Weld thru primer ?

[DEEPWOODS]

Do you use weld thru primer on you panel replacements ? Is zinc or copper type the best I don't think ford used anything looks like bare metal to me











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[broncodriver99]

I have some of the copper type but havent used it yet. You don't want to use the zinc if you are welding. Zinc is poisonous when burned.

 

[sp71eb]

Yes most definitely use weld thru primer. I would use Sherwin Williams Shield weld thru primer. You can get it at any place that sells Sherwin Williams automotive paint. It is expensive but alittle goes along ways. I have used 3m, Sem, Upol and Kent brand weld thru primers and have found that the Sherwin brand welds the best and seems to have the best corrosion protection. Just a note it just takes a small amount and will be somewhat silver and still see through when applied. It leaves a thin film plastic type coating on the metal that flows back around the weld after it cools.

 

[Crawdad]

Yes most definitely use weld thru primer. I would use Sherwin Williams Shield weld thru primer. You can get it at any place that sells Sherwin Williams automotive paint. It is expensive but alittle goes along ways. I have used 3m, Sem, Upol and Kent brand weld thru primers and have found that the Sherwin brand welds the best and seems to have the best corrosion protection. Just a note it just takes a small amount and will be somewhat silver and still see through when applied. It leaves a thin film plastic type coating on the metal that flows back around the weld after it cools.

I couldnt find the Shield version, do you have a parts number maybe? I saw on amazon it sells a SW's weld thru for like $19 plus s/h.

 

[Timmy390]

I used the zinc (3M brand) when replaceing my rockers......

Tim

 

[sp71eb]

I'm not sure if Sherwin or Like90 makes the actual primer but it is the same stuff. The Sherwin stuff can only be bought in a Sherwin Williams store. The Like90 you can buy from TCPglobal.com. Here is a link to the I-car website that explains thin film weld thru primers and how they work.

http://www.i-car.com/html_pages/tec...e/advantage_online_archives/2011/042811.shtml

http://www.tcpglobal.com/spraypaintdepot/weld-through-primers.aspx

 

[AZ73]

I used zinc on my actual weld seams, and a rust sealer on prepped metal that won't be visible once the panels are welded on like the inside of the rockers where they are not welded. For places where I'm not replacing the metal (like inside the cowl and door post) I'm using KBS cavity seal (with a tip of the hat to NicksTrix for that tidbit)

 

[stupidboy]

I used weld through primer for the first time yesterday. Bought it at napa and it was zinc weld thru primer. used a small amount and tried it and wish I wouldn't have. It made welding splatter and smoky, like welding galvanized, was harder to get a clean weld that I would trust. That can will set full on my shelf for the rest of my life. I'm not a welder, but I have been welding cars back together since I was 12 yrs old, and I just turned 44 yesterday!

 

[Timmy390]

It made welding splatter and smoky, like welding galvanized, was harder to get a clean weld that I would trust.

I'm no welder either.....but I do find myseld welding more and more. I did notice some issues like that when doing my rockers. I was only plug welding not laying down a bead. I was using a Miller 250 and found adjusting/turning up the voltage just a touch really helpped. It's the initial burn through on the primer that's the issue.....

Tim

 

[bknbronco]

i used weld through primer when i assemblem my front inner clip. I just used the cheep stuff my local paint place had. It kinda welds wierd and found that when i welded it it helped to burn the primer off first. I use a TIG welder so preheating or burning paint is easy.

Prime just the areas that overlap and scuff the overspray prior to priming or sealing. Also use of a seam sealor like LORD FUSOR will do alot to help with future rust in them areas also.

 

[Rustytruck]

When I used weld through primer I primed the parts and clamped the pieces and marked the weld holes. then disassembled and spot sand blasted the actual weld spots. this allowed me to get a good weld going.

http://www.harborfreight.com/abrasive-blast-gun-with-bag-96972.html

 

[sp71eb]

Trust me, the sherwin/Like90 primer isn't like other weld thru primers. I weld in replacement panels all day. The other brand weld thru primers are more (weld around) primers. I used to use a 6" philips drill bit that I flattened the end on to clean out the weld holes before welding. Most weld thru primers are just a type of etch primer that usually burns away when you weld still leaving some unprotected bare metal around your weld. And yes it sucks to weld and usually makes a very porous weld unless you weld with enough heat to burn it out of the plug weld. I had to help a friend of mine weld up some panels on his 50 Chebby truck and he had some Napa weld thru primer that was pure garbage. He thought he had the welder messed up when welding but it was just the primer making the nasty welds. I know that using some form of weld thru primer isn't usually as fun as welding raw steel, but if you want your panel replacements to last longer than a few years I would recommend using weld thru. Here is a picture of a car I had at work that didn't have any weld thru and also someone just "filled the weld hole" and didn't actually weld the two panels together.

 

[Crawdad]

Wanted to bring this thread back to the top. Good info here!