Welding in Patch Panels on a Cowl

[bdave_mcc]

Originally Posted by tbirdtbird

surprisingly no one has mentioned weld-thru primer......

lets keep it that way

[tbirdtbird]

oh, right, no sense in doing it correctly

[bdave_mcc]

Originally Posted by tbirdtbird

oh, right, no sense in doing it correctly

You need weld through primer if youre using a lap, flange joint or spot or plug welds for your panels since youll have areas where you wont be able to get primer on afterwards. there lol

[Terry, NJ]

One more thing! Once, during a visit to a high end restoration shop, (Not a model A or Chevy in the bunch) I was "Brain picking" their two metal guys for any tips. And they gave me this, They always rounded the corners on their patches (Maybe a 3/4" radius). And they always filled holes with a disc. Why? They felt that the rounded corners pulled less when welded. I don't know! But I have used this method myself with good results.
Another thing, I don't know what kind of welding you're doing, but I grade welding like this.
1 TIG (Heliarc) the best.
2 MIG (Wire feed) OK
3 Stick MMA The worst! Forget it!
I hope this helps!
Terry

[Flop]

Some proper cowl panel installaion ... Tig weld if you can . Make sure that patch has the proper contour or you will fight the panel the whole way . Make your cut above the subframe connector so
You have access to hammer the weld . Honestly this is the patch I hate putting in the most .


No need for weld through primer . To expensive to coat a whole back of the panel . Spray the back with whatever primer you have skip the weld area so you don't breathe the stuff all day while welding then spray the whole panel down after you are finished welding and finishing .

[Flop]

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[Kevin in NJ]

I probably should not correct some things people have wrote, but I will.
I am not trying to be mean or cruel.

Hammer welding is what a blacksmith does. You get the metal hot and hammer it together. What I talked about is not hammer welding. It is using the science of metal that it shrinks with every weld and you have to correct it.

TIG welding is not heliarc. You use helium when welding aluminum. Some aluminum has to be welded where there is little oxygen or other gases.

Most people have MIG and that is what they have to learn to do their best. MIG is a PIA for doing good shrink correction. You need to grind both sides very flat so the hammer process does not cause more distortion locally from the 'blob'. Been there done that a lot.

Having been fortunate to have a TIG welder I can say that is the absolute best for doing wonderful sheet metal work. The heat control allows for laying in just enough heat to get full weld penetration while using little or no filler. Couple that with hammer corrections for shrinkage and even a bad welder can make panels come together and leave the metal close to the original contour.
Another advantage to TIG is the heat control makes it such you can run welds right up to the edge and not have the nasty burn back. The first time I did that I was in heaven.

Another method that works is oxy/act welding with a very small tip and low pressures. You also need to use the correct welding rod for best results. TIG rod (or MIG wire -er70-s6) is not the right stuff! As with TIG you do lots of spot welds and frequent hammering to correct shrinkage.

There are various metal fabrication websites with lots of info and you can rent videos from smartflix if you want to learn more.

[Flop]

If this is one of your panels Bill good stuff ... I always make everything in shop but this patch was screwed to the car when I got it . It actually fits

[bdave_mcc]

Originally Posted by Kevin in NJ

I probably should not correct some things people have wrote, but I will.
I am not trying to be mean or cruel.

Hammer welding is what a blacksmith does. You get the metal hot and hammer it together. What I talked about is not hammer welding. It is using the science of metal that it shrinks with every weld and you have to correct it.

TIG welding is not heliarc. You use helium when welding aluminum. Some aluminum has to be welded where there is little oxygen or other gases.

Most people have MIG and that is what they have to learn to do their best. MIG is a PIA for doing good shrink correction. You need to grind both sides very flat so the hammer process does not cause more distortion locally from the 'blob'. Been there done that a lot.

Having been fortunate to have a TIG welder I can say that is the absolute best for doing wonderful sheet metal work. The heat control allows for laying in just enough heat to get full weld penetration while using little or no filler. Couple that with hammer corrections for shrinkage and even a bad welder can make panels come together and leave the metal close to the original contour.
Another advantage to TIG is the heat control makes it such you can run welds right up to the edge and not have the nasty burn back. The first time I did that I was in heaven.

Another method that works is oxy/act welding with a very small tip and low pressures. You also need to use the correct welding rod for best results. TIG rod (or MIG wire -er70-s6) is not the right stuff! As with TIG you do lots of spot welds and frequent hammering to correct shrinkage.

