• Mustang Forums
  • 1965 - 1973 Classic Mustangs -General/Talk-
  • Classic Mustang Specific Tech

I hate spot welds and rust!!!

  • Thread starter Thread starter 65nProgress
  • Start date Start date Sep 19, 2005
6

65nProgress

New Member
Jul 27, 2005
53
0
0
Sep 19, 2005
#1
  • Sep 19, 2005
  • #1
Just a rant! I am currently replacing the floor pans in my 65. I'm tired of spot welds!!!!!!!! There is no real easy way I have found, although some ways are easier than others. And the real fun of replacing the top hats hasn't even began yet. Thats the next project after the floor pans. And while wire wheeling away at seem sealer and rust I have discovered that the seam where the firewall meets the cowl (starting at just under the export brace location) all the way to the passenger side and down the cowl side panel is like swiss cheese. Basically everywhere there was seam sealer is rusted through. This isn't a huge deal since this is a project and it doesn't have to be completed anytime soon...but it definately added monthes and monthes on the project.

I figure after I drill out 150 spot welds for the cowl, I can go ahead and drill out the rest for the passenger fender apron and then either fabricate or buy a new firewall piece and cut out the areas I need. Im going to be getting more than enough practice at welding sheet metal.
 

allcarfan

The Answer Man
Founding Member
Apr 8, 2001
2,458
1
56
North Atlanta
Sep 19, 2005
#2
  • Sep 19, 2005
  • #2
you ARE using correct spot weld drill bits, correct?
 
6

65nProgress

New Member
Jul 27, 2005
53
0
0
Sep 19, 2005
#3
  • Sep 19, 2005
  • #3
I have done some research and I have read where people say that using a 3/8" flatted drill bit works better than the actual spot weld cutting bits. I start with a 1/4" bit and then use the somewhat flattened 3/8" to finish the job. On the old floor pans, its not a big deal to mangle up the old pan getting the old welds broken. I need to perfect the technique before moving on the cowl.

Should I bite the bullet and get the actual cutting bits?
 
D

danny clemens

Member
May 4, 2005
728
0
16
Sep 19, 2005
#4
  • Sep 19, 2005
  • #4
I haven't ever used the flattened bit but a quality spot weld cutter works great. Barely grinding the areas where the welds are make them easier to find. Use a center punch and go to town. I used a cheap cutter and I kept breaking bits.

Are you sure that there are 150 spot welds in a cowl? When I drilled mine out it seemed more like 1,150. LOL
 
6

65nProgress

New Member
Jul 27, 2005
53
0
0
Sep 19, 2005
#5
  • Sep 19, 2005
  • #5
haha, nah Im not sure of the number. I read one guy had like 187 and another only found 130. Im going to check into the spot weld cutter. $50 for a bit is worth it if it saves hassle!
 
1

10secgoal

Active Member
Dec 1, 2003
2,801
3
49
San Diego
Sep 19, 2005
#6
  • Sep 19, 2005
  • #6
Once I used a drill with variable torque settings, I never broke another bit or tooth. If it grabbed too hard, the drill would click instead of breaking a tooth.
 

Thenemesis

Member
Nov 16, 2004
321
0
17
chuckletown, sc
Sep 19, 2005
#7
  • Sep 19, 2005
  • #7
we put a cowl, right frame rail, fire wall, aprons, core support and alot of other stuff just on the front of my old fastback.. 160 welds to get the old cowl off.. 160 just to get one off another car lol
 
6

65nProgress

New Member
Jul 27, 2005
53
0
0
Sep 19, 2005
#8
  • Sep 19, 2005
  • #8
Thenemesis: What was your preferred method of drilling the welds?
 

Thenemesis

Member
Nov 16, 2004
321
0
17
chuckletown, sc
Sep 19, 2005
#9
  • Sep 19, 2005
  • #9
took a small bit and popped a whole straight through the center of all of them.. then took a bit the average size of all the welds and drilled em about.. we got spot weld cutters just they were more like a standard style bit lol had to of worked out good.. saved what we needed of the car lol after they were drilled for the most part and maybe had some more weld (a tiny bit) we took like a thick bladed puddy and a hammer and popped it loose.. dont use a chisel, it will bend the metal.. found that out the hard way
 
6

65nProgress

New Member
Jul 27, 2005
53
0
0
Sep 19, 2005
#10
  • Sep 19, 2005
  • #10
I'm thinking about just buying and installing the complete new firewall. Since Im going to be replacing the cowls, both toe boards, floor pans (almost have the passenger side ready to be welded). It's just A LOT of welds to drill.... but it would be done right with zero rust to worry about.
 

Thenemesis

Member
Nov 16, 2004
321
0
17
chuckletown, sc
Sep 19, 2005
#11
  • Sep 19, 2005
  • #11
its a big project man.. we had.. this will be hard to explain though.. the entire front frame rail clip and aprons detached but the car never moved once we started.. we built a brace thats came up from the frame rails inside the car, then back to the rear wheel housings, the another one to each shock tower.. its hard to explain lol kinda like this.. /I\ from a side view.. it was then connected in the center.. i can find some pics for you if you'd like.. but let me warn you its a HUGE job and the firewalls that are reproduced arent the greatest.. then again the gave us a 65 conv firewall so anyone who gets that car will wonder what happened lol
 
6

65nProgress

New Member
Jul 27, 2005
53
0
0
Sep 19, 2005
#12
  • Sep 19, 2005
  • #12
I was wondering about the bracing that I would have to do. Maybe I'll just fabricate replacement pieces for the rusted out areas... i guess just having half of the firewall disconnected is structurally better than all of it. And I can do most of it when I do the right top hat.
 

