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Time to re-think sheet metal covering

PostPosted: Sat Feb 17, 2007 1:02 pm
by jumpingjackflash1960
I am having serious trouble bending 29 gauge steel sheet metal covering.
I have found a source for sheets of aluminum 2'x3' aprox for $0.25 each. Lighter easier to bend, but more joints. This would mean trashing $120.00 in 29 gauge sheet steel and buying all those sheets of aluminum and dealing with sealing every joint. Input Please!!! Dale G. Smith

PostPosted: Sat Feb 17, 2007 1:31 pm
by grant whipp
Dale!

I am assuming (afer looking at your album) that you are referring to the sheet metal that you want to put on your roof? Well, I'm not sure what 29 guage steel equates to dimensionally (.040" ... .050" ...?), but it seems to me that you shouldn't have too much trouble getting a simple break for your three top bends. I've done it with .040" and .050" aluminum by clamping the metal between a couple of 4x4s (lining them up on the line where you want to make the bend) and using another 4x4 and a 3# hammer as a poor-mans' break. It takes a while, but if you work slowly and carefully, you'll get a decent bend out of it. Failing that, you could mark where you want the bends, and take the material to a pro sheet metal shop to have them break it for you, but not many shops have a break with a throat deep enough to get that top front bend you want.

Whatever your soultion, good luck with your build!

CHEERS!

Grant

PostPosted: Sat Feb 17, 2007 5:01 pm
by Classic Finn
Ive got about 10 sheets of 1.5mm in thickness that is not wide enough either... I can put it on length wise but there is about 3 feet on the width..

Should I use it? Not for the sides but front to back ...ceiling.. there sure would be a lot of seams though...and tight radius at the front and hatch.

Plus Ive got stainless that is the same size...but a way thinner...

Is there anyplace that would show how to make the seams so it would look proper? Has anyone else used narrower sheets?

Ive got other stuff too but hate to see it just sit..

Classic Finn

PostPosted: Sat Feb 17, 2007 7:10 pm
by angib
According to the University of North Carolina, 29 gauge is 0.0135". There seems to be some doubt about the exact measurement, but it's around there.

Andrew

PostPosted: Sat Feb 17, 2007 8:01 pm
by madjack
I'm thinking along the lines of Grant...29ga is pretty light and you should be able to make a break, like what he descibes...or the local sheet metal or fab shop...you could use the AL but with all the seams, it will end up looking like a patchwork quilt, which in it's self could be done nicely...to seam the AL reliably, I would overlap a couple of inches, apply a urethane based sealant (auto windshield sealant) and a SS screw every couple of inches...dab a little sealant on/under/in all the screw/screw holes...
madjack 8)

PostPosted: Sat Feb 17, 2007 10:34 pm
by grant whipp
Classic Finn wrote:Ive got about 10 sheets of 1.5mm in thickness that is not wide enough either... I can put it on length wise but there is about 3 feet on the width..

Should I use it? Not for the sides but front to back ...ceiling.. there sure would be a lot of seams though...and tight radius at the front and hatch.

Plus Ive got stainless that is the same size...but a way thinner...

Is there anyplace that would show how to make the seams so it would look proper? Has anyone else used narrower sheets?

Ive got other stuff too but hate to see it just sit..

Classic Finn


Hey, Heikki!

There is a very clean way of "stitching" those 3' wide pices of sheet metal together ... if you don't mind a somewhat noticeable seam across your roof every 3'. Look to see if you have any local HVAC sheet metal shops, and then ask them if they have a double-sided Lockformer or Pittsburg machine ... then ask if one side is set up to roll a "J" into the edge of your guage of sheet metal ... if they do have it and can roll it, ask them if they also have the "C" shaped "clamping" strip and the roll press that they can run the whole seam through. Basically, it works like this:
• you roll a "J" into each side of each piece of metal that you want to stitch together (make sure the lower lip of the "J" is under the surface of the metal you want exposed)
• fill each cup of the "C" shaped "clamping" strip with a good quality sealant and slide it into and under the bottom side of the "J" lips of two pieces of sheet metal butted together
• run that whole seam through the roll press to squeeze everything together, then proceed to the next seam (if you don't have a roll press, you can lay a 4x4 over the seam and start pounding from one side to the other with that 3# hammer)

When I was building campers and trailers back in the early '80s, that's the way they made up all our roofs (out of 4' wide stock), and sometimes we had rolls 8' wide by over 40' long.

If you can, make friends with a sheet metal guy (especially the HVAC types) ... believe me, you won't regret it ... ;) ...

Good Luck, and as always ...

CHEERS!

Grant

PostPosted: Sun Feb 18, 2007 11:27 am
by Classic Finn
Grant thanks indeed... I,ll give a few places a call.. I know where there are several places that have a fairly good size shop...

I,ll check around... Should the seams be installed at all with sheet metal screws as well?

Thanks again Grant
I,ll let you know what they say... :thumbsup:

Heikki :thumbsup:

PostPosted: Sun Feb 18, 2007 1:41 pm
by grant whipp
Classic Finn wrote:... Should the seams be installed at all with sheet metal screws as well?...


No, Heikki ...

... at least, not the seams as I described. If you do an overlap seam, then yes (pop rivets would would work better if the seam doesn't fall on a cross-beam).

Again, Good Luck, and as always ...

CHEERS!

Grant

Thanks again for the feedback.

PostPosted: Tue Feb 20, 2007 1:12 pm
by jumpingjackflash1960
I have tried the "poor man's" metal break. Did not turn out so good. 29ga. may seem thin but it sure is tough when you try to bend it. As for the 2x3 sheets, lap joints, screws, rivits and a lot of sealant. I will buy a few of the 2x3 sheets and see how it goes. There are not any sheet metal shops around here that can handle this size sheet metal. Thanks again for the input, fell free to add more if the urge arises. I will keep you all posted.
Dale G. Smith