Insulated FRP -- Where to buy?

pauldub wrote:
If you don't want a smooth panel, here's a pebbled panel. Be sure to choose an adhesive that is compatible with whichever foam insulation you choose. I'd probably look for a spray adhesive to bond the foam to the panel, maybe from 3m.

Yep, that brings me full circle. That is what I found as well as some foil-clad insulation.

Now the question is how to make them stick together since not much sticks to frp and that which does eats foam. The foil should help out with that.

If you don't want a smooth panel, here's a pebbled panel. Be sure to choose an adhesive that is compatible with whichever foam insulation you choose. I'd probably look for a spray adhesive to bond the foam to the panel, maybe from 3m.

lordnorth wrote:
Gdetrailer... I appreciate that you are trying to help. But we are talking apples and oranges. You have an '81 and an '84 TRAILER. I'm talking about the door on a 2011 Class A Motorhome. They are nothing alike.

Maybe its my fault for not being specific enough, but on the other hand maybe it has something to do with the fact that you think I'm an idiot who can't figure out how to fit a piece of plastic under the metal trim. Instead of answering my question, you assumed that I was asking an idiotic question and started telling me the way I *SHOULD* do it instead of just helping me out with what I asked.

Maybe on older RV's they were made of wood. Maybe travel trailers have wood. My door has no wood. Took out the window and the latch to look at different places. NO WOOD.

Smooth fiberglass outer surface, bonded to foam, bonded to pebble surface FRP, with a metal frame around the entire door.

It looks something like this: https://www.lci1.com/assets/content/img/gen/640_601_lippert-rv-entry-door-optimized.jpg

No, there is no structural door damage. The frame is intact. It hangs plumb, it opens and closes easily.

ITS JUST THAT THE FREAKING PLASTIC CRACKED ON THE INSIDE.

I 'appreciate' the suggestions on what I 'need' to do to replace or repair the door, but I know what I need to do, thank you. I'm just asking about the best way to go about it.

Rant over. I do appreciate that people are trying to help, but if I ask how to get to Orlando, please don't tell me I really should go to Houston instead because its a much nicer place. Just help me get to Orlando, and if you can't help me get to Orlando then......

Hate to tell you, look closely at the pix I posted to the door on the RIGHT..

They DO NOT FRAME THE WINDOW OPENING AT ALL, you cannot base anything on pulling the window.

The one on the left is the one I made, and I FRAMED the window opening to make the door stronger and to stop the window opening from allowing leakage.

Pull off the metal trim going around your door, you WILL FIND SOME WOOD under there.

That outside metal trim is TRIM, not "structural".

The wood frame under the metal IS structural..

Your inside FRP did not crack for no reason, it cracked because of a STRUCTURAL ISSUE..

Oh, and I will add that YOU CANNOT BUY FRP GLUED TO FOAM AS IN A DOOR BLANK, IT IS JUST NOT MADE, PERIOD!

No one just randomly makes RV DOOR THICKNESS INSULATED FRP PANELS WHICH IS WHY YOU CANNOT FIND THEM.

If you insist to continue down that rabbit hole then you WILL HAVE TO SIMPLY BUY A NEW DOOR WILL ALL THE TRIM.

LOOK AT THE WEBSITE I POSTED..

Otherwise go to YOUR LOCAL RV DEALER AND HAVE THEM ORDER A NEW DOOR.

Personally, I would simply cover up the cracks with some fiberglass and resin and call it a day which WILL be the cheaper route.

Oh, yeah, about the insulation..

If you did manage to remove the insulation with the old FRP, you CAN use ANY insulation you like that you can find at any Home center like Lowes/Home Depot.

There is nothing special with the RV door insulation, in fact mine was from a 1980s trailer and only had fiberglass insulation inside.

From plain old Styrofoam to Polyisocyanurate Rigid Foam, any of that CAN be used.

I would recommend the PolyIso since it does have a much higher R value per inch than any other foam board or fiberglass insulation..

Can get PolyIso from 1/2", 1" and even thicker.

You can also layer it to fill in the max thickness of your door by gluing up different thicknesses.

My door, I used 1/2" PolyIso with a layer of 1/4" FOAMULAR Extruded Polystyrene (XPS)all glued together with paneling adhesive in order to get the max R value and fill the entire door cavity.

Gdetrailer... I appreciate that you are trying to help. But we are talking apples and oranges. You have an '81 and an '84 TRAILER. I'm talking about the door on a 2011 Class A Motorhome. They are nothing alike.

Maybe its my fault for not being specific enough, but on the other hand maybe it has something to do with the fact that you think I'm an idiot who can't figure out how to fit a piece of plastic under the metal trim. Instead of answering my question, you assumed that I was asking an idiotic question and started telling me the way I *SHOULD* do it instead of just helping me out with what I asked.

