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

Caulk, sealer, or undercoating? Need info please

  • Thread starter Thread starter Stangsx2
  • Start date Start date Nov 13, 2007
S

Stangsx2

Founding Member
May 7, 2001
99
0
6
Riverton,Utah (Near Salt Lake City)
Nov 13, 2007
#1
  • Nov 13, 2007
  • #1
Working on my '69 Mach 1.
I've primed my frame and am ready to re-apply seam sealer, caulk, and or the black rubberized undercoating.
I have some seam sealer in a tube, and I have some automotive strip caulking.
But I'm not sure what was on the body to start with (see photo). It looks like there was a bit of undercoating material that I scraped off, but it seemed to be in odd and random places. And I can't really tell where the seam sealer was or if there even was any. Also, if I used some automotive strip caulking, is that a type of seam sealer, and is that stuff paintable?
Can I use the seam sealer where ever there are seams, even if there was none there originally?
This all sounds rather rambling and random. I just can't seem to find adequate information about the seam sealing/caulking in my restoration books or on the net.
Thanks for any and all feedback and help.
Brian.
 

Attachments

  • body work.webp
    17.6 KB · Views: 286
C

chromedog

New Member
Jan 13, 2006
554
0
0
worlds center for speed
Nov 14, 2007
#2
  • Nov 14, 2007
  • #2
ok... the stuff ford used was junk, it was fine for a few years, then dried out and crumbled. strip caulk is not going to harden, so if you are sealing anything you want to be really watertight, dont use it. the best thing to use, imho, is either a two part epoxy based product, such as sem, or fusor.the best idea is to seal anywhere there are two pieces of metal overlapping each other.
 

66 Restomod

Member
Jan 2, 2007
203
0
16
Raleigh, NC
Nov 14, 2007
#3
  • Nov 14, 2007
  • #3
In the cowl area and the side boxes behind the fenders there's far more seam sealer than that area actually needs, particularly with today's high-quality seam sealers. That old seam sealer looks like it was applied with a big brush and they just wanted complete coverage to last as long as possible (and wanted to do it really quickly). We are in the process of seam sealing my stripped car now, and we are just going along ALL the seams with a small brush rather than making a big mess.
 
C

chromedog

New Member
Jan 13, 2006
554
0
0
worlds center for speed
Nov 14, 2007
#4
  • Nov 14, 2007
  • #4
i personally dont like a brush at all, but if you use the stuff in a can, you have no choice, unless you put it in a heavy plastic bag that youve cut one corner out of. also, to get a really neat job, run a strip of masking tape on each side of the seam, as wide as you want the seam sealer to be. run your sealer, then smooth it down with your wet finger. you can then remove the tape, and astound everyone with the neatest seam ever!
 
You must log in or register to reply here.

Similar threads

M
Progress Thread mnky99 2001 V6 evap core, ac compressor, heater core replacement
  • mnky99
  • Sep 5, 2025
  • 1996 - 2004 SN95 Mustang -General/Talk-
Replies
1
Views
476
1996 - 2004 SN95 Mustang -General/Talk- Sep 5, 2025
mnky99
M
Place to Avoid: Jamison Auto Group in Gulfport, MS
  • D Durden
  • Oct 20, 2025
  • 1965 - 1973 Classic Mustangs -General/Talk-
  • 2 3
Replies
45
Views
2K
1965 - 1973 Classic Mustangs -General/Talk- Feb 4, 2026
nickyb
A
I need help please!
  • Azhi23
  • Oct 26, 2022
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 2
Replies
21
Views
3K
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Nov 1, 2022
limp
J
*New guy* Microsquirt questions regarding required engine info.
  • jack.stand.racing
  • Sep 23, 2020
  • Digital Self-tuning Forum
Replies
10
Views
3K
Digital Self-tuning Forum Sep 24, 2020
jack.stand.racing
J
Holley Sniper review - The good, the bad, and learn from my frustration
  • LX Dave
  • Aug 14, 2020
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 2
Replies
34
Views
60K
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Jun 2, 2026
Robin Rhino
R
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?