Has anyone used a sealant/caulking on the outside cab seams; I'm considering filling the seam but would like to retain the stock look. I've also thought of using 1/8" steel rod, tacked in the seam.

I've heard of using welding rod , laid in and welded but did not have much success when trying this method in the past; using MIG. Does one use continuous bead, is warpage a factor ?

Tom

 

I used silconized caulk in the seams up behind the door, going around the back, above the back window and between the doors and cowl. You have to make sure the caulk is paintable. Regular silcone caulk will leave a mess and cause fish eying in your paint. Make sure it says "paintable".

 

A body shop would use a seam sealer on exterior seams. A 2k type will be better then a 1k which will eventually dry out, shrink and crack. If you clean up any rust in seams well and spray on some epoxy over the bare metal followed by a 2k seam sealer, you should have a well protected seam that will hold up well for many many years. If you want to smooth out the seam on the other hand, you should weld the seam up solid before filling with any type of body filler, or else it will likely crack eventually at the seams. You should skip weld, weld short sections at a time skipping around until you have all filled in. Warpage is always a problem on sheetmetal if you don't keep the heat down and localized. Welding creates shrinkage and gonna get that, making area around the weld want to suck in, but also does stretch areas. But should be minimal if you keep the heat and heat effected zone down. Normally when welding I will take it slow, keep cool with a blow gun. You can straighten as you go, and hammer on dolly on the weld seam to stretch. Harder when you don't have good access. If you want to learn more about proper metal work, visit metalmeet.com. A lot of experts there that are much wiser about exactly what is going on with metal when damaged or being welded, and how to properly reverse it, meaning little filler and avoid creating a mess of overworked metal or chasing damage.

 

Weld It!
Caulk will eventually crack\separate and show up in the paint....paint is expensive. I smoothed cab, cowel, rear fenders, screw heads on the vent and firewall....see pic below. You will like it all smoothed when painted.
good luck!, Ed

 

e william,

Nice look, is that back window the standard size? It looks bigger to me.

Ron

 

Sure I always use a 3m seam sealer product when repairing older cars. And joints I apply it ans the visible seams on the cab I use it and wipe away the excess.

 

Hi Ron, No, that's a standard size back glass...I guess justs looks bigger at that angle.

OldgreenF1, Dont get me wrong, I use 3m seam sealer on door edges and inside cab areas too...just not my choice under exterior finnished paint. I like the smooth look you can get with weld and\or good bodyfiller.
It's all in what look you want....just my humble opinion.


Hey Tip49, I have heard of people using rod to build up door edges or fix rails...as you can see in my pic I shaved the rail too. Gives the truck an old school\hot rod look I think. I've gotten alot of good ideas and advice from this site and the great users! p.s. (didnt mean to hijack the thread...)
later, Ed

 

Folks at the Rod shops my son works with use Marine Tex, after tacking the seam, about every 3 in.

Sam

 

I used caulking in the seams of my truck because I tried to keep as close to stock as possible and didn't want to get rid of the factory seams. The body seams in the '48-52 trucks are usually where the rust starts and works it's way out, bubbling up the paint. I wanted to avoid this problem so I blasted the seams as best as I could and applied epoxy primer and then the seam sealer, wiping off as much as I could while forcing as much as possible into the seams. It's been over eight years and I haven't had a problem with the paint cracking over the sealer. That's because I use as little as possible.

 

Thanks for all the input; I want to retain the stock look, while eliminating potential rust out so I will probably try a combination of welding and sealer, I have used seam sealer on all inside seams to date.

I will likely experiment again with using welding rod and hitting it with the MIG

Tom

 

This question was in a Ron Covell q+a column a couple of years ago. He suggested using seam sealer on the seam above the rear window, after the appropriate prep work, then smooting it to match the contour that meets it. The seam sealer would remain flexible enough to prevent cracking. His reasoning was that welding that seam would be easy, but grinding it would be difficult without grinding thru the sheet metal. He did suggest welding the horizontal seam that runs forward to the door.

 

Thanks for everyone's input; I'll go with tacking seam, using caulk to retain line above window; will fill cowl seams with metal.


Tom

 

Great thread!I am at the stage on my 48 to be thinking about this same thing.I welded the seams by the doors but will be using seam sealer on seam above back window.this info will help.Thanks

 

Well I started welding/ filling seams today on cowl and backcab corners; had too much blow through, even when using gas and smaller wire. Now I've got repairs and sections to cut out and re-do; the metal seemed thin and on one location looked like it had been brazed. Looks like my weekend schedule has had a minor setback. I did discuss products with a body man; he spoke of a product called "liquid metal" which may be the answer to filling the rear cab seam. Tomorow I'm going to a body repair supplier that carries it.


Tom

 

I was wondering about the brazing in the seams too. The seams at the rear top of the doors appear to be brazed in my '52 F1. I always assumed it was the previous owner that did this, but maybe not? Anyone else have this?
...Terry