BUILD THREAD “The Juggernaut”

[Rktpwrd]

Wouldn't some Panel Bond have held the piece in place getting the job done w/o the impact of heat on the exterior sheet metal? You'd still have to weld the inner portions back but that likely wouldn't transfer heat beyond that piece of the inner structure.

Absolutely.
There’s always more than one way to skin the proverbial cat. The only consideration factor though is that I wanted some sort of corrosion protection in between the reinforcement and the door skin though, and panel bond requires clean bare metal surfaces to properly adhere to. If I bonded the reinforcement to the skin, I could’ve coated all around the two pieces, but not had anything directly in between.

Since this was already a problematic area with corrosion on Olds Cool, I wanted as much protection in there as I could get.
For what it was, two plug welds to the outer skin were acceptable for me.

 

[scoti]

Absolutely.
There’s always more than one way to skin the proverbial cat. The only consideration factor though is that I wanted some sort of corrosion protection in between the reinforcement and the door skin though, and panel bond requires clean bare metal surfaces to properly adhere to. If I bonded the reinforcement to the skin, I could’ve coated all around the two pieces, but not had anything directly in between.

Since this was already a problematic area with corrosion on Olds Cool, I wanted as much protection in there as I could get.
For what it was, two plug welds to the outer skin were acceptable for me.

I considered the 'corrosion protection' aspect. My logic was slathering the Panel Bond or similar epoxy over the surface area being bonded together would effectively seal that from external elements. Then epoxy sealing the perimeter edges as well (like caulk sealing windows/tubs/etc). But, yes.... More than one way to get the task done.

 

[Rktpwrd]

Mirror Reinforcement Update #2

So after a couple of horrible days at work this week, I finally had a half-a$$ed normal day today and felt like getting back out into the shop again tonight.

I’ve got another iron in the fire with the 3D printed mirror gaskets I’m having made (more to come on that soon), so I already had the mirror mounted up with the new reinforcement. It’s going to work well.

The goal here is to cut back some of the outer door skin material so that we have access to the inner structure underneath it for welding and grinding. I shot for around a 1/2” on the topside, and around 3/4” on the insides where I have more material to work with.

After removing the mirror, I prepared by laying out some new cut lines:

While the regular 3” cutoff wheel works fine for the topside, don’t throw away your old worn down wheels. This small worn down one is the only thing that would fit in the tight area where the window goes:

I have a whole assortment of these worn down cutoff wheels in various sizes that I keep for just this sort of thing.

Next I made my cuts. Using the biggest hammer in the toolbox is not the name of the game here, think more like surgical precision. A steady hand, light pressure, and multiple passes so that it only cuts through the first layer and not through the underlying structure is the goal.

No reason why we can’t reuse the original piece that came out of there to weld back in…

…we just have to prep it first by removing all the old paint. I like to use the fibre wheel on the die grinder for this, it quickly removes old coatings and surface rust without removing any of the base material like a grinding disc would.

Set up the freshly prepared original piece in place with a couple of magnets…

…then tack in place with a couple of really ugly tack welds:
😅

Most of you have seen my process for this before, fully weld it in…

…then grind it down and dress it out.

Just like it never happened. Just as before, we need to protect the area with some sort of corrosion protection, so next it was masked off and hit with more zinc weld-through coating.

The orange tape is new to me, CarWorx brand, and I’ve gotta say I’m not a fan. It’s cheap (not literally, it was just as expensive as my 3M stuff), it’s thin, tears easily (usually when you don’t want it to), and is difficult to get to lay down nicely without wrinkling and creasing. And I don’t find it sticks any better either.

Once I use it up I won’t be buying it again, but it’ll work for little BS stuff like this.

After unmasking, I prepared the outer skin for the next stage by stripping back the primer.

I won’t be trying to reuse these couple pieces of original sheetmetal, instead I’ll just use them as template pieces to make a new one to weld in:

But that’ll be tomorrow night or on the weekend, I’m out of time for tonight. This whole repair only took 2 hours from start to finish, so I figure that ain’t too bad.

