Tape for skinning question

[travelingfools]

A few years ago I built an alum trailer for the fire service. For my skin, I welded the outer perimeters and used a 3M 4950 VHB double side tape for the inner struts. As I'm close to doing my skin, I am planning on riveting the outer perimeter as the rivets will be covered by existing trim. I would then use the tape on the center areas. As I was looking for the tape again, I came upon a JVCC DC-UHB45 tape. The specs are close and both list skinning of vehicles as typical use to replace rivets etc. The major difference appears to be the adhesion. The 3M has 400oz psi and the JVCC claims 240 oz psi. Does anyone have any experience in this field ? Is the difference in adhesion something Id ever notice in my application. There is a significant difference in price. Has anyone used the JVCC product or is there another ?

[jjrbus]

 My thinking when I reskined my bus was. I am riveting the perimeter of the sheet so the adhesive I use in the field while necessary to stop rattles and squeaks was not critical. Structurally it was a window which opened!! I planed on having the bus spray foamed which also "glues" the skin to the framing members.
For the perimeter I used a decent quality butyl rubber caulk, this was for weather proofing only the rivets will do the adhesion. I cannot remember what I used on the field, it was nothing expensive just a decent metal to metal adhesive caulk. Seven years no problem.    HTH Jim

[belfert]

The aluminum skin on "screwless" enclosed trailers is held on with some sort of tape.  I have seen at least two of these trailers recently with a panel coming loose, but they did not use any screws or rivets at all.

My Dina bus has all of the aluminum skin held on with either tape or some sort of adhesive and I have had only one minor issue with the skin coming loose. 

[coachconverter]

I don't know if this is the truth, but I had someone at Sika tell me once that they were being sued by a customer because they could not replace panels on their trucks because they were Sikaflexed on.  We were talking about the 252 product.

Again, it was a salesman, so take that into consideration. 

I've never tried to remove a panel affixed with 252, but I've panned in several buses now with only 252 (two beads around perimeter with 1/8th inch spacers, used the cleaner/etcher and primer on both surfaces, followed instructions to the T) and have never had a problem. 

The first bus I did was about the time my wife was due, I got the panels on but not the windows just in time for a rare hurricane that hit the DC area, it blew through with category 3 winds and the skins held on perfect.  I imagine there was a lot of force blowing around in that manmade tunnel that night.  The wind was strong enough to push rain through the window frames on my house!!!

Anyways, it's late, I'm rambling, the point - I recommend Sikaflex 252!

Todd

[TomC]

From a truck stand point- most all the dry van manufacturers are now using the 3M VHB double sided tape.  I questioned how it could work so well until I found that once the tape is in place and the two sides are together, the van manufacturer then rolls over the joint with a heavy roller popping the foam in between the layers of tape that has the hardener in it.  By the next day the two panels will be chemically welded together.  From what I have seen, it works well. Good Luck, TomC

[JackConrad]

Pat McNeil, the owner of the beautiful 45' scenicruiser, also owns a race team (Late Model Stock Car).  Pat said they use Sikaflex to install the side panels.  If replacement of a panel is required, they remove the old panel by usung a heat gun to heat the sikaflax and slowly pulling on the panel as the Sikaflax is heated. He said they have found this method is much quicker than pop rivets.  Jack

[Nick Badame Refrig/ACC]

Hi TF,

I originally used Sika on my exterior skins. Followed all the directions to the tee, proper thickness, I even preheated/baked the aluminum

[which is an almost impossible task to do with 12ft sheets of .080] I even supported the sheets while they set-up overnight.

My problems started while my bus was in Black Primer... The sun would heat the aluminum too much. [I have recorded 190 deg's on the skin]

and the aluminum would grow from expansion so much that it would rip the sika right from the seams.... Don't use dark colors when using Sika....

Good thing I waited a year before the paint job was done!  I ended up using 3/16 stainless rivits and umbrella caps everywhere. Then had it painted. 

All my seams are holding very well now and with my full body paint, you can't even notice where the rivets are...

Good Luck
Nick-