Sika horror Stories! Anyone have any?

[muddog16]

Getting ready to put new skins on! I like the idea of no rivets but i'm sure some are going to be used!  Any one have bad results from using Sika?  I've heard a few comments.  While I'm thinking about it, just how much does the skin thickness affect how much thermal expansion you will encounter?  I hate the idea of going through all of this prep work and it not holding!........Any and all suggestions will be appreciated........as always!                       Pat

[rv_safetyman]

I do not have any direct experience with Sika Flex, but it is used widely in many industries from what I am told.

The expansion rate is not a function of thickness according to the textbooks.  Each material has an expansion coefficient and it will expand according to that coefficient in all directions.  As you know, aluminum has about twice the expansion rate as that of steel. 

It has been quite a while since I looked at the numbers, but I believe that aluminum will grow about 1/2 inch in 40 feet (to lazy to look it up again ).

Thickness will affect the "look" of the expansion in my opinion.  A thin sheet will distort more non-uniformly.  This is especially true with aluminum.  The expansion has to go somewhere and a thicker gage will distort more evenly - again my opinion (textbooks don't talk about this subject - at least they didn't back in the old days )

Jim

[jjrbus]

 When applying Sika or others. Big mistake many people make is squeezeing it out of joint. A certain thickness must be maintained. Should be in the specs somewhere. How to maintaine that thickness is the big problem.  HTH Jim

[Nick Badame Refrig/ACC]

Hi Pat,

Aluminum is the hardest to adhere with sika.

Keeping the surface heated while waithng for the sika to set up is a pain. I applied my aluminum on a hot day and heated with rosebud oxy/acc. setup.

and still I had the aluminum buckle on a very hot day which forced me to install some vertical revets with umbrella caps. On the horrizonal seems, I used

Eagle moldings and stainless steel machine screws with self tapping threads. I just had to drill 3/16th's pilot holes first. Holds Tight...

I'm just glad that the seems tore before the big paint job was done! Now, all is holding great a year later.

Good Luck
Nick-

[prevost82]

I guess that why I use Kemlite. I didn't want any rivits showing ether and use Sikaflex ... this is the 4th year my sides have been on with no problems as Nick described.
Ron

[niles500]

Muddog - as stated above some applications of Sika require spacers - their site should give you the specs for each type - HTH

[JackConrad]

Somwhere I read or heard someone used the ceramic tile spacers of the appropriate thickness.  They removed them as the glue was setting up. Jack

[Kristinsgrandpa]

Pat, not much experience here as I've only used 3 tubes but I have horror stories to tell you about removing it from your hands if it dries on them.

Ed.

[H3Jim]

Its very important to have the surface clean before application.  While that seems pretty obvious, what was not obvious to me is some solvents do not leave a totaly clean surface.   I used lacquer thinner, and it leaves a thin oiy film that prevents teh Sikaflex from adhering properly.  alchohol and others do ot leave a film.  Make sure that you use the correct "cleaner" prior to application. 

It can be a real mess to have to remove and redo it, especially if some of the areas do stick / hold well while others do not.  Sikaflex when it adheres is not meant to be removed.  Yes, this is the voice of experience, and it was not fun.