Hey guys,
Working on the front end of my 73 F250 2WD. In the below pictures on the firewall, below the blower hole, above the cab mount, appears to be a caulking or sealant of some kind which is now just flaking off.
Anyone know what it is or what I should replace it with?

Thank you!

 

I used seam sealer on mine. A caulk tube of whatever O'Reillys sells. The original stuff cracked real bad, when that pinch-weld/standing-seam hung up on my bedside, when I was getting my then-new cab out of the bed. The seam bent back into shape, but the seam sealer in that area took a real beating, and I was getting water coming in through a spot on that seam.

 

My pick for those types of seams is 3M 08367, stays nice and flexible and its single part.

 

Thank you, I will grab some of the 3M stuff and get it sealed up.

 

I've heard for years that the 3M sealer is the way to go. Adheres well and doesn't shrink.

Pay attention to the prep. I've heard horror stories about guys seam sealing, paining over it to find a few months later that the seam sealer didn't stick and starts popping off.

 

Proper solvent cleaning before seam sealing and warming will give best results. Also remember the 3m is a moisture cure urethane so humidity needs to be above 30% for it to work or you will need to mist it with water.

 

go with 3m you can't go wrong I've used 08050

 

Real seam sealer that’s used in the factory these days is a 2 part epoxy like this:
https://www.eastwood.com/ew-2k-self-...cartridge.html
I’ve used this type before. Preparation is a must.