Vintage Mustang Forums banner

1 - 11 of 11 Posts

·
Premium Member
Joined
·
19,203 Posts
Discussion Starter #1
Talked with a guy today who's a professional welder and restoring a 65FB. He says never ever butt weld any sheet metal (warpage) nor run a continuous weld. He always plug welds. He recommends using a flanger for sheet metal, drilling holes in the patch prior to tacking it in, and then plug welding it. Makes a lot of sense. He said the only butt welds he has on his car is for the floor pans.

I told him my ideas of continuous weld (actually stitch welding) frame rails to floor pans, and he said no...use plug welds. The thickness of the floor pans just won't allow continuous welding. The guy manages a welding company, knows all the welding equipment, and is restoring a mustang. You've said butt welds are the way to go...I'm confused!

http://clubs.hemmings.com/baymustang/platesmall.jpgLet me check your shorts! My multimeter is just a-waiting! Formerly known as Midlife in the old VMF.
King of the Old Farts *struts*
 
G

·
Guest
Joined
·
0 Posts
Well, I'm not a welding expert by any means, but here's what I've always heard / been told: Plug welds are weaker than butt welds because they generally do not penetrate the second layer well. They are basically used for the look more than anything. For Example. I've heard from several sources that when replacing shock towers or inner fender aprons to plug weld where the original spot welds were, but also to stitch weld the perimeter on the tire side, where you won't see it, to make up for the weaker plug welds.

Personally, I'd say for patch panels, do whatever will work easiest, and provide the best end result for the labor involved. I honestly don't see how he could strictly use plug welds for his patches without using a ton of filler. They just don't provide as clean of a surface as stitch welds that have been ground down. Also, I agree with you on the floor pan issue.


-Brian

66restomod's Home Page
[color:red]Updated: 4/13/2001</font color=red>
"In preparing for battle I have always found that plans are useless, but planning is indispensable."-Eisenhower
 

·
Registered
Joined
·
1,797 Posts
Just out of curiosity, what is a stitch weld?? I will be doing some sheet metal replacement, both body patch panels, floors, and subframe connectors. What is the best way to weld each? I am familiar with butt welds and lap welds, and a few other types of welded joints (I took a welding class to learn the basics, I recommend it to anyone), but I don't know what a stitch weld is.

In addition, any web sites that you can point me at to give hints would be very appreciative.

Dave

Watch my progress at:
http://members.home.net/dciab/index.html
http://members.home.net/dciab/pics/67mustg.gif
 

·
Premium Member
Joined
·
19,203 Posts
Discussion Starter #4
Stitch welding is running a short bead, then jumping a distance, running a short bead, etc. When the old welds are cool, you go back and fill in a short bead between existing welds, or continue on for a short distance if the gap is large. Does this help?

http://clubs.hemmings.com/baymustang/platesmall.jpgLet me check your shorts! My multimeter is just a-waiting! Formerly known as Midlife in the old VMF.
King of the Old Farts *struts*
 
G

·
Guest
Joined
·
0 Posts
In one of the mustang mags they did an article on replacing quarterpanels, they used a butt weld, I guess you call it stitch weld. I figure if these guys publish it it must work, the end picture show a quality job. I've personally done this. I guess it depends on what you are working on. My floors have on continuous bead all around and spot welds on the frames. I think it's what ever works best for you.


Michael Wigton
1964.5 Mustang Convertible
 
G

·
Guest
Joined
·
0 Posts
In one of the mustang mags they did an article on replacing quarterpanels, they used a butt weld, I guess you call it stitch weld. I figure if these guys publish it it must work, the end picture show a quality job. I've personally done this. I guess it depends on what you are working on. My floors have on continuous bead all around and spot welds on the frames. I think it's what ever works best for you.


Michael Wigton
1964.5 Mustang Convertible
 

·
Registered
Joined
·
487 Posts
Midlife, If you ever have the opportunity to go through one of the shops that rebuilds cars for the ultra high end stuff like the antique Ferrari's, Deusenberg's and the like, you would never see someone using a flanged piece of metal for making a patch panel (of course they usually form a new piece from scratch). Anything that is done at these shops is done to be a permanent fix, not some low level patch panel that will end up with hidden rust areas due to flanging.

I had the chance to do this several years ago and I'm sure that is hasn't changed a bit. These guys are the real craftsmen of cars. It is simply amazing to see someone spend a week on just one fender. Anyplace that there is a weld on the car, you just can't see it. Front side or back!

Dang! Just when I got used to being "strange", I became a "newbie", then a "tire-kicker". Now I'm a "beginner"?.....hmmmmmm...where do I start?
 

·
Registered
Joined
·
1,004 Posts
Flanging makes sence in some situations. I always butt weld patch panels. I use a spot weld method. I tack about every inch, then 1/2", then 1/4". I keep going till the whole section is welded. I han't had problems with warping. Flanging is used because its a fast way to do it, fit up is a snap. Its bad because itsa great place for rust to start and it looks like crap from the inside.
 
G

·
Guest
Joined
·
0 Posts
On repro floorpans it is hard to get good welds to the rockers & frame rails anyway, because of the thickness of those metals compared to the thin floorpans. I had very little success with plug welds for the floorpans to the rocker panel areas - I ended up doing a continous weld.

Butt welds ground clean are absolutely the best looking welds - on good ones, as Kelly said, you can't even tell there was a patch welded in. The sheet metal screw method works good in some spots on floorpans, like from the pan to the inner floor support.

Most cars since the 60's have almost all plug welds, and then the entire body treated and painted. It's not so easy to dip an entire car that's already been assembled once (meaning me and you), which is why flanged welds are not quite as desirable as butt welds.

Visit my repair page for Repair info, with pictures! http://home.dencity.com/mustangcub
 

·
Registered
Joined
·
131 Posts
Your welder buddy I think is worried alot about warpage And in my opinion you have to do alot of welding to get spot welds as good and strong as a good butt or lap weld.Last word take your time hast makes waste [ warpage ]
 
G

·
Guest
Joined
·
0 Posts
I know this is an old thread, but I had a question for you all regarding patch panels and welding.

If I decide to use the flange method how difficult is it to flange a round edge, like a fender?

For a butt weld, I'm sure it has to be an exact cut. What do you all use to cut the metal? Say I'm going to patch the lower part of the quarter panel, do you just take the patch panel, place it against the original fender, trace around it and then cut???

Sorry for all the questions... I'm a rookie!! :)

Roland
 
1 - 11 of 11 Posts
Top