Question shet metal repair

Hello,
I have a question to the group, regarding the repair od sheet-metal, in particular it the repair of a truck roof.
This roof is off another (similar model) which I cut-off, and is to fit on top of my existing roof.
This roof has a formed gutter all around which needs repair in several places because of rust.
That is the best way to repair this gutter. Id it better to Mig weld or spot weld.
The steel is approx. 18 grade (1.8mm) thickness.
Any ideas on repairing this channel.
Also, I have cut the roof soo that it will fit on top of existing.
What is the best method to attach this roof panel.
Pop-rivet, Spot-weld, adhesives or Mig-weld.
Thanks for all help.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Never had to do a roof, but mig will most likely warp that steel. Spot or tack weld i would think would be the best choice. good luck, walt
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Tue, 18 May 2004 00:09:18 -0700, "libra1958"

"Cut, grind, mig, grind, lead, prime, and paint" were the steps the guys used in the body shop I used to wrench for. The lead was used both for a sealant and filler. (Bodyman's solder = 30% tin, 70% lead.) They'd fill rusted out pieces with formed sheetmetal and lead over it.
-- Remember: Every silver lining has a cloud. ---- http://diversify.com Comprehensive Website Development
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.