what material do I use on the walls that will bend to the curve above the window

[4104bigred]

I'm hoping that someone that has converted a 4104 or 4106 can enlighten me on how they got plywood to bend on the ceiling above the windows. i have tried 1/4 inch ply and can not get it to bend and becoming very frustated. so your help is needed

BTW i have insulated with foil faced foam and installed 1 x 3 furring strips running fore and aft so i have something to attach the plywood to

thanks

chris

[4104bigred]

Hey Nick, maybe your Dad can offer some insight on this

chris

[Dallas]

Chris,

I used luaun (1/4") and kerfed the back sarting at 3" apart and working closer to 1" apart.

I mad the kerfs between 1/16" and 1/8" deep.

Or you could go high dollar and use "bender board" which is available through many specialty stores.

I hope this helps.

Dallas

[4104bigred]

thank you dallas, I did the knerf cuts also and the result was the plywood broke instead of bending maybe I should try more cuts closer like 1 inch and not so deep

chris

[Melbo]

I used tempered masonite in my 8

I am not sure how tight the bend is in your coach

Where my bend was a little intense I would score the back side about every inch with a utility knife

Some of it I am not happy with but most of it came out great

Melbo

[4104bigred]

Hi Melbo, I too had the idea of using masonite hardboard. what did you do to finish off the masonite? wood or fabric???

thanks

chris

[KC Eagle]

I'm in the process right now using 1/4 plywood. I have been cutting it to width, spraying it down with hot water then placing three ratchet straps on the 8' length to get it bent on the correct radius. After I get the bend right I use strapping tape in 4 places to maintain the radius then remove the ratchett straps. I allready have my walls covered in plywood and the center 4' of ceiling so I am only applying this 1/4" to the curved portion. I then screw my 'trussed up" piece of ply to the ceiling, place a 1x12 board resting on a hydraulic jack under the lower end on my ply, pump the jack until it takes some of the pressure off the tape then cut the tape adjacent to the jack. I jack up the board until it 'pops' into place between the ceiling pieces and the wall pieces. I suually nedd to reposition the jack once or twice to get the whole panel snapped into place.

[Melbo]

I like that idea of using water and straps -- wish I had thought of that

I am going to use vinyl headliner to a point on the curve and laminate below that

As a transition to the laminate I am installing antique copper cornice like on tin ceilings

I can use it as a transition and a chase for low voltage wiring.

Melbo

[TomC]

I used used 1x2 fir strips and attached 1/8" plywood on the roof (how thick does it have to be over the insulation?).  Course my transit doesn't have the severe roof bends that the GMC does.  Look into using wiggle wood.  It is made in one way (bends one way but not the other direction) or 2 way, but that is pretty flimsy in that it needs alot of support.  After installing my 1/8" plywood on the roof, I painted it semi gloss white then used 2" wide oak molding to go over the screw holes.  Instead of trying to hide the screws, used finishing washers to accentuate them.  I like the look and it is easily removable for any reason in the future.  Good Luck, TomC

[4104bigred]

  Thanks Guys for the replies. I think I will use masonite and just get her done

chris

[Ace]

I used 3\8 plywood in our eagle without any kerfs. I also ran firring strips front to rear and that made it easy. Run the plywood down the center of the bus 4 foot wide and 8 foot long. That piece will give you a strong foundation to brace the side piece against. Your next 4x8 I cut down the middle making it a 2 foot wide piece 8 foot long which worked for 2 sides. Take the 8 foot side of the 2 footer and put it next to the full sheet. Secure it at the seam. Use a block of wood like a 2x2 or such and a bumper jack from a older car. As your jacking it up, make sure you keep the block and jack next to the wall. You can jack it right up into the curve and once there, secure it good at all points. One person CAN do it but two is always better and a little easier!
It worked great for me!
Ace

[Dave Siegel]

Instead of trying to re-invent the wheel. Use bender board. You can get it at your local millwork supply (not the box stores. Bender board is designed to bend in the tightest of radii with out a splinter. It comes in almost every thickness conventional plywood comes in.

Dave Siegel

[Skykingrob]

Hey Chris
I just finished this project in my Prevost. I was able to purchase bendable luan plywood in 1/4" and 3/8" from OP Hardwoods locally. 1/4" was $38.00 and 3/8" was $44.00 per 4x8 sheet.  Other options are wiggle wood, wonder wood but no local distributor for me. Do a web search for bendable plywood to see if someone is close to you.  I came down 16" from the ceiling and put two pieces of the 1/4" together to match up the 1/2" plywood that I sheeted everything else with. HTH

Rob
91 Prevost LeMirage XL
Missouri

[Greg Roberts]

Bender board  as was mentioned by Dave, is designed just for this type of application. I used it and it worked perfectly on my Eagle. It might work on a GMC too.

[Rodsmc5c]

   
     I used baltic birch 1/4" for the ceiling and wall and two layers of 1/8"  on the curve. works really well. It comes in 5' by 5' sheets.
                             Rod