Thenemesis

Member
Nov 16, 2004
321
0
17
chuckletown, sc
Sep 19, 2005
#13
  • Sep 19, 2005
  • #13
well it came out straight and clear.. i think our problem was we had to modify the aftermarket fire wall.. which is a bit more work lol its just alot of work.. if your good with grinding and welding your good to go, and dont be discourage, just think if you take it then you will be one hell of a body guy lol just take your time and make ALOT of bracing.. we used jack stands under the body everywhere we could.. wether it moved or not we stuck one there just in case to catch it..
 
L

lauras70mach1

Member
Aug 1, 2004
202
0
17
minnesota
Sep 20, 2005
#14
  • Sep 20, 2005
  • #14
Replacing the firewall is a big job. Don't replace anything you don't have to!

Just my $.02

FWIW, I used a Wurth spotweld cutter when I did floorpans, torque boxes, floor pan extensions, rear torque box patch and toe boards. After all that I'm still using it and it still cuts good!
 
6

65nProgress

New Member
Jul 27, 2005
53
0
0
Sep 20, 2005
#15
  • Sep 20, 2005
  • #15
I went ahead and bought the right firewall replacement patch that should take care of most of the rust for that side. I will still need to fab the metal on the area directly under the export brace mount. I also ordered the replacment cowls last night. I'm thinking about ordering the spot weld cutters from eastwood co. I have nothing but time and I want to do it right.
 
B

BB1966

New Member
Dec 1, 2004
297
1
0
Beaufort , NC USA!!!!
Sep 20, 2005
#16
  • Sep 20, 2005
  • #16
TWO words....Plasma Cutter!! Depending on the location of the spot it is without a doubt the BEST spot weld cutter EVER!! I know I know they are $$$$$ but man do they work great........BTW in an area like where the floor meets the rocker a thin chisel will remove a spot and a quick pass with a grinder will smooth it up...worked for me anyway! Also I to have noticed that any where Ford put the hard pink looking seam sealer has rust,that stuff is total crap!
 
6

65nProgress

New Member
Jul 27, 2005
53
0
0
Sep 22, 2005
#17
  • Sep 22, 2005
  • #17
Time for the fun to begin...

Well, I broke down and bought a 3/8" spot weld cutting bit. I just got my cowl & firewall replacements in last night. Time to tackle the dreaded cowls. It'll probably take me a few weeks to get through all of the welds at the pace I work at.

I have decided to stop what Im doing on the passender floor pan till I can patch the firewall and cowls. After patching the toe board will be welded to the new metal of the firewall patch.
 
B

bgs66

Member
Oct 28, 2003
31
0
7
Jax.,FL
Sep 22, 2005
#18
  • Sep 22, 2005
  • #18
I am welding in the cowl panel today. I have also repaced the complete firewall and side cowl panels and both floorpans. My firewall panel was also swiss cheese under the export brace. I put jackstands under the front of each rocker panel and the front was held up by a rotisserrie. Nothing moved and all looks good so far. I did a lot of fitting and checking by putting the hood and fenders in place to make sure the cowl is not going to be to high or too low and centered when it goes back together. I bought a spot weld removal bit from Eastwood and it didnt take long to dull, I didn't keep it lubricated. Since I had to do so much removal of metal I just drilled out the spot welds with a regular drill bit. The firewall panel saved me a lot of time so that I didn't have to fabricate small sections to fix the bad spots and it fit pretty well. It looks kind of scary with the firewall out of the car but once you get going it's not that bad. Just have to do a lot of prep work to make sure you're lined up. Good luck
 
6

65nProgress

New Member
Jul 27, 2005
53
0
0
Sep 22, 2005
#19
  • Sep 22, 2005
  • #19
bgs66: I bought one from eastwood also. I'll try to keep it lubed. If it dulls too quickly, i'll go back to using drill bits. Last night I practiced drilling on the cowl to fender apron pieces. I got those off pretty easily once I got the hang of how deep to drill. I have a feeling that like everything else, its only hard the first 20 times then it gets easier.
 

rusted-resto

Member
May 11, 2005
37
0
6
eureka, ca
Sep 22, 2005
#20
  • Sep 22, 2005
  • #20
Having tried all of the above methods of removing spot welds, and after lots of frustration. I recommend the spot weld cutter in the Eastwwod catalog the cuts around the spot weld verses throught it. Then you just grind it off! Have used mine 300+ times and still works great!
 
You must log in or register to reply here.

Similar threads

Can makes noises when driving poping
  • Creomod
  • Oct 14, 2025
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
17
Views
621
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Oct 19, 2025
Creomod
S
I don know what im doing!
  • Sha_lala_pookie
  • May 5, 2025
  • 1965 - 1973 Classic Mustangs -General/Talk-
Replies
11
Views
563
1965 - 1973 Classic Mustangs -General/Talk- May 11, 2025
Sha_lala_pookie
S
R
Starting my 1979 notch build
  • redneck15431
  • Dec 28, 2024
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
10
Views
561
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Jan 4, 2025
redneck15431
R
L
2012 Seats in 98 GT Convertible - pictures coming
  • lparsons42
  • Aug 11, 2025
  • 1996 - 2004 SN95 Mustang -General/Talk-
Replies
3
Views
287
1996 - 2004 SN95 Mustang -General/Talk- Aug 17, 2025
lparsons42
L
Drivetrain 83’ Glx convertible C5 Trans help!
  • JacksonJared2113
  • Dec 25, 2025
  • Fox 5.0 Mustang Tech
Replies
2
Views
416
Fox 5.0 Mustang Tech Dec 26, 2025
JacksonJared2113
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1965 - 1973 Classic Mustangs -General/Talk-
  • Classic Mustang Specific Tech
Menu
Log in

Register

  • Forums
  • What's new
  • Media
  • Resources
  • Contact
  • Sponsor
X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?

X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?