Window Removal & New Skins

[Doug1968]

I have removed some of the windows from my 102a3 and will be installing 14ga cold roll sheeting in their place. I removed two windows on each side, made a drawing of the required skin shape and had a local metal supplier laser burn the skins for me. I am installing 1-1/2" square tubing for added structural support in the window openings. The sheeting will span the length of the open areas and slide under the mounting flange of the mating windows. Should look very clean.

I plan on placing the panel to check fit and then if all is well I will apply a urethane adhesive to all of the structural member behind the new skin. Starting at one end I plan to attach the skin to the original vertical tube frame with 3 sheet metal screws. Then I will work the skin backwards towards the mating window at the rear of the bus while keeping the skin level and in position. I plan on applying heat to the panel using a kerosene heater during this process. Once I have the skin in the proper position I plan on attaching another set of screws at the rear of the skin just as I had done at the front.

On this bus the drip channel sits on top of the new skin at the top. This results in the new skin being clamped to the bus body when the drip channel is fastened. O the bottom side of the skin I could add a few fasteners but this could result in the skin buckling due to not being able to expand with heat?

In reading earlier posts I see that most everyone likes the Sika Flex product. I have not purchased an adhesive as of yet and would like some advise from those of you that have installed skins. The Lord Corporation has a two part bonding adhesive that is supplied by NAPA but it is more expensive due to needing a special application gun?

I would like to have the end result be that the skin is free of waves and hopefully without rivits or screws in the middle of the panel. Any suggestions or changes to my plan would be greatly appreciated. I greatly respect the experience and advise of those who have been down this road.

Thanks, Doug

[Dreamscape]

There must be someone here who could answer his questions. I have never done what Doug is attempting to do so I'm not much help, so therefore the Bump!

~Paul~

[Jerry32]

sonds strong! I just screwed aluminium over mine , tried steel but too heavy for me. I put 1 1/2 insulation board inbetween. Jerry

[TomC]

I just filled in the holes with 2 thicknesses of 3/4" plywood screwed and glued together, then covered with aluminum sheet on the outside that is glued and riveted (mostly for looks) to match the bus. The 1x2's that were used to line the interior are continued through where the window spaces are along with the sprayed foam.  So layered from the outside where the windows were is aluminum sheet, 2-3/4" thicknesses of plywood, 1x2 strips with spray foam in between, 1/4" wall covering.  Strong, quiet, yet could reopen them up for any reason.  Welding in extra gussets is just not necessary since the bus was already made with the window openings in mind.  Good Luck, TomC

[bottomacher]

Does that mean that each of your skins is about 3 by 10 feet? You will need to clean the framing members and corresponding skin surfaces very thoroughly before using Sika or other similar adhesive. The panels will be heavy and need to be supported precisely to avoid smearing the adhesive upon installation. I riveted mine, so I can't be a lot of help.

[TomC]

I used 3M 90 spray contact glue. Have one chance to get it right, and it works well.  Good Luck, TomC

[ArtGill]

If you use Sika, follow the directions.  I used a grinder to clean the steel to bare metal.  Then the Sika cleaner and primer.  I purchase an air operated caulking gun from Harbor Freight to put the Sika on with.  I worked great and only cost around $15.00.  The Sika is thick enough to wear out your hands if you do it manual.  I added vertical ribs in the window opening on 16 inch centers.  I used clamps on each end and drilled one hole in the middle, put a board across two verticals and ran a bolt through.  Sika calls for spacers and I used the little plastic crosses that are designed for spacing floor tiles.  They worked great and were cheap. If you can support the steel long enough to set, it will stay.  Don't mess it up with too many screw holes.  Again read and follow the directions and you will be pleased with the result.

Art

[Doug1968]

Jerry - TomC

I realize that the bus was designed to be adequate with the window openings but I thought I should add the vertical supports to support the new skin sheeting and to keep it flat for looks?

Bottomacher

You are correct. The panels are 41" x 117 3/4" long. Approximately 115 lbs each. I will clamp a 12 ft. long piece of angle at the proper height using the adjacent window openings to clamp. Then I will set the panel on top of the angle and move it front to back to get the proper position. I will then also be able to shim under the panel if necessary to obtain the proper height.

When you installed your skins using the SikaFlex did you add spacers between the tube frame and the skin? If so how thick. I would really like to have these panel come out without any waves. Do you have any problems with the skins becoming wavy in the heat? What was the size of your panels?

TomC

When installing the 3M 90 contact glue did it require a spacer between the frame and the skin? Do you have any issues with the panels expanding and becoming wavy in the heat?

Art

How large were your skins?
Which SikaFlex did you use?

Fellows - I'm mostly concerned with the panels expanding in the heat. It seems if I was to add rivits to hold the panel it would not allow the panel to expand and contract as required to eliminate the waves? I'm also concerned about the amount of work-time prior to setup of the adhesive?

Also, if I add the spacers between the frame and the skins I will not be able to place them on the ends of the panel as the ends need to slide under the adjacent window frame? Will only having the spacers in the middle of the panel make it appear correct?

I appreciate all of your responses and look forward to getting past this stage.

Thanks, Doug

[niles500]

Doug - A lot of people heat the panels during installation - HTH

[luvrbus]

Doug, there are better adhesives on the market than SilaFlex check with these guys they sell all brand including SilaFlex and are very knowledgeable about adhesives  www.ellsworth.com       good luck

[Airbag]

If you are looking for that smooth look why not flush rivet it and not worry about gooey glues? You can countersink it with a microstop countersink cage and get the heads smooth as a baby's butt. Or even pull them a little high and shave them with a micro shaver. These tools can be had now on e-bay for a song.

[Nick Badame Refrig/ACC]

Hi Doug,

Since you are using cold rolled steel and not aluminum, I would use both adhisive and rivits.

Reason, the sheer weight of the steel.. I used 080 alum with sika only at first. Good thing I waited a year before my paint job

because, the sika failed in spots. I then added rivits to every panel and you can barely notice all the rivits with the full body paint.

One more word of advise with cold rolled, Primer the inside of all panels before you hang them... This will rust without a doubt if not primered.

That space where you will be insulating will accumulate alot of moisture, more so on the steel then your inside panel. Whenever you have 2

different climates, condensation happens..

Your cold rolled steel will not expand as much as aluminum will but, having rivets will not cause any stress on the panel if spaced properly.  I went every 3".

Good Luck
Nick-