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welding hard top support channels to top??

hmh800

Sr. Member
Joined
Nov 5, 2009
Messages
365
Someone must have sat on the top of my '68 at some point....The two support channels are buckeled down. So my plan is to drill out the spot welds at either end to remove and straighten the bows.
Now the question- I was thinking of taking off the rubber strip between the bow and the top and spot welding the two together. Anyone done this or see a problem with fastening the two together? Seems like it may even cut down on the rattling of the top, but I'm wondering about expansion/contraction of the top sheet metal and what might happen..
Thanks and sorry for the long- winded question!
 

Wyflyer

Bronco Guru
Joined
Apr 1, 2008
Messages
2,920
Drill the spotwelds, straighten the bows, reinstall. Then squirt a small bead of flexible expandable spray foam insulation. Consider putting a layer of plastic so it wont stick the bow to the top. Don't overdo it with so much foam that it pushes the bow down. It'll evenly support the top, stiffen the bow too
 

Explorer

Bronco Guru
Joined
Mar 2, 2008
Messages
4,390
Loc.
Raphine, Virginia
Welding to the top will more than likely warp it. I was thinking auto panel adhesive would be a good choice, but haven't tried it.
 

68rockcrawler

Bronco Guru
Joined
Sep 18, 2006
Messages
1,417
Someone must have sat on the top of my '68 at some point....The two support channels are buckeled down. So my plan is to drill out the spot welds at either end to remove and straighten the bows.
Now the question- I was thinking of taking off the rubber strip between the bow and the top and spot welding the two together. Anyone done this or see a problem with fastening the two together? Seems like it may even cut down on the rattling of the top, but I'm wondering about expansion/contraction of the top sheet metal and what might happen..
Thanks and sorry for the long- winded question!

I thought about doing that too but I haven't because I think the support channels are supposed to be straight across (not curved like the roof) to support the headliner. The roof flexing and the bows moving around is driving me nuts though so I'm interested to hear how you fix this.
 
OP
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hmh800

Sr. Member
Joined
Nov 5, 2009
Messages
365
I think the bows follow the curve of the roof- at least that's what mine seem like. There's stilll the strip of rubber attached to the roof that used to be sandwiched between the bow & hard top sheet metal. I too thought of panel adhesive- I've wanted to try that stuff out. But I have a welder here and no panel adhesive. I'm not so much worried about warping the top welding it as I am having it bind or buckle in weather extremes. I'm picturing parking it somewhere on a hot sunny day and coming back to the top folded like a taco!!
 

Pokey71

Bronco Guru
Joined
Feb 24, 2007
Messages
1,010
my boxs are only spot welded on the outside. The center section (like 85% of the bow) has silicone underneath it. doesnt pop
 
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hmh800

Sr. Member
Joined
Nov 5, 2009
Messages
365
Wyflyer did you do this to your top? Are you talking something like Great Stuff? I'm wondering if it lifted the top up off the bows.
 

flousberg

Sr. Member
Joined
Apr 28, 2002
Messages
742
someone layed my top on its top also and bent the bows. I drilled the spot welds, straightened them out, and put them back in so they are in tension. I did not put anything between the top and bow and it drives me nutz the noise it makes. I was going to drill some holes in the bow and use Great Stuff to quiet it down. I haven't got around to it yet.
 

Tito

CB Fire Starter
Joined
Jan 29, 2006
Messages
10,781
Loc.
Bakersfield, CA
My bows were bent, was in the process of restoring and painting the top, I did weld up the bows, real easy to burn through it so be careful. A little filler on the top where I spot welded and it is real solid.
 

Wyflyer

Bronco Guru
Joined
Apr 1, 2008
Messages
2,920
Wyflyer did you do this to your top? Are you talking something like Great Stuff? I'm wondering if it lifted the top up off the bows.

Yes and it worked great. The old foam was pretty violent but this new stuff is tame and its flexible too. Get the door/window foam. Just put little pads of it all the way across between the bow and the roof skin. It form fits the bow to the top and after curing it evenly distributes the roof weight. Also stiffens the bow
 

rjrobin2002

Contributor
Bronco Guru
Joined
Oct 13, 2007
Messages
2,664
I also put the expanding foam in my support and it did an amazing job at quitening it down and making the top seem more solid. It no longer sounds like someone is playing the drums on my top when I get over 50 MPH.
 
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hmh800

Sr. Member
Joined
Nov 5, 2009
Messages
365
So you guys that put foam between the bow and top did the foam open a gap between the two? Would you say that the foam is adhered to both the bow and the top? Gotta say I'm still leaning towards welding like Tito...
 

Wyflyer

Bronco Guru
Joined
Apr 1, 2008
Messages
2,920
I already had an irregular gap between the top and the bows. I taped a piece of black plastic to the top and let the foam swell to it. I didn't want to bond the bows to the top, wanted them to be able to move.
In the olden days there was just one type of spray foam, the closed cell foam that swelled like 100 times it's original size and would distort walls and door jambs and also dried hard.
The foam I used was window/door foam from Home Depot. This newer stuff swells more gently so it doesn't expand or distort so much, and it dries pliable and soft. Think of the stuff nerf balls are made of.
And I applied my carefully by pushing the little hose nozzle between the bow and the top and giving it a small squirt about the size of a golf ball. Then moving 5 or 6 inches away and doing it again, then later came back and filled in the gaps.
Do whatever works for you, but I did this method and can say it worked great and cost very little in time and only a few dollars for the can of foam.
 
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