Another aluminum question

[Gary T]

Because I don't have access to 5 foot wide aluminum (my tear is 50 inches wide( bad engineering )), I will have to split 2-4X10's and have a seam up the middle. I was thinking about gluing the centre seam and floating the rest.
Is this my best course of action?
My thought is that the glued section will stay tight and the rest will expand.
Any comment would be appreciated

Gary T

[madjack]

Gary, iff'n it were me, I would just overlap the AL about 2"s worth, applying a bead of urethane sealant/adhesive such as SikaFlex 221 and a SS screw about every 2"s...there are also a couple of profiles of AL extrusion that are flat and meant for covering a seam.....
madjack

[Gary T]

Thanks Jack

I had planned on covering the seam but would have never thought to overlap the sheets.(dah) I guess thats why you know and I dont.
Thanks for the adhesive advise as well. I dont know what I was going to use but Im sure my choice it would have been more evpensive.

Gary T

[madjack]

Gary, using the technique I described, you don't need the "seam" trim...as long as you seal and use a SS screw every 2"s...however some like the trim look better...using the pahhead SS screws, gives a "riveted" look to the seam......
madjack

[Gary T]

Will the screws bite enough into the 1/4 baltic birch.( I guess they are going to have to because I'm not tearing it all apart again)
I like the rivited look my self and I think I will go with that option.
So let me ask 1 last question to get this all straight.
Do I glue the 2 peices together with the sikaflex or do I glue the aluminum to the top of the tear or do I do both?
I'm assuming SS screws are stainless steel. I dont know, but is there a dis-similar metal concern with Stainless and Aluminum (I have to ask, I dont really doubt you)
I guess that was really 2 questions.
Thanks again
Gary T

[madjack]

...personally, I would float the Al and seal the overlap...the galvanic reaction between the SS and the AL should not be a problem because there is no water(especially salt water) or current(voltage) flow to worry about...also put a dab of sealant on the screw theads to help in the sealing...this will also help with any galvanic reaction...the 1/4" is a bit thin so just use a fatter screw, such a #10 (a #8 would probably work) pan head screw...be sure to be carefull about how tight you run the screw down....when using the urethane sealant/adhesive, allow it to set before trying to clean up the excess...once set, the excess should just peel off...if you just gotta clean as you go, spray a little water onit(after install) as this will keep the urethane from sticking to surrounding areas...
madjack

p.s. Fastenal is one of the best suppliers of SS screws and fasteners that I have found...they have store fronts all over the country and do mail/internet ordering as well........MJ