Delamination repair

[TNGW1500SE]

I've got a 2003 Itasca Sunova 30B and I have delaminated on both sides of the RV. It's down low and almost the whole side. It also feels soft behind the areas as well.

What what I understand, the fiberglass is just a thin layer, glued to a thin plywood, that is glued to Styrofoam in a sandwich.

I've watched some videos where they drill small holes and pump in epoxy and "clamp" the fiberglass to cure. That seems like you're just gluing the fiberglass back to rotten wood and Styrofoam that has lost its integrity. Might fix a small area but seems like a waste of time.

I'm contemplating a major (Winter project) as follows:

Cut off bottom 2 foot of fiberglass sidewall.

Remove rotten plywood exposing Styrofoam and aluminum square tubing.

Allow time for RV to dry out if any moisture is present.

Spray expanding foam insulation anywhere the Styrofoam is damaged.

Cut spray foam off flush with sidewall.

Add more aluminum tubing where needed to "beef it up" and where seams meet.

Recover area with aluminum diamond plate, riveting and gluing to aluminum square tubing, sealing all seams.

Finished product would be a 2 foot wide strip of diamond plate going from front to rear on both sides.

I would also remove all windows and reseal EVERYTHING above that could have leaked.

I could paint diamond plate and lower (existing) storage doors to match.

Sure it will look like a repair but I really don't care. We've looked at new RV's and for 100 grand, I don't really like them any better than the (paid for) RV what we have. I've found the diamond plate in 4x8 sheets for 100 bucks a sheet. I think 5 sheets would more than do it. They also sell a trim piece that goes between sheets. I'd seal between each sheet and trim out the top with a molding.

It seems like a big project but the RV is in great shape. It has less than 20K on the clock and we've made it our own (so to speak) inside. If I could get this problem REALLY fixed, we could get years out of this RV. It's kept in the garage.

Seems like the way to go.

Thoughts?

All advice is welcome even if not followed 😉

[fourthclassC]

Well I love the look of aluminum diamond plate and I continue to try to find a place to put some on my rv. That being said, I have done a lot of delam repair by removing the necessary moldings, prying up the filon and replacing the luan with new luan or the same thickness plexiglass with holes in it then clamping it with cargo bars against my garage. The adheasive I swear by is gorrilla glue for this. I believe it will last longer then the substrates. I line the idea of replacing the filon with al dimond plate. Make sure you do not cause any galvanic corosion. PS I am sure gorrilla glue will bond aluminium to aluminium (as strange as that soiunds.

[jandjbaums]

Interested.

[Gjac]

bingford wrote:
Thinning the epoxy with a solvent could damage the styrofoam. The solvent will melt it.

The FG is bonded to plywood first then comes the closed cell foam. Most use a polyurethane or polystyrene foam which are not attacked by solvents in the resin.

[BarneyS]

Moved to Tech Issues forum from DIY.

[bingford]

Thinning the epoxy with a solvent could damage the styrofoam. The solvent will melt it.

[Gjac]

It really depends on how bad the delamination is and how much damage there is to the substructure. There are a number of thin epoxies like water glass or git rot. You can also just add more solvent to epoxy or polyester resin to thin it down. The solvent will flash off leaving a good bond. To use epoxy or polyester resin the substrate needs to be completely dry which may prove difficult. I removed the window on mine and put wedges between the FG and the wood and foam and parked that side in the sun for 5 days. That still was not enough to dry the substrate. I also add acetone to replace the moisture which helped but still did not get all the water out. I ended up using polyurethane resin because it will react to moisture and cause a foaming action which will weaken the bond somewhat. If you have a lot of rot underneath I like your diamond plate approach, The .050-.125 plate will be stronger than .030 FG outer skin especially if you mechanically fasted to the Al framing. You can also use thicker FG skins or smooth Al skin to better match what you have now. Either way it will be a big project and good luck to you either way you go.

[matt_m_]

http://www.delamrepair.com/index.html

this is what i used..

[SpeakEasy]

In my opinion, the diamondplate repair would give you a better appearance than what you'd get by injecting e-poxy, but the e-poxy injection will give you a better structural repair.

When you cut out the damaged material you'll be removing the structural components of that area. The diamondplate won't replace that structural strength.

When done properly, e-poxy injection actually penetrates the damaged wood fibers and replaces the lost wood strength with new fiberglass strength. You would be surprised by how much strength you can restore through this method. Unfortunately, when you're all finished, you will see the repair "holes" where you injected the e-poxy. Unless you're an expert at body work.

For my money, I'd go with the structural repair over the diamondplate.

-Speak

[TNGW1500SE]

RVcircus wrote:
I agree with Westend on this. I'd try the epoxy repair method 1st before cutting the bottom off all the way around the trailer. If you can get enough epoxy in there it should turn into a solid piece.

You guys are tempting me! I just worry that I'll be doing a bunch of work that will not last long. The diamond plate would last the life of the motorhome. But like I said, it's a wintertime project so I've got plenty of time to let it bounce around.

[RVcircus]

I agree with Westend on this. I'd try the epoxy repair method 1st before cutting the bottom off all the way around the trailer. If you can get enough epoxy in there it should turn into a solid piece.

[skiles]

I'm following this as well. That's a problem I might run into. I've seen a video or two on the epoxy/clamp method.

[westend]

Your process seems like a lot more work than may be necessary. Most folks that DIY with delamination either tackle it through the inside, or inject epoxy adhesive from the outside. I'd suggest to do the latter.

If you can inject enough thinned epoxy into the interface of fiberglass and plywood skins, then brace and clamp until cured, you would probably end up with a reinforced wall. It helps to have a structure close to the RV like a garage or shed, something you can force a brace against to keep contact between the layers while curing. I would do small sections at a time (maybe six feet?) and use small, patchable holes to inject epoxy. The small holes could be filled, sanded, and painted when done.

[ddndoug]

Interested in the responses, so I'm following.

Doug