Any feed back on weldable primer? I'm getting ready to weld a hollow area up and and thought some bare metal protection would be advantageous on the inside. Once I weld the cavity shut there won't be anyway to get in there.
I used Spies Heckers etch primer for years and swear by it. I am now using PPG's etch primer. Both are weldable. You will get a bit of a rough start up with these and any other weldable primer, but they both are great products, the burn area around the weld is minimal and doesn't peel up afterwards.
I do collision for a living here in CO and weld through primer is a must. I use the 3M product pictured above. And I use it on everything. My opinion is that it helps the longevity of the build. I have seen peoples projects that didn't use any kind of weld through primer a few years after the build, and you can clearly see where rust is starting where there seams and such are. I have also used a basic self etching primer as well, but sometimes it is hard to get a good weld started. When I weld something like a cavity where once it is welded shut there will be no way to get in there, I will sand the whole panel so your material will stick then I will self etch the entire area (I have even used some kind of rattle can undercoating) and mask the edges with some 3/4" tape then spray some weld through on the edge so you can get a nice weld and the rest of the panel is nice and protected.
Weld thru primer is for application to the immediate weld area only and any excess should be removed from areas outside the weld zone as it has poor adhesion qualities. Dont confuse weld thru with self etching primer. They are not the same product and are designed to be used in completely different situations. Here is a link to an ICAR article on weld through primers. http://www.i-car.com/pdf/program_support/advantage/1996/julaug96.pdf corrosion protection ...... http://www.i-car.com/html_pages/tec.../advantage_online_archives/2004/031504a.shtml http://www.i-car.com/html_pages/tec...e/advantage_online_archives/2011/080411.shtml I know this is info is for late model applications but it applies anytime when using these materials. Hope this is helps.
There's a few weldthru primers out there. I'd say its an absolute must between two pieces of metal, but just there. You may have to mask the joint area and prep, prime and or paint the rest of the piece. AFTER its welded, you could drill a hole and shoot some under coating over top of the primer/paint in the cavity..
you guys should try the SEM 40783 copperweld. it is a bigger can, and wont set up like the 3m cans have a tendency to do, and last time i checked is cheaper than the 3m 40783 COPPERWELD WELD-THRU PRIMER is designed to eliminate the corrosion that forms between welded substrates. 40783 has excellent adhesion and the copper enriched formula provides superior conductive properties that minimize the heat zone, thereby reducing distortion and welding splatter. Features Exceptional weldability Great sprayability Fast drying Superior corrosion protection Excellent adhesion to bare metal
Eastwoods bloxide seems to stick really well to gl*** blasted metal i am dipping my body mounts. Brushing it on everything else a day before welding. It welds very well. They sell it by the gal.my 2 cents.
I bought the SEM before posting the question. Looks like I made the right choice. I had a Jeep and took it to Ziebart for rust proofing. They drilled holes in all the hollow areas, inserted a wand and sprayed what appeared to be some sort of paraffin petroleum product in there. The hype was that the stuff would creep. It seemed to do the job but I don't see any of their places in business anymore either. At least not around here. I was thinking of rigging a wand set up and spraying ch***is saver in my boxed frame and hollow places on the car.
The Jalopy Journal
