Thoughts on this panel repair plan

[6munro]

Originally Posted by DRM901

On the fairing, I suggest West Systems with their light filler. Sands easily and will hold up better than Bondo, or I just didn't do the Bondo right.

This is just an inside wall which is why im just using bondo brand. I know its not the best body filler. Do you think it would matter inside though?

[Dav L]

What are you using bondo for? On the inside? Can't think of an application for it on the inside...

confusing thread...because no pictures to get context on what you are trying to do.

[6munro]

Originally Posted by Dav L

What are you using bondo for? On the inside? Can't think of an application for it on the inside...

confusing thread...because no pictures to get context on what you are trying to do.

Ha... yes the thread started as a discussion on interior pannel replacement and then kind of hooked into exterior delam.

I have replaced some water damaged interior luan. Instead of replacing it with Luan, I fiberglassed it with 3 layers and epoxy resin (dont get me into why I did this but i had My reasons). So anyway, now I have to feather and smooth the fiberglassed section. Im doing bondo instead of something like joint compound because bondo will handle the road vibrations. Its really an overbuilt repair.

[Dav L]

Ok, so the topic title asks for "thoughts on this repair"....thats nutty
You will have EVERYTHING in the RV covered and filled with sanding dust....
A $30 sheet of quality Luan and you would have been ready to wallpaper / paint.
Again, hard to tell what you are up to because no pics...
But you might consider covering the fiberglass with a sheet of Luan instead of trying to body finish the rough fiberglass.

Use Sitka glue to bond the Luan to whatever (studs / fiberglass / old (but dry) Luan).

You don't "clamp" this stuff together. You brace against the opposing wall to press the material to the studs. For exterior (if you even need to mess with that as you should have done the repairs from the inside...) you brace against a tree / house / vehicle / trailer parked next to it. You can even put 2x6's on edge on both sides of the RV, connect them with rope across the roof and below the floor, and then use wedges to brace the outside wall against the 2x6. For the ceiling, it's simple...just prop the ceiling up to the joists with some furring strips to the floor. Wait overnight till the glue is set and remove.

Everything should be perfectly dry before it gets put together. And if it won't dry, then replace whatever that is (insulation, luan etc). Otherwise it will never dry and will rot / mold away. It took about a month of exposure before my ceiling Luan was dry enough to recover. I slide the decayed stuff out from under the studs (joists) to replace with new / fresh material.

Anyway, sounds like you are past these steps...

[HopsBrewster]

bondo will eventually break out because it is less flexible than fiberglass. It's heavy, too. If you ever look to buy a Corvette that has had bondo used in body repairs, run away.
The fiberglass resin could have/ should have been feathered out when applied, then all you would have had to do is apply some wall paper. It might not be too late to do this. See if a skim coat of FG resin will feather out, then paper it. Painting would involve more fine sanding and priming.

[Dav L]

Without seeing pictures, hard to tell how big an area or how flat / pit free the glass he used is. But I would be surprised if he used half a pound of body plastic once it's all sanded flat.

And, body plastic is plenty flexible enough. There really isn't much flexing on an interior wall.

Using resin will help seal pin holes, but won't fix any waves or depressions which is likely what he is having to deal with. If he is wallpapering, no need to seal pin holes anyway. The paper will cover them.

Doesn't sound like a good implementation for wet glass. I did just purchase flat FRP white board from Home Depot (paneling aisle) to redo my wetbay. This might be a good material to cover the wet glass issues. Thin, strong, smooth, available, inexpensive ($25/sheet). I have used it to replace Filon for exterior too. Just glue it to what he has. Paint ready.

[6munro]

The glass is already done and I did have my own reasons for it. Given that, I still need to smooth. I will look into using resin instead of bondo. and yes I will be wallpapering over to cover the tiny surface defects. It does not need a ton of bondo or whatever I use. Just some feathering and knockdown to get it completely flat. I would not anticipate that any of the filler will be over 1/32" thick.

[DRM901]

If the epoxy is fully cured, you will want to prep the surface first before you add the filler/fairing layer.

See: https://www.westsystem.com/instructi...e-preparation/

[Roy-c]

If you used epoxy resin and not polyester ( fiberglass ) you need to use an epoxy fairing compound such as West system fairing filler. Bondo ( which is polyester based ) won't adhere well to the epoxy.

[Dav L]

Originally Posted by Roy-c

If you used epoxy resin and not polyester ( fiberglass ) you need to use an epoxy fairing compound such as West system fairing filler. Bondo ( which is polyester based ) won't adhere well to the epoxy.

Hmm, tell that to every body shop in the land.
Bondo works perfectly fine on fiberglass.
Just needs to be roughed up with some 36 first.

[Jay D.]

Originally Posted by Dav L

Hmm, tell that to every body shop in the land.
Bondo works perfectly fine on fiberglass.
Just needs to be roughed up with some 36 first.

It's not EPOXY resin used in auto body shops. i think Roy is probably correct, i remember a job i did for a guy that he had someone else use epoxy on and regular bondo over it. it stuck but not very good you could scrape it off .it just doesn't adhere to epoxy good
Jay D.