Part 3 will be coming up next to finish off this side, then it’ll be repeating the whole process over again on the driver’s side. Until then, keep the shiny side up friends.

D.

 

[Sweet_Johnny]

Well this is progressing nicely. Those mirrors will be laser straight (surely) and rock solid to boot, and I'm definitely interested in seeing the 3D printed parts. And the next time someone tells me I need to toss my old cutoff wheels or die grinder stones I'll show 'em this post- I always keep at least one or two "special" ones that can fit "all up in there".

Thanks for the notes on the tape too. Bad news for anyone using it, but I definitely appreciate the heads up and will probably not try it unless it's free.

 

[Tony1968]

Nice work Donovan 👏
I also try to keep the worn down cut off discs, unfortunately, too many times I frag them. And that's a lot of fun...

 

[liquidh8]

I always keep my old death wheels for that same reason. Looking good!

 

[Longroof79]

Lookin' good, D.
I'm also an advocate for keeping worn down cutoff wheel discs, unless of course they got snagged and ripped to shreds. As you said, you can't fit the 3" disc in tight corners. That's where the worn down discs come in handy.

 

[oldsofb]

…then tack in place with a couple of really ugly tack welds:

He thinks those are ugly tack welds...... Stay away from my welding pics then

 

[Rktpwrd]

Mirror Reinforcement Update Number 3
The Final Chapter

I began the final bit of work on this today by marking out some 3/4” lines on a scrap piece of sheetmetal and cutting out 4 pieces from it.

These 4 pieces are going to be sacrificial “coupons” for use in setting up the fence on my metal brake. Using the original piece that was cut out…

…I squared and cleaned up the one end so that I could accurately compare the bend radiuses against each coupon:

I bent the first coupon to get a baseline and compared it against the original piece.

As you can see, the coupon on the right has too tight of a bend radius, it needs to be softened up a bit.

After adjusting the fence back slightly, the second attempt was considerably closer. Again, the coupon is on the right:

Very close, but still not perfect.

Third coupon, third adjustment, and third comparison:

Now we’re getting somewhere. Using this setting on the brake, I measured, laid out, cut, bent, and mocked up the final piece, complete with spot weld hole in the original location.

As you can see at this point, the fitment was very good with adequate gaps between the pieces for penetration, with the exception of the long edge along the top:

As beautifully as it fits here, there is zero gap for penetration, so welding along this seam won’t really do anything. It’ll be weak and could possibly crack in the future if not corrected.

Here, I’ve removed approximately a 1/16” off the edge, and mocked it back up in place again:

This is what we want to see now.

The placement of your first couple of tacks will determine the outcome of the rest of the welding. Notice I placed the first two tacks on the outer edges, and not along the long edge or on the vertical seams. This is because heat from the welds will draw the two pieces together slightly throwing off the alignment and closing up the gaps.

Note how all the gaps are still present and intact this way without altering the alignment.

Next I went after the vertical seams, welding them up, along with the spot weld hole, and two others I drilled after I had it in place.

With the inside edges finished off, only the topside was left to address. A couple of tack welds evenly distributed across the length locked it in place…

…then started adding more and more in between each previous two.

Before long, the entire length was welded, and the first pass with the grinder was made with a 2” diameter 24 grit disc. I only take it down to nearly flush with this.

Once I have it to this point, I switch to an 80 grit disc, and take it the rest of the way down. This leaves a much finer scratch, and a nicer finish:

The other benefit to this is, because it’s already an 80 grit scratch, a little sanding with 80 grit on a DA sander results in a really nice end product.

And that pretty much wraps up the whole process. I’ll post up a couple more pictures from different angles in the next post, but overall I’d say this was a very successful project.

Now to repeat the whole procedure over again on the driver’s side.

D.

 

[Rktpwrd]

The end result: