Going through the thread on bmarkline's killer '78 buildup, he mentions how he cut out the cowl to replace the dried-out seam sealer, which was allowing for water to leak into the cab above the fuse box. I PM'd him to see if he had a less drastic solution, since I really don't want to cut up my virgin (original paint) cab, but he couldn't think of any other way to do it right. Does anyone know of a way to re-seal the cowl, which doesn't involve cutting and welding?

 

can you get in there with more replacement seam sealer?

 

I too have this problem, and am subscribing to this thread because I also want to see if there is a less intrusive fix.

 

seam seal, let dry, water test, seam seal, let dry, water test, and seam seal some more!


When I finially got enough seam sealer in my cowl, I bought some ruberized undercoating in cans with a long nozzle and coated the whole inside of the cowl with a nice coating of the undercoating.

Others may not agree, but this was my solution!

 

Rubberized undercoating sounds like a really viable solution! I haven't used that stuff in probably 30 years, but it sticks to almost anything.

I have two questions:

• How did you apply the seam sealer? There's not a lot of room to get in there through the obround vent holes in the cowl panel.
• Did you get the undercoating in an aerosol can? If so, what brand? We always used to use 3M Body Schutz, but, as I recall, in comes in quart cans and you need a special gun to apply it.

 

·I took a hose and positioned it on my cowl and layed under the
dash to figure out where the leaks were. Then I cleaned off all the
old seam sealer and re-sealed the cowl. Leak tested when dry and
repeat. It took me three tries before I got all the pin holes.

· I used SEM undercoating part number 40523. It comes with an nice
long nozzle like brakeKleen but with a lager opening. I pointed it in
the cowl and went to town.

 

Perfect! It'll probably be a month before I can do this, but will report back results. Thanks!

 

well...I did it! I took your advice and seam sealed and undercoated my cowl yesterday. It was easier than I expected. I ended up taping a drinking straw to the caulk tube end and then spreading it into the crack a little better with a Kabob stick. I sprayed it down with a whole can of undercoat and it looks great and keeps the leaks away. Thanks again.

 

SEM is a much better product than 3M. My bed got both and also what I carried at Ace. Cant remember the brand now.

 

Hey hey hey! Nice thread! lol. Yeah this was the other idea we had talked about that I never tried, with the undercoating. Glad to see I wasnt alone in thinking it up haha. And thats also nice to know that SEM has a straw thingy like brake clean. Like I said, this was the only way I could think of with out cutting or welding anything. Otherwise you would have to remove the entire cowl section from the cab with a spotweld cutter, then reinstall like original( in order to keep the vents) This is why I just shaved mine off. And thanks for the compliment on my 78, always good to hear someone likes what you did with something.

How much of the cowl did you guys seal up doing this method? Reason I ask is I dont see how you could really get to the top corners too well. Thats what I was afraid of on mine.

 

I was just trying to find your original post, but you have so many I had no luck. I do like your 78...you do really clean work. I didn't hit the top corners very well to be honest. I hope I don't have a problem in that area in the future. At the time it didn't even occur to me to protect that high up. I was able to get up to the bottom of the vents and back to the drain holes and everywhere in between. I was looking for a finished pic of your cowl to see how the body line looked when it was finished. If you have a pic it is something I would like to see for a possible future project.

 

Glad It worked for those of you trying it out. It was the easiest way I could come up with doing the repair! And the undercoat covers up the seam sealer and gives it a nice camo!

 

Jetfixer74: Heres my thread: https://www.ford-trucks.com/forums/9...ruck-pics.html Sorry for thread hyjacking lol.

76F100guy: I was thinking about it, and at this point you may want to just go ahead with the undercoating idea. Its at least worth a shot at this point, even if it needs done every few years. Only you and us on here will know you did it, and you get to keep your original paint. I dont blame you for not wanting to mess that up, its only original once. And if it doesnt work, well then your not out much more than you are now, short of having to remove the undercoating if you decide to tear into it for real. Like I said, worth a shot. Good luck buddy!

 

I like how the sealed/no vent cowl looks. I only wish I knew how to weld better and actually had a welder. I would go the extra mile. No worries on the thread jack. I am glad I got to see another option for the future.

 

I used to like my Ford truck until water started coming in the cab from the cowl everytime I wash my truck or when it rains. Is this something that normally craps out with my toe of truck?...I seriously hate my truck now!..I thought Ford makes their trucks to last!...*****in Junk!!!!