GM 1956 GMC gets an upgrade or two!

[J Mack]

I’m not familiar with the bonding process.

It's worth a few minuets to look into it.

https://www.3m.com/3M/en_US/p/d/b40066467/

Lots of video showing application on the YouTube

 

[bobm]

Less distortion too

 

[J Mack]

Less distortion too

Stronger and less prone to water getting back in and rusting the seam/joint too!

 

[bobm]

Too fo Too

 

[Michael B]

It's worth a few minuets to look into it.

https://www.3m.com/3M/en_US/p/d/b40066467/

Lots of video showing application on the YouTube

J this will effectively be a butt weld. Will there be enough surface area in this scenario to use the bonding product? Or should I use a lot of tack welds and then apply the bonding product to complete the seam?

 

[J Mack]

J this will effectively be a butt weld.

For me personally a butt weld on a long seam would be my last choice for controlling warpage, especially if I couldn't get to the back side to metal finish afterwards.
If you've already prepped everything for it to be butt welded you could build a bunch of doubler plates and still bond it together, at the end of the day it would probably be much stronger that way anyway.

Edit to add, you really only need an inch or so of overlap so a 2-in doubler plate would be pretty easy to make

 

[Michael B]

For me personally a butt weld on a long seam would be my last choice for controlling warpage, especially if I couldn't get to the back side to metal finish afterwards.
If you've already prepped everything for it to be butt welded you could build a bunch of doubler plates and still bond it together, at the end of the day it would probably be much stronger that way anyway.

Edit to add, you really only need an inch or so of overlap so a 2-in doubler plate would be pretty easy to make

A concern with a doubler plate would be that there is no access to apply pressure, ensuring that the patch panel flushes out with the grafting/cut line.

 

[J Mack]

A concern with a doubler plate would be that there is no access to apply pressure, ensuring that the patch panel flushes out with the grafting/cut line.

I have used small self tapper screws and came back and filled holes the next day.

Or cleco's and small clamps..

 

[bobm]

Used cleco's for years locating panels for welding and bonding on DOD work . Highly recommend . Tech screws are awesome for locating panels also

 

[Michael B]

@J Mack after taking your advice and evaluating the situation, it just wasn’t possible to use the bonding method you recommended. There simply wasn’t enough area to bond to. I don’t think the pictures show it sufficiently.

 

[Michael B]

After weeks of staring and maneuvering the patch around, I started tacking it down. Apparently all 55/56 cabs are not identical. The patch was not a 100% match. Honestly a lot of the issues were probably me and my inexperience. Once I had it tacked on I had a “bulge” on both sides. They also were not “bulging” equally. My resolution was to make a strategic “relief” cut. I think this is going to work well enough.

Don’t laugh too much at my terrible welds. I may be an awful welder, but I’m a terrific grinder