Maybe on older RV's they were made of wood. Maybe travel trailers have wood. My door has no wood. Took out the window and the latch to look at different places. NO WOOD.

Smooth fiberglass outer surface, bonded to foam, bonded to pebble surface FRP, with a metal frame around the entire door.

It looks something like this: https://www.lci1.com/assets/content/img/gen/640_601_lippert-rv-entry-door-optimized.jpg

No, there is no structural door damage. The frame is intact. It hangs plumb, it opens and closes easily.

ITS JUST THAT THE FREAKING PLASTIC CRACKED ON THE INSIDE.

I 'appreciate' the suggestions on what I 'need' to do to replace or repair the door, but I know what I need to do, thank you. I'm just asking about the best way to go about it.

Rant over. I do appreciate that people are trying to help, but if I ask how to get to Orlando, please don't tell me I really should go to Houston instead because its a much nicer place. Just help me get to Orlando, and if you can't help me get to Orlando then......

westend wrote:
Sounds like it would be a good opprtunity to build a new door. Alternatively, replacement doors should be available.

I would agree, but I think the OP is over their head for attempting to make a new door from scratch if they could not figure out how to fit a piece of plastic with the thickness of a credit card under the metal trim.

Buying a new door may be tricky, RV doors tend to lack uniformity in size and design, unlike doors for sticks and bricks RV doors lack any real standards..

I would suggest RV PARTS NATION as a possible source for replacement doors.. They purchase leftovers from RV manufacturers and may have a warehouse full..

OP might wish to give them a call but most likely may need to make a trip there..

Sounds like it would be a good opprtunity to build a new door. Alternatively, replacement doors should be available.

Found a picture of my door..



You should get a good idea of the construction of a typical RV door.

Door on the right is the ORIGINAL DOOR that had severe rot.

Door on the LEFT is a NEW DOOR that I made from scratch.

lordnorth wrote:
Thanks guys. Appreciate the link to the filon... but I am looking for the interior of the door, not the exterior.

As for reusing the existing insulation... that is already bonded to the FRP that is used for the interior of the door (that is cracked badly). You can't remove the FRP without removing the insulation, unless you tried to cut it off - which I can't imagine would go well.

And you can't just put a new piece over it since it would be too thick to fit within the door framing.

I'm looking at two options to bond it at this point... either a Contact Cement or an FRP approved adhesive like DAP's Dynagrip Heavy Duty Max (has to be the MAX because the regular heavy duty isn't compatible with FRP...)

I will update as to my progress.

You give up to easy.

RV Filon is .045" thick or about 3/64" thick.

FRP at Home depot is .090" thick or 3/32" thick.

Your inside of the door IS covered in Filon, yes?

You ARE wanting to REPLACE the Filon on the inside, yes?

You will most likely need to grind or sand (belt sander with coarse grit) a SLIGHT amount of the OLD FRP from the door EDGES.

Should not have to remove the existing surface, just taper down the EDGES of the door in order to fit the FRP under the metal edging.

YES, you WILL have to remove the metal edging in order to do this properly.

Your door latch/lock AND WINDOW WILL accommodate the SLIGHT increase of the depth of the door.

To recap, you do not have to be precise with the door depth other than the EDGES were the door trim covers the inside FRP surface.

It would be optional to grind or belt sand all of the old FRP off.

This isn't brain surgery so you do not need exact dimensions.

You WILL NOT find ANY FRP with insulation preglued, product is not made that way and would not work in your application.

Your door WILL have a WOODEN FRAME WORK hidden under the metal trim strip. The current insulation IS GLUED to not only the inside panel but the OUTSIDE PANEL and is also glued to the WOODEN FRAMEWORK of the door.

Honestly, I suspect that you have bigger troubles, that inside FRP cracking is possibly a sign that the wooden door frame is compromised and is sagging due to water damage..

You may end up having to build a new door from scratch.

For the record, Filon IS a "brand name" for FRP (Fiberglass Reinforced Panels)for those that don't realize it.

Thanks guys. Appreciate the link to the filon... but I am looking for the interior of the door, not the exterior.

As for reusing the existing insulation... that is already bonded to the FRP that is used for the interior of the door (that is cracked badly). You can't remove the FRP without removing the insulation, unless you tried to cut it off - which I can't imagine would go well.

And you can't just put a new piece over it since it would be too thick to fit within the door framing.

I'm looking at two options to bond it at this point... either a Contact Cement or an FRP approved adhesive like DAP's Dynagrip Heavy Duty Max (has to be the MAX because the regular heavy duty isn't compatible with FRP...)

I will update as to my progress.