Glue Canopy Question ???

I have decided to glue the canopy and have read about it til my eyes are tired ! LOL . I have a question to the people who tack glue the canopy and then go BACK and reglue,
"this is all with the sikaflex 295uv , 209D primer , and 226 cleaner."

Now as I understand , their is a TWO hr. window to do the entire proscess .

So if you tack it together with sickaflex and wait for it to cure and bond , is there enough time left to go Back and re do it ALL ?????

Clean, primer, and tack. Wait a few hours. Remove spacers, and fill the rest in. You'll be fine.

I have done two canopies this way and had to destroy the first due to a polishing accident, and I can tell you that you will have to absolutely destroy the canopy before a bond will break.

I think the word "tack" in this process is a little misleading as the only area you will not "glue" the first time through are those occupied by the rubber spacers you use around the perimeter of the frame. These non-glued sections represent a very small % of the total glue surface so in reality you really are accomplishing the majority of the final bond strength on the first pass. In truth filling in those spaces afterwards probably isn't even necessary as the SIKA bond is amazingly strong. Of course I did fill them in, if for no other reason than it looks better.

Sika away!

Ken

I originally made spacers by cutting short pieces of vinyl hose, as I saw others had done. Then saw where someone had made spacers out of small rectangles of rubber sheet and just left them in. So I cut the vinyl hose pieces into bits (approx. 1/4" x 3/8" rectangles), glued them to the canopy frame with superglue, primered right over them, and Sika'd over the whole mess.

Like Bob I've done two canopies, in my case on the same frame, since I managed to pull a bonehead move- dropped pliers on my finished canopy and shattered it. I cut the broken canopy off the frame with a razor blade. The vinyl spacers were utterly stuck in place, both to the frame and the Sika. I don't see leaving them in as risking the integrity of the bond system at all.

It's been a while since I SIKA'd my canopy.
I used the 'sections of garden hose' spacer method.
I waited overnight for the original application to set, then removed the clamps & spacers ( I wasn't sure how long it would take to set) Then I filled in the spacer gaps without additional treatment. If I Recall Correctly, your not supposed to wipe the cleaner over the primer??
After that was done, someone posted that you can smooth the SIKA fillets by soaping your gloved finger and wiping the SIKA immediatley after applying it. As a result, my SIKA joint is strong but ugly on the inside.
I do know that you have only a few minutes to pull off the edge tape before the SIKA begins to skin over. If you do it right you get the most perfect seam edge.
I did get that right
Wasn't it Chalkie Stobbart, in South Africa that started the whole SIKA thing?
Here's a link:
http://www.rvclubsa.com/rvsa_article_2_canopy_glue.htm

Thanks all

Thanks for all you responses . I understand that the tack is a complete sealing of the frame to the canopy and it in it's self is the actual bond , then you go back and pretty up for looks. I am in the auto body repair business and have intstalled many windshields and side glass with urithane . I can say that I have never seen a bonded windshield come loose unless it was rusted between the urithane and the vehicle. That being said I want to use this sikaflex properly with in the scope of it's designe.

2-hr limit was a dust-accumulation thing?

Before I did mine, I tried to find as much info as I could on the consequences of applying Sika to the primer surface that had already been applied 26 hrs or more prior (because of the first application between the spacers).

Ultimately, I could not really find anything definitive in the product literature, other than a statement that the 2-hr window minimized dust accumulation. At least, that's what I recall.

Bottom line is that, like others have said, there is no adhesion problem putting second application over the day-old primer once you take the spacers out.

If I had to do it again, I would consider permanently embedded spacers as described by Lars.

The real key is to do the fillet process in one pass. Resist the tempation to build most of the fillet between the spacers on the first pass. You can get most of the length bonded, as Ken said, but do not fill all the way to where the fillet is going to be.