There are various metal fabrication websites with lots of info and you can rent videos from smartflix if you want to learn more.

Good stuff, bottom line is there are many, many methods out there to use for patch panels. Youll have people telling you this way or that way is the best and so on.
Use the best method you can for whatever type welding or process you have available and what your experience level is. For instance, usually a flange seam or a backing plate seam is easier than a butted seam.
Take your time, manage the heat in your panel, and as long as you don't leave pin holes in your welds that can allow moisture to seep in under your filler/paint and everything is treated properly, they will last for years.

Also the statement about rounding your edges is helpful. The way I do them is to slightly round outside corners and inside corners you can simply round the corner with a rat tail file or something similar. Sort of like drilling a hole to stop an engine block crack.

[Kevin in NJ]

Overlap seams are bad because you can not correct for weld shrinkage with hammer on dolly. I never do them except when replicating how the factory does a panel. Never liked the idea and I know now the butt weld is really easier and a much better weld.

While it may seem like a lot of work, getting a matched panel with a tight line is not that hard. I remember the first couple taking a while then it was old hat. Took no time, probably less time to do it right then the work an overlapped seam would cause trying to level with bondo later. That is not just my opinion. I read about an autobody guy who decided to do all his work with correct welding techniques that left a finish metal. Well it took him longer to get to primer, but his overall time was less then the guys leveling with bondo and the jobs came out looking better.

If you are MIG welding some have reported easier welds by having a slight gap. Some very experienced guys will taper the edges of the butt weld creating a V at the gap.

Also if MIG welding, if you blow through, get some TIG rod (ER70S6 like your wire). Put copper behind (I use copper a lot to keep the work down or to control heat in delicate situations) Then strike the MIG on the TIG rod and feed the two in together. The TIG rod will take the heat and not burn back the edges more. You will get a faster cleaner fill of a hole.

A minor note. With MIG welding it is easy to not get good penetration. I know I ran many feet of them when I was learning. Found out welding upside down that if the welder is not set right you cant weld MIG upside down. Magically, when the MIG is set right you also get the right penetration. I re-did a few feet of floor pan welds on a Mustang.

[Bill Stipe]

Yes Flop that sure looks like my panel. I have been stamping them since 2002. I had 5 model A's that needed cowl patches and the only thing I could find was straight formed and the bead was not shaped correctly. So I decided to make my own for my cars. the dies where patterned off an old 30 coupe front cowl I had laying around.

[pooch]

A shrinking/stretching machine is like seeing magic on metal.

After a folder, this is the best piece of manual sheetmetal shaping machinery to own.

[Terry, NJ]

Nice to have a real shop instead of having to do everything half assed or pay too much for stuff! I bought my panels at Hershey about 3-4 years ago and they had the much discussed, compound bend. I bought them from a dealer from a southern state. I can't recall their name now (No, it wasn't Smith and Jones) The fit was good and now after a coat of body filler, some sanding and filler primer, more sanding, only the sharpest, most experienced eyes could pick up the repair.
Terry

Originally Posted by Bill Stipe

Yes Flop that sure looks like my panel. I have been stamping them since 2002. I had 5 model A's that needed cowl patches and the only thing I could find was straight formed and the bead was not shaped correctly. So I decided to make my own for my cars. the dies where patterned off an old 30 coupe front cowl I had laying around.

[Terry, NJ]

Kevin, You're one of the last people on here I want to debate with over anything, But I want to point out that heliarc is merely TIG with a different gas. The equipment is the same (Cups, handle, Tungsten electrode,variable power through either a footswitch or thumbswitch) but most welders use the 25% argon, 75% CO2 mix for costs. We used the gas interchangeably for aluminum and steel. The only the we changed was the polarity, AC with high freq. start for aluminum, IIRC. It's been a while. I agree with you on every other point.
Terry

Originally Posted by Kevin in NJ

I probably should not correct some things people have wrote, but I will.
I am not trying to be mean or cruel.

Hammer welding is what a blacksmith does. You get the metal hot and hammer it together. What I talked about is not hammer welding. It is using the science of metal that it shrinks with every weld and you have to correct it.

TIG welding is not heliarc. You use helium when welding aluminum. Some aluminum has to be welded where there is little oxygen or other gases.

