[LarryD]

I want to do a butt weld on my 80% quarter replacement. Which point for the cut line is best and/or easiest? Is it along the current cut line (left arrow), along the body ridge line (center arrow) or over on the flat inside of the body ridge line (right arrow)? Thanks.

 

[Bob Tiley]

I would raise your cut line to about 1" below the body ridge top edge. That area will have more strength than where it is now.

 

[R66]

I Agree. The bend in the metal will help prevent warpage also.

 

[dhutton]

As close to the body ridge as you can get it, 1/4” or so

Don

 

[RealSS396]

Definitely just below the ridge. In addition to what's already been said, I think its easier to get a good result in finishing the metal and filler at the very top of the panel before the ridge line.

 

[jadams]

Good advice above. As important as it is to get a good smooth cut line, it is equally important to skip around and not overheat your metal on your existng QP. I shorten lots of GM bedsides and I like about

3/8" to work with.

 

[scblucam]

Just an opinion but if it was me I would replace the full quarter.

 

[LarryD]

Thanks all for the help. I will go with a cut line just below the body ridge line. Now I have to figure out how to cut them so there is minimal gap between them. I took a 2 hour autobody welding class last night to improve my stitch weld. The instructor suggested to use a scribe line, cut close but a very little overlap, then sand (light grind) to get them to butt up tight. He recommended a Diablo 0.040 thick cutoff wheel and to not use cheap wheels. He also mentioned a new weld wire called Easy Grind to significantly reduce the grind work.

 

[jadams]

Never used the easy grind wire. Let us know how it does.

 

[dhutton]

I thought easy grind wire was discontinued by ESAB a few years ago.

 

[RealSS396]

Trying to match the cut lines of two distinct large panels is almost impossible. The best way to accomplish a best result for welding is to lay the new skin over your existing quarter. Align the skin from bottom and work you way up. Once you are satisfied with fit, anchor the skin to existing quarter with a just few small diameter sheet metal screws or Cleco fasteners above & outside where you want the panels to butt up. You can use the outer wheelhouse and trunk drop off panel as lower anchor surfaces. Once completely anchored, scribe a cut line on the new skin. Then cut through both panels with a thin cut off wheel (<=1/16") along the cut line. Once cut, both panels will be pretty much matched with a good weldable gap all the way around.

There's quite a few videos on YouTube that demonstrate the technique. I strongly suggest reviewing as many as you can.

Good luck!

 

[jadams]

I replaced the qtrs on this glacier blue 69 years ago. I had full qtrs to work with, but the idea was to save the factory date codes in the corners of the trunk channels. Instead of cutting below the body line, I made my cuts about 1 inch inward, leaving that clean stamp. I tacked it all up and did the other side. Then welded seams about every 6 inches. I would say it took me 3 or 4 days to knock it out, but turned out great.
I will edit and show a finished pic if I can.
This is another option.

 

[Luwi67]

On you-tube look up Fitzee's fabrications and check out his "cut&butt" technique. He cuts like described in post 11 but, cuts at a 45° angle to lessen the gap of the cut.

 

[srode]

On you-tube look up Fitzee's fabrications and check out his "cut&butt" technique. He cuts like described in post 11 but, cuts at a 45° angle to lessen the gap of the cut.

Yep, that's what I was going to suggest - it works great. You can get cut off wheels thinner than .040 too if you decide you want a tighter gap but cutting at a 45 will make the really small already. Practice on some scrap metal first so you get the hang of it would be my reco

 

[LarryD]

I have seen the video's and tried that on replacing the speaker cutouts on the rear package tray. I ended up with too much of a gap. I don't seem to do as good welding with much of a gap. The Harbor Freight cutoff wheels 1/16 inch (.0625) are too thick to get a small gap. I have noticed that they tend to shred when cutting on an angle too. I will look for some thinner ones of better quality.

 

[dhutton]

I don’t think I would trust a cutoff wheel sold by Harbor Freight. My favorite Dewalt ones are no longer available but these ones are pretty good.

Amazon.com: DEWALT Cutting Wheel, All Purpose, 4-1/2-Inch, 5-Pack (DW8424B5) : Industrial & Scientific

Buy DEWALT Cutting Wheel, All Purpose, 4-1/2-Inch, 5-Pack (DW8424B5): Cut-Off Wheels - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

Don

 

[srode]

I have seen the video's and tried that on replacing the speaker cutouts on the rear package tray. I ended up with too much of a gap. I don't seem to do as good welding with much of a gap. The Harbor Freight cutoff wheels 1/16 inch (.0625) are too thick to get a small gap. I have noticed that they tend to shred when cutting on an angle too. I will look for some thinner ones of better quality.

yeah, that's thick.

 

[tp_smith]

When I needed to slice sheet metal and needed a thin kerf, I used a Dremel tool. The Dremel tool has very thin cut off wheels. I would be very expensive to cut as much as you need to with those little wheels.

 

[LarryD]

I have a Dremel tool but that is going to take a long time and lots of disks to cut that much. A Dremel seems like better control though.

 

[tp_smith]

I have a Dremel tool but that is going to take a long time and lots of disks to cut that much. A Dremel seems like better control though.

I don't know why the Dremel cutoff wheels are so expensive. There some that are made with reinforced fiber. You can get about two feet of cut with them on car sheet metal.

Your Dremel tool will be good for the tight curves.

Here is another example of cutting sheet metal with a Dremel cutoff wheel. I had to cut the fender because it did not line up with my hood. When the kerf (gap) gets too wide, I use TIG welding rods to fill in the gap.

Beveling the cut is a very good idea. You don't want to grind all the weld off when you are makeing the metal smooth again.