permabond polyurethane adhesives offer high strength, high peel strength, and good impact resistance.

And this for PVC:

How to bond PVC

– To understand how to bond PVC we first need to understand what variety of PVC is at play. PVC or polyvinyl chloride is available in many forms. For adhesion purposes, we will loosely categorize PVC as:

Plasticized PVC = PVC
Rigid PVC = RPVC or uPVC (unplasticized PVC)
“Green” PVC
The surface energy of rigid PVC is 39 mJ/m² while the surface energy of plasticized PVC can be as low as 33 mJ/m². “Green” PVC are relatively new blends of PVC resulting from new chemical restrictions and recycling rules. Some “Green” varieties can be quite difficult to bond with conventional PVC bonding adhesives.

Below are some guidelines on which chemistries work best on the different types.

Plasticized PVC = PVC is best bonded with either cyanoacrylates or UV Curable adhesives. There are various grades of cyanoacrylates available. Flexible grades such as 2050 and 731 are ideal for bonds in which the flexibility needs to be maintained. Medical grades are available for medical device applications requiring biocompatibility.

Many plastic bonding UV curable adhesives bond well to PVC. One substrate must transmit UV light. Flexible and medical grades of UV curable adhesives are also available.

Rigid PVC = RPVC or uPVC can be bonded with Cyanoacrylates and UV Curables, however, for this type of PVC, 2 component epoxy adhesive or structural acrylic adhesives can also be used.

Ultra Fast Surface Insensity PVC bonder



“Green” PVC = There are a variety of grades available – many require a surface insensitive cyanoacrylate such as Permabond 792 to achieve a strong bond.

For information on how to bond PVC in your application please contact our technical support team.

Tips for surface preparation and bonding PVC:

1. Providing the surface is clean and dry and free from contamination,
PVC can be bonded “As Received”.
2. If you do wish to do a solvent wipe before bonding or for clean up
afterward, use isopropanol or Permabond Cleaner A; acetone is too aggressive and can attack the plastic.
3. For highly plasticized PVC, consider testing the longevity of bond life due to the potential of plasticizers migrating into the bond area.

So, it sounds like a 2-part epoxy adhesive is the best match to bond these two surfaces together.

[dkperez]

Thanks for the material and bonding info. Using that, I found a product that should work.


Update: Done...




The whole process was pretty straightforward once I got the crud off the fiberglass cover.


Bought a 4x8 sheet of 1/2" PVC, cut it down so I had 2, 2 foot by 5 foot pieces, one for this door, one for the other side when I do it.


I did a little looking and found a Liquid Nails product called Fuze It that says it works well bonding PVC to fiberglass. I scuffed the surface of the PVC with a random orbit sander and 60 grit, then cleaned everything with denatured alcohol. Laid the cover on the pvc, marked where it would go, used a caulking gun to lay a bead around the edges, then liberally around the whole PVC panel, laid the fiber glass on it, positioned it, clamped the bottom edge since I wanted to be SURE that was absolutely adhered, and put a bunch of weight on the rest of the panel after rolling it, then left it overnight, I'd say about 16 hours.


This morning it was VERY solid. Cut it down as needed on the table saw, then did the corners and ends with a jigsaw, a little sanding to smooth, and voila it matched the fiberglass panel perfectly. Put it back in the frame, laid it down and made some pvc shims to go around the back of the panel to fill the gap between the 5/8 inch thick panel and the 3/4 inch wide frame. A little silicone to keep the spacers in place, and everything was good.



Put new pop rivets in the frame where they'd been, made sure the holes in the bottom of the frame were open so any water that got in could exit, and voila, time for new holes...


BTW: When I cleaned out the frame, it turns out they'd put silicone or some sort of rubbery stuff all the way around the frame. And covered at LEAST 2 of the three drain holes in the bottom. Which may have been part of the problem.



Drilled a 5/8" hole where the 3 latches went, and used a Dremel tool with a small rotary sander to elongate the holes to sort-of fit the fiberglass cutouts - the problem was, the door had been so rotted, nothing was holding the latches in place, BUT all the chemicals that leached out of the plywood had corroded and essentially destroyed the latches. They got very hard to turn and with nothing to hold them they stretched the holes in the fiberglass as the whole latch cylinder would turn. So I had to be sure NOT to make the holes as big as the holes in the fiberglass.


THEN I decided I wanted more solidity against the latches turn in the current panel, so I added plywood pieces on the back of the door, where the three holes are. Used the Dremel tool again to make those just the right size and shape for the latches to go through and it was ready to put back on.


I was able to save the existing lock, so I installed that, but the other two latches were destroyed. I have a container with at LEAST a half dozen of the latches with 7/8 " cylinder, so NATURALLY this door needs the 1 1/8" cylinder latches! Thus two holes while I get latches.


Slid the door back on the hanger on the trailer, and it fits!


It feels very solid, not heavy, and unless I'm missing something, should outlast me!


Next I'll have to pull the door off the other side and do the same thing.

[dkperez]

Trailer has been out for a couple outings. Doors have stayed together! It seems to have worked fine, is SLIGHTLY heavier than the original door, but it's a WHOLE lot less prone to water damage!


I rand into a guy in Duluth who has the same trailer. He bought it used a few months ago and asked me how ours was... told him sort-of OK, but certainly not great - between the slide that wouldn't go in and out, the rear jack motor that failed repeatedly, some other things, and finally the passthrough doors rotting away, it's hardly Keystone Cougar has been far from high quality...


The slide problem was a bad <whatever the thing is that it rides on when going in and out>. That was fixed by a different dealer because the selling dealer - who now is deservedly out of business - wouldn't fix it when it was in warranty.


The jack motor kept getting water inside and the springs on the brushes would rot away in a few months. I fixed it twice with new springs and after the second time I installed a big PVC pipe over the motor so water couldn't get inside - tried silicone caulk on the whole thing first and that DIDN'T work - thus the second replacement of springs.


HIS comment was that he was seeing the SAME thing on both the passthrough AND the propane compartment doors. He didn't check those when he bought it used, and now he's going to have to do similar repairs.


In any case, doors are working at the moment, and I TOO am going to have to do the propane compartment doors sometime 'cause they're doing the same thing at the bottom...