"CORRECT" assembly procedure to avoid rust?

[SUPERSTAR14]

I am currently restoring a 69 charger, it is currently just a media blasted shell. I will be spaying it with epoxy primer and single stage urethane satin black before the assembly begins.
Or at least that is what I think I should do........

My question is..... How to properly seal the panels where they attach? I noticed while taking it apart that all seams were seam sealed and spot welded. Without a very expensive heavy duty spot welder you cannot do that. So what are the guys doing to seal the seams "properly" to avoid rust leaching through the seams? I know I'll have to grind off some paint in order to plug weld but the thought of that untreated metal especially at the bottom of the quarters is not too comforting. Thanks in advance!

[green69rt]

Something that might help is weld-thru-primer applied before welding (if you are doing any.)   This type of primer has copper or aluminum dust in it (I use the type with aluminum.)   The heat of the weld process causes the metal dust to melt and coat the weld spot.  The solvent carrier pretty much burns or vaporizes off.  I don't know if there is anything you can do to be 100% sure the metal is protected in the area inside the seams other than a full body dip and then a full body e-coat. Most of the seams do need sealer but that is mostly to keep water out of the passenger compartment, not to protect against corrosion (I think.)

The other side of the coin is how much is needed?   My 69 is 44 years old and spent most of its life in Colorado and Chicago, Lots of rust for sure but it survived.   Now that is in the south and will be kept in a garage I would bet that the new metal I put on it, plus the care in assembly that I'm doing will make it last a lot longer than 44 years.   More than once I've heard or thought ---  do what I can and move on!

[richRTSE]

 Someone one here recommended this before, and its what I've been using while doing the floors and trunk of my Charger...U-Pol Copper Weldthru Primer....works pretty well. Just don't drop the can and break the plastic spray nozzle, none of the other cans I had would interchange nozzles, so I had to buy another can.... 

http://www.autobodytoolmart.com/u-pol-weld-2-weld-through-primers-p-15138.aspx

Also, in a couple of areas I used Zerorust, and instead of grinding it off and spraying it with the weldthru primer, I just clamped up the panels after pre-drilling all the holes, and then used my dremel to clean the paint off the underneath panel before plug welding it.

[SUPERSTAR14]

Ok thanks guys, was planning on the weld through primer but thought i would ask anyway. I had a hunch I was over-thinking the whole thing....... Just don't wanna be wrong as I am spending alot of money on this project.

Next question then....... would you seam seal before epoxy primer or after? I was thinking epoxy primer first, then seam seal, then single stage urethane. Is that correct?  Remember this is just the shell of the car, no body panels on it yet. Again thanks in advance. This is my first restoration and I would like to do it the best as possible.

[green69rt]

Epoxy primer goes on before anything else.   Others can chime in but I use primer first then... sealer, any filler for body work, high build primer for minor imperfections, blocking and anything else you may be doing before final paint.  After all the work is done and depending on the amount of raw metal I uncover I will either shoot another coat of epoxy primer or a single stage  primer.  I keep up on this thread because I will be interested in what others do.

[cdr]

i use a spray nozzle off spray carb cleaner that has a tube on it on red oxide primer spray can & can spray into the seams after its all plug welded.i also do same as RICHRTSE  IE. grinding out the primer in the punched holes.

[green69rt]

i use a spray nozzle off spray carb cleaner that has a tube on it on red oxide primer spray can & can spray into the seams after its all plug welded.i also do same as RICHRTSE  IE. grinding out the primer in the punched holes.

That's a really good idea to get those hard to reach places.  I'm getting down to the last of the welding and I think I'll give that a try.  Thanks Charlie.

[cdr]

gumout carb cleaner fits the rustoleum red oxide 

[Chatt69chgr]

The areas that I would worry about the most would be inside frame rails.  If these are exposed, then you can derust them and then paint in epoxy primer.  It will stay liquid in the pot for a couple of days.  O/W, you can spray in a material that Eastwood sells just for this purpose.  I'm not sure about what would be the best between two body sheet metal panels that are being joined.  I guess infusing a spray primer, as suggested, would be good.  I've heard of the weld thru primer but have no experience with it.  Sounds like a good idea.

[SUPERSTAR14]

The areas that I would worry about the most would be inside frame rails.  If these are exposed, then you can derust them and then paint in epoxy primer.  It will stay liquid in the pot for a couple of days.  O/W, you can spray in a material that Eastwood sells just for this purpose.  I'm not sure about what would be the best between two body sheet metal panels that are being joined.  I guess infusing a spray primer, as suggested, would be good.  I've heard of the weld thru primer but have no experience with it.  Sounds like a good idea.

Inside the frame rails is not the problem, they have been blasted, epoxy primed and painted with single stage urethane. After assembly they will then be treated to 3M rust fighter. A gun is available with long hose to stick up into the rails and spray the entire area as it comes out in 360 degrees. I think I may try this inside at the bottom of the quarters and around the wheel wells too.

Someone mentioned spraying primer down there after welding, I always thought primer was much like a sponge and would grab moisture, is the red oxide different?

[elitecustombody]

I use weld-through primer and after few welds I spray metal prep Picklex while it's still hot, saturate the joint and wipe off excess . Then scuff and  shoot epoxy primer. Seam sealer goes after epoxy.    

[Patronus]

I'd have to agree, prime it. Then work it. I'd also prime the seam-sealer. The whole thing should be primer prior to sealer/paints.

[SUPERSTAR14]

I have another question for ya........ What is the proper way to seal the deck filler panel to the quarter panels? is the seam suppose to be visible when completed?
Thanks

[Dino]

I have another question for ya........ What is the proper way to seal the deck filler panel to the quarter panels? is the seam suppose to be visible when completed?
Thanks

Yes.  All seams need to have a thin bead of sealer tooled to give a nice, smooth finish.  It needs to go on last before paint, but make sure it has plenty time to dry or the pain may not stick.

Oh and there is no way to stop rust, you can only minimize it and I think just about everything that can be done is in this thread so follow these guys' advice and your car will be fine.