Most people have MIG and that is what they have to learn to do their best. MIG is a PIA for doing good shrink correction. You need to grind both sides very flat so the hammer process does not cause more distortion locally from the 'blob'. Been there done that a lot.

Having been fortunate to have a TIG welder I can say that is the absolute best for doing wonderful sheet metal work. The heat control allows for laying in just enough heat to get full weld penetration while using little or no filler. Couple that with hammer corrections for shrinkage and even a bad welder can make panels come together and leave the metal close to the original contour.
Another advantage to TIG is the heat control makes it such you can run welds right up to the edge and not have the nasty burn back. The first time I did that I was in heaven.

Another method that works is oxy/act welding with a very small tip and low pressures. You also need to use the correct welding rod for best results. TIG rod (or MIG wire -er70-s6) is not the right stuff! As with TIG you do lots of spot welds and frequent hammering to correct shrinkage.

There are various metal fabrication websites with lots of info and you can rent videos from smartflix if you want to learn more.

[Rex_A_Lott]

Heliarc is a brand name, that refers to what some people call TIG. So for a lot of folks, especially ones that have been around a while, Heliarc= TIG. Sort of like most people say Kleenex, regardless of who made it. I dont recall ever hearing the term TIG until the late 70's, and after the guy got finished explaining it, I said "oh, you mean Heliarc". He said "Yeah".
Not really worth getting wound up in the wording, IMHO.
Nice thread, good info here.

[Tom Wesenberg]

I agree with Rex, and now I need to find my Cresent wrench and go to work..................I mean my adjustable open end wrench.

In high school that was always a pet peeve of my shop teacher.

[Afordman31]

Originally Posted by Tom Wesenberg

I agree with Rex, and now I need to find my Cresent wrench and go to work..................I mean my adjustable open end wrench.

In high school that was always a pet peeve of my shop teacher.

Have heard them also called "Fits All"

[Kevin in NJ]

I messed up my point on Heliarc. Yes it is TIG welding, but it is really descriptive of aluminum welding in certain conditions.
For better or worse, I try to get people talking a more correct terminology. I know Heliarc has become synonymous with TIG to an older generation, but what is being discussed here is just plane old TIG.

Same goes for the hammer welding. Not the right description for what is happening. You weld with the welder and correct with hammer work.

Early on I got pretty messed up with various terms that were being used incorrectly and I try to keep a common and hopefully more correct language for those starting out. I probably just come out as a pain in the ass, but I mean well.

Now I much go find by cresent wrench, vice grips and weller and get back to work.

[Bud]

Aren't most of the patch panels for the cowl available today have too flat of a bead compared to the factory bead? If not, who makes a properly formed patch panel?

[Terry, NJ]

Again! You're correct about us Fold Arts, We do confuse the two! And Hammer welding wasn't a term I was familiar with, We preferred "Tack it and Smack it". I Was a a Machinist/ toolmaker and we looked down on the welding trade, but it was something I wanted to know how to do. So I got a job, as a trainee, at Interpace Corp. in Rockaway ,NJ. There I learned stick welding and most of it was at least 1/4 " thick, so you just crank up the old Lincoln and burn the 7018 in. That will not work with 18 gauge. Later, I worked for Mikropul, in Summit nj and learned TIG and MIG. Then I worked for a company in Ocean Co as both a toolmaker and a part time welder. But I agree, Hammer welding is something that blacksmiths used to do. I like "Tack it and smack it" It's more accurate. And I have a real "Cresent" wrench and a couple of old "Monkey Wrenches. I also have a Ford wrench that was one of the handiest things when I was changing the plugs on my Triumph, Spitfire. Does that make it a Triumph wrench?
Terry

Originally Posted by Kevin in NJ

I messed up my point on Heliarc. Yes it is TIG welding, but it is really descriptive of aluminum welding in certain conditions.
For better or worse, I try to get people talking a more correct terminology. I know Heliarc has become synonymous with TIG to an older generation, but what is being discussed here is just plane old TIG.

Same goes for the hammer welding. Not the right description for what is happening. You weld with the welder and correct with hammer work.

Early on I got pretty messed up with various terms that were being used incorrectly and I try to keep a common and hopefully more correct language for those starting out. I probably just come out as a pain in the ass, but I mean well.

Now I much go find by cresent wrench, vice grips and weller and